sentence1
stringlengths 1
133k
| sentence2
stringlengths 1
131k
|
|---|---|
Oirots were called Altai Kalmyks by Russians. They were not Muslims or Kazakhs.) But Boris Shaposhnikov, who served with Pyotr Kornilov, the brother of Lavr, in 1903, mentioned the "Kyrgyz" ancestry of their mother - this name was usually used in reference to Kazakhs in 1903. Kornilov's Siberian Cossack father was a friend of Potanin (1835-1920), a prominent figure in the Siberian autonomy movement. Kornilov entered military school in Omsk in 1885 and went on to study at the Mikhailovsky Artillery School in St. Petersburg in 1889. In August 1892 he was assigned as a lieutenant to the Turkestan Military District, where he led several exploration missions in Eastern Turkestan, Afghanistan and Persia, learned several Central Asian languages, and wrote detailed reports about his observations. Kornilov returned to St. Petersburg to attend the Mykolayiv General Staff Academy and graduated as a captain in 1897. Again refusing a posting at St. Peterburg, he returned to the Turkestan Military District, where he resumed his duties as a military intelligence officer. Among his missions at this post was an attempt at traveling incognito to British India in 1904, though he was quickly discovered and subsequently kept under close surveillance. During the Russo-Japanese War of 1904-1905 Kornilov became the Chief of staff of the 1st Infantry Brigade, and was heavily involved in the Battle of Sandepu (January 1905) and the Battle of Mukden (February/March 1905). He was awarded the Order of St. George (4th class) for bravery and promoted to the rank of colonel. Following the end of the war, Kornilov served as military attache in China from 1907 to 1911. He studied the Chinese language, travelled extensively (researching data on the history, traditions and customs of the Chinese, which he intended to use as material for a book about life in contemporary China), and regularly sent detailed reports to the General Staff and Foreign Ministry. Kornilov paid much attention to the prospects of cooperation between Russia and China in the Far East and met with the future president of China, Chiang Kai-shek. In 1910 Kornilov was recalled from Beijing but remained in St. Petersburg for only five months before departing for western Mongolia and Kashgar to examine the military situation along China's border with Russia. On 2 February 1911 he became Commander of the 8th Infantry Regiment of Estonia and was later appointed commander of the 9th Siberian Rifle Division, stationed in Vladivostok. In 1914, at the start of World War I, Kornilov was appointed commander of the 48th Infantry Division, which saw combat in Galicia and the Carpathians. In 1915, he was promoted to the rank of major general. During heavy fighting, he was captured by the Austrians in April 1915, when his division became isolated from the rest of the Russian forces. After his capture, Field Marshal Conrad, the commander of the Austro-Hungarian Army, made a point of meeting him in person. As a major general, he was a high-value prisoner of war, but in July 1916 Kornilov managed to escape back to Russia and return to duty. After the abdication of Tsar Nicholas II, he was given command of the Petrograd Military District in March 1917. On 8 March, Kornilov placed the Empress Alexandra and her children under house arrest at the Alexander Palace (Nicholas was still held at Stavka), replacing the Tsar's Escort and Combined Regiments of the Imperial Guard with 300 revolutionary troops. But when the Provisional Government declined to give him the authority he sought to deal with indiscipline, he was transferred at his request to command the Russian Eighth Army. His army inflicted a spectacular defeat on the Austrians, taking ten thousand prisoners - Russia's only notable military success in the year 1917 - though after five days, was forced to retreat. On 24 July, he was appointed commander of the southern front. A week later, he replaced Aleksei Brusilov as Supreme Commander-in-Chief of the Provisional Government's armed forces. Kornilov Affair In the mass discontent following the July Days, the Russian populace grew highly skeptical about the Provisional Government's abilities to alleviate the economic distress and social resentment among the lower classes. Pavel Milyukov, the Kadet leader, describes the situation in Russia in late July as, "Chaos in the army, chaos in foreign policy, chaos in industry and chaos in the nationalist questions".Kornilov, appointed commander-in-chief of the Russian army in July 1917, considered the Petrograd Soviet responsible for the breakdown in the military in recent times and believed that the Provisional Government lacked the power and confidence to dissolve the Petrograd Soviet. Following several ambiguous correspondences between Kornilov and Alexander Kerensky, Kornilov commanded an assault on the Petrograd Soviet. Because the Petrograd Soviet was able to quickly gather a powerful army of workers and soldiers in defence of the Revolution, Kornilov's coup was an abysmal failure, and he was placed under arrest. The Kornilov Affair resulted in significantly increased distrust among Russians towards the Provisional Government. Russian Civil War After the alleged coup collapsed as his troops disintegrated, Kornilov and his fellow conspirators were placed under arrest in the Bykhov jail. On 19 November, a few weeks after the proclamation of Soviet power in Petrograd, they escaped from their confinement (eased by the fact that the jail was guarded by Kornilov's supporters) and made their way to the Don region, which was controlled by the Don Cossacks. Here they linked up with General Mikhail Alekseev. Kornilov became the military commander of the anti-Bolshevik Volunteer Army with Alekseev
|
major general, he was a high-value prisoner of war, but in July 1916 Kornilov managed to escape back to Russia and return to duty. After the abdication of Tsar Nicholas II, he was given command of the Petrograd Military District in March 1917. On 8 March, Kornilov placed the Empress Alexandra and her children under house arrest at the Alexander Palace (Nicholas was still held at Stavka), replacing the Tsar's Escort and Combined Regiments of the Imperial Guard with 300 revolutionary troops. But when the Provisional Government declined to give him the authority he sought to deal with indiscipline, he was transferred at his request to command the Russian Eighth Army. His army inflicted a spectacular defeat on the Austrians, taking ten thousand prisoners - Russia's only notable military success in the year 1917 - though after five days, was forced to retreat. On 24 July, he was appointed commander of the southern front. A week later, he replaced Aleksei Brusilov as Supreme Commander-in-Chief of the Provisional Government's armed forces. Kornilov Affair In the mass discontent following the July Days, the Russian populace grew highly skeptical about the Provisional Government's abilities to alleviate the economic distress and social resentment among the lower classes. Pavel Milyukov, the Kadet leader, describes the situation in Russia in late July as, "Chaos in the army, chaos in foreign policy, chaos in industry and chaos in the nationalist questions".Kornilov, appointed commander-in-chief of the Russian army in July 1917, considered the Petrograd Soviet responsible for the breakdown in the military in recent times and believed that the Provisional Government lacked the power and confidence to dissolve the Petrograd Soviet. Following several ambiguous correspondences between Kornilov and Alexander Kerensky, Kornilov commanded an assault on the Petrograd Soviet. Because the Petrograd Soviet was able to quickly gather a powerful army of workers and soldiers in defence of the Revolution, Kornilov's coup was an abysmal failure, and he was placed under arrest. The Kornilov Affair resulted in significantly increased distrust among Russians towards the Provisional Government. Russian Civil War After the alleged coup collapsed as his troops disintegrated, Kornilov and his fellow conspirators were placed under arrest in the Bykhov jail. On 19 November, a few weeks after the proclamation of Soviet power in Petrograd, they escaped from their confinement (eased by the fact that the jail was guarded by Kornilov's supporters) and made their way to the Don region, which was controlled by the Don Cossacks. Here they linked up with General Mikhail Alekseev. Kornilov became the military commander of the anti-Bolshevik Volunteer Army with Alekseev as the political chief. The Kornilov Shock Detachment of the 8th Army was the most famous and longest-lived volunteer unit in the Russian Imperial Army. It was also the last regiment of the Russian Imperial Army and the first of the Volunteer Army. In late 1917, the Kornilov Shock Regiment, one of the crack units of the Volunteer Army, was named after him, as well as many other autonomous White Army formations, such as the Kuban Cossack Kornilov Horse Regiment. Kornilov's forces became recognizable for their Totenkopf insignia, which appeared on the regiment's flags, pennants, and soldiers' sleeve patches. Even before the Red Army was formed, Lavr Kornilov promised, "the greater the terror, the greater our victories." He vowed that the goals of his forces must be fulfilled even if
|
de gramatiko de novjuda lingvo (An attempt at a grammar of neo-Jewish language), Helsinki, pp. 9–36. In this work, not only does he provide a review of Yiddish grammar, but also proposes its transition to the Latin script and other orthographic innovations. In the same period Zamenhof wrote some other works in Yiddish, including perhaps the first survey of Yiddish poetics (see p. 50 in the above-cited book). In 1882 a wave of pogroms within the Russian Empire, including Congress Poland, motivated Zamenhof to take part in the early Zionist movement, the Hibbat Zion. He left the movement in 1887, and in 1901 published a statement in Russian with the title Hillelism, in which he argued that the Zionist project could not solve the problems of the Jewish people. In 1914 he declined an invitation to join a new organization of Jewish Esperantists, the TEHA. In his letter to the organizers, he said, "I am profoundly convinced that every nationalism offers humanity only the greatest unhappiness .... It is true that the nationalism of oppressed peoples – as a natural self-defensive reaction – is much more excusable than the nationalism of peoples who oppress; but, if the nationalism of the strong is ignoble, the nationalism of the weak is imprudent; both give birth to and support each other ...." The Hebrew Bible is among the many works that Zamenhof translated into Esperanto. Zamenhof died in Warsaw on 14 April 1917, possibly of a heart attack, and was buried at the Okopowa Street Jewish Cemetery. The farewell speech was delivered by the chief rabbi and preacher of the Great Synagogue in Warsaw, Samuel Abraham Poznański, who said: "There will be a time where the Polish soil and nation will understand what fame gave this great son of God to his homeland." Family Zamenhof and his wife Klara Silbernik raised three children, a son, Adam, and two daughters, Zofia and Lidia. All three were murdered in the Holocaust. Lidia Zamenhof in particular took a keen interest in Esperanto, and as an adult became a teacher of the language, traveling through Europe and to America to teach classes in it. Through her friendship with Martha Root, Lidia accepted Bahá'u'lláh and became a member of the Baháʼí Faith. As one of its social principles, the Baháʼí Faith teaches that an auxiliary world language should be selected by the representatives of all the world's nations. Zamenhof's grandson, Louis-Christophe Zaleski-Zamenhof (Adam's son), lived in France from the 1960s until his death in 2019. As of 2020 Louis-Christophe's daughter, Margaret Zaleski-Zamenhof, is active in the Esperanto movement. Religious philosophy Besides his linguistic work, Zamenhof published a religious philosophy he called Homaranismo (the term in Esperanto, usually rendered as "humanitism" in English, sometimes rendered loosely as humanitarianism or humanism), based on the principles and teachings of Hillel the Elder. He said of Homaranismo: "It is indeed the object of my whole life. I would give up everything for it." Name Zamenhof came from a multilingual area. His name is variously transliterated, depending on the language: English: – English prononciation: Esperanto: – French: – German: – Hebrew: – Hebrew translitteration: Eli'ezer Ludwig Zamenhof Lithuanian: Polish: – Russian: – Russian translitteration: Lyudvik Lazar' (Leyzer) Markovich Zamengof Yiddish: – Yiddish translitteration: Leyzer "Levi" Zamenhof Born into an Ashkenazi family, at his birth Zamenhof was given the common Hebrew name Eliezer by his parents, the equivalent of the English Lazarus. However as the area was a part of the Russian empire at the time, his name was recorded on his birth certificate as Leyzer Zamengov, using the Yiddish form of the forename and a russified version of his surname; many later Russian language documents also include the patronymic Markovich « son of Mark » (in reference to his father, Markus), as is the custom in the language. His family name is of German origin and was originally written Samenhof; this was later transcribed into Yiddish as , then re-romanized back as Zamenhof. The change of the initial letter from « S » to « Z » is not unusual, as in German an initial « s » is pronounced . In his adolescence he used both the Yiddish Leyzer and the Russian Lazar when writing his first name. While at university, Zamenhof began using the Russian name Lyudovik (also transcribed Ludovic or translated as Ludwig) in place of Lazar, possibly in honor of Francis Lodwick, who in 1652 had published an early conlang proposal. When his brother Leon became a doctor and started signing his name "Dr L. Zamenhof", Zamenhof reclaimed his birth name Lazar and from 1901 signed his name "Dr L. L. Zamenhof" to avoid confusion with his brother. The two L's do not seem to have specifically represented either name, and the order Ludwik Lejzer is a modern convention. Honours and namesakes In 1905 Zamenhof received the Légion d'honneur for creating Esperanto. In 1910, Zamenhof was first nominated for the Nobel Peace Prize, by four British Members of Parliament (including James O'Grady and Philip Snowden) and Professor Stanley Lane Poole. (The Prize was instead awarded to the International Peace Bureau.) Ultimately Zamenhof was nominated 12 times for the Nobel Peace Prize. On the occasion of the fifth Universala Kongreso de Esperanto in Barcelona, Zamenhof was made a Commander of the Order of Isabella the Catholic by King Alfonso XIII of Spain. A monument or place linked to Zamenhof or Esperanto is known as a Zamenhof-Esperanto object (or ZEO). The minor planet 1462 Zamenhof is named in his honour. It was discovered on 6 February 1938 by Yrjö Väisälä. There is also a minor planet named in honour of Esperanto (1421 Esperanto). Hundreds of city streets, parks, and bridges worldwide have also been named after Zamenhof. In Lithuania, the best-known Zamenhof Street is in Kaunas, where he lived and owned a house for some time. There are others in Poland, the United Kingdom, France, Hungary, Croatia, the Czech Republic, Spain (mostly in Catalonia), Italy, Israel, Belgium and Brazil. There are Zamenhof Hills in Hungary and Brazil, and a Zamenhof Island in the Danube. In some Israeli cities, street signs identify Esperanto's creator and give his birth and death dates, but refer to him solely by his Jewish name Eliezer (a variant of which, El'azar, is the origin of Lazarus). Zamenhof is honoured as a deity by the Japanese religion Oomoto, which encourages the use of Esperanto among its followers. Also, a genus of lichen has been named Zamenhofia in his honour. Russian writer Nikolai Afrikanovich Borovko, who lived in Odessa, together with Vladimir Gernet, founded a branch of the first official Esperanto society Esrero in Russia. In the years 1896-97 N.A. Borovko became its chairman.
|
it." Name Zamenhof came from a multilingual area. His name is variously transliterated, depending on the language: English: – English prononciation: Esperanto: – French: – German: – Hebrew: – Hebrew translitteration: Eli'ezer Ludwig Zamenhof Lithuanian: Polish: – Russian: – Russian translitteration: Lyudvik Lazar' (Leyzer) Markovich Zamengof Yiddish: – Yiddish translitteration: Leyzer "Levi" Zamenhof Born into an Ashkenazi family, at his birth Zamenhof was given the common Hebrew name Eliezer by his parents, the equivalent of the English Lazarus. However as the area was a part of the Russian empire at the time, his name was recorded on his birth certificate as Leyzer Zamengov, using the Yiddish form of the forename and a russified version of his surname; many later Russian language documents also include the patronymic Markovich « son of Mark » (in reference to his father, Markus), as is the custom in the language. His family name is of German origin and was originally written Samenhof; this was later transcribed into Yiddish as , then re-romanized back as Zamenhof. The change of the initial letter from « S » to « Z » is not unusual, as in German an initial « s » is pronounced . In his adolescence he used both the Yiddish Leyzer and the Russian Lazar when writing his first name. While at university, Zamenhof began using the Russian name Lyudovik (also transcribed Ludovic or translated as Ludwig) in place of Lazar, possibly in honor of Francis Lodwick, who in 1652 had published an early conlang proposal. When his brother Leon became a doctor and started signing his name "Dr L. Zamenhof", Zamenhof reclaimed his birth name Lazar and from 1901 signed his name "Dr L. L. Zamenhof" to avoid confusion with his brother. The two L's do not seem to have specifically represented either name, and the order Ludwik Lejzer is a modern convention. Honours and namesakes In 1905 Zamenhof received the Légion d'honneur for creating Esperanto. In 1910, Zamenhof was first nominated for the Nobel Peace Prize, by four British Members of Parliament (including James O'Grady and Philip Snowden) and Professor Stanley Lane Poole. (The Prize was instead awarded to the International Peace Bureau.) Ultimately Zamenhof was nominated 12 times for the Nobel Peace Prize. On the occasion of the fifth Universala Kongreso de Esperanto in Barcelona, Zamenhof was made a Commander of the Order of Isabella the Catholic by King Alfonso XIII of Spain. A monument or place linked to Zamenhof or Esperanto is known as a Zamenhof-Esperanto object (or ZEO). The minor planet 1462 Zamenhof is named in his honour. It was discovered on 6 February 1938 by Yrjö Väisälä. There is also a minor planet named in honour of Esperanto (1421 Esperanto). Hundreds of city streets, parks, and bridges worldwide have also been named after Zamenhof. In Lithuania, the best-known Zamenhof Street is in Kaunas, where he lived and owned a house for some time. There are others in Poland, the United Kingdom, France, Hungary, Croatia, the Czech Republic, Spain (mostly in Catalonia), Italy, Israel, Belgium and Brazil. There are Zamenhof Hills in Hungary and Brazil, and a Zamenhof Island in the Danube. In some Israeli cities, street signs identify Esperanto's creator and give his birth and death dates, but refer to him solely by his Jewish name Eliezer (a variant of which, El'azar, is the origin of Lazarus). Zamenhof is honoured as a deity by the Japanese religion Oomoto, which encourages the use of Esperanto among its followers. Also, a genus of lichen has been named Zamenhofia in his honour. Russian writer Nikolai Afrikanovich Borovko, who lived in Odessa, together with Vladimir Gernet, founded a branch of the first official Esperanto society Esrero in Russia. In the years 1896-97 N.A. Borovko became its chairman. A monument to L. Zamenhof was installed in Odessa in an ordinary residential courtyard. Esperantist sculptor Nikolai Vasilyevich Blazhkov lived in this house, who in the early 1960s brought a sculptural portrait into the courtyard, because the customs authorities did not allow the sculpture to be sent to the Esperanto Congress in Vienna. In Gothenburg, Sweden a public square is named Esperantoplatsen. In Italy, a few streets are named after Esperanto, including Largo Esperanto in Pisa. In 1959, UNESCO honoured Zamenhof in the occasion of his centenary. In 2015 it decided to support the celebration of the 100th anniversary of his death. His birthday, 15 December, is celebrated annually as Zamenhof Day by users of Esperanto. On 15 December 2009, Esperanto's green-starred flag flew on the Google homepage to commemorate Zamenhof's 150th birthday. The house of the Zamenhof family and a monument to Zamenhof are sites on the Jewish Heritage Trail in Białystok, which was opened in June 2008 by volunteers at The University of Białystok Foundation. Białystok is also home to the Ludwik Zamenhof Centre. In 1960, Esperanto summer schools were established in Stoke-on-Trent in the United Kingdom by the Esperanto Association of Britain (EAB), which began to provide lessons and promote the language locally. There is a road named after Zamenhof in the city: Zamenhof Grove. As Dr. Zamenhof was born on 15 December 1859, the Esperanto Society of New York gathers every December to celebrate Zamenhofa Tago (Zamenhof Day in Esperanto). Partial bibliography Original works Unua Libro, 1887 (First Book) Dua Libro, 1888 (Second Book) Hilelismo – propono pri solvo de la hebrea demando, 1901 (Hillelism: A Project in Response to the Jewish Question) Esenco kaj estonteco de la ideo de lingvo internacia, 1903 (Essence and Future of the Idea of an International Language) Fundamenta Krestomatio de la Lingvo Esperanto, 1903 (Basic Anthology of the Esperanto Language) Fundamento de Esperanto, 1905 (Foundation of Esperanto) Declaration of Boulogne, 1905 Homaranismo, 1913 (Humanitism) Periodicals La Esperantisto, 1889–1895 (The Esperantist) Lingvo Internacia, 1895–1914 (International Language) La Revuo, 1906–1914 (The Review) Poems "Al la fratoj" ("To the Brothers") "Ho, mia kor'" ("Oh, My Heart") "La Espero" ("The Hope") "La vojo" ("The Way") "Mia penso" ("My Thought") Translations Hamleto, Reĝido de Danujo (Hamlet, Prince
|
matrix depend on the bases chosen. The matrices of a linear transformation can be represented visually: Matrix for relative to : Matrix for relative to : Transition matrix from to : Transition matrix from to : Such that starting in the bottom left corner and looking for the bottom right corner , one would left-multiply—that is, . The equivalent method would be the "longer" method going clockwise from the same point such that is left-multiplied with , or . Examples in two dimensions In two-dimensional space R2 linear maps are described by 2 × 2 matrices. These are some examples: rotation by 90 degrees counterclockwise: by an angle θ counterclockwise: reflection through the x axis: through the y axis: through a line making an angle θ with the origin: scaling by 2 in all directions: horizontal shear mapping: squeeze mapping: projection onto the y axis: Vector space of linear maps The composition of linear maps is linear: if and are linear, then so is their composition . It follows from this that the class of all vector spaces over a given field K, together with K-linear maps as morphisms, forms a category. The inverse of a linear map, when defined, is again a linear map. If and are linear, then so is their pointwise sum , which is defined by . If is linear and is an element of the ground field , then the map , defined by , is also linear. Thus the set of linear maps from to itself forms a vector space over , sometimes denoted . Furthermore, in the case that , this vector space, denoted , is an associative algebra under composition of maps, since the composition of two linear maps is again a linear map, and the composition of maps is always associative. This case is discussed in more detail below. Given again the finite-dimensional case, if bases have been chosen, then the composition of linear maps corresponds to the matrix multiplication, the addition of linear maps corresponds to the matrix addition, and the multiplication of linear maps with scalars corresponds to the multiplication of matrices with scalars. Endomorphisms and automorphisms A linear transformation is an endomorphism of ; the set of all such endomorphisms together with addition, composition and scalar multiplication as defined above forms an associative algebra with identity element over the field (and in particular a ring). The multiplicative identity element of this algebra is the identity map . An endomorphism of that is also an isomorphism is called an automorphism of . The composition of two automorphisms is again an automorphism, and the set of all automorphisms of forms a group, the automorphism group of which is denoted by or . Since the automorphisms are precisely those endomorphisms which possess inverses under composition, is the group of units in the ring . If has finite dimension , then is isomorphic to the associative algebra of all matrices with entries in . The automorphism group of is isomorphic to the general linear group of all invertible matrices with entries in . Kernel, image and the rank–nullity theorem If is linear, we define the kernel and the image or range of by is a subspace of and is a subspace of . The following dimension formula is known as the rank–nullity theorem: The number is also called the rank of and written as , or sometimes, ; the number is called the nullity of and written as or . If and are finite-dimensional, bases have been chosen and is represented by the matrix , then the rank and nullity of are equal to the rank and nullity of the matrix , respectively. Cokernel A subtler invariant of a linear transformation is the cokernel, which is defined as This is the dual notion to the kernel: just as the kernel is a subspace of the domain, the co-kernel is a quotient space of the target. Formally, one has the exact sequence These can be interpreted thus: given a linear equation f(v) = w to solve, the kernel is the space of solutions to the homogeneous equation f(v) = 0, and its dimension is the number of degrees of freedom in the space of solutions, if it is not empty; the co-kernel is the space of constraints that the solutions must satisfy, and its dimension is the maximal number of independent constraints. The dimension of the co-kernel and the dimension of the image (the rank) add up to the dimension of the target space. For finite dimensions, this means that the dimension of the quotient space W/f(V) is the dimension of the target space minus the dimension of the image. As a simple example, consider the map f: R2 → R2, given by f(x, y) = (0, y). Then for an equation f(x, y) = (a, b) to have a solution, we must have a = 0 (one constraint), and in that case the solution space is (x, b) or equivalently stated, (0, b) + (x, 0), (one degree of freedom). The kernel may be expressed as the subspace (x, 0) < V: the value of x is the freedom in a solution – while the cokernel may be expressed via the map W → R, : given a vector (a, b), the value of a is the obstruction to there being a solution. An example illustrating the infinite-dimensional case is afforded by the map f: R∞ → R∞, with b1 = 0 and bn + 1 = an for n > 0. Its image consists of all sequences with first element 0, and thus its cokernel consists of the classes of sequences with identical first element. Thus, whereas its kernel has dimension 0 (it maps only the zero sequence to the zero sequence), its co-kernel has dimension 1. Since the domain and the target space are the same, the rank and the dimension of the kernel add up to the same sum as the rank and the dimension of the co-kernel (), but in the infinite-dimensional case it cannot be inferred that the kernel and the co-kernel of an endomorphism have the same dimension (0 ≠ 1). The reverse situation obtains for the map h: R∞ → R∞, with cn = an + 1. Its image is the entire target space, and hence its co-kernel has dimension 0, but since it maps all sequences in which only the first element is non-zero to the zero sequence, its kernel has dimension 1. Index For a linear operator with finite-dimensional kernel and co-kernel, one may define index as: namely the degrees of freedom minus the number of constraints. For a transformation between finite-dimensional vector spaces, this is just the difference dim(V) − dim(W), by rank–nullity. This gives an indication of how many solutions or how many constraints one has: if mapping from a larger space to a smaller one, the map may be onto, and thus will have degrees of freedom even without constraints. Conversely, if mapping from a smaller space to a larger one, the map cannot be onto, and thus one will have constraints even without degrees of freedom. The index of an operator is precisely the Euler characteristic of the 2-term complex 0 → V → W → 0. In operator theory, the index of Fredholm operators is an object of study, with a major result being the Atiyah–Singer index theorem. Algebraic classifications of linear transformations No classification of linear maps could be exhaustive. The following incomplete list enumerates some important classifications that do not require any additional structure on the vector space. Let and denote vector spaces over a field and let be a linear map. Monomorphism is said to be injective or a monomorphism if any of the following equivalent conditions are true: is one-to-one as a map of sets. is monic or left-cancellable, which is to say, for any vector space and any pair of linear maps and , the equation implies . is left-invertible, which is to say there exists a linear map such that is the identity map on . Epimorphism is said to be surjective or an epimorphism if any of the following equivalent conditions are
|
spaces and by and respectively, it follows that Let and in the equation for homogeneity of degree 1: A linear map with viewed as a one-dimensional vector space over itself is called a linear functional. These statements generalize to any left-module over a ring without modification, and to any right-module upon reversing of the scalar multiplication. Examples A prototypical example that gives linear maps their name is a function , of which the graph is a line through the origin. More generally, any homothety where centered in the origin of a vector space is a linear map. The zero map between two vector spaces (over the same field) is linear. The identity map on any module is a linear operator. For real numbers, the map is not linear. For real numbers, the map is not linear (but is an affine transformation). If is a real matrix, then defines a linear map from to by sending a column vector to the column vector . Conversely, any linear map between finite-dimensional vector spaces can be represented in this manner; see the , below. If is an isometry between real normed spaces such that then is a linear map. This result is not necessarily true for complex normed space. Differentiation defines a linear map from the space of all differentiable functions to the space of all functions. It also defines a linear operator on the space of all smooth functions (a linear operator is a linear endomorphism, that is, a linear map with the same domain and codomain). An example is A definite integral over some interval is a linear map from the space of all real-valued integrable functions on to . For example, An indefinite integral (or antiderivative) with a fixed integration starting point defines a linear map from the space of all real-valued integrable functions on to the space of all real-valued, differentiable functions on . Without a fixed starting point, the antiderivative maps to the quotient space of the differentiable functions by the linear space of constant functions. If and are finite-dimensional vector spaces over a field , of respective dimensions and , then the function that maps linear maps to matrices in the way described in (below) is a linear map, and even a linear isomorphism. The expected value of a random variable (which is in fact a function, and as such a element of a vector space) is linear, as for random variables and we have and , but the variance of a random variable is not linear. Linear extensions Often, a linear map is constructed by defining it on a subset of a vector space and then to the linear span of the domain. A of a function refers to an extension of to some vector space that is a linear map. Suppose and are vector spaces and is a function defined on some subset Then can be extended to a linear map if and only if whenever is an integer, are scalars, and are vectors such that then necessarily If a linear extension of exists then the linear extension is unique and holds for all and as above. If is linearly independent then every function into any vector space has a linear extension to a (linear) map (the converse is also true). For example, if and then the assignment and can be linearly extended from the linearly independent set of vectors to a linear map on The unique linear extension is the map that sends to Every (scalar-valued) linear functional defined on a vector subspace of a real or complex vector space has a linear extension to all of Indeed, the Hahn–Banach dominated extension theorem even guarantees that when this linear functional is dominated by some given seminorm (meaning that holds for all in the domain of ) then there exists a linear extension to that is also dominated by Matrices If and are finite-dimensional vector spaces and a basis is defined for each vector space, then every linear map from to can be represented by a matrix. This is useful because it allows concrete calculations. Matrices yield examples of linear maps: if is a real matrix, then describes a linear map (see Euclidean space). Let be a basis for . Then every vector is uniquely determined by the coefficients in the field : If is a linear map, which implies that the function f is entirely determined by the vectors . Now let be a basis for . Then we can represent each vector as Thus, the function is entirely determined by the values of . If we put these values into an matrix , then we can
|
on a shaft. When Guericke held his hand against the ball and turned the shaft quickly, a static electric charge built up. This experiment inspired the development of several forms of "friction machines", that greatly helped in the study of electricity. The Leyden jar was effectively discovered independently by two parties: German deacon Ewald Georg von Kleist, who made the first discovery, and Dutch scientists Pieter van Musschenbroek and Andreas Cunaeus, who figured out how it worked only when held in the hand. The Leyden jar is a high-voltage device; it is estimated that at a maximum the early Leyden jars could be charged to 20,000 to 60,000 volts. The center rod electrode has a metal ball on the end to prevent leakage of the charge into the air by corona discharge. It was first used in electrostatics experiments, and later in high-voltage equipment such as spark-gap radio transmitters and electrotherapy machines. Von Kleist Ewald Georg von Kleist discovered the immense storage capability of the Leyden jar while working under a theory that saw electricity as a fluid, and hoped a glass jar filled with alcohol would "capture" this fluid. He was the deacon at the cathedral of Camin in Pomerania, a region now divided between Germany and Poland. In October 1745, von Kleist tried to accumulate electricity in a small medicine bottle filled with alcohol with a nail inserted in the cork. He was following up on an experiment developed by Georg Matthias Bose where electricity had been sent through water to set alcoholic spirits alight. He attempted to charge the bottle from a large prime conductor (invented by Bose) suspended above his friction machine. Kleist was convinced that a substantial electric charge could be collected and held within the glass which he knew would provide an obstacle to the escape of the 'fluid'. He received a significant shock from the device when he accidentally touched the nail through the cork while still cradling the bottle in his other hand. He communicated his results to at least five different electrical experimenters, in several letters from November 1745 to March 1746, but did not receive any confirmation that they had repeated his results, until April 1746. Polish-Lithuanian physicist Daniel Gralath learned about Kleist's experiment from seeing Kleist's letter to Paul Swietlicki, written in November 1745. After Gralath's failed first attempt to reproduce the experiment in December 1745, he wrote to Kleist for more information (and was told that the experiment would work better if the tube half-filled with alcohol was used). Gralath (in collaboration with ) succeeded in getting the intended effect on 5 March 1746, holding a small glass medicine bottle with a nail inside in one hand, moving it close to an electrostatic generator, and then moving the other hand close to the nail. Kleist didn't understand the significance of his conducting hand holding the bottle — and both he and his correspondents were loath to hold the device when told that the shock could throw them across the room. It took some time before Kleist's student associates at Leyden worked out that the hand provided an essential element. Musschenbroek and Cunaeus The Leyden jar's invention was long credited to Pieter van Musschenbroek, the physics professor at Leiden University, who also ran a family foundry which cast brass cannonettes, and a small business (De Oosterse Lamp – "The Eastern Lamp") which made scientific and medical instruments for the new university courses in physics and for scientific gentlemen keen to establish their own 'cabinets' of curiosities and instruments. Ewald Kleist is credited with first using the fluid analogy for electricity and demonstrated this to Bose by drawing sparks from water with his finger. Like Kleist, Musschenbroek was also interested in, and attempting to repeat, Bose's experiment. During this time, Andreas Cunaeus, a lawyer, came to learn about this experiment from visiting Musschenbroek's laboratory and Cunaeus attempted to duplicate the experiment at home with household items. Using a glass of beer, Cunaeus was unable to make it work. Cunaeus was the first to discover that such an experimental setup could deliver a severe shock when he held his jar in his hand while charging it rather than placing it on an insulated stand, not realizing that was the standard practice, thus making himself part of the circuit. He reported his procedure and experience to Swiss-Dutch natural philosopher Jean-Nicolas-Sebastian Allamand, Musschenbroek's colleague. Allamand and Musschenbroek also received severe shocks. Musschenbroek communicated the experiment in a letter from 20 January 1746 to French entomologist René Antoine Ferchault de
|
at Leiden University, who also ran a family foundry which cast brass cannonettes, and a small business (De Oosterse Lamp – "The Eastern Lamp") which made scientific and medical instruments for the new university courses in physics and for scientific gentlemen keen to establish their own 'cabinets' of curiosities and instruments. Ewald Kleist is credited with first using the fluid analogy for electricity and demonstrated this to Bose by drawing sparks from water with his finger. Like Kleist, Musschenbroek was also interested in, and attempting to repeat, Bose's experiment. During this time, Andreas Cunaeus, a lawyer, came to learn about this experiment from visiting Musschenbroek's laboratory and Cunaeus attempted to duplicate the experiment at home with household items. Using a glass of beer, Cunaeus was unable to make it work. Cunaeus was the first to discover that such an experimental setup could deliver a severe shock when he held his jar in his hand while charging it rather than placing it on an insulated stand, not realizing that was the standard practice, thus making himself part of the circuit. He reported his procedure and experience to Swiss-Dutch natural philosopher Jean-Nicolas-Sebastian Allamand, Musschenbroek's colleague. Allamand and Musschenbroek also received severe shocks. Musschenbroek communicated the experiment in a letter from 20 January 1746 to French entomologist René Antoine Ferchault de Réaumur, who was Musschenbroek's appointed correspondent at the Paris Academy. Abbé Jean-Antoine Nollet read this report, confirmed the experiment, and then read Musschenbroek's letter in a public meeting of the Paris Academy in April 1746 (translating from Latin to French). Musschenbroek's outlet in France for the sale of his company's 'cabinet' devices was the Abbé Nollet (who started building and selling duplicate instruments in 1735). Nollet then gave the electrical storage device the name "Leyden jar" and promoted it as a special type of flask to his market of wealthy men with scientific curiosity. The "Kleistian jar" was therefore promoted as the Leyden jar, and as having been discovered by Pieter van Musschenbroek and his acquaintance Andreas Cunaeus. Musschenbroek, however, never claimed that he had invented it, and some think that Cunaeus was mentioned only to diminish credit to him. Further developments Within months after Musschenbroek's report about how to reliably create a Leyden jar, other electrical researchers were making and experimenting with their own Leyden jars. One of his expressed original interests was to see if the total possible charge could be increased. Johann Heinrich Winckler, whose first experience with a single Leyden jar was reported in a letter to the Royal Society on 29 May 1746, had connected three Leyden jars together in a kind of electrostatic battery on 28 July 1746. In 1746, Abbé Nollet performed two experiments for the edification of King Louis XV of France, in the first of which he discharged a Leyden jar through 180 royal guardsmen, and in the second through a larger number of Carthusian monks; all of whom sprang into the air more or less simultaneously. The opinions of neither the king nor the experimental subjects have been recorded. Daniel Gralath reported in 1747 that in 1746 he had conducted experiments with connecting two or three jars, probably in series. In 1746-1748, Benjamin Franklin experimented with charging Leyden jars in series, and developed a system involving 11 panes of glass with thin lead plates glued on each side, and then connected together. He used the term "electrical battery" to describe his electrostatic battery in a 1749 letter about his electrical research in 1748. It is possible that Franklin's choice of the word battery was inspired by the humorous wordplay at the conclusion of his letter, where he wrote, among other things, about a salute to electrical researchers from a battery of guns. This is the first recorded use of the term electrical battery. The multiple and rapid developments for connecting Leyden jars during the period 1746–1748 resulted in a variety of divergent accounts in secondary literature about who made the first "battery" by connecting Leyden jars, whether they were in series or parallel, and who first used the term "battery". The term was later used for combinations of multiple electrochemical cells, the modern meaning of the term "battery". The Swedish physicist, chemist and meteorologist, Tobern Bergman translated much of Benjamin Franklin's writings on electricity into German and continued to study electrostatic properties. Starting in late 1756, Franz Aepinus, in a complicated interaction of cooperation and independent work with Johan Wilcke, developed an "air condenser", a variation on the Leyden jar, by using air rather than glass as the
|
which allowed the graffiti, and is located at Velkopřevorské náměstí (Grand Priory Square), Malá Strana. On 17 November 2014, the 25th anniversary of the Velvet Revolution, the wall was painted over in pure white by a group of art students, leaving only the text "wall is over" . The Knights of Malta initially filed a criminal complaint for vandalism against the students, which they later retracted after contacting them. The wall mural is still there as of 23 July 2017. And the "Wall is Over" bit has been changed to "War Is Over" from the song Happy Xmas (War Is Over). On 22 April 2019, Earth Day, the action group Extinction Rebellion repainted the entire wall with slogans demanding action from the Czech government on climate change. "KLIMATICKÁ NOUZE" was painted in large block print letters, which reads "climate emergency" in Czech. Members of the public were encouraged to add their own messages during the process, resulting in calls for action painted in several languages. A giant image of a skull was also painted. The repaint was carried out in a manner which allowed some of the existing artwork to be included on the new wall. In July 2019, artists painted a memorial on the wall for Hong Kong democracy activist Marco Leung Ling-kit, who became known as a martyr and a symbol of hope for the 2019 anti-extradition bill protest movement. The image on the wall depicts the yellow raincoat he was wearing during the banner drop that eventually led to a fall from the building, along with some words of solidarity: "Hong Kong, Add oil." On 4 August 2019 it was reported that the wall will be put under CCTV surveillance to block "unlawful graffiti" and combat the swaths of tourists that pass by it every day. In October 2019, the Sovereign Military Order of Malta together with Prague 1 started the reconstruction of the Lennon Wall which lasted until November. They reacted thus to the recent situation of vandalism on the Wall and its surroundings connected to the overtourism which became unbearable this summer. The place should regain its respectable form which was going to be introduced on the occasion of the 30th anniversary of the Velvet Revolution in November as an open-air gallery with new rules. On 7 November 2019, the new face of the Lennon Wall as an open-air gallery was created and introduced to the public. Over 30 Czech and foreign professional artists gathered by the Czech designer Pavel Šťastný painted on the Wall. New rules of the Wall makes spraying no longer allowed, people can leave their messages connected to freedom and love only in the white free zones andy in more sensitive materials than sprays, e.g. pencil, marker or chalk. Cameras and police will monitor the wall to ensure the artistic portion is not defaced. Lennon Walls in Hong Kong During the 2014 democracy
|
of the singer-songwriter and some lyrics. In 1988, the wall was a source of irritation for Gustáv Husák's communist regime. Following a short-lived era of democratization and political liberalization known as the Prague Spring, the newly-installed communist government dismantled the reforms, inspiring anger and resistance. Young Czechs wrote their grievances on the wall and, according to a report of the time, this led to a clash between hundreds of students and security police on the nearby Charles Bridge. The liberalization movement these students followed was described as "Lennonism" (not to be confused with "Leninism"), and Czech authorities described participants variously as alcoholic, mentally deranged, sociopathic, and agents of Western free market capitalism. The wall continuously undergoes change, and the original portrait of Lennon is long lost under layers of new paint. Even when the wall was repainted by authorities, by the next day it was again full of poems and flowers. Today, the wall represents a symbol of global ideals such as love and peace. The wall is owned by the Sovereign Military Order of Malta, which allowed the graffiti, and is located at Velkopřevorské náměstí (Grand Priory Square), Malá Strana. On 17 November 2014, the 25th anniversary of the Velvet Revolution, the wall was painted over in pure white by a group of art students, leaving only the text "wall is over" . The Knights of Malta initially filed a criminal complaint for vandalism against the students, which they later retracted after contacting them. The wall mural is still there as of 23 July 2017. And the "Wall is Over" bit has been changed to "War Is Over" from the song Happy Xmas (War Is Over). On
|
increased to about 650 residents. Today, the pueblo is commemorated in the historic district of Los Angeles Pueblo Plaza and Olvera Street, the oldest part of Los Angeles. Mexican rule New Spain achieved its independence from the Spanish Empire in 1821, and the pueblo continued as a part of Mexico. During Mexican rule, Governor Pío Pico made Los Angeles Alta California's regional capital. 1847 to present Mexican rule ended during the Mexican–American War: Americans took control from the Californios after a series of battles, culminating with the signing of the Treaty of Cahuenga on January 13, 1847. Railroads arrived with the completion of the transcontinental Southern Pacific line from New Orleans to Los Angeles in 1876 and the Santa Fe Railroad in 1885. Petroleum was discovered in the city and surrounding area in 1892, and by 1923, the discoveries had helped California become the country's largest oil producer, accounting for about one-quarter of the world's petroleum output. By 1900, the population had grown to more than 102,000, putting pressure on the city's water supply. The completion of the Los Angeles Aqueduct in 1913, under the supervision of William Mulholland, ensured the continued growth of the city. Because of clauses in the city's charter that prevented the City of Los Angeles from selling or providing water from the aqueduct to any area outside its borders, many adjacent cities and communities felt compelled to join Los Angeles. Los Angeles created the first municipal zoning ordinance in the United States. On September 14, 1908, the Los Angeles City Council promulgated residential and industrial land use zones. The new ordinance established three residential zones of a single type, where industrial uses were prohibited. The proscriptions included barns, lumber yards, and any industrial land use employing machine-powered equipment. These laws were enforced against industrial properties after the fact. These prohibitions were in addition to existing activities that were already regulated as nuisances. These included explosives warehousing, gas works, oil drilling, slaughterhouses, and tanneries. Los Angeles City Council also designated seven industrial zones within the city. However, between 1908 and 1915, Los Angeles City Council created various exceptions to the broad proscriptions that applied to these three residential zones, and as a consequence, some industrial uses emerged within them. There are two differences between the 1908 Residence District Ordinance and later zoning laws in the United States. First, the 1908 laws did not establish a comprehensive zoning map as the 1916 New York City Zoning Ordinance did. Second, the residential zones did not distinguish types of housing; they treated apartments, hotels, and detached-single-family housing equally. In 1910, Hollywood merged into Los Angeles, with 10 movie companies already operating in the city at the time. By 1921, more than 80 percent of the world's film industry was concentrated in L.A. The money generated by the industry kept the city insulated from much of the economic loss suffered by the rest of the country during the Great Depression. By 1930, the population surpassed one million. In 1932, the city hosted the Summer Olympics. During World War II, Los Angeles was a major center of wartime manufacturing, such as shipbuilding and aircraft. Calship built hundreds of Liberty Ships and Victory Ships on Terminal Island, and the Los Angeles area was the headquarters of six of the country's major aircraft manufacturers (Douglas Aircraft Company, Hughes Aircraft, Lockheed, North American Aviation, Northrop Corporation, and Vultee). During the war, more aircraft were produced in one year than in all the pre-war years since the Wright brothers flew the first airplane in 1903, combined. Manufacturing in Los Angeles skyrocketed, and as William S. Knudsen, of the National Defense Advisory Commission put it, "We won because we smothered the enemy in an avalanche of production, the like of which he had never seen, nor dreamed possible." In the 1930s–1940s, Los Angeles County was the national leader in agriculture. Following the end of World War II, Los Angeles grew more rapidly than ever, sprawling into the San Fernando Valley. The expansion of the Interstate Highway System during the 1950s and 1960s helped propel suburban growth and signaled the demise of the city's electrified rail system, once the world's largest. As a consequence of World War II, suburban growth, and population density, many amusement parks were built and operated in this area. An example is Beverly Park, which was located at the corner of Beverly Boulevard and La Cienega before being closed and substituted by the Beverly Center. Racial tensions led to the Watts riots in 1965, resulting in 34 deaths and over 1,000 injuries. In 1969, California became the birthplace of the Internet, as the first ARPANET transmission was sent from the University of California, Los Angeles (UCLA) to the Stanford Research Institute in Menlo Park. In 1973, Tom Bradley was elected as the city's first African American mayor, serving for five terms until retiring in 1993. Other events in the city during the 1970s included the Symbionese Liberation Army's South Central standoff in 1974 and the Hillside Stranglers murder cases in 1977–1978. In 1984, the city hosted the Summer Olympic Games for the second time. Despite being boycotted by 14 Communist countries, the 1984 Olympics became more financially successful than any previous, and the second Olympics to turn a profit; the other, according to an analysis of contemporary newspaper reports, was the 1932 Summer Olympics, also held in Los Angeles. Racial tensions erupted on April 29, 1992, with the acquittal by a Simi Valley jury of four Los Angeles Police Department (LAPD) officers captured on videotape beating Rodney King, culminating in large-scale riots. In 1994, the magnitude 6.7 Northridge earthquake shook the city, causing $12.5 billion in damage and 72 deaths. The century ended with the Rampart scandal, one of the most extensive documented cases of police misconduct in American history. In 2002, Mayor James Hahn led the campaign against secession, resulting in voters defeating efforts by the San Fernando Valley and Hollywood to secede from the city. Los Angeles will host the 2028 Summer Olympics and Paralympic Games, making Los Angeles the third city to host the Olympics three times. Pronunciation The English pronunciation of the name of the city has varied. A 1953 article in the journal of the American Name Society asserts that the pronunciation was established following the 1850 incorporation of the city and that since the 1880s the pronunciation emerged out of a trend in California to give places Spanish, or Spanish-sounding, names and pronunciations. In 1908, librarian Charles Fletcher Lummis, who argued for the pronunciation with , reported that there were at least 12 pronunciation variants. In the early 1900s, the Los Angeles Times advocated for pronouncing it Loce AHNG-hayl-ais (), approximating Spanish , by printing the respelling under its masthead for several years. This did not find favor. Since the 1930s, has been most common. In 1934, the United States Board on Geographic Names decreed that this pronunciation be used. This was also endorsed in 1952 by a "jury" appointed by Mayor Fletcher Bowron to devise an official pronunciation. Geography Topography The city of Los Angeles covers a total area of , comprising of land and of water. The city extends for north-south and for east-west. The perimeter of the city is . Los Angeles is both flat and hilly. The highest point in the city proper is Mount Lukens at , located at the northeastern end of the San Fernando Valley. The eastern end of the Santa Monica Mountains stretches from Downtown to the Pacific Ocean and separates the Los Angeles Basin from the San Fernando Valley. Other hilly parts of Los Angeles include the Mt. Washington area north of Downtown, eastern parts such as Boyle Heights, the Crenshaw district around the Baldwin Hills, and the San Pedro district. Surrounding the city are much higher mountains. Immediately to the north lie the San Gabriel Mountains, which is a popular recreation area for Angelenos. Its high point is Mount San Antonio, locally known as Mount Baldy, which reaches . Further afield, the highest point in the Greater Los Angeles area is San Gorgonio Mountain, with a height of . The Los Angeles River, which is largely seasonal, is the primary drainage channel. It was straightened and lined in of concrete by the Army Corps of Engineers to act as a flood control channel. The river begins in the Canoga Park district of the city, flows east from the San Fernando Valley along the north edge of the Santa Monica Mountains, and turns south through the city center, flowing to its mouth in the Port of Long Beach at the Pacific Ocean. The smaller Ballona Creek flows into the Santa Monica Bay at Playa del Rey. Vegetation Los Angeles is rich in native plant species partly because of its diversity of habitats, including beaches, wetlands, and mountains. The most prevalent plant communities are coastal sage scrub, chaparral shrubland, and riparian woodland. Native plants include: the California poppy, matilija poppy, toyon, Ceanothus, Chamise, Coast Live Oak, sycamore, willow and Giant Wildrye. Many of these native species, such as the Los Angeles sunflower, have become so rare as to be considered endangered. Although it is not native to the area, the official tree of Los Angeles is the Coral Tree (Erythrina caffra) and the official flower of Los Angeles is the Bird of Paradise (Strelitzia reginae). Mexican Fan Palms, Canary Island Palms, Queen Palms, Date Palms, and California Fan Palms are common in the Los Angeles area, although only the last is native to California, though still not native to the City of Los Angeles. Geology Los Angeles is subject to earthquakes because of its location on the Pacific Ring of Fire. The geologic instability has produced numerous faults, which cause approximately 10,000 earthquakes annually in Southern California, though most of them are too small to be felt. The strike-slip San Andreas Fault system, which sits at the boundary between the Pacific Plate and the North American Plate, passes through the Los Angeles metropolitan area. The segment of the fault passing through Southern California experiences a major earthquake roughly every 110 to 140 years, and seismologists have warned about the next "big one", as the last major earthquake was the 1857 Fort Tejon earthquake. The Los Angeles basin and metropolitan area are also at risk from blind thrust earthquakes. Major earthquakes that have hit the Los Angeles area include the 1933 Long Beach, 1971 San Fernando, 1987 Whittier Narrows, and the 1994 Northridge events. All but a few are of low intensity and are not felt. The USGS has released the UCERF California earthquake forecast, which models earthquake occurrence in California. Parts of the city are also vulnerable to tsunamis; harbor areas were damaged by waves from Aleutian Islands earthquake in 1946, Valdivia earthquake in 1960, Alaska earthquake in 1964, Chile earthquake in 2010 and Japan earthquake in 2011. Cityscape The city is divided into many different districts and neighborhoods, some of which were incorporated cities that merged with Los Angeles. These neighborhoods were developed piecemeal, and are well-defined enough that the city has signage marking nearly all of them. Overview The city's street patterns generally follow a grid plan, with uniform block lengths and occasional roads that cut across blocks. However, this is complicated by rugged terrain, which has necessitated having different grids for each of the valleys that Los Angeles covers. Major streets are designed to move large volumes of traffic through many parts of the city, many of which are extremely long; Sepulveda Boulevard is long, while Foothill Boulevard is over long, reaching as far east as San Bernardino. Drivers in Los Angeles suffer from one of the worst rush hour periods in the world, according to an annual traffic index by navigation system maker, TomTom. LA drivers spend an additional 92 hours in traffic each year. During the peak rush hour, there is 80% congestion, according to the index. Los Angeles is often characterized by the presence of low-rise buildings, in contrast to New York City. Outside of a few centers such as Downtown, Warner Center, Century City, Koreatown, Miracle Mile, Hollywood, and Westwood, skyscrapers and high-rise buildings are not common in Los Angeles. The few skyscrapers built outside of those areas often stand out above the rest of the surrounding landscape. Most construction is done in separate units, rather than wall-to-wall. That being said, Downtown Los Angeles itself has many buildings over 30 stories, with fourteen over 50 stories, and two over 70 stories, the tallest of which is the Wilshire Grand Center. Also, Los Angeles is increasingly becoming a city of apartments rather than single-family dwellings, especially in the dense inner city and Westside neighborhoods. Climate Los Angeles has a Mediterranean climate (Köppen Csb on the coast and most of downtown, Csa near the metropolitan region to the west), and receives just enough annual precipitation to avoid being classified as a semi-arid climate (BSh). Daytime temperatures are generally temperate all year round. In winter, they average around giving it a tropical feel although it is a few degrees too cool to be a true tropical climate on average due to cool night temperatures. Los Angeles has plenty of sunshine throughout the year, with an average of only 35 days with measurable precipitation annually. Temperatures in the coastal basin exceed on a dozen or so days in the year, from one day a month in April, May, June and November to three days a month in July, August, October and to five days in September. Temperatures in the San Fernando and San Gabriel Valleys are considerably warmer. Temperatures are subject to substantial daily swings; in inland areas the difference between the average daily low and the average daily high is over . The average annual temperature of the sea is , from in January to in August. Hours of sunshine total more than 3,000 per year, from an average of 7 hours of sunshine per day in December to an average of 12 in July. The Los Angeles area is also subject to phenomena typical of a microclimate, causing extreme variations in temperature in close physical proximity to each other. For example, the average July maximum temperature at the Santa Monica Pier is whereas it is in Canoga Park, away. The city, like much of the Southern Californian coast, is subject to a late spring/early summer weather phenomenon called "June Gloom". This involves overcast or foggy skies in the morning that yield to sun by early afternoon. Downtown Los Angeles averages of precipitation annually, mainly occurring between November and March, generally in the form of moderate rain showers, but sometimes as heavy rainfall during winter storms. Rainfall is usually higher in the hills and coastal slopes of the mountains because of orographic uplift. Summer days are usually rainless. Rarely, an incursion of moist air from the south or east can bring brief thunderstorms in late summer, especially to the mountains. The coast gets slightly less rainfall, while the inland and mountain areas get considerably more. Years of average rainfall are rare. The usual pattern is a year-to-year variability, with a short string of dry years of rainfall, followed by one or two wet years with more than . Wet years are usually associated with warm water El Niño conditions in the Pacific, dry years with cooler water La Niña episodes. A series of rainy days can bring floods to the lowlands and mudslides to the hills, especially after wildfires have denuded the slopes. Both freezing temperatures and snowfall are extremely rare in the city basin and along the coast, with the last occurrence of a reading at the downtown station being January 29, 1979; freezing temperatures occur nearly every year in valley locations while the mountains within city limits typically receive snowfall every winter. The greatest snowfall recorded in downtown Los Angeles was on January 15, 1932. While the most recent snowfall occurred in February 2019, the first snowfall since 1962, with snow falling in areas adjacent to Los Angeles as recently as January 2021. At the official downtown station, the highest recorded temperature is on September 27, 2010, while the lowest is , on January 4, 1949. Within the City of Los Angeles, the highest temperature ever officially recorded is , on September 6, 2020, at the weather station at Pierce College in the San Fernando Valley neighborhood of Woodland Hills. During autumn and winter, Santa Ana winds sometimes bring much warmer and drier conditions to Los Angeles, and raise wildfire risk. Environmental issues A Gabrielino settlement in the area was called iyáangẚ (written Yang-na by the Spanish), which has been translated as "poison oak place". Yang-na has also been translated as "the valley of smoke". Owing to geography, heavy reliance on automobiles, and the Los Angeles/Long Beach port complex, Los Angeles suffers from air pollution in the form of smog. The Los Angeles Basin and the San Fernando Valley are susceptible to atmospheric inversion, which holds in the exhausts from road vehicles, airplanes, locomotives, shipping, manufacturing, and other sources. The percentage of small particle pollution (the kind that penetrates into the lungs) coming from vehicles in the city can get as high as 55 percent. The smog season lasts from approximately May to October. While other large cities rely on rain to clear smog, Los Angeles gets only of rain each year: pollution accumulates over many consecutive days. Issues of air quality in Los Angeles and other major cities led to the passage of early national environmental legislation, including the Clean Air Act. When the act was passed, California was unable to create a State Implementation Plan that would enable it to meet the new
|
are more than 1,100 annual theatrical productions and 21 openings every week." The Los Angeles Music Center is "one of the three largest performing arts centers in the nation", with more than 1.3 million visitors per year. The Walt Disney Concert Hall, centerpiece of the Music Center, is home to the prestigious Los Angeles Philharmonic. Notable organizations such as Center Theatre Group, the Los Angeles Master Chorale, and the Los Angeles Opera are also resident companies of the Music Center. Talent is locally cultivated at premier institutions such as the Colburn School and the USC Thornton School of Music. Museums and galleries There are 841 museums and art galleries in Los Angeles County, more museums per capita than any other city in the U.S. Some of the notable museums are the Los Angeles County Museum of Art (the largest art museum in the Western United States), the Getty Center (part of the J. Paul Getty Trust, the world's wealthiest art institution), the Petersen Automotive Museum, the Huntington Library, the Natural History Museum, the Battleship Iowa, and the Museum of Contemporary Art. A significant number of art galleries are on Gallery Row, and tens of thousands attend the monthly Downtown Art Walk there. Libraries The Los Angeles Public Library system operates 72 public libraries in the city. Enclaves of unincorporated areas are served by branches of the County of Los Angeles Public Library, many of which are within walking distance to residents. Landmarks Important landmarks in Los Angeles include the Hollywood Sign, Walt Disney Concert Hall, Capitol Records Building, the Cathedral of Our Lady of the Angels, Angels Flight, Grauman's Chinese Theatre, Dolby Theatre, Griffith Observatory, Getty Center, Getty Villa, Stahl House, the Los Angeles Memorial Coliseum, L.A. Live, the Los Angeles County Museum of Art, the Venice Canal Historic District and boardwalk, Theme Building, Bradbury Building, U.S. Bank Tower, Wilshire Grand Center, Hollywood Boulevard, Los Angeles City Hall, Hollywood Bowl, battleship , Watts Towers, Staples Center, Dodger Stadium, and Olvera Street. Sports The city of Los Angeles and its metropolitan area are the home of eleven top-level professional sports teams, several of which play in neighboring communities but use Los Angeles in their name. These teams include the Los Angeles Dodgers and Los Angeles Angels of Major League Baseball (MLB), the Los Angeles Rams and Los Angeles Chargers of the National Football League (NFL), the Los Angeles Lakers and Los Angeles Clippers of the National Basketball Association (NBA), the Los Angeles Kings and Anaheim Ducks of the National Hockey League (NHL), the Los Angeles Galaxy and Los Angeles FC of Major League Soccer (MLS), and the Los Angeles Sparks of the Women's National Basketball Association (WNBA). Other notable sports teams include the UCLA Bruins and the USC Trojans in the National Collegiate Athletic Association (NCAA), both of which are Division I teams in the Pac-12 Conference. Los Angeles is the second-largest city in the United States but hosted no NFL team between 1995 and 2015. At one time, the Los Angeles area hosted two NFL teams: the Rams and the Raiders. Both left the city in 1995, with the Rams moving to St. Louis, and the Raiders moving back to their original home of Oakland. After 21 seasons in St. Louis, on January 12, 2016, the NFL announced the Rams would be moving back to Los Angeles for the 2016 NFL season with its home games played at the Los Angeles Memorial Coliseum for four seasons. Prior to 1995, the Rams played their home games in the Coliseum from 1946 to 1979 which made them the first professional sports team to play in Los Angeles, and then moved to Anaheim Stadium from 1980 until 1994. The San Diego Chargers announced on January 12, 2017, that they would also relocate back to Los Angeles (the first since its inaugural season in 1960) and become the Los Angeles Chargers beginning in the 2017 NFL season and played at Dignity Health Sports Park in Carson, California for three seasons. The Rams and the Chargers would soon move to the newly built SoFi Stadium, located in nearby Inglewood during the 2020 season. Los Angeles boasts a number of sports venues, including Dodger Stadium, the Los Angeles Memorial Coliseum, Banc of California Stadium and the Crypto.com Arena. The Forum, SoFi Stadium, Dignity Health Sports Park, the Rose Bowl, Angel Stadium and Honda Center are also in adjacent cities and cities in Los Angeles's metropolitan area. Los Angeles has twice hosted the Summer Olympic Games: in 1932 and in 1984, and will host the games for a third time in 2028. Los Angeles will be the third city after London (1908, 1948 and 2012) and Paris (1900, 1924 and 2024) to host the Olympic Games three times. When the tenth Olympic Games were hosted in 1932, the former 10th Street was renamed Olympic Blvd. Los Angeles also hosted the Deaflympics in 1985 and Special Olympics World Summer Games in 2015. 7 NFL Super Bowls were also held in the city and its surrounding areas- 2 at the Memorial Coliseum (the first Super Bowl, I and VII) and 5 at the Rose Bowl in suburban Pasadena (XI, XIV, XVII, XXI, and XXVII), 10 miles north of downtown Los Angeles. Super Bowl LVI will be held at SoFi Stadium in Inglewood in 2022. The Rose Bowl also hosts an annual and highly prestigious NCAA college football game called the Rose Bowl, which happens every New Year's Day. Los Angeles also hosted 8 FIFA World Cup soccer games at the Rose Bowl in 1994, including the final, where Brazil won. The Rose Bowl also hosted 4 matches in the 1999 FIFA Women's World Cup, including the final, where the United States won against China on penalty kicks. This was the game where Brandi Chastain took her shirt off after she scored the tournament-winning penalty kick, creating an iconic image. Los Angeles is one of six North American cities to have won championships in all five of its major leagues (MLB, NFL, NHL, NBA and MLS), having completed the feat with the Kings' 2012 Stanley Cup title. Government Los Angeles is a charter city as opposed to a general law city. The current charter was adopted on June 8, 1999, and has been amended many times. The elected government consists of the Los Angeles City Council and the mayor of Los Angeles, which operate under a mayor–council government, as well as the city attorney (not to be confused with the district attorney, a county office) and controller. The mayor is Eric Garcetti. There are 15 city council districts. The city has many departments and appointed officers, including the Los Angeles Police Department (LAPD), the Los Angeles Board of Police Commissioners, the Los Angeles Fire Department (LAFD), the Housing Authority of the City of Los Angeles (HACLA), the Los Angeles Department of Transportation (LADOT), and the Los Angeles Public Library (LAPL). The charter of the City of Los Angeles ratified by voters in 1999 created a system of advisory neighborhood councils that would represent the diversity of stakeholders, defined as those who live, work or own property in the neighborhood. The neighborhood councils are relatively autonomous and spontaneous in that they identify their own boundaries, establish their own bylaws, and elect their own officers. There are about 90 neighborhood councils. Residents of Los Angeles elect supervisors for the 1st, 2nd, 3rd, and 4th supervisorial districts. Federal and state representation In the California State Assembly, Los Angeles is split between fourteen districts. In the California State Senate, the city is split between eight districts. In the United States House of Representatives, it is split among ten congressional districts. Education Colleges and universities There are three public universities within the city limits: California State University, Los Angeles (CSULA), California State University, Northridge (CSUN) and University of California, Los Angeles (UCLA). Private colleges in the city include: American Film Institute Conservatory Alliant International University American Academy of Dramatic Arts (Los Angeles Campus) American Jewish University Abraham Lincoln University The American Musical and Dramatic Academy – Los Angeles campus Antioch University's Los Angeles campus Charles R. Drew University of Medicine and Science Colburn School Columbia College Hollywood Emerson College (Los Angeles Campus) Emperor's College Fashion Institute of Design & Merchandising's Los Angeles campus (FIDM) Los Angeles Film School Loyola Marymount University (LMU is also the parent university of Loyola Law School in Los Angeles) Marymount College Mount St. Mary's College National University of California Occidental College ("Oxy") Otis College of Art and Design (Otis) Southern California Institute of Architecture (SCI-Arc) Southwestern Law School University of Southern California (USC) Woodbury University The community college system consists of nine campuses governed by the trustees of the Los Angeles Community College District: East Los Angeles College (ELAC) Los Angeles City College (LACC) Los Angeles Harbor College Los Angeles Mission College Los Angeles Pierce College Los Angeles Valley College (LAVC) Los Angeles Southwest College Los Angeles Trade-Technical College West Los Angeles College There are numerous additional colleges and universities outside the city limits in the Greater Los Angeles area, including the Claremont Colleges consortium, which includes the most selective liberal arts colleges in the U.S., and the California Institute of Technology (Caltech), one of the top STEM-focused research institutions in the world. Schools Los Angeles Unified School District serves almost all of the city of Los Angeles, as well as several surrounding communities, with a student population around 800,000. After Proposition 13 was approved in 1978, urban school districts had considerable trouble with funding. LAUSD has become known for its underfunded, overcrowded and poorly maintained campuses, although its 162 Magnet schools help compete with local private schools. Several small sections of Los Angeles are in the Inglewood Unified School District, and the Las Virgenes Unified School District. The Los Angeles County Office of Education operates the Los Angeles County High School for the Arts. Media The Los Angeles metro area is the second-largest broadcast designated market area in the U.S. (after New York) with 5,431,140 homes (4.956% of the U.S.), which is served by a wide variety of local AM and FM radio and television stations. Los Angeles and New York City are the only two media markets to have seven VHF allocations assigned to them. As part of the region's aforementioned creative industry, the Big Four major broadcast television networks, ABC, CBS, FOX, and NBC, all have production facilities and offices throughout various areas of Los Angeles. All four major broadcast television networks, plus major Spanish-language networks Telemundo and Univision, also own and operate stations that both serve the Los Angeles market and serve as each network's West Coast flagship station: ABC's KABC-TV (Channel 7), CBS's KCBS-TV (Channel 2), Fox's KTTV-TV (Channel 11), NBC's KNBC-TV (Channel 4), MyNetworkTV's KCOP-TV (Channel 13), Telemundo's KVEA-TV (Channel 52), and Univision's KMEX-TV (Channel 34). The region also has three PBS stations, as well as KCET (Channel 28), the nation's largest independent public television station. KTBN (Channel 40) is the flagship station of the religious Trinity Broadcasting Network, based out of Santa Ana. A variety of independent television stations, such as KCAL-TV (Channel 9) and KTLA-TV (Channel 5), also operate in the area. The major daily English-language newspaper in the area is the Los Angeles Times. La Opinión is the city's major daily Spanish-language paper. The Korea Times is the city's major daily Korean language paper while The World Journal is the city and county's major Chinese newspaper. The Los Angeles Sentinel is the city's major African-American weekly paper, boasting the largest African-American readership in the Western United States. Investor's Business Daily is distributed from its LA corporate offices, which are headquartered in Playa del Rey. There are also a number of smaller regional newspapers, alternative weeklies and magazines, including the Los Angeles Register, Los Angeles Community News, (which focuses on coverage of the greater Los Angeles area), Los Angeles Daily News (which focuses coverage on the San Fernando Valley), LA Weekly, L.A. Record (which focuses coverage on the music scene in the Greater Los Angeles Area), Los Angeles Magazine, the Los Angeles Business Journal, the Los Angeles Daily Journal (legal industry paper), The Hollywood Reporter, Variety (both entertainment industry papers), and Los Angeles Downtown News. In addition to the major papers, numerous local periodicals serve immigrant communities in their native languages, including Armenian, English, Korean, Persian, Russian, Chinese, Japanese, Hebrew, and Arabic. Many cities adjacent to Los Angeles also have their own daily newspapers whose coverage and availability overlaps with certain Los Angeles neighborhoods. Examples include The Daily Breeze (serving the South Bay), and The Long Beach Press-Telegram. Los Angeles arts, culture and nightlife news is also covered by a number of local and national online guides, including Time Out Los Angeles, Thrillist, Kristin's List, DailyCandy, Diversity News Magazine, LAist, and Flavorpill. Infrastructure Transportation Freeways The city and the rest of the Los Angeles metropolitan area are served by an extensive network of freeways and highways. The Texas Transportation Institute, which publishes an annual Urban Mobility Report, ranked Los Angeles road traffic as the most congested in the United States in 2005 as measured by annual delay per traveler. The average traveler in Los Angeles experienced 72 hours of traffic delay per year according to the study. Los Angeles was followed by San Francisco/Oakland, Washington, D.C., and Atlanta (each with 60 hours of delay). Despite the congestion in the city, the mean travel time for commuters in Los Angeles is shorter than other major cities, including New York City, Philadelphia and Chicago. Los Angeles's mean travel time for work commutes in 2006 was 29.2 minutes, similar to those of San Francisco and Washington, D.C. The major highways that connect LA to the rest of the nation include Interstate 5, which runs south through San Diego to Tijuana in Mexico and north through Sacramento, Portland, and Seattle to the Canada–US border; Interstate 10, the southernmost east–west, coast-to-coast Interstate Highway in the United States, going to Jacksonville, Florida; and U.S. Route 101, which heads to the California Central Coast, San Francisco, the Redwood Empire, and the Oregon and Washington coasts. Transit systems The LA County Metropolitan Transportation Authority (LA County Metro) and other agencies operate an extensive system of bus lines, as well as subway and light rail lines across Los Angeles County, with a combined monthly ridership (measured in individual boardings) of 38.8 million . The majority of this (30.5 million) is taken up by the city's bus system, the second busiest in the country. The subway and light rail combined average the remaining roughly 8.2 million boardings per month. LA County Metro recorded over 397 million boardings for the 2017 calendar year, including about 285 million bus riders and about 113 million riding on rail transit. For the first quarter of 2018, there were just under 95 million system-wide boardings, down from about 98 million in 2017, and about 105 million in 2016. In 2005, 10.2% of Los Angeles commuters rode some form of public transportation. According to the 2016 American Community Survey, 9.2% of working Los Angeles (city) residents made the journey to work via public transportation. The city's subway system is the ninth busiest in the United States and its light rail system is the country's busiest. The rail system includes the B and D subway lines, as well as the A, C, E, and L light rail lines. In 2016, the E Line was extended to the Pacific Ocean at Santa Monica. The Metro G and J lines are bus rapid transit lines with stops and frequency similar to those of light rail. , the total number of light rail stations is 93. The city is also central to the commuter rail system Metrolink, which links Los Angeles to all neighboring counties as well as many suburbs. Besides the rail service provided by Metrolink and the Los Angeles County Metropolitan Transportation Authority, Los Angeles is served by inter-city passenger trains from Amtrak. The main rail station in the city is Union Station just north of Downtown. In addition, the city directly contracts for local and commuter bus service through the Los Angeles Department of Transportation, or LADOT. Airports The main international and domestic airport serving Los Angeles is Los Angeles International Airport , commonly referred to by its airport code, LAX. Other major nearby commercial airports include: Ontario International Airport, owned by the city of Ontario, CA; serves the Inland Empire. Hollywood Burbank Airport, jointly owned by the cities of Burbank, Glendale, and Pasadena. Formerly known as Bob Hope Airport and Burbank Airport, the closest airport to Downtown Los Angeles serves the San Fernando, San Gabriel, and Antelope Valleys. Long Beach Airport, serves the Long Beach/Harbor area. John Wayne Airport of Orange County. One of the world's busiest general-aviation airports is also in Los Angeles: Van Nuys Airport . Seaports The Port of Los Angeles is in San Pedro Bay in the San Pedro neighborhood, approximately south of Downtown. Also called Los Angeles Harbor and WORLDPORT LA, the port complex occupies of land and water along of waterfront. It adjoins the separate Port of Long Beach. The sea ports of the Port of Los Angeles and Port of Long Beach together make up the Los Angeles/Long Beach Harbor. Together, both ports are the fifth busiest container port in the world, with a trade volume of over 14.2 million TEU's in 2008. Singly, the Port of Los Angeles is the busiest container port in the United States and the largest cruise ship center on the West Coast of the United States – The Port of Los Angeles's World Cruise Center served about 590,000 passengers in 2014. There are also smaller, non-industrial harbors
|
Lepus. Alpha Leporis, the brightest star of Lepus, is a white supergiant of magnitude 2.6, 1300 light-years from Earth. Its traditional name, Arneb (أرنب ’arnab), means "hare" in Arabic. Beta Leporis, traditionally known as Nihal (Arabic for "quenching their thirst"), is a yellow giant of magnitude 2.8, 159 light-years from Earth. Gamma Leporis is a double star divisible in binoculars. The primary is a yellow star of magnitude 3.6, 29 light-years from Earth. The secondary is an orange star of magnitude 6.2. Delta Leporis is a yellow giant of magnitude 3.8, 112 light-years from Earth. Epsilon Leporis is an orange giant of magnitude 3.2, 227 light-years from Earth. Kappa Leporis is a double star divisible in medium aperture amateur telescopes, 560 light-years from Earth. The primary is a blue-white star of magnitude 4.4 and the secondary is a star of magnitude 7.4. There are several variable stars in Lepus. R Leporis is a Mira variable star. It is also called "Hind's Crimson Star" for its striking red color and because it was named for John Russell Hind. It varies in magnitude from a minimum of 9.8 to a maximum of 7.3, with a period of 420 days. R Leporis is at a distance of 1500 light-years. The color intensifies as the star brightens. It can be as dim as magnitude 12 and as bright as magnitude 5.5. T Leporis is also a Mira variable observed in detail by ESO's Very Large Telescope Interferometer. RX Leporis is a semi-regular red giant that has a period of 2 months. It has a minimum magnitude of 7.4 and a maximum magnitude of
|
pursue it. The constellation is also associated with the Moon rabbit. Four stars of this constellation (α, β, γ, δ Lep) form a quadrilateral and are known as ‘Arsh al-Jawzā', "the Throne of Jawzā'" or Kursiyy al-Jawzā' al-Mu'akhkhar, "the Hindmost Chair of Jawzā'" and al-Nihāl, "the Camels Quenching Their Thirst" in Arabic. Features Stars There are a fair number of bright stars, both single and double, in Lepus. Alpha Leporis, the brightest star of Lepus, is a white supergiant of magnitude 2.6, 1300 light-years from Earth. Its traditional name, Arneb (أرنب ’arnab), means "hare" in Arabic. Beta Leporis, traditionally known as Nihal (Arabic for "quenching their thirst"), is a yellow giant of magnitude 2.8, 159 light-years from Earth. Gamma Leporis is a double star divisible in binoculars. The primary is a yellow star of magnitude 3.6, 29 light-years from Earth. The secondary is an orange star of magnitude 6.2. Delta Leporis is a yellow giant of magnitude 3.8, 112 light-years from Earth. Epsilon Leporis is an orange giant of magnitude 3.2, 227 light-years from Earth. Kappa Leporis is a double star divisible in medium aperture amateur telescopes, 560 light-years from Earth. The primary is a blue-white star of magnitude 4.4 and the secondary is a star of magnitude 7.4. There are several variable stars in Lepus. R Leporis is a Mira variable star. It is also called "Hind's Crimson Star" for its striking red color and because it was named for John Russell Hind. It varies in magnitude from a minimum of 9.8 to a maximum of 7.3, with a period of 420 days. R Leporis is at a distance of 1500 light-years. The color intensifies as the star brightens. It can be as dim as magnitude 12 and as bright as magnitude
|
in modern transliteration as Qíguān, the Imperial Guards. Most of the brightest stars in Lupus are massive members of the nearest OB association, Scorpius–Centaurus. Alpha Lupi is an ageing blue giant star of spectral type B1.5 III that is 460 ± 10 light-years distant from Earth. It is a Beta Cephei variable, pulsating in brightness by 0.03 of a magnitude every 7 hours and 6 minutes. Deep-sky objects Towards the north of the constellation are globular clusters NGC 5824 and NGC 5986, and close by the dark nebula B 228. To the south are two open clusters, NGC 5822 and NGC 5749, as well as globular cluster NGC 5927 on the eastern border with Norma. On the western border are two spiral galaxies and the Wolf–Rayet planetary nebula IC 4406, containing some of the hottest stars in existence. IC 4406, also called the Retina Nebula, is a cylindrical nebula at a distance of 5,000 light-years. It has dust lanes throughout its center. Another planetary nebula, NGC 5882, is towards the center of the constellation. The transiting exoplanet Lupus-TR-3b lies in this constellation. The historic supernova SN 1006 is described by various sources as appearing on April 30 to May 1, 1006, in the constellation of Lupus. ESO 274-1 is a spiral galaxy seen from edge-on that requires an amateur telescope with at least 12 inches of aperture to view. It can be found by using Lambda Lupi and Mu Lupi as markers, and can only be seen under very dark skies. It is 9 arcminutes by 0.7 arcminutes with a small, elliptical nucleus. See also SN 1006, a supernova widely observed in the year 1006, as well as the brightest stellar event in recorded history. Chinese star names Lupus in Chinese astronomy Notes References cited texts Ian Ridpath and Wil Tirion (2007). Stars and Planets Guide'', Collins, London. . Princeton University
|
separated from Centaurus until Hipparchus of Bithynia named it ( meaning "beast") in the 2nd century BC. The Greek constellation is probably based on the Babylonian figure known as the Mad Dog (UR.IDIM). This was a strange hybrid creature that combined the head and torso of a man with the legs and tail of a lion (the cuneiform sign 'UR' simply refers to a large carnivore; lions, wolves and dogs are all included). It is often found in association with the sun god and another mythical being called the Bison-man, which is supposedly related to the Greek constellation of Centaurus. In Arab folk astronomy, Lupus, together with Centaurus were collectively called الشماريخ , meaning the dense branches of the date palm's fruit. Later, in Islamic Medieval astronomy, it was named السبع , which is a term used for any predatory wild beast (same as the Greek ), as a separate constellation, but drawn together with Centaurus. In some manuscripts of Al-Sufi's Book of Fixed Stars and celestial globes, it was drawn as a lion; in others, it is drawn as a wolf, both conforming to the Sab''' name. In Europe, no particular animal was associated with it until the Latin translation of Ptolemy's work identified it with the wolf. Characteristics Lupus is bordered by six different constellations, although one of them (Hydra) merely touches at the corner. The other five are Scorpius (the scorpion), Norma (the right angle), Circinus (the compass), Libra (the balance scale), and Centaurus (the centaur). Covering 333.7 square degrees and 0.809% of the night sky, it ranks 46th of the 88 modern constellations. The three-letter abbreviation for the constellation, as adopted by the International Astronomical Union in 1922, is Lup. The official constellation boundaries are defined by a twelve-sided polygon (illustrated
|
so, it would be by far the hottest such variable discovered. In the extreme east is RR Lyrae, the prototype of the large class of variables known as RR Lyrae variables, which are pulsating variables similar to Cepheids, but are evolved population II stars of spectral types A and F. Such stars are usually not found in a galaxy's thin disk, but rather in the galactic halo. Such stars serve as standard candles, and thus are a reliable way to calculate distances to the globular clusters in which they reside. RR Lyrae itself varies between magnitudes 7 and 8 while exhibiting the Blazhko effect. The easternmost star designated by Flamsteed, 19 Lyrae, is also a small-amplitude variable, an Alpha2 Canum Venaticorum variable with a period of just over one day. Another evolved star is the naked-eye variable XY Lyrae, a red bright giant just north of Vega that varies between 6th and 7th magnitudes over a period of 120 days. Also just visible to the naked eye is the peculiar classical Cepheid V473 Lyrae. It is unique in that it is the only known Cepheid in the Milky Way to undergo periodic phase and amplitude changes, analogous to the Blazhko effect in RR Lyrae stars. At 1.5 days, its period was the shortest known for a classical Cepheid at the time of its discovery. W and S Lyrae are two of the many Mira variables in Lyra. W varies between 7th and 12th magnitudes over approximately 200 days, while S, slightly fainter, is a silicate carbon star, likely of the J-type. Another evolved star is EP Lyrae, a faint RV Tauri variable and an "extreme example" of a post-AGB star. It and a likely companion are surrounded by a circumstellar disk of material. Rather close to Earth at a distance of only is Gliese 758. The sunlike primary star has a brown dwarf companion, the coldest to have been imaged around a sunlike star in thermal light when it was discovered in 2009. Only slightly farther away is V478 Lyrae, an eclipsing RS Canum Venaticorum variable whose primary star shows active starspot activity. One of the most peculiar systems in Lyra is MV Lyrae, a nova-like star consisting of a red dwarf and a white dwarf. Originally classified as a VY Sculptoris star due to spending most time at maximum brightness, since around 1979 the system has been dominantly at minimum brightness, with periodic outbursts. Its nature is still not fully understood. Another outbursting star is AY Lyrae, an SU Ursae Majoris-type dwarf nova that has undergone several superoutbursts. Of the same type is V344 Lyrae, notable for an extremely short period between superoutbursts coupled with one of the highest amplitudes for such a period. The true nova HR Lyrae flared in 1919 to a maximum magnitude of 6.5, over 9.5 magnitudes higher than in quiescence. Some of its characteristics are similar to those of recurring novae. Deep-sky objects M57, also known as the "Ring Nebula" and NGC 6720, at a distance of 2,000 light-years from Earth is one of the best known planetary nebulae and the second to be discovered; its integrated magnitude is 8.8. It was discovered in 1779 by Antoine Darquier, 15 years after Charles Messier discovered the Dumbbell Nebula. Astronomers have determined that it is between 6,000 and 8,000 years old; it is approximately one light-year in diameter. The outer part of the nebula appears red in photographs because of emission from ionized hydrogen. The middle region is colored green; doubly ionized oxygen emits greenish-blue light. The hottest region, closest to the central star, appears blue because of emission from helium. The central star itself is a white dwarf with a temperature of 120,000 kelvins. In telescopes, the nebula appears as a visible ring with a green tinge; it is slightly elliptical because its three-dimensional shape is a torus or cylinder seen from a slight angle. It can be found halfway between Gamma Lyrae and Beta Lyrae. Another planetary nebula in Lyra is Abell 46. The central star, V477 Lyrae, is an eclipsing post-common-envelope binary, consisting of a white dwarf primary and an oversized secondary component due to recent accretion. The nebula itself is of relatively low surface brightness compared to the central star, and is undersized for the primary's mass for reasons not yet fully understood. NGC 6791 is a cluster of stars in Lyra. It contains three age groups of stars: 4 billion year-old white dwarfs, 6 billion year-old white dwarfs and 8 billion year-old normal stars. NGC 6745 is an irregular spiral galaxy in Lyra that is at a distance of 208 million light-years. Several million years ago, it collided with a smaller galaxy, which created a region
|
similar to Cepheids, but are evolved population II stars of spectral types A and F. Such stars are usually not found in a galaxy's thin disk, but rather in the galactic halo. Such stars serve as standard candles, and thus are a reliable way to calculate distances to the globular clusters in which they reside. RR Lyrae itself varies between magnitudes 7 and 8 while exhibiting the Blazhko effect. The easternmost star designated by Flamsteed, 19 Lyrae, is also a small-amplitude variable, an Alpha2 Canum Venaticorum variable with a period of just over one day. Another evolved star is the naked-eye variable XY Lyrae, a red bright giant just north of Vega that varies between 6th and 7th magnitudes over a period of 120 days. Also just visible to the naked eye is the peculiar classical Cepheid V473 Lyrae. It is unique in that it is the only known Cepheid in the Milky Way to undergo periodic phase and amplitude changes, analogous to the Blazhko effect in RR Lyrae stars. At 1.5 days, its period was the shortest known for a classical Cepheid at the time of its discovery. W and S Lyrae are two of the many Mira variables in Lyra. W varies between 7th and 12th magnitudes over approximately 200 days, while S, slightly fainter, is a silicate carbon star, likely of the J-type. Another evolved star is EP Lyrae, a faint RV Tauri variable and an "extreme example" of a post-AGB star. It and a likely companion are surrounded by a circumstellar disk of material. Rather close to Earth at a distance of only is Gliese 758. The sunlike primary star has a brown dwarf companion, the coldest to have been imaged around a sunlike star in thermal light when it was discovered in 2009. Only slightly farther away is V478 Lyrae, an eclipsing RS Canum Venaticorum variable whose primary star shows active starspot activity. One of the most peculiar systems in Lyra is MV Lyrae, a nova-like star consisting of a red dwarf and a white dwarf. Originally classified as a VY Sculptoris star due to spending most time at maximum brightness, since around 1979 the system has been dominantly at minimum brightness, with periodic outbursts. Its nature is still not fully understood. Another outbursting star is AY Lyrae, an SU Ursae Majoris-type dwarf nova that has undergone several superoutbursts. Of the same type is V344 Lyrae, notable for an extremely short period between superoutbursts coupled with one of the highest amplitudes for such a period. The true nova HR Lyrae flared in 1919 to a maximum magnitude of 6.5, over 9.5 magnitudes higher than in quiescence. Some of its characteristics are similar to those of recurring novae. Deep-sky objects M57, also known as the "Ring Nebula" and NGC 6720, at a distance of 2,000 light-years from Earth is one of the best known planetary nebulae and the second to be discovered; its integrated magnitude is 8.8. It was discovered in 1779 by Antoine Darquier, 15 years after Charles Messier discovered the Dumbbell Nebula. Astronomers have determined that it is between 6,000 and 8,000 years old; it is approximately one light-year in diameter. The outer part of the nebula appears red in photographs because of emission from ionized hydrogen. The middle region is colored green; doubly ionized oxygen emits greenish-blue light. The hottest region, closest to the central star, appears blue because of emission from helium. The central star itself is a white dwarf with a temperature of 120,000 kelvins. In telescopes, the nebula appears as a visible ring with a green tinge; it is slightly elliptical because its three-dimensional shape is a torus or cylinder seen from a slight angle. It can be found halfway between Gamma Lyrae and Beta Lyrae. Another planetary nebula in Lyra is Abell 46. The central star, V477 Lyrae, is an eclipsing post-common-envelope binary, consisting of a white dwarf primary and an oversized secondary component due to recent accretion. The nebula itself is of relatively low surface brightness compared to the central star, and is undersized for the primary's mass for reasons not yet fully understood. NGC 6791 is a cluster of stars in Lyra. It contains three age groups of stars: 4 billion year-old white dwarfs, 6 billion year-old white dwarfs and 8 billion year-old normal stars. NGC 6745 is an irregular spiral galaxy in Lyra that is at a distance of 208 million light-years. Several million years ago, it collided with a smaller galaxy, which created a region filled with young, hot, blue stars. Astronomers do not know if the collision was simply a glancing blow or a prelude to a full-on merger, which would end with the two galaxies incorporated into one larger, probably elliptical galaxy. A remarkable long-duration gamma-ray burst was GRB 050525A, which flared in 2005. The afterglow re-brightened at 33 minutes after the original burst, only the third found to exhibit such an effect in the timeframe, and unable to be completely explained by known phenomena. The light curve observed over the next 100 days was consistent with that of a supernova or even a hypernova, dubbed SN 2005nc. The host galaxy proved elusive to find at first, although it was subsequently identified. Exoplanets In orbit around the orange subgiant star HD 177830 is one of the earliest exoplanets to be detected. A jovian-mass planet, it orbits in an eccentric orbit with a period of 390 days. A second planet closer to the star was discovered in 2011. Visible to the naked eye are HD 173416, a yellow giant hosting a planet over twice the mass of Jupiter discovered in 2009; and HD 176051, a low-mass binary star containing another high-mass planet. Just short of naked-eye visibility is HD 178911, a triple system consisting of a close binary and a visually separable sunlike star. The sunlike star has a planet with over 6 Jupiter masses discovered in 2001, the second found in a triple system after that of 16 Cygni. One of the most-studied exoplanets in the night sky
|
Liegnitz and all of Silesia east of the Neisse was preliminarily transferred to Poland following the Potsdam Conference in 1945. Majority of the German population was either expelled or fled from the city. The city was repopulated with Poles, some of whom were expelled from pre-war eastern Poland after its annexation by the Soviet Union. Also Greeks, refugees of the Greek Civil War, settled in Legnica in 1950. As the medieval Polish name Lignica was considered archaic, the town was renamed Legnica. The transfer to Poland decided at Potsdam in 1945 was officially recognized by East Germany in 1950, by West Germany under Chancellor Willy Brandt in the Treaty of Warsaw signed in 1970, and finally by the reunited Germany by the Two Plus Four Agreement in 1990. By 1990 only a handful of Polonized Germans, prewar citizens of Liegnitz, remained of the pre-1945 German population. In 2010 the city celebrated the 65th anniversary of the return of Legnica to Poland and its liberation from the Nazi Germany. The city was only partly damaged in World War II. In June 1945 Legnica was briefly the capital of the Lower Silesian (Wrocław) Voivodship, after the administration was moved there from Trzebnica and before it was finally moved to Wrocław. In 1947, the Municipal Library was opened, in 1948 a piano factory was founded, and in the years 1951-1959 Poland's first copper smelter was built in Legnica. After 1965 most parts of the preserved old town with its town houses were demolished, the historical layout was abolished, and the city was rebuilt in modern form.<ref>Dehio - Handbuch der Kunstdenkmäler in Polen: Schlesien, Herder-Institut Marburg and Krajowy Osrodek Badan i Dokumentacji Zabytkow Warszawa, Deutscher Kunstverlag 2005, , page 521</ref> From 1945 to 1990, during the Cold War, the headquarters of the Soviet forces in Poland, the so-called Northern Group of Forces, was located in the city. This fact had a strong influence on the life of the city. For much of the period, the city was divided into Polish and Soviet areas, with the latter closed to the public. These were first established in July 1945, when the Soviets forcibly ejected newly arrived Polish inhabitants from the parts of the city they wanted for their own use. The ejection was perceived by some as a particularly brutal action, and rumours circulated exaggerating its severity, though no evidence of anyone being killed in the course of it has come to light. In April 1946 city officials estimated that there were 16,700 Poles, 12,800 Germans, and 60,000 Soviets in Legnica. In October 1956, the largest anti-Soviet demonstrations in Lower Silesia took place in Legnica. The last Soviet units left the city in 1993. In 1992 the Roman Catholic Diocese of Legnica was established, Tadeusz Rybak became the first bishop of Legnica. New local newspapers and a radio station were founded in the 1990s. In 1997, Legnica was visited by Pope John Paul II. The city suffered in the 1997 Central European flood. Climate Legnica has an oceanic climate (Köppen climate classification: Cfb). Sights Legnica is a city with rich historical architecture, ranging from Romanesque and Gothic through the Renaissance and Baroque to Historicist styles. Among the landmarks of Legnica are: the Piast Castle, former seat of the local dukes of the Piast dynasty Cathedral of Saints Peter and Paul Market Square (Rynek) with: Baroque Old Town Hall (Stary Ratusz) Helena Modrzejewska Theatre Kamienice Śledziowe ("Herring Houses") Dom Pod Przepiórczym Koszem ("Under the Quail Basket House") former Dominican and later Benedictine monastery, founded by Bolesław II the Horned, who was buried there as the only monarch of Poland to be buried in Legnica; nowadays housing the I Liceum Ogólnokształcące im. Tadeusza Kościuszki (high school) Saint John the Baptist church with a mausoleum of the last Piast dukes New Town Hall (Nowy Ratusz), seat of city authorities Saint Mary church Copper Museum (Muzeum Miedzi) Medieval Chojnów and Głogów Gates, remnants of the medieval city walls Former Knight Academy, now housing municipal offices and a branch of the Copper Museum Public Library and archive Park Miejski ("City Park"), the oldest and largest park of Legnica There is also a monument of Pope John Paul II and a postal milestone of King Augustus II the Strong from 1725 in Legnica. Economy In the 1950s and 1960s the local copper and nickel industries became a major factor in the economic development of the area. Legnica houses industrial plants belonging to KGHM Polska Miedź, one of the largest producers of copper and silver in the world. The company owns a large copper mill on the western outskirts of town. There is a Special Economic Zone in Legnica, where Lenovo was going to open a factory in summer 2008. Education Legnica is a regional academic center with seven universities enrolling approximately 16,000 students. State-run colleges and universities Witelon University of Applied Sciences (Państwowa Wyższa Szkoła Zawodowa im. Witelona) Wrocław University of Technology Foreign Language Teacher Training College in Legnica Other Wyższa Szkoła Zarządzania / The Polish Open University Legnica University of Management Wyższe Seminarium Duchowne / Seminary Environment Legnica is noted for its parks and gardens, and has seven hundred hectares of green space, mostly along the banks of the Kaczawa; the Tarninow district is particularly attractive. Roads To the south of Legnica is the A4 motorway. Legnica has also a district, which is a part of national road no 3. The express road S3 building has been planned nearby. Public transport In the city there are 20 regular bus lines, 1 belt-line, 2 night lines and 3 suburban. The town has an airport (airport code EPLE) with a 1600-metre runway,
|
Legnica was established. After the death of King Louis II of Hungary and Bohemia at Mohács in 1526, Legnica became a fief of the Habsburg Monarchy of Austria. The first map of Silesia was made by native son Martin Helwig. The city suffered during the Thirty Years' War. In 1633 a plague epidemic broke out, and in 1634 the Austrian army destroyed the suburbs. In 1668 Duke of Legnica Christian presented his candidacy to the Polish throne, however, in the 1669 Polish–Lithuanian royal election he wasn't chosen as King. In 1676, Legnica passed to direct Habsburg rule after the death of the last Silesian Piast duke and the last Piast duke overall, George William (son of Duke Christian), despite the earlier inheritance pact by Brandenburg and Silesia, by which it was to go to Brandenburg. The last Piast duke was buried in the St. John's church in Legnica in 1676. 18th and 19th centuries Silesian aristocracy was trained at the Liegnitz Ritter-Akademie, established in the early 18th century. One of two main routes connecting Warsaw and Dresden ran through the city in the 18th century and Kings Augustus II the Strong and Augustus III of Poland traveled that route many times. The postal milestone of King Augustus II comes from that period. In 1742 most of Silesia, including Liegnitz, became part of the Kingdom of Prussia after King Frederick the Great's defeat of Austria in the War of the Austrian Succession. In 1760 during the Seven Years' War, Liegnitz was the site of the Battle of Liegnitz when Frederick's army defeated an Austrian army led by Laudon. During the Napoleonic Wars and Polish national liberation fights, in 1807 Polish uhlans were stationed in the city, and in 1813, the Prussians, under Field Marshal Blücher, defeated the French forces of MacDonald in the Battle of Katzbach (Kaczawa) nearby. After the administrative reorganization of the Prussian state following the Congress of Vienna, Liegnitz and the surrounding territory (Landkreis Liegnitz) were incorporated into the Regierungsbezirk (administrative district) of Liegnitz, within the Province of Silesia on 1 May 1816. Along with the rest of Prussia, the town became part of the German Empire in 1871 during the unification of Germany. On 1 January 1874 Liegnitz became the third city in Lower Silesia (after Breslau and Görlitz) to be raised to an urban district, although the district administrator of the surrounding Landkreis of Liegnitz continued to have his seat in the city. Its military garrison was home to Königsgrenadier-Regiment Nr. 7 a military unit formed almost exclusively out of Polish soldiers. The 20th century The census of 1910 gave Liegnitz's population as 95.86% German, 0.15% German and Polish, 1.27% Polish, 2.26% Wendish, and 0.19% Czech. On 1 April 1937 parts of the Landkreis of Liegnitz communities of Alt Beckern (Piekary), Groß Beckern (Piekary Wielkie), Hummel, Liegnitzer Vorwerke, Pfaffendorf (Piątnica) und Prinkendorf (Przybków) were incorporated into the city limits. After the Treaty of Versailles following World War I, Liegnitz was part of the newly created Province of Lower Silesia from 1919 to 1938, then of the Province of Silesia from 1938 to 1941, and again of the Province of Lower Silesia from 1941 to 1945. After the Nazi Party came to power in Germany, as early as 1933, a boycott of local Jewish premises was ordered, during the Kristallnacht in 1938 the synagogue was burned down, and in 1939 the local Polish population was terrorized and persecuted. A Nazi court prison was operated in the city with a forced labour subcamp. During World War II, the Germans established two forced labour camps in the city, as well as two prisoner of war labor subcamps of the prisoner of war camp located in Żagań (then Sagan), and one labor subcamp of the Stalag VIII-A POW camp in Zgorzelec (then Görlitz). After the defeat of Nazi Germany during World War II, Liegnitz and all of Silesia east of the Neisse was preliminarily transferred to Poland following the Potsdam Conference in 1945. Majority of the German population was either expelled or fled from the city. The city was repopulated with Poles, some of whom were expelled from pre-war eastern Poland after its annexation by the Soviet Union. Also Greeks, refugees of the Greek Civil War, settled in Legnica in 1950. As the medieval Polish name Lignica was considered archaic, the town was renamed Legnica. The transfer to Poland decided at Potsdam in 1945 was officially recognized by East Germany in 1950, by West Germany under Chancellor Willy Brandt in the Treaty of Warsaw signed in 1970, and finally by the reunited Germany by the Two Plus Four Agreement in 1990. By 1990 only a handful of Polonized Germans, prewar citizens of Liegnitz, remained of the pre-1945 German population. In 2010 the city celebrated the 65th anniversary of the return of Legnica to Poland and its liberation from the Nazi Germany. The city was only partly damaged in World War II. In June 1945 Legnica was briefly the capital of the Lower Silesian (Wrocław) Voivodship, after the administration was moved there from Trzebnica and before it was finally moved to Wrocław. In 1947, the Municipal Library was opened, in 1948 a piano factory was founded, and in the years 1951-1959 Poland's first copper smelter was built in Legnica. After 1965 most parts of the preserved old town with its town houses were demolished, the historical layout was abolished, and the city was rebuilt in modern form.<ref>Dehio - Handbuch der Kunstdenkmäler in Polen: Schlesien, Herder-Institut Marburg and Krajowy Osrodek Badan i Dokumentacji Zabytkow Warszawa, Deutscher Kunstverlag 2005, , page 521</ref> From 1945 to 1990, during the Cold War, the headquarters of the Soviet forces in Poland, the so-called Northern Group of Forces, was located in the city. This fact had a strong influence on the life of the city. For much of the period, the city was divided into Polish and Soviet areas, with the latter closed to the public. These were first established in July 1945, when the Soviets forcibly ejected newly arrived Polish inhabitants from the parts of the city they wanted for their own use. The ejection was perceived by some as a particularly brutal action, and rumours circulated exaggerating its severity, though no evidence of anyone being killed in the course of it has come to light. In April 1946 city officials estimated that there were 16,700 Poles, 12,800 Germans, and 60,000 Soviets in Legnica. In October 1956, the largest anti-Soviet demonstrations in Lower Silesia took place in Legnica. The last Soviet units left the city in 1993. In 1992 the Roman Catholic Diocese of Legnica was established, Tadeusz Rybak became the first bishop of Legnica. New local newspapers and a radio station were founded in the 1990s. In 1997, Legnica was visited by Pope John Paul II. The city suffered in the 1997 Central European flood. Climate Legnica has an oceanic climate (Köppen climate classification: Cfb). Sights Legnica is a city with rich historical architecture, ranging from Romanesque and Gothic through the Renaissance and Baroque to Historicist styles. Among the landmarks of Legnica are: the Piast Castle, former seat of the local dukes of the Piast dynasty Cathedral of Saints Peter and Paul Market Square (Rynek) with: Baroque Old Town Hall (Stary Ratusz) Helena Modrzejewska Theatre Kamienice Śledziowe ("Herring Houses") Dom Pod Przepiórczym Koszem ("Under the Quail Basket House") former Dominican and later Benedictine monastery, founded by Bolesław II the Horned, who was buried there as the only monarch of Poland to be buried in Legnica; nowadays housing the I Liceum Ogólnokształcące im. Tadeusza Kościuszki (high school) Saint John the Baptist church with a mausoleum of the last Piast dukes New Town Hall (Nowy Ratusz), seat of city authorities Saint Mary church Copper Museum (Muzeum Miedzi) Medieval Chojnów and Głogów Gates, remnants of the medieval city walls Former Knight Academy, now housing municipal offices and a branch of the Copper Museum Public Library and archive Park Miejski ("City Park"), the oldest and largest park of Legnica There is also a monument of Pope John Paul II and a postal milestone of King Augustus II the Strong from 1725 in Legnica. Economy In the 1950s and 1960s the local copper and nickel industries became a major factor in the economic development of the area. Legnica houses industrial plants belonging to KGHM Polska Miedź, one of the largest producers of copper and silver in the world. The company owns a large copper mill on the western outskirts of town. There is a Special Economic Zone in Legnica, where Lenovo was going to open
|
Anderlecht, as Ian St John recalled in his autobiography: The Liverpool away strip has more often than not been all yellow or white shirts and black shorts, but there have been several exceptions. An all grey kit was introduced in 1987, which was used until the 1991–92 centenary season when it was replaced by a combination of green shirts and white shorts. After various colour combinations in the 1990s, including gold and navy, bright yellow, black and grey, and ecru, the club alternated between yellow and white away kits until the 2008–09 season, when it re-introduced the grey kit. A third kit is designed for European away matches, though it is also worn in domestic away matches on occasions when the current away kit clashes with a team's home kit. Between 2012 and 2015, the kits were designed by Warrior Sports, who became the club's kit providers at the start of the 2012–13 season. In February 2015, Warrior's parent company New Balance announced it would be entering the global football market, with teams sponsored by Warrior now being outfitted by New Balance. The only other branded shirts worn by the club were made by Umbro until 1985, when they were replaced by Adidas, who produced the kits until 1996 when Reebok took over. They produced the kits for 10 years before Adidas made the kits from 2006 to 2012. Nike became the club's official kit supplier at the start of the 2020–21 season. Liverpool was the first English professional club to have a sponsor's logo on its shirts, after agreeing a deal with Hitachi in 1979. Since then the club has been sponsored by Crown Paints, Candy, Carlsberg and Standard Chartered. The contract with Carlsberg, which was signed in 1992, was the longest-lasting agreement in English top-flight football. The association with Carlsberg ended at the start of the 2010–11 season, when Standard Chartered Bank became the club's sponsor. The Liverpool badge is based on the city's liver bird symbol, which in the past had been placed inside a shield. In 1977, a red liver bird standing on a football (blazoned as "Statant upon a football a Liver Bird wings elevated and addorsed holding in the beak a piece of seaweed gules") was granted as a heraldic badge by the College of Arms to the English Football League intended for use by Liverpool. However, Liverpool never made use of this badge. In 1992, to commemorate the centennial of the club, a new badge was commissioned, including a representation of the Shankly Gates. The next year twin flames were added at either side, symbolic of the Hillsborough memorial outside Anfield, where an eternal flame burns in memory of those who died in the Hillsborough disaster. In 2012, Warrior Sports' first Liverpool kit removed the shield and gates, returning the badge to what had adorned Liverpool shirts in the 1970s; the flames were moved to the back collar of the shirt, surrounding the number 96 for the number who died at Hillsborough. Kit suppliers and shirt sponsors Stadium Anfield was built in 1884 on land adjacent to Stanley Park. Situated 2 miles (3 km) from Liverpool city centre, it was originally used by Everton before the club moved to Goodison Park after a dispute over rent with Anfield owner John Houlding. Left with an empty ground, Houlding founded Liverpool in 1892 and the club has played at Anfield ever since. The capacity of the stadium at the time was 20,000, although only 100 spectators attended Liverpool's first match at Anfield. The Kop was built in 1906 due to the high turnout for matches and was called the Oakfield Road Embankment initially. Its first game was on 1 September 1906 when the home side beat Stoke City 1–0. In 1906 the banked stand at one end of the ground was formally renamed the Spion Kop after a hill in KwaZulu-Natal. The hill was the site of the Battle of Spion Kop in the Second Boer War, where over 300 men of the Lancashire Regiment died, many of them from Liverpool. At its peak, the stand could hold 28,000 spectators and was one of the largest single-tier stands in the world. Many stadiums in England had stands named after Spion Kop, but Anfield's was the largest of them at the time; it could hold more supporters than some entire football grounds. Anfield could accommodate more than 60,000 supporters at its peak and had a capacity of 55,000 until the 1990s, when, following recommendations from the Taylor Report, all clubs in the Premier League were obliged to convert to all-seater stadiums in time for the 1993–94 season, reducing its capacity to 45,276. The findings of the report precipitated the redevelopment of the Kemlyn Road Stand, which was rebuilt in 1992, coinciding with the centenary of the club, and was known as the Centenary Stand until 2017 when it was renamed the Kenny Dalglish Stand. An extra tier was added to the Anfield Road end in 1998, which further increased the capacity of the ground but gave rise to problems when it was opened. A series of support poles and stanchions were inserted to give extra stability to the top tier of the stand after movement of the tier was reported at the start of the 1999–2000 season. Because of restrictions on expanding the capacity at Anfield, Liverpool announced plans to move to the proposed Stanley Park Stadium in May 2002. Planning permission was granted in July 2004, and in September 2006, Liverpool City Council agreed to grant Liverpool a 999-year lease on the proposed site. Following the takeover of the club by George Gillett and Tom Hicks in February 2007, the proposed stadium was redesigned. The new design was approved by the Council in November 2007. The stadium was scheduled to open in August 2011 and would hold 60,000 spectators, with HKS, Inc. contracted to build the stadium. Construction was halted in August 2008, as Gillett and Hicks had difficulty in financing the £300 million needed for the development. In October 2012, BBC Sport reported that Fenway Sports Group, the new owners of Liverpool FC, had decided to redevelop their current home at Anfield stadium, rather than building a new stadium in Stanley Park. As part of the redevelopment the capacity of Anfield was to increase from 45,276 to approximately 60,000 and would cost approximately £150m. When construction was completed on the new Main stand the capacity of Anfield was increased to 54,074. This £100 million expansion added a third tier to the stand. This was all part of a £260 million project to improve the Anfield area. Jürgen Klopp the manager at the time described the stand as "impressive." In June 2021, it was reported that Liverpool Council had given planning permission for the club to renovate and expand the Anfield Road stand, boosting the capacity by around 7,000 and taking the overall capacity at Anfield to 61,000. The expansion, which is estimated to cost £60m, was described as "a huge milestone" by managing director Andy Hughes, and would also see rail seating being trialled in the Kop for the 2021-22 Premier League season. Support Liverpool is one of the best supported clubs in the world. The club states that its worldwide fan base includes more than 200 officially recognised Supporters Clubs in at least 50 countries. Notable groups include Spirit of Shankly. The club takes advantage of this support through its worldwide summer tours, which has included playing in front of 101,000 in Michigan, U.S., and 95,000 in Melbourne, Australia. Liverpool fans often refer to themselves as Kopites, a reference to the fans who once stood, and now sit, on the Kop at Anfield. In 2008 a group of fans decided to form a splinter club, A.F.C. Liverpool, to play matches for fans who had been priced out of watching Premier League football. The song "You'll Never Walk Alone", originally from the Rodgers and Hammerstein musical Carousel and later recorded by Liverpool musicians Gerry and the Pacemakers, is the club's anthem and has been sung by the Anfield crowd since the early 1960s. It has since gained popularity among fans of other clubs around the world. The song's title adorns the top of the Shankly Gates, which were unveiled on 2 August 1982 in memory of former manager Bill Shankly. The "You'll Never Walk Alone" portion of the Shankly Gates is also reproduced on the club's badge. The club's supporters have been involved in two stadium disasters. The first was the 1985 Heysel Stadium disaster, in which 39 Juventus supporters were killed. They were confined to a corner by Liverpool fans who had charged in their direction; the weight of the cornered fans caused a wall to collapse. UEFA laid the blame for the incident solely on the Liverpool supporters, and banned all English clubs from European competition for five years. Liverpool was banned for an additional year, preventing it from participating in the 1990–91 European Cup, even though it won the League in 1990. Twenty-seven fans were arrested on suspicion of manslaughter and were extradited to Belgium in 1987 to face trial. In 1989, after a five-month trial in Belgium, 14 Liverpool fans were given three-year sentences for involuntary manslaughter; half of the terms were suspended. The second disaster took place during an FA Cup semi-final between Liverpool and Nottingham Forest at Hillsborough Stadium, Sheffield, on 15 April 1989. Ninety-six Liverpool fans died as a consequence of overcrowding at the Leppings Lane end, in what became known as the Hillsborough disaster. In the following days, The Suns coverage of the event spread falsehoods, particularly an article entitled "The Truth" that claimed that Liverpool fans had robbed the dead and had urinated on and attacked the police. Subsequent investigations proved the allegations false, leading to a boycott of the newspaper by Liverpool fans across the city and elsewhere; many still refuse to buy The Sun 30 years later. Many support organisations were set up in the wake of the disaster, such as the Hillsborough Justice Campaign, which represents bereaved families, survivors and supporters in their efforts to secure justice. Rivalries Liverpool's longest-established rivalry is with fellow Liverpool team Everton, against whom they contest the Merseyside derby. The rivalry stems from Liverpool's formation and the dispute with Everton officials and the then owners of Anfield. The Merseyside derby is one of the few local derbies which do not enforce fan segregation, and hence has been known as the "friendly derby". Since the mid-1980s, the rivalry has intensified both on and off the field and, since the inception of the Premier League in 1992, the Merseyside derby has had more players sent off than any other Premier League game. It has been referred to as "the most ill-disciplined and explosive fixture in the Premier League". In terms of support within the city, the number of Liverpool fans outweighs Everton supporters by a ratio of 2:1. Liverpool's rivalry with Manchester United stems from the cities' competition in the Industrial Revolution of the 19th century. Connected by the world's first inter-city railway, by road Liverpool and Manchester are separated by approximately 30 miles (48 km) along the East Lancs Road. Ranked the two biggest clubs in England by France Football magazine, Liverpool and Manchester United are the most successful English teams in both domestic and international competitions, and both clubs have a global fanbase. Viewed as one of the biggest rivalries in world football, it is considered the most famous fixture in English football. The two clubs alternated as champions between 1964 and 1967, and Manchester United became the first English team to win the European Cup in 1968, followed by Liverpool's four European Cup victories. Despite the 39 league titles and nine European Cups between them the two rivals have rarely been successful at the same time – Liverpool's run of titles in the 1970s and 1980s coincided with Manchester United's 26-year title drought, and United's success in the Premier League-era likewise coincided with Liverpool's 30-year title drought, and the two clubs have finished first and second in the league only five times. Such is the rivalry between the clubs they rarely do transfer business with each other. The last player to be transferred between the two clubs was Phil Chisnall, who moved to Liverpool from Manchester United in 1964. Ownership and finances As the owner of Anfield and founder of Liverpool, John Houlding was the club's first chairman, a position he held from its founding in 1892 until 1904. John McKenna took over as chairman after Houlding's departure. McKenna subsequently became President of the Football League. The chairmanship changed hands many times before John Smith, whose father was a shareholder of the club, took up the role in 1973. He oversaw the most successful period in Liverpool's history before stepping down in 1990. His successor was Noel White who became chairman in 1990. In August 1991 David Moores, whose family had owned the club for more than 50 years, became chairman. His uncle John Moores was also a shareholder at Liverpool and was chairman of Everton from 1961 to 1973. Moores owned 51 percent of the club, and in 2004 expressed his willingness to consider a bid for his shares in Liverpool. Moores eventually sold the club to American businessmen George Gillett and Tom Hicks on 6 February 2007. The deal valued the club and its outstanding debts at £218.9 million. The pair paid £5,000 per share, or £174.1m for the total shareholding and £44.8m to cover the club's debts. Disagreements between Gillett and Hicks, and the fans' lack of support for them, resulted in the pair looking to sell the club. Martin Broughton was appointed chairman of the club on 16 April 2010 to oversee its sale. In May 2010, accounts were released showing the holding company of the club to be £350m in debt (due to leveraged takeover) with losses of £55m, causing auditor KPMG to qualify its audit opinion. The group's creditors, including the Royal Bank of Scotland, took Gillett and Hicks to court to force them to allow the board to proceed with the sale of the club, the major asset of the holding company. A High Court judge, Mr Justice Floyd, ruled in favour of the creditors and paved the way for the sale of the club to Fenway Sports Group (formerly New England Sports Ventures), although Gillett and Hicks still had the option to appeal. Liverpool was sold to Fenway Sports Group on 15 October 2010 for £300m. Liverpool has been described as a global brand; a 2010 report valued the club's trademarks and associated intellectual property at £141m, an increase of £5m on the previous year. Liverpool was given a brand rating of AA (Very Strong). In April 2010 business magazine Forbes ranked Liverpool as the sixth most valuable football team in the world, behind Manchester United, Real Madrid, Arsenal, Barcelona and Bayern Munich; they valued the club at $822m (£532m), excluding debt. Accountants Deloitte ranked Liverpool eighth in the Deloitte Football Money League, which ranks the world's football clubs in terms of revenue. Liverpool's income in the 2009–10 season was €225.3m. According to a 2018 report by Deloitte, the club had an annual revenue of €424.2 million for the previous year, and Forbes valued the club at $1.944 billion. In 2018, annual revenue increased to €513.7 million, and Forbes valued the club at $2.183 billion. In 2019 revenue increased to €604 million (£533 million) according to Deloitte, with the club breaching the half a billion pounds mark. In April 2020, the owners of the club came under fire from fans and the media for deciding to furlough all non-playing staff during the COVID-19 pandemic. In response to this, the club made a U-turn on the decision and apologised for their initial decision. In April 2021 Forbes valued the club at $4.1 billion, a
|
been all yellow or white shirts and black shorts, but there have been several exceptions. An all grey kit was introduced in 1987, which was used until the 1991–92 centenary season when it was replaced by a combination of green shirts and white shorts. After various colour combinations in the 1990s, including gold and navy, bright yellow, black and grey, and ecru, the club alternated between yellow and white away kits until the 2008–09 season, when it re-introduced the grey kit. A third kit is designed for European away matches, though it is also worn in domestic away matches on occasions when the current away kit clashes with a team's home kit. Between 2012 and 2015, the kits were designed by Warrior Sports, who became the club's kit providers at the start of the 2012–13 season. In February 2015, Warrior's parent company New Balance announced it would be entering the global football market, with teams sponsored by Warrior now being outfitted by New Balance. The only other branded shirts worn by the club were made by Umbro until 1985, when they were replaced by Adidas, who produced the kits until 1996 when Reebok took over. They produced the kits for 10 years before Adidas made the kits from 2006 to 2012. Nike became the club's official kit supplier at the start of the 2020–21 season. Liverpool was the first English professional club to have a sponsor's logo on its shirts, after agreeing a deal with Hitachi in 1979. Since then the club has been sponsored by Crown Paints, Candy, Carlsberg and Standard Chartered. The contract with Carlsberg, which was signed in 1992, was the longest-lasting agreement in English top-flight football. The association with Carlsberg ended at the start of the 2010–11 season, when Standard Chartered Bank became the club's sponsor. The Liverpool badge is based on the city's liver bird symbol, which in the past had been placed inside a shield. In 1977, a red liver bird standing on a football (blazoned as "Statant upon a football a Liver Bird wings elevated and addorsed holding in the beak a piece of seaweed gules") was granted as a heraldic badge by the College of Arms to the English Football League intended for use by Liverpool. However, Liverpool never made use of this badge. In 1992, to commemorate the centennial of the club, a new badge was commissioned, including a representation of the Shankly Gates. The next year twin flames were added at either side, symbolic of the Hillsborough memorial outside Anfield, where an eternal flame burns in memory of those who died in the Hillsborough disaster. In 2012, Warrior Sports' first Liverpool kit removed the shield and gates, returning the badge to what had adorned Liverpool shirts in the 1970s; the flames were moved to the back collar of the shirt, surrounding the number 96 for the number who died at Hillsborough. Kit suppliers and shirt sponsors Stadium Anfield was built in 1884 on land adjacent to Stanley Park. Situated 2 miles (3 km) from Liverpool city centre, it was originally used by Everton before the club moved to Goodison Park after a dispute over rent with Anfield owner John Houlding. Left with an empty ground, Houlding founded Liverpool in 1892 and the club has played at Anfield ever since. The capacity of the stadium at the time was 20,000, although only 100 spectators attended Liverpool's first match at Anfield. The Kop was built in 1906 due to the high turnout for matches and was called the Oakfield Road Embankment initially. Its first game was on 1 September 1906 when the home side beat Stoke City 1–0. In 1906 the banked stand at one end of the ground was formally renamed the Spion Kop after a hill in KwaZulu-Natal. The hill was the site of the Battle of Spion Kop in the Second Boer War, where over 300 men of the Lancashire Regiment died, many of them from Liverpool. At its peak, the stand could hold 28,000 spectators and was one of the largest single-tier stands in the world. Many stadiums in England had stands named after Spion Kop, but Anfield's was the largest of them at the time; it could hold more supporters than some entire football grounds. Anfield could accommodate more than 60,000 supporters at its peak and had a capacity of 55,000 until the 1990s, when, following recommendations from the Taylor Report, all clubs in the Premier League were obliged to convert to all-seater stadiums in time for the 1993–94 season, reducing its capacity to 45,276. The findings of the report precipitated the redevelopment of the Kemlyn Road Stand, which was rebuilt in 1992, coinciding with the centenary of the club, and was known as the Centenary Stand until 2017 when it was renamed the Kenny Dalglish Stand. An extra tier was added to the Anfield Road end in 1998, which further increased the capacity of the ground but gave rise to problems when it was opened. A series of support poles and stanchions were inserted to give extra stability to the top tier of the stand after movement of the tier was reported at the start of the 1999–2000 season. Because of restrictions on expanding the capacity at Anfield, Liverpool announced plans to move to the proposed Stanley Park Stadium in May 2002. Planning permission was granted in July 2004, and in September 2006, Liverpool City Council agreed to grant Liverpool a 999-year lease on the proposed site. Following the takeover of the club by George Gillett and Tom Hicks in February 2007, the proposed stadium was redesigned. The new design was approved by the Council in November 2007. The stadium was scheduled to open in August 2011 and would hold 60,000 spectators, with HKS, Inc. contracted to build the stadium. Construction was halted in August 2008, as Gillett and Hicks had difficulty in financing the £300 million needed for the development. In October 2012, BBC Sport reported that Fenway Sports Group, the new owners of Liverpool FC, had decided to redevelop their current home at Anfield stadium, rather than building a new stadium in Stanley Park. As part of the redevelopment the capacity of Anfield was to increase from 45,276 to approximately 60,000 and would cost approximately £150m. When construction was completed on the new Main stand the capacity of Anfield was increased to 54,074. This £100 million expansion added a third tier to the stand. This was all part of a £260 million project to improve the Anfield area. Jürgen Klopp the manager at the time described the stand as "impressive." In June 2021, it was reported that Liverpool Council had given planning permission for the club to renovate and expand the Anfield Road stand, boosting the capacity by around 7,000 and taking the overall capacity at Anfield to 61,000. The expansion, which is estimated to cost £60m, was described as "a huge milestone" by managing director Andy Hughes, and would also see rail seating being trialled in the Kop for the 2021-22 Premier League season. Support Liverpool is one of the best supported clubs in the world. The club states that its worldwide fan base includes more than 200 officially recognised Supporters Clubs in at least 50 countries. Notable groups include Spirit of Shankly. The club takes advantage of this support through its worldwide summer tours, which has included playing in front of 101,000 in Michigan, U.S., and 95,000 in Melbourne, Australia. Liverpool fans often refer to themselves as Kopites, a reference to the fans who once stood, and now sit, on the Kop at Anfield. In 2008 a group of fans decided to form a splinter club, A.F.C. Liverpool, to play matches for fans who had been priced out of watching Premier League football. The song "You'll Never Walk Alone", originally from the Rodgers and Hammerstein musical Carousel and later recorded by Liverpool musicians Gerry and the Pacemakers, is the club's anthem and has been sung by the Anfield crowd since the early 1960s. It has since gained popularity among fans of other clubs around the world. The song's title adorns the top of the Shankly Gates, which were unveiled on 2 August 1982 in memory of former manager Bill Shankly. The "You'll Never Walk Alone" portion of the Shankly Gates is also reproduced on the club's badge. The club's supporters have been involved in two stadium disasters. The first was the 1985 Heysel Stadium disaster, in which 39 Juventus supporters were killed. They were confined to a corner by Liverpool fans who had charged in their direction; the weight of the cornered fans caused a wall to collapse. UEFA laid the blame for the incident solely on the Liverpool supporters, and banned all English clubs from European competition for five years. Liverpool was banned for an additional year, preventing it from participating in the 1990–91 European Cup, even though it won the League in 1990. Twenty-seven fans were arrested on suspicion of manslaughter and were extradited to Belgium in 1987 to face trial. In 1989, after a five-month trial in Belgium, 14 Liverpool fans were given three-year sentences for involuntary manslaughter; half of the terms were suspended. The second disaster took place during an FA Cup semi-final between Liverpool and Nottingham Forest at Hillsborough Stadium, Sheffield, on 15 April 1989. Ninety-six Liverpool fans died
|
to its substrate, and that the enzymes were able to diffuse after a few days (and react with their substrate). They described this membrane-like barrier as a "saclike structure surrounded by a membrane and containing acid phosphatase." It became clear that this enzyme from the cell fraction came from membranous fractions, which were definitely cell organelles, and in 1955 De Duve named them "lysosomes" to reflect their digestive properties. The same year, Alex B. Novikoff from the University of Vermont visited de Duve's laboratory, and successfully obtained the first electron micrographs of the new organelle. Using a staining method for acid phosphatase, de Duve and Novikoff confirmed the location of the hydrolytic enzymes of lysosomes using light and electron microscopic studies. de Duve won the Nobel Prize in Physiology or Medicine in 1974 for this discovery. Originally, De Duve had termed the organelles the "suicide bags" or "suicide sacs" of the cells, for their hypothesized role in apoptosis. However, it has since been concluded that they only play a minor role in cell death. Function and structure Lysosomes contain a variety of enzymes, enabling the cell to break down various biomolecules it engulfs, including peptides, nucleic acids, carbohydrates, and lipids (lysosomal lipase). The enzymes responsible for this hydrolysis require an acidic environment for optimal activity. In addition to being able to break down polymers, lysosomes are capable of fusing with other organelles & digesting large structures or cellular debris; through cooperation with phagosomes, they are able to conduct autophagy, clearing out damaged structures. Similarly, they are able to break down virus particles or bacteria in phagocytosis of macrophages. The size of lysosomes varies from 0.1 μm to 1.2 μm. With a pH ranging from ~4.5–5.0, the interior of the lysosomes is acidic compared to the slightly basic cytosol (pH 7.2). The lysosomal membrane protects the cytosol, and therefore the rest of the cell, from the degradative enzymes within the lysosome. The cell is additionally protected from any lysosomal acid hydrolases that drain into the cytosol, as these enzymes are pH-sensitive and do not function well or at all in the alkaline environment of the cytosol. This ensures that cytosolic molecules and organelles are not destroyed in case there is leakage of the hydrolytic enzymes from the lysosome. The lysosome maintains its pH differential by pumping in protons (H+ ions) from the cytosol across the membrane via proton pumps and chloride ion channels. Vacuolar-ATPases are responsible for transport of protons, while the counter transport of chloride ions is performed by ClC-7 Cl−/H+ antiporter. In this way a steady acidic environment is maintained. It sources its versatile capacity for degradation by import of enzymes with specificity for different substrates; cathepsins are the major class of hydrolytic enzymes, while lysosomal alpha-glucosidase is responsible for carbohydrates, and lysosomal acid phosphatase is necessary to release phosphate groups of phospholipids. Formation Many components of animal cells are recycled by transferring them inside or embedded in sections of membrane. For instance, in endocytosis (more specifically, macropinocytosis), a portion of the cell's plasma membrane pinches off to form vesicles that will eventually fuse with an organelle within the cell. Without active replenishment, the plasma membrane would continuously decrease in size. It is thought that lysosomes participate in this dynamic membrane exchange system and are formed by a gradual maturation process from endosomes. The production of lysosomal proteins suggests one method of lysosome sustainment. Lysosomal protein genes are transcribed in the nucleus in a process that is controlled by transcription factor EB (TFEB). mRNA transcripts exit the nucleus into the cytosol, where they are translated by ribosomes. The nascent peptide chains are translocated into the rough endoplasmic reticulum, where they are modified. Lysosomal soluble proteins exit the endoplasmic reticulum via COPII-coated vesicles after recruitment by the EGRESS complex (ER-to-Golgi relaying of enzymes of the lysosomal system), which is composed of CLN6 and CLN8 proteins. COPII vesicles then deliver lysosomal enzymes to the Golgi apparatus, where a specific lysosomal tag, mannose 6-phosphate, is added to the peptides. The presence of these tags allow for binding to mannose 6-phosphate receptors in the Golgi apparatus, a phenomenon that is crucial for proper packaging into vesicles destined for the lysosomal system. Upon leaving the Golgi apparatus, the lysosomal enzyme-filled vesicle fuses with a late endosome, a relatively acidic organelle with an approximate pH of 5.5. This acidic environment causes dissociation of the lysosomal enzymes from the mannose 6-phosphate receptors. The enzymes are packed into vesicles for further transport to established lysosomes. The late endosome itself can eventually grow into a mature lysosome,
|
that this enzyme played a key role in regulating blood sugar levels. However, even after a series of experiments, they failed to purify and isolate the enzyme from the cellular extracts. Therefore, they tried a more arduous procedure of cell fractionation, by which cellular components are separated based on their sizes using centrifugation. They succeeded in detecting the enzyme activity from the microsomal fraction. This was the crucial step in the serendipitous discovery of lysosomes. To estimate this enzyme activity, they used that of the standardized enzyme acid phosphatase and found that the activity was only 10% of the expected value. One day, the enzyme activity of purified cell fractions which had been refrigerated for five days was measured. Surprisingly, the enzyme activity was increased to normal of that of the fresh sample. The result was the same no matter how many times they repeated the estimation, and led to the conclusion that a membrane-like barrier limited the accessibility of the enzyme to its substrate, and that the enzymes were able to diffuse after a few days (and react with their substrate). They described this membrane-like barrier as a "saclike structure surrounded by a membrane and containing acid phosphatase." It became clear that this enzyme from the cell fraction came from membranous fractions, which were definitely cell organelles, and in 1955 De Duve named them "lysosomes" to reflect their digestive properties. The same year, Alex B. Novikoff from the University of Vermont visited de Duve's laboratory, and successfully obtained the first electron micrographs of the new organelle. Using a staining method for acid phosphatase, de Duve and Novikoff confirmed the location of the hydrolytic enzymes of lysosomes using light and electron microscopic studies. de Duve won the Nobel Prize in Physiology or Medicine in 1974 for this discovery. Originally, De Duve had termed the organelles the "suicide bags" or "suicide sacs" of the cells, for their hypothesized role in apoptosis. However, it has since been concluded that they only play a minor role in cell death. Function and structure Lysosomes contain a variety of enzymes, enabling the cell to break down various biomolecules it engulfs, including peptides, nucleic acids, carbohydrates, and lipids (lysosomal lipase). The enzymes responsible for this hydrolysis require an acidic environment for optimal activity. In addition to being able to break down polymers, lysosomes are capable of fusing with other organelles & digesting large structures or cellular debris; through cooperation with phagosomes, they are able to conduct autophagy, clearing out damaged structures. Similarly, they are able to break down virus particles or bacteria in phagocytosis of macrophages. The size of lysosomes varies from 0.1 μm to 1.2 μm. With a pH ranging from ~4.5–5.0, the interior of the lysosomes is acidic compared to the slightly basic cytosol (pH 7.2). The lysosomal membrane protects the cytosol, and therefore the rest of the cell, from the degradative enzymes within the lysosome. The cell is additionally protected from any lysosomal acid hydrolases that drain into the cytosol, as these enzymes are pH-sensitive and do not function well or at all in the alkaline environment of the cytosol. This ensures that cytosolic molecules and organelles are not destroyed in case there is leakage of the hydrolytic enzymes from the lysosome. The lysosome maintains its pH differential by pumping in protons (H+ ions) from the cytosol across the membrane via proton pumps and chloride ion channels. Vacuolar-ATPases are responsible for transport of protons, while the counter transport of chloride ions is performed by ClC-7 Cl−/H+ antiporter. In this way a steady acidic environment is maintained. It sources its versatile capacity for degradation by import of enzymes with specificity for different substrates; cathepsins are the major class of hydrolytic enzymes, while lysosomal alpha-glucosidase is responsible for carbohydrates, and lysosomal acid phosphatase is necessary to release phosphate groups of phospholipids. Formation Many components of animal cells are recycled by transferring them inside or embedded in sections of membrane. For instance, in endocytosis (more specifically, macropinocytosis), a portion of the cell's plasma membrane pinches off to form vesicles that will eventually fuse with an organelle within the cell. Without active replenishment, the plasma membrane would continuously decrease in size. It is thought that lysosomes participate in this dynamic membrane exchange system and are formed by a gradual maturation process from endosomes. The production of lysosomal proteins suggests one method of lysosome sustainment. Lysosomal protein genes are transcribed in the nucleus in a process that is controlled by transcription factor EB (TFEB). mRNA transcripts exit the nucleus into the cytosol, where they are translated by ribosomes. The nascent peptide chains are translocated into the rough endoplasmic reticulum, where they are modified. Lysosomal soluble proteins exit the endoplasmic reticulum via COPII-coated vesicles after recruitment by the EGRESS complex (ER-to-Golgi relaying of enzymes of the lysosomal system), which is composed of CLN6 and CLN8 proteins. COPII vesicles then deliver lysosomal enzymes to the Golgi apparatus, where a specific lysosomal tag, mannose 6-phosphate, is added to the peptides. The presence of these tags allow for binding to mannose 6-phosphate receptors in the Golgi apparatus, a phenomenon that is crucial for proper packaging into vesicles destined for the lysosomal system. Upon leaving the Golgi apparatus, the lysosomal enzyme-filled vesicle fuses with a late endosome, a relatively acidic organelle with an approximate pH of 5.5. This acidic environment causes dissociation of the lysosomal enzymes from the mannose 6-phosphate receptors. The enzymes are packed into vesicles for further transport to established lysosomes. The late endosome itself can eventually grow into a mature lysosome, as evidenced by the
|
pitch. For a right-handed batsman, that is away from the leg side, and this is where it gets the name leg break. Leg spinners bowl mostly leg breaks, varying them by adjusting the line and length, and amount of side spin versus topspin of the deliveries. Leg spinners also typically use variations of flight by sometimes looping the ball in the air, allowing any cross-breeze and the aerodynamic effects of the spinning ball to cause the ball to dip and drift before bouncing and spinning or "turning", sharply. Leg spinners also bowl other types of delivery, which spin differently, such as the googly. The terms 'leg spin', 'leg spinner', 'leg break' and 'leggie' are used in slightly different ways by different sources. The bowlers with the second and fourth highest number of wickets in the history of Test cricket, Shane Warne and Anil Kumble, were leg spinners. One famous example of leg spin is Warne's Ball of the Century. History In the 1970s and 1980s it was thought that leg spin would disappear from the game due to the success of West Indian, and later Australian teams, exclusively using fast bowlers. During this time Abdul Qadir of Pakistan was the highest-profile leg spinner in the world and is sometimes credited with "keeping the art alive". However, leg spin has again become popular with cricket fans and a successful part of cricket teams, driven largely by the success of Shane Warne, beginning with his spectacular Ball of the Century to Mike Gatting in 1993. Comparison with other types of bowling A left-handed bowler who bowls with the same (wrist spin) action as a leg spinner is known as a left-arm unorthodox spin bowler. The ball itself spins in the opposite direction. The same kind of trajectory, which spins from right to left on pitching, when performed by a left-arm bowler is known as left-arm orthodox spin bowling. As with all spinners, leg spinners bowl the ball far more slowly (70–90 km/h or 45–55 mph) than fast bowlers. The fastest leg spinners will sometimes top 100 km/h (60 mph). While very difficult to bowl accurately, good leg spin is considered one of the most threatening types of bowling to bat against for a right-handed batsman, since the flight and sharp turn make the ball's movement extremely hard to read, and the turn away from the right-handed batsman is more dangerous than the turn into the right-handed batsman generated by an off spinner. Any miscalculation can result in an outside edge off the bat and a catch
|
the offside, and so can also be bowled by other types of bowler. In this case, leg breaks are (only) mostly bowled by leg spinners. Leg spinner: The term leg spinner can be used to mean either the bowler or the leg break delivery. Leggie: The term leggie can also be used to mean either the bowler or the leg break delivery. Technique A leg break is bowled by holding the cricket ball in the palm of the hand with the seam running across under all the fingers. As the ball is released, the wrist is rotated to the left and the ball flicked by the ring finger, giving the ball an anti-clockwise spin as seen from behind. To grip the ball for a leg-spinning delivery, the ball is placed into the palm with the seam parallel to the palm. The first two fingers then spread and grip the ball, and the third and fourth fingers close together and rest against the side of the ball. The first bend of the third finger should grasp the seam. The thumb resting against the side is up to the bowler but should impart no pressure. When the ball is bowled, the third finger will apply most of the spin. The wrist is cocked as it comes down by the hip, and the wrist moves sharply from right to left as the ball is released, adding more spin. The ball is tossed up to provide flight. The batsman will see the hand with the palm facing towards them when the ball is released. Notable leg spin bowlers Players listed below have been included as they meet specific criteria which the general cricketing public would recognise as having achieved significant success in the art of leg spin bowling. For example: leading wicket-takers, and inventors of new deliveries. Shane Warne – 708 Test wickets (second all-time), one of five Wisden Cricketers of the Century Bernard Bosanquet – credited with inventing the googly B. S. Chandrasekhar – took 16 five-wicket hauls Clarrie Grimmett – 216 Test wickets Anil Kumble – 619 Test wickets (currently 4th on the list of all-time Test cricket wicket takers), best bowling in an innings of 10/74 Abdul Qadir – took 10 wickets in a match on five occasions Other deliveries bowled by leg spin bowlers Highly skilled leg spin bowlers are also able to bowl deliveries that behave unexpectedly, including the googly, which turns the opposite way to a normal leg break and the topspinner, which does not turn but dips sharply and bounces higher than other deliveries. A few leg spinners such as Abdul Qadir, Anil Kumble, Shane Warne and Mushtaq Ahmed have also mastered the flipper, a delivery that like a topspinner goes straight on landing, but floats through the air before skidding and keeping low, often dismissing batsmen leg before wicket or bowled. Another variation in the arsenal of some leg spinners is the slider, a leg break pushed out of the hand somewhat faster, so that it does not spin as much, but travels more straight on. See also Ball of the Century Flipper Googly Off break Topspinner References External links About Leg Spin – talkCricket Leg Spin Definition – Oxford Dictionaries Leg Spin Basics video – wisdomtalkies How to bowl leg spin – BBC Sport
|
machine was well known for its advanced development environment (InterLisp-D), the ROOMS window manager, for its early graphical user interface and for novel applications like NoteCards (one of the first hypertext applications). Xerox also worked on a Lisp machine based on reduced instruction set computing (RISC), using the 'Xerox Common Lisp Processor' and planned to bring it to market by 1987, which did not occur. Integrated Inference Machines In the mid-1980s, Integrated Inference Machines (IIM) built prototypes of Lisp machines named Inferstar. Developments of Lisp machines outside the United States In 1984–85 a UK firm, Racal-Norsk, a joint subsidiary of Racal and Norsk Data, attempted to repurpose Norsk Data's ND-500 supermini as a microcoded Lisp machine, running CADR software: the Knowledge Processing System (KPS). There were several attempts by Japanese manufacturers to enter the Lisp machine market: the Fujitsu Facom-alpha mainframe co-processor, NTT's Elis, Toshiba's AI processor (AIP) and NEC's LIME. Several university research efforts produced working prototypes, among them are Kobe University's TAKITAC-7, RIKEN's FLATS, and Osaka University's EVLIS. In France, two Lisp Machine projects arose: M3L at Toulouse Paul Sabatier University and later MAIA. In Germany Siemens designed the RISC-based Lisp co-processor COLIBRI. End of the Lisp machines With the onset of the AI winter and the early beginnings of the microcomputer revolution, which would sweep away the minicomputer and workstation makers, cheaper desktop PCs soon could run Lisp programs even faster than Lisp machines, with no use of special purpose hardware. Their high profit margin hardware business eliminated, most Lisp machine makers had gone out of business by the early 90s, leaving only software based firms like Lucid Inc. or hardware makers who had switched to software and services to avoid the crash. , besides Xerox and TI, Symbolics is the only Lisp machine firm still operating, selling the Open Genera Lisp machine software environment and the Macsyma computer algebra system. Legacy Several attempts to write open-source emulators for various Lisp Machines have been made: CADR Emulation, Symbolics L Lisp Machine Emulation, the E3 Project (TI Explorer II Emulation), Meroko (TI Explorer I), and Nevermore (TI Explorer I). On 3 October 2005, the MIT released the CADR Lisp Machine source code as open source. In September 2014, Alexander Burger, developer of PicoLisp, announced PilMCU, an implementation of PicoLisp in hardware. The Bitsavers' PDF Document Archive has PDF versions of the extensive documentation for the Symbolics Lisp Machines, the TI Explorer and MicroExplorer Lisp Machines and the Xerox Interlisp-D Lisp Machines. Applications Domains using the Lisp machines were mostly in the wide field of artificial intelligence applications, but also in computer graphics, medical image processing, and many others. The main commercial expert systems of the 80s were available: Intellicorp's Knowledge Engineering Environment (KEE), Knowledge Craft, from The Carnegie Group Inc., and ART (Automated Reasoning Tool) from Inference Corporation. Technical overview Initially the Lisp machines were designed as personal workstations for software development in Lisp. They were used by one person and offered no multi-user mode. The machines provided a large, black and white, bitmap display, keyboard and mouse, network adapter, local hard disks, more than 1 MB RAM, serial interfaces, and a local bus for extension cards. Color graphics cards, tape drives, and laser printers were optional. The processor did not run Lisp directly, but was a stack machine with instructions optimized for compiled Lisp. The early Lisp machines used microcode to provide the instruction set. For several operations, type checking and dispatching was done in hardware at runtime. For example, only one addition operation could be used with various numeric types (integer, float, rational, and complex numbers). The result was a very compact compiled representation of Lisp code. The following example uses a function that counts the number of elements of a list for which a predicate returns true. (defun example-count (predicate list) (let ((count 0)) (dolist (i list count) (when (funcall predicate i) (incf count))))) The disassembled machine code for above function (for the Ivory microprocessor from Symbolics): Command: (disassemble (compile #'example-count)) 0 ENTRY: 2 REQUIRED, 0 OPTIONAL ;Creating PREDICATE and LIST 2 PUSH 0 ;Creating COUNT 3 PUSH FP|3 ;LIST 4 PUSH NIL ;Creating I 5 BRANCH 15 6 SET-TO-CDR-PUSH-CAR FP|5 7 SET-SP-TO-ADDRESS-SAVE-TOS SP|-1 10 START-CALL FP|2 ;PREDICATE 11 PUSH FP|6 ;I 12 FINISH-CALL-1-VALUE 13 BRANCH-FALSE 15 14 INCREMENT FP|4 ;COUNT 15 ENDP FP|5 16 BRANCH-FALSE 6 17 SET-SP-TO-ADDRESS SP|-2 20 RETURN-SINGLE-STACK The operating system used virtual memory to provide a large address space. Memory management was done with garbage collection. All code shared a single address space. All data objects were stored with a tag in memory, so that the type could be determined at runtime. Multiple execution threads were supported and termed processes. All processes ran in the one address space. All operating system software was written in Lisp. Xerox used Interlisp. Symbolics, LMI, and TI used Lisp Machine Lisp (descendant of MacLisp). With the appearance of Common Lisp, Common Lisp was supported on the Lisp Machines and some system software was ported to Common Lisp or later written in Common Lisp. Some later Lisp machines (like the TI MicroExplorer, the Symbolics MacIvory or the Symbolics UX400/1200) were no longer complete workstations, but boards designed to be embedded in host computers: Apple Macintosh II and SUN 3 or 4. Some Lisp machines, such as the Symbolics XL1200, had extensive graphics abilities using special graphics boards. These machines were used in domains like medical image processing, 3D animation, and CAD. See also ICAD – example of knowledge-based engineering software originally developed on a Lisp machine that was useful enough to be then ported via Common Lisp to Unix Orphaned technology References General "LISP Machine Progress Report", Alan Bawden, Richard Greenblatt, Jack Holloway, Thomas Knight, David A. Moon, Daniel Weinreb, AI Lab memos, AI-444, 1977. "CADR", Thomas Knight, David A. Moon, Jack Holloway, Guy L. Steele. AI Lab memos, AIM-528, 1979. "Design of LISP-based Processors, or SCHEME: A Dielectric LISP, or Finite Memories Considered Harmful, or LAMBDA: The Ultimate Opcode", Guy Lewis Steele, Gerald Jay Sussman, AI Lab memo, AIM-514, 1979 David A. Moon. Chaosnet. A.I. Memo 628, Massachusetts Institute of Technology Artificial Intelligence Laboratory, June 1981. "Implementation of a List Processing Machine". Tom Knight, Master's thesis. Lisp Machine manual, 6th ed. Richard Stallman, Daniel Weinreb, David A. Moon. 1984. "Anatomy of a LISP Machine", Paul Graham, AI Expert, December 1988 Free as in Freedom: Richard Stallman's Crusade for Free Software External links Symbolics website Medley Bitsavers, PDF documents LMI documentation MIT CONS documentation MIT CADR documentation Lisp Machine Manual, Chinual "The Lisp Machine manual, 4th Edition, July 1981" "The Lisp Machine manual, 6th Edition, HTML/XSL version" "The Lisp Machine manual" Information and code for LMI Lambda and LMI K-Machine – A set of links and locally stored documents regarding all manner of Lisp machines "A Few Things I Know About LISP Machines" – A set of links, mostly discussion of buying Lisp machines Ralf Möller's Symbolics Lisp Machine Museum Vintage Computer
|
abandoned the CADR architecture and developed its own K-Machine, but LMI went bankrupt before the machine could be brought to market. Before its demise, LMI was working on a distributed system for the LAMBDA using Moby space. These machines had hardware support for various primitive Lisp operations (data type testing, CDR coding) and also hardware support for incremental garbage collection. They ran large Lisp programs very efficiently. The Symbolics machine was competitive against many commercial super minicomputers, but was never adapted for conventional purposes. The Symbolics Lisp Machines were also sold to some non-AI markets like computer graphics, modeling, and animation. The MIT-derived Lisp machines ran a Lisp dialect named Lisp Machine Lisp, descended from MIT's Maclisp. The operating systems were written from the ground up in Lisp, often using object-oriented extensions. Later, these Lisp machines also supported various versions of Common Lisp (with Flavors, New Flavors, and Common Lisp Object System (CLOS)). Interlisp, BBN, and Xerox Bolt, Beranek and Newman (BBN) developed its own Lisp machine, named Jericho, which ran a version of Interlisp. It was never marketed. Frustrated, the whole AI group resigned, and were hired mostly by Xerox. So, Xerox Palo Alto Research Center had, simultaneously with Greenblatt's own development at MIT, developed their own Lisp machines which were designed to run InterLisp (and later Common Lisp). The same hardware was used with different software also as Smalltalk machines and as the Xerox Star office system. These included the Xerox 1100, Dolphin (1979); the Xerox 1132, Dorado; the Xerox 1108, Dandelion (1981); the Xerox 1109, Dandetiger; and the Xerox 1186/6085, Daybreak. The operating system of the Xerox Lisp machines has also been ported to a virtual machine and is available for several platforms as a product named Medley. The Xerox machine was well known for its advanced development environment (InterLisp-D), the ROOMS window manager, for its early graphical user interface and for novel applications like NoteCards (one of the first hypertext applications). Xerox also worked on a Lisp machine based on reduced instruction set computing (RISC), using the 'Xerox Common Lisp Processor' and planned to bring it to market by 1987, which did not occur. Integrated Inference Machines In the mid-1980s, Integrated Inference Machines (IIM) built prototypes of Lisp machines named Inferstar. Developments of Lisp machines outside the United States In 1984–85 a UK firm, Racal-Norsk, a joint subsidiary of Racal and Norsk Data, attempted to repurpose Norsk Data's ND-500 supermini as a microcoded Lisp machine, running CADR software: the Knowledge Processing System (KPS). There were several attempts by Japanese manufacturers to enter the Lisp machine market: the Fujitsu Facom-alpha mainframe co-processor, NTT's Elis, Toshiba's AI processor (AIP) and NEC's LIME. Several university research efforts produced working prototypes, among them are Kobe University's TAKITAC-7, RIKEN's FLATS, and Osaka University's EVLIS. In France, two Lisp Machine projects arose: M3L at Toulouse Paul Sabatier University and later MAIA. In Germany Siemens designed the RISC-based Lisp co-processor COLIBRI. End of the Lisp machines With the onset of the AI winter and the early beginnings of the microcomputer revolution, which would sweep away the minicomputer and workstation makers, cheaper desktop PCs soon could run Lisp programs even faster than Lisp machines, with no use of special purpose hardware. Their high profit margin hardware business eliminated, most Lisp machine makers had gone out of business by the early 90s, leaving only software based firms like Lucid Inc. or hardware makers who had switched to software and services to avoid the crash. , besides Xerox and TI, Symbolics is the only Lisp machine firm still operating, selling the Open Genera Lisp machine software environment and the Macsyma computer algebra system. Legacy Several attempts to write open-source emulators for various Lisp Machines have been made: CADR Emulation, Symbolics L Lisp Machine Emulation, the E3 Project (TI Explorer II Emulation), Meroko (TI Explorer I), and Nevermore (TI Explorer I). On 3 October 2005, the MIT released the CADR Lisp Machine source code as open source. In September 2014, Alexander Burger, developer of PicoLisp, announced PilMCU, an implementation of PicoLisp in hardware. The Bitsavers' PDF Document Archive has PDF versions of the extensive documentation for the Symbolics Lisp Machines, the TI Explorer and MicroExplorer Lisp Machines and the Xerox Interlisp-D Lisp Machines. Applications Domains using the Lisp machines were mostly in the wide field of artificial intelligence applications, but also in computer graphics, medical image processing, and many others. The main commercial expert systems of the 80s were available: Intellicorp's Knowledge Engineering Environment (KEE), Knowledge Craft, from The Carnegie Group Inc., and ART (Automated Reasoning Tool) from Inference Corporation. Technical overview Initially the Lisp machines were designed as personal workstations for software development in Lisp. They were used by one person and offered no multi-user mode. The machines provided a large, black and white, bitmap display, keyboard and mouse, network adapter, local hard disks, more than 1 MB RAM, serial interfaces, and a local bus for extension cards. Color graphics cards, tape drives, and laser printers were optional. The processor did not run Lisp directly, but was a stack machine with instructions optimized for compiled Lisp. The early Lisp machines used microcode to provide the instruction set. For several operations, type checking and dispatching was done in hardware at runtime. For example, only one addition operation could be used with various numeric types (integer, float, rational, and complex numbers). The result was a very compact compiled representation of Lisp code. The following example uses a function that counts the number of elements of a list for which a predicate returns true. (defun example-count (predicate list) (let ((count 0)) (dolist (i list count) (when (funcall predicate i) (incf count))))) The disassembled machine code for above function (for the Ivory microprocessor from Symbolics): Command: (disassemble (compile #'example-count)) 0 ENTRY: 2 REQUIRED, 0 OPTIONAL ;Creating PREDICATE and LIST 2 PUSH 0 ;Creating COUNT 3 PUSH FP|3 ;LIST 4 PUSH NIL ;Creating I 5 BRANCH 15 6 SET-TO-CDR-PUSH-CAR FP|5 7 SET-SP-TO-ADDRESS-SAVE-TOS SP|-1 10 START-CALL FP|2 ;PREDICATE 11 PUSH FP|6 ;I 12 FINISH-CALL-1-VALUE 13 BRANCH-FALSE 15 14 INCREMENT FP|4 ;COUNT 15 ENDP FP|5 16 BRANCH-FALSE 6 17 SET-SP-TO-ADDRESS SP|-2 20 RETURN-SINGLE-STACK The operating system used virtual memory to provide a large address space. Memory management was done with garbage collection. All code shared a single address space. All data objects were stored with a tag in memory, so that the type could be determined at runtime. Multiple execution threads were supported and termed processes. All processes ran in the one address space. All operating system software was written in Lisp. Xerox used Interlisp. Symbolics, LMI, and TI used Lisp Machine Lisp (descendant of MacLisp). With the appearance of Common Lisp, Common Lisp was supported on the Lisp Machines and some system software was ported to Common Lisp or later written in Common Lisp. Some later Lisp machines (like the TI MicroExplorer, the Symbolics MacIvory or the Symbolics UX400/1200) were no longer complete workstations, but boards designed to be embedded in host computers: Apple Macintosh II and SUN 3 or 4. Some Lisp machines, such as the Symbolics XL1200, had extensive graphics abilities using special graphics boards. These machines were used in domains like medical image processing, 3D animation, and CAD. See also ICAD – example of knowledge-based engineering software originally developed on a Lisp machine that was useful enough to be then ported via Common Lisp to Unix Orphaned technology References General "LISP Machine Progress Report", Alan Bawden, Richard Greenblatt, Jack Holloway, Thomas Knight, David A. Moon, Daniel Weinreb, AI Lab memos, AI-444, 1977. "CADR", Thomas Knight, David A. Moon, Jack Holloway, Guy L. Steele. AI Lab memos, AIM-528, 1979. "Design of LISP-based Processors, or SCHEME: A Dielectric LISP, or Finite Memories Considered Harmful, or LAMBDA: The Ultimate Opcode", Guy Lewis Steele, Gerald Jay Sussman, AI Lab memo, AIM-514, 1979 David A. Moon. Chaosnet. A.I. Memo 628, Massachusetts Institute of Technology Artificial Intelligence Laboratory, June 1981. "Implementation of a List Processing Machine". Tom Knight, Master's thesis. Lisp Machine manual, 6th ed. Richard Stallman, Daniel Weinreb, David A. Moon. 1984. "Anatomy of a LISP Machine", Paul Graham, AI Expert, December 1988 Free as in Freedom: Richard Stallman's Crusade for Free Software External links Symbolics website Medley Bitsavers, PDF documents LMI documentation MIT CONS documentation MIT CADR documentation Lisp Machine Manual, Chinual "The Lisp Machine manual, 4th Edition, July 1981" "The Lisp Machine manual, 6th Edition, HTML/XSL version" "The Lisp Machine manual" Information and code for LMI Lambda and LMI K-Machine
|
but it does not display many pages as they were intended. The graphical mode works even on Unix systems without the X Window System or any other window environment, using either SVGAlib or the framebuffer of the system's graphics card. The source code is available on Github. Graphics stack The graphics stack has several peculiarities unusual for a web browser. The fonts displayed by Links are not derived from the system, but compiled into the binary as grayscale bitmaps in Portable Network Graphics (PNG) format. This allows the browser to be one executable file independent of the system libraries. However this increases the size of the executable to about 5 MB. The fonts are anti-aliased without hinting and for small line pitch an artificial sharpening is employed to increase legibility. Subpixel sampling further increases legibility on LCD displays. This allowed Links to have anti-aliased fonts at a time when anti-aliased font libraries were uncommon. All graphic elements (images and text) are first converted from given gamma space (according to known or assumed gamma information in PNG, JPEG etc.) through known user gamma setting into a 48 bits per pixel photometrically linear space where they are resampled with bilinear resampling to the target size, possibly taking aspect ratio correction into account. Then the data are passed through high-performance restartable dithering engine which is used regardless of monitor bit depth, i.e., also for 24 bits per pixel colour. This Floyd-Steinberg dithering engine takes into account the gamma characteristics of the monitor and uses 768 KiB of dithering tables to avoid time expensive calculations. A technique similar to self-modifying code, function templates, is used to maximise the speed of the dithering engine without using assembly language optimization. Images which are scaled down also use subpixel sampling on LCD to increase level of detail. The reason for this high quality processing is: provide proper realistic up and down sampling of images, and photorealistic display regardless of the monitor gamma, without colour fringing caused by 8-bit gamma correction built into the X server. It also increases the perceived colour depth over 24 bits per pixel. Links has graphics drivers
|
legibility on LCD displays. This allowed Links to have anti-aliased fonts at a time when anti-aliased font libraries were uncommon. All graphic elements (images and text) are first converted from given gamma space (according to known or assumed gamma information in PNG, JPEG etc.) through known user gamma setting into a 48 bits per pixel photometrically linear space where they are resampled with bilinear resampling to the target size, possibly taking aspect ratio correction into account. Then the data are passed through high-performance restartable dithering engine which is used regardless of monitor bit depth, i.e., also for 24 bits per pixel colour. This Floyd-Steinberg dithering engine takes into account the gamma characteristics of the monitor and uses 768 KiB of dithering tables to avoid time expensive calculations. A technique similar to self-modifying code, function templates, is used to maximise the speed of the dithering engine without using assembly language optimization. Images which are scaled down also use subpixel sampling on LCD to increase level of detail. The reason for this high quality processing is: provide proper realistic up and down sampling of images, and photorealistic display regardless of the monitor gamma, without colour fringing caused by 8-bit gamma correction built into the X server. It also increases the perceived colour depth over 24 bits per pixel. Links has graphics drivers for the X Server, Linux framebuffer, svgalib, OS/2 PMShell and AtheOS GUI. Forks ELinks Experimental/Enhanced Links (ELinks) is a fork of Links led by Petr Baudis. It is based on Links 0.9. It has a more open development and incorporates patches from other Links versions (such as additional extension scripting in Lua) and from Internet users. Hacked Links Hacked Links is another version
|
or training". Chiappe defined Learning Objects as: "A digital self-contained and reusable entity, with a clear educational purpose, with at least three internal and editable components: content, learning activities and elements of context. The learning objects must have an external structure of information to facilitate their identification, storage and retrieval: the metadata." The following definitions focus on the relation between learning object and digital media. RLO-CETL, a British inter-university Learning Objects Center, defines "reusable learning objects" as "web-based interactive chunks of e-learning designed to explain a stand-alone learning objective". Daniel Rehak and Robin Mason define it as "a digitized entity which can be used, reused or referenced during technology supported learning". Adapting a definition from the Wisconsin Online Resource Center, Robert J. Beck suggests that learning objects have the following key characteristics: Learning objects are a new way of thinking about learning content. Traditionally, content comes in a several hour chunk. Learning objects are much smaller units of learning, typically ranging from 2 minutes to 15 minutes. Are self-contained – each learning object can be taken independently Are reusable – a single learning object may be used in multiple contexts for multiple purposes Can be aggregated – learning objects can be grouped into larger collections of content, including traditional course structures Are tagged with metadata – every learning object has descriptive information allowing it to be easily found by a search Components The following is a list of some of the types of information that may be included in a learning object and its metadata: General Course Descriptive Data, including: course identifiers, language of content (English, Spanish, etc.), subject area (Maths, Reading, etc.), descriptive text, descriptive keywords Life Cycle, including: version, status Instructional Content, including: text, web pages, images, sound, video Glossary of Terms, including: terms, definition, acronyms Quizzes and Assessments, including: questions, answers Rights, including: cost, copyrights, restrictions on Use Relationships to Other Courses, including prerequisite courses Educational Level, including: grade level, age range, typical learning time, and difficulty. [IEEE 1484.12.1:2002] Typology as defined by Churchill (2007): presentation, practice, simulation, conceptual models, information, and contextual representation Metadata One of the key issues in using learning objects is their identification by search engines or content management systems. This is usually facilitated by assigning descriptive learning object metadata. Just as a book in a library has a record in the card catalog, learning objects must also be tagged with metadata. The most important pieces of metadata typically associated with a learning object include: objective: The educational objective the learning object is instructing prerequisites: The list of skills (typically represented as objectives) which the learner must know before viewing the learning object topic: Typically represented in a taxonomy, the topic the learning object is instructing interactivity: The Interaction Model of the learning object. technology requirements: The required system requirements to view the learning object. Mutability A mutated learning object is, according to Michael Shaw, a learning object that has been "re-purposed and/or re-engineered, changed or simply re-used in some way different from
|
IEEE 1484.12 Learning object metadata. To support reusability, the IMS Consortium proposed a series of specifications such as the IMS Content package. And to support interoperability, the U.S. military's Advanced Distributed Learning organization created the Sharable Content Object Reference Model. Learning objects were designed in order to reduce the cost of learning, standardize learning content, and to enable the use and reuse of learning content by learning management systems. Definitions The Institute of Electrical and Electronics Engineers (IEEE) defines a learning object as "any entity, digital or non-digital, that may be used for learning, education or training". Chiappe defined Learning Objects as: "A digital self-contained and reusable entity, with a clear educational purpose, with at least three internal and editable components: content, learning activities and elements of context. The learning objects must have an external structure of information to facilitate their identification, storage and retrieval: the metadata." The following definitions focus on the relation between learning object and digital media. RLO-CETL, a British inter-university Learning Objects Center, defines "reusable learning objects" as "web-based interactive chunks of e-learning designed to explain a stand-alone learning objective". Daniel Rehak and Robin Mason define it as "a digitized entity which can be used, reused or referenced during technology supported learning". Adapting a definition from the Wisconsin Online Resource Center, Robert J. Beck suggests that learning objects have the following key characteristics: Learning objects are a new way of thinking about learning content. Traditionally, content comes in a several hour chunk. Learning objects are much smaller units of learning, typically ranging from 2 minutes to 15 minutes. Are self-contained – each learning object can be taken independently Are reusable – a single learning object may be used in multiple contexts for multiple purposes Can be aggregated – learning objects can be grouped into larger collections of content, including traditional course structures Are tagged with metadata – every learning object has descriptive information allowing it to be easily found by a search Components The following is a list of some of the types of information that may be included in a learning object and its metadata: General Course Descriptive Data, including: course identifiers, language of content (English, Spanish, etc.), subject area (Maths, Reading, etc.), descriptive text, descriptive keywords Life Cycle, including: version, status Instructional Content, including: text, web pages, images, sound, video Glossary of Terms, including: terms, definition, acronyms Quizzes and Assessments, including: questions, answers Rights, including: cost, copyrights, restrictions on Use Relationships to Other Courses, including prerequisite courses Educational Level, including: grade level, age range, typical learning time, and difficulty. [IEEE 1484.12.1:2002] Typology as defined by Churchill (2007): presentation, practice, simulation, conceptual models, information, and contextual representation Metadata One of the key issues in using learning objects is their identification by search engines or content management systems. This is usually facilitated by assigning descriptive learning object metadata. Just as a book in a library has a record in the card catalog, learning objects must also be tagged with metadata. The most important pieces of metadata
|
name Labour (or Labor) Party, or similar, is used by political parties around the world, particularly in countries of the Commonwealth of Nations. They are usually, but not exclusively, social-democratic or democratic-socialist and traditionally allied to trade unions and the labour movement. Many labour parties are members of
|
parties See also Labour Party (disambiguation) Communist party List of communist parties Democratic Socialist Party (disambiguation) Labour government Labour movement List of left-wing political parties Social Democratic Party List of social democratic parties Socialist Labour Party (disambiguation) Socialist Party Socialist Workers Party (disambiguation) Workers' Party Socialism Labour
|
BC. The Poverty Point culture was followed by the Tchefuncte and Lake Cormorant cultures of the Tchula period, local manifestations of Early Woodland period. The Tchefuncte culture were the first people in the area of Louisiana to make large amounts of pottery. These cultures lasted until AD 200. The Middle Woodland period started in Louisiana with the Marksville culture in the southern and eastern part of the state, reaching across the Mississippi River to the east around Natchez, and the Fourche Maline culture in the northwestern part of the state. The Marksville culture was named after the Marksville Prehistoric Indian Site in Avoyelles Parish. These cultures were contemporaneous with the Hopewell cultures of present-day Ohio and Illinois, and participated in the Hopewell Exchange Network. Trade with peoples to the southwest brought the bow and arrow. The first burial mounds were built at this time. Political power began to be consolidated, as the first platform mounds at ritual centers were constructed for the developing hereditary political and religious leadership. By 400 the Late Woodland period had begun with the Baytown culture, Troyville culture, and Coastal Troyville during the Baytown period and were succeeded by the Coles Creek cultures. Where the Baytown peoples built dispersed settlements, the Troyville people instead continued building major earthwork centers. Population increased dramatically and there is strong evidence of a growing cultural and political complexity. Many Coles Creek sites were erected over earlier Woodland period mortuary mounds. Scholars have speculated that emerging elites were symbolically and physically appropriating dead ancestors to emphasize and project their own authority. The Mississippian period in Louisiana was when the Plaquemine and the Caddoan Mississippian cultures developed, and the peoples adopted extensive maize agriculture, cultivating different strains of the plant by saving seeds, selecting for certain characteristics, etc. The Plaquemine culture in the lower Mississippi River Valley in western Mississippi and eastern Louisiana began in 1200 and continued to about 1600. Examples in Louisiana include the Medora Site, the archaeological type site for the culture in West Baton Rouge Parish whose characteristics helped define the culture, the Atchafalaya Basin Mounds in St. Mary Parish, the Fitzhugh Mounds in Madison Parish, the Scott Place Mounds in Union Parish, and the Sims Site in St. Charles Parish. Plaquemine culture was contemporaneous with the Middle Mississippian culture that is represented by its largest settlement, the Cahokia site in Illinois east of St. Louis, Missouri. At its peak Cahokia is estimated to have had a population of more than 20,000. The Plaquemine culture is considered ancestral to the historic Natchez and Taensa peoples, whose descendants encountered Europeans in the colonial era. By 1000 in the northwestern part of the state, the Fourche Maline culture had evolved into the Caddoan Mississippian culture. The Caddoan Mississippians occupied a large territory, including what is now eastern Oklahoma, western Arkansas, northeast Texas, and northwest Louisiana. Archaeological evidence has demonstrated that the cultural continuity is unbroken from prehistory to the present. The Caddo and related Caddo-language speakers in prehistoric times and at first European contact were the direct ancestors of the modern Caddo Nation of Oklahoma of today. Significant Caddoan Mississippian archaeological sites in Louisiana include Belcher Mound Site in Caddo Parish and Gahagan Mounds Site in Red River Parish. Many current place names in Louisiana, including Atchafalaya, Natchitouches (now spelled Natchitoches), Caddo, Houma, Tangipahoa, and Avoyel (as Avoyelles), are transliterations of those used in various Native American languages. Exploration and colonization by Europeans The first European explorers to visit Louisiana came in 1528 when a Spanish expedition led by Pánfilo de Narváez located the mouth of the Mississippi River. In 1542, Hernando de Soto's expedition skirted to the north and west of the state (encountering Caddo and Tunica groups) and then followed the Mississippi River down to the Gulf of Mexico in 1543. Spanish interest in Louisiana faded away for a century and a half. In the late 17th century, French and French Canadian expeditions, which included sovereign, religious and commercial aims, established a foothold on the Mississippi River and Gulf Coast. With its first settlements, France laid claim to a vast region of North America and set out to establish a commercial empire and French nation stretching from the Gulf of Mexico to Canada. In 1682, the French explorer Robert Cavelier de La Salle named the region Louisiana to honor King Louis XIV of France. The first permanent settlement, Fort Maurepas (at what is now Ocean Springs, Mississippi, near Biloxi), was founded in 1699 by Pierre Le Moyne d'Iberville, a French military officer from Canada. By then the French had also built a small fort at the mouth of the Mississippi at a settlement they named La Balise (or La Balize), "seamark" in French. By 1721 they built a wooden lighthouse-type structure here to guide ships on the river. A royal ordinance of 1722—following the Crown's transfer of the Illinois Country's governance from Canada to Louisiana—may have featured the broadest definition of Louisiana: all land claimed by France south of the Great Lakes between the Rocky Mountains and the Alleghenies. A generation later, trade conflicts between Canada and Louisiana led to a more defined boundary between the French colonies; in 1745, Louisiana governor general Vaudreuil set the northern and eastern bounds of his domain as the Wabash valley up to the mouth of the Vermilion River (near present-day Danville, Illinois); from there, northwest to le Rocher on the Illinois River, and from there west to the mouth of the Rock River (at present day Rock Island, Illinois). Thus, Vincennes and Peoria were the limit of Louisiana's reach; the outposts at Ouiatenon (on the upper Wabash near present-day Lafayette, Indiana), Chicago, Fort Miamis (near present-day Fort Wayne, Indiana), and Prairie du Chien, Wisconsin, operated as dependencies of Canada. The settlement of Natchitoches (along the Red River in present-day northwest Louisiana) was established in 1714 by Louis Juchereau de St. Denis, making it the oldest permanent European settlement in the modern state of Louisiana. The French settlement had two purposes: to establish trade with the Spanish in Texas via the Old San Antonio Road, and to deter Spanish advances into Louisiana. The settlement soon became a flourishing river port and crossroads, giving rise to vast cotton kingdoms along the river that were worked by imported African slaves. Over time, planters developed large plantations and built fine homes in a growing town. This became a pattern repeated in New Orleans and other places, although the commodity crop in the south was primarily sugar cane. Louisiana's French settlements contributed to further exploration and outposts, concentrated along the banks of the Mississippi and its major tributaries, from Louisiana to as far north as the region called the Illinois Country, around present-day St. Louis, Missouri. The latter was settled by French colonists from Illinois. Initially, Mobile and then Biloxi served as the capital of La Louisiane. Recognizing the importance of the Mississippi River to trade and military interests, and wanting to protect the capital from severe coastal storms, France developed New Orleans from 1722 as the seat of civilian and military authority south of the Great Lakes. From then until the United States acquired the territory in the Louisiana Purchase of 1803, France and Spain jockeyed for control of New Orleans and the lands west of the Mississippi. In the 1720s, German immigrants settled along the Mississippi River, in a region referred to as the German Coast. France ceded most of its territory to the east of the Mississippi to Great Britain in 1763, in the aftermath of Britain's victory in the Seven Years' War (generally referred to in North America as the French and Indian War). The rest of Louisiana, including the area around New Orleans and the parishes around Lake Pontchartrain, had become a colony of Spain by the Treaty of Fontainebleau (1762). The transfer of power on either side of the river would be delayed until later in the decade. In 1765, during Spanish rule, several thousand Acadians from the French colony of Acadia (now Nova Scotia, New Brunswick, and Prince Edward Island) made their way to Louisiana after having been expelled from Acadia by the British government after the French and Indian War. They settled chiefly in the southwestern Louisiana region now called Acadiana. The governor Luis de Unzaga y Amézaga, eager to gain more settlers, welcomed the Acadians, who became the ancestors of Louisiana's Cajuns. Spanish Canary Islanders, called Isleños, emigrated from the Canary Islands of Spain to Louisiana under the Spanish crown between 1778 and 1783. In 1800, France's Napoleon Bonaparte reacquired Louisiana from Spain in the Treaty of San Ildefonso, an arrangement kept secret for two years. Expansion of slavery Jean-Baptiste Le Moyne, Sieur de Bienville brought the first two African slaves to Louisiana in 1708, transporting them from a French colony in the West Indies. In 1709, French financier Antoine Crozat obtained a monopoly of commerce in La Louisiane, which extended from the Gulf of Mexico to what is now Illinois. According to historian Hugh Thomas, "that concession allowed him to bring in a cargo of blacks from Africa every year". Physical conditions, including disease, were so harsh there was high mortality among both the colonists and the slaves, resulting in continuing demand and importation of slaves. Starting in 1719, traders began to import slaves in higher numbers; two French ships, the Du Maine and the Aurore, arrived in New Orleans carrying more than 500 black slaves coming from Africa. Previous slaves in Louisiana had been transported from French colonies in the West Indies. By the end of 1721, New Orleans counted 1,256 inhabitants, of whom about half were slaves. In 1724, the French government issued a law called the Code Noir ("Black Code" in English) which "regulate[d] the interaction of whites [blancs] and blacks [noirs] in its colony of Louisiana (which was much larger than the current state of Louisiana). The law consisted of 57 articles, which regulated religion in the colony, outlawed "interracial" marriages (those between people of different skin color, the varying shades of which were also defined by law), restricted manumission, outlined legal punishment of slaves for various offenses, and defined some obligations of owners to their slaves. The main intent of the French government was to assert control over the slave system of agriculture in Louisiana and to impose restrictions on slaveowners there. In practice, the Code Noir was exceedingly difficult to enforce from afar. Some priests continued to perform interracial marriage ceremonies, for example, and some slaveholders continued to manumit slaves without permission while others punished slaves brutally. Article II of the Code Noir of 1724 required owners to provide their slaves with religious education in the state religion, Roman Catholicism. Sunday was to be a day of rest for slaves. On days off, slaves were expected to feed and take care of themselves. During the 1740s economic crisis in the colony, owners had trouble feeding their slaves and themselves. Giving them time off also effectively gave more power to slaves, who started cultivating their own gardens and crafting items for sale as their own property. They began to participate in the economic development of the colony while at the same time increasing independence and self-subsistence. Article VI of the Code Noir forbade mixed marriages, forbade but did little to protect slave women from rape by their owners, overseers or other slaves. On balance, the code benefitted the owners but had more protections and flexibility than did the institution of slavery in the southern Thirteen Colonies. The Louisiana Black Code of 1806 made the cruel punishment of slaves a crime, but owners and overseers were seldom prosecuted for such acts. Fugitive slaves, called maroons, could easily hide in the backcountry of the bayous and survive in small settlements. The word "maroon" comes from the Spanish "cimarron", meaning "fugitive cattle." In the late 18th century, the last Spanish governor of the Louisiana territory wrote: When the United States purchased Louisiana in 1803, it was soon accepted that enslaved Africans could be brought to Louisiana as easily as they were brought to neighboring Mississippi, though it violated U.S. law to do so. Despite demands by United States Rep. James Hillhouse and by the pamphleteer Thomas Paine to enforce existing federal law against slavery in the newly acquired territory, slavery prevailed because it was the source of great profits and the lowest-cost labor. At the start of the 19th century, Louisiana was a small producer of sugar with a relatively small number of slaves, compared to Saint-Domingue and the West Indies. It soon thereafter became a major sugar producer as new settlers arrived to develop plantations. William C. C. Claiborne, Louisiana's first United States governor, said African slave labor was needed because white laborers "cannot be had in this unhealthy climate." Hugh Thomas wrote that Claiborne was unable to enforce the abolition of the Atlantic slave trade, which the U.S. and Great Britain enacted in 1807. The United States continued to protect the domestic slave trade, including the coastwise trade—the transport of slaves by ship along the Atlantic Coast and to New Orleans and other Gulf ports. By 1840, New Orleans had the biggest slave market in the United States, which contributed greatly to the economy of the city and of the state. New Orleans had become one of the wealthiest cities, and the third largest city, in the nation. The ban on the African slave trade and importation of slaves had increased demand in the domestic market. During the decades after the American Revolutionary War, more than one million enslaved African Americans underwent forced migration from the Upper South to the Deep South, two thirds of them in the slave trade. Others were transported by their owners as slaveholders moved west for new lands. With changing agriculture in the Upper South as planters shifted from tobacco to less labor-intensive mixed agriculture, planters had excess laborers. Many sold slaves to traders to take to the Deep South. Slaves were driven by traders overland from the Upper South or transported to New Orleans and other coastal markets by ship in the coastwise slave trade. After sales in New Orleans, steamboats operating on the Mississippi transported slaves upstream to markets or plantation destinations at Natchez and Memphis. Interestingly, for a slave-state, Louisiana harbored escaped Filipino slaves from the Manila Galleons. The members of the Filipino community were then commonly referred to as Manila men, or Manilamen, and later Tagalas, as they were free when they created the oldest settlement of Asians in the United States in the village of Saint Malo, Louisiana, the inhabitants of which, even joined the United States in the War of 1812 against the British Empire while they were being lead by the French-American Jean Lafitte. Haitian migration and influence Spanish occupation of Louisiana lasted from 1769 to 1800. Beginning in the 1790s, waves of immigration took place from Saint-Domingue, following a slave rebellion that started in 1791. Over the next decade, thousands of migrants landed in Louisiana from the island, including ethnic Europeans, free people of color, and African slaves, some of the latter brought in by each free group. They greatly increased the French-speaking population in New Orleans and Louisiana, as well as the number of Africans, and the slaves reinforced African culture in the city. The process of gaining independence in Saint-Domingue was complex, but uprisings continued. In 1803, France pulled out its surviving troops from the island, having suffered the loss of two-thirds sent to the island two years before, mostly to yellow fever. In 1804, Haiti (the second republic in the western hemisphere) proclaimed its independence, achieved by slave leaders. Pierre Clément de Laussat (Governor, 1803) said: "Saint-Domingue was, of all our colonies in the Antilles, the one whose mentality and customs influenced Louisiana the most." Purchase by the United States When the United States won its independence from Great Britain in 1783, one of its major concerns was having a European power on its western boundary, and the need for unrestricted access to the Mississippi River. As American settlers pushed west, they found that the Appalachian Mountains provided a barrier to shipping goods eastward. The easiest way to ship produce was to use a flatboat to float it down the Ohio and Mississippi rivers to the port of New Orleans, where goods could be put on ocean-going vessels. The problem with this route was that the Spanish owned both sides of the Mississippi below Natchez. Napoleon's ambitions in Louisiana involved the creation of a new empire centered on the Caribbean sugar trade. By the terms of the Treaty of Amiens of 1802, Great Britain returned control of the islands of Martinique and Guadeloupe to the French. Napoleon looked upon Louisiana as a depot for these sugar islands, and as a buffer to U.S. settlement. In October 1801 he sent a large military force to take back Saint-Domingue, then under control of Toussaint Louverture after the Haitian revolution. When the army led by Napoleon's brother-in-law Leclerc was defeated, Napoleon decided to sell Louisiana. Thomas Jefferson, third president of the United States, was disturbed by Napoleon's plans to re-establish French colonies in North America. With the possession of New Orleans, Napoleon could close the Mississippi to U.S. commerce at any time. Jefferson authorized Robert R. Livingston, U.S. minister to France, to negotiate for the purchase of the city of New Orleans, portions of the east bank of the Mississippi, and free navigation of the river for U.S. commerce. Livingston was authorized to pay up to $2million. An official transfer of Louisiana to French ownership had not yet taken place, and Napoleon's deal with the Spanish was a poorly kept secret on the frontier. On October 18, 1802, however, Juan Ventura Morales, acting intendant of Louisiana, made public the intention of Spain to revoke the right of deposit at New Orleans for all cargo from the United States. The closure of this vital port to the United States caused anger and consternation. Commerce in the west was virtually blockaded. Historians believe the revocation of the right of deposit was prompted by abuses by the Americans, particularly smuggling, and not by French intrigues as was believed at the time. President Jefferson ignored public pressure for war with France, and appointed James Monroe a special envoy to Napoleon, to assist in obtaining New Orleans for the United States. Jefferson also raised the authorized expenditure to $10million. However, on April 11, 1803, French foreign minister Talleyrand surprised Livingston by asking how much the United States was prepared to pay for the entirety of Louisiana, not just New Orleans and the surrounding area (as Livingston's instructions covered). Monroe agreed with Livingston that Napoleon might withdraw this offer at any time (leaving them with no ability to obtain the desired New Orleans area), and that approval from President Jefferson might take months, so Livingston and Monroe decided to open negotiations immediately. By April 30, they closed a deal for the purchase of the entire Louisiana territory of for sixty million Francs (approximately $15million). Part of this sum, $3.5million, was used to forgive debts owed by France to the United States. The payment was made in United States bonds, which Napoleon sold at face value to the Dutch firm of Hope and Company, and the British banking house of Baring, at a discount of per each $100 unit. As a result, France received only $8,831,250 in cash for Louisiana. English banker Alexander Baring conferred with Marbois in Paris, shuttled to the United States to pick up the bonds, took them to Britain, and returned to France with the money—which Napoleon used to wage war against Baring's own country. When news of the purchase reached the United States, Jefferson was surprised. He had authorized the expenditure of $10million for a port city, and instead received treaties committing the government to spend $15million on a land package which would double the size of the country. Jefferson's political opponents in the Federalist Party argued the Louisiana purchase was a worthless desert, and that the U.S. constitution did not provide for the acquisition of new land or negotiating treaties without the consent of the federal legislature. What really worried the opposition was the new states which would inevitably be carved from the Louisiana territory, strengthening western and southern interests in U.S. Congress, and further reducing the influence of New England Federalists in national affairs. President Jefferson was an enthusiastic supporter of westward expansion, and held firm in his support for the treaty. Despite Federalist objections, the U.S. Senate ratified the Louisiana treaty on October 20, 1803. By statute enacted on October 31, 1803, President Thomas Jefferson was authorized to take possession of the territories ceded by France and provide for initial governance. A transfer ceremony was held in New Orleans on November 29, 1803. Since the Louisiana territory had never officially been turned over to the French, the Spanish took down their flag, and the French raised theirs. The following day, General James Wilkinson accepted possession of New Orleans for the United States. A similar ceremony was held in St. Louis on March 9, 1804, when a French tricolor was raised near the river, replacing the Spanish national flag. The following day, Captain Amos Stoddard of the First U.S. Artillery marched his troops into town and had the American flag run up the fort's flagpole. The Louisiana territory was officially transferred to the United States government, represented by Meriwether Lewis. The Louisiana Territory, purchased for less than three cents an acre, doubled the size of the United States overnight, without a war or the loss of a single American life, and set a precedent for the purchase of territory. It opened the way for the eventual expansion of the United States across the continent to the Pacific Ocean. Shortly after the United States took possession, the area was divided into two territories along the 33rd parallel north on March 26, 1804, thereby organizing the Territory of Orleans to the south and the District of Louisiana (subsequently formed as the Louisiana Territory) to the north. Statehood Louisiana became the eighteenth U.S. state on April 30, 1812; the Territory of Orleans became the State of Louisiana and the Louisiana Territory was simultaneously renamed the Missouri Territory. At its creation, the state of Louisiana did not include the area north and east of the Mississippi River known as the Florida Parishes. On April 14, 1812, Congress had authorized Louisiana to expand its borders to include the Florida Parishes, but the border change required approval of the state legislature, which it did not give until August 4. For the roughly three months in between, the northern border of eastern Louisiana was the course of Bayou Manchac and the middle of Lake Maurepas and Lake Pontchartrain. From 1824 to 1861, Louisiana moved from a political system based on personality and ethnicity to a distinct two-party system, with Democrats competing first against Whigs, then Know Nothings, and finally only other Democrats. Secession and the Civil War According to the 1860 census, 331,726 people were enslaved, nearly 47% of the state's total population of 708,002. The strong economic interest of elite whites in maintaining the slave society contributed to Louisiana's decision to secede from the Union on January 26, 1861. It followed other U.S. states in seceding after the election of Abraham Lincoln as president of the United States. Louisiana's secession was announced on January 26, 1861, and it became part of the Confederate States of America. The state was quickly defeated in the Civil War, a result of Union strategy to cut the Confederacy in two by controlling the Mississippi River. Federal troops captured New Orleans on April 25, 1862. Because a large part of the population had Union sympathies (or compatible commercial interests), the federal government took the unusual step of designating the areas of Louisiana under federal control as a state within the Union, with its own elected representatives to the U.S. Congress. Post–Civil War to mid–20th century Following the American Civil War and emancipation of slaves, violence rose in the southern U.S. as the war was carried on by insurgent private and paramilitary groups. During the initial period afer the war, there was a massive rise in Black participation in terms of voting and holding political office. Louisiana saw the United States' first and second Black governors with Oscar Dunn and P.B.S. Pinchback, both taking the office after serving as Lieutenant Governors (Dunn having been elected to the post of Lieutenant Governor while Pinchback was appointed after being elected as a member of the state Sentate and President Pro Tempore of that body), with 125 Black members of the state legislature being elected during this time, while Charles E. Nash was elected to represent the state's 6 Congressional District in the U.S. House of Representatives. Eventually former Confederates came to dominante the state legislature after the end of Reconstruction and federal occupation in the late 1870s, and black codes were implemented to regulate freedmen and increasinlgy restricted the right to vote. They refused to extend voting rights to African Americans who had been free before the war and had sometimes obtained education and property (as in New Orleans). Following the Memphis riots of 1866 and the New Orleans riot the same year, the Fourteenth Amendment was passed that provided suffrage and full citizenship for freedmen. Congress passed the Reconstruction Act, establishing military districts for those states where conditions were considered the worst, including Louisiana. It was grouped with Texas in what was administered as the Fifth Military District. African Americans began to live as citizens with some measure of equality before the law. Both freedmen and people of color who had been free before the war began to make more advances in education, family stability and jobs. At the same time, there was tremendous social volatility in the aftermath of war, with many whites actively resisting defeat and the free labor market. White insurgents mobilized to enforce white supremacy, first in Ku Klux Klan chapters. By 1877, when federal forces were withdrawn, white Democrats in Louisiana and other states had regained control of state legislatures, often by paramilitary groups such as the White League, which suppressed black voting through intimidation and violence. Following Mississippi's example in 1890, in 1898, the white Democratic, planter-dominated legislature passed a new constitution that effectively disfranchised people of color by raising barriers to voter registration, such as poll taxes, residency requirements and literacy tests. The effect was immediate and long lasting. In 1896, there were 130,334 black voters on the rolls and about the same number of white voters, in proportion to the state population, which was evenly divided. The state population in 1900 was 47% African American: a total of 652,013 citizens. Many in New Orleans were descendants of Creoles of color, the sizeable population of free people of color before the Civil War. By 1900, two years after the new constitution, only 5,320 black voters were registered in the state. Because of disfranchisement, by 1910 there were only 730 black voters (less than 0.5 percent of eligible African-American men), despite advances in education and literacy among blacks and people of color. Blacks were excluded from the political system and also unable to serve on juries. White Democrats had established one-party Democratic rule, which they maintained in the state for decades deep into the 20th century until after congressional passage of the 1965 Voting Rights Act provided federal oversight and enforcement of the constitutional right to vote. In the early decades of the 20th century, thousands of African Americans left Louisiana in the Great Migration north to industrial cities for jobs and education, and to escape Jim Crow society and lynchings. The boll weevil infestation and agricultural problems cost many sharecroppers and farmers their jobs. The mechanization of agriculture also reduced the need for laborers. Beginning in the 1940s, blacks went west to California for jobs in its expanding defense industries. During some of the Great Depression, Louisiana was led by Governor Huey Long. He was elected to office on populist appeal. His public works projects provided thousands of jobs to people in need, and he supported education and increased suffrage for poor whites, but Long was criticized for his allegedly demogogic and autocratic style. He extended patronage control through every branch of Louisiana's state government. Especially controversial were his plans for wealth redistribution in the state. Long's rule ended abruptly when he was assassinated in the state capitol in 1935. Mid–20th century to present Mobilization for World War II created jobs in the state. But thousands of other workers, black and white alike, migrated to California for better jobs in its burgeoning defense industry. Many African Americans left the state in the Second Great Migration, from the 1940s through the 1960s to escape social oppression and seek better jobs. The mechanization of agriculture in the 1930s had sharply cut the need for laborers. They sought skilled jobs in the defense industry in California, better education for their children, and living in communities where they could vote. On November 26, 1958, at Chennault Air Force Base, a USAF B-47 bomber with a nuclear weapon on board developed a fire while on the ground. The aircraft wreckage and the site of the accident were contaminated after a limited explosion of non-nuclear material. In the 1950s the state created new requirements for a citizenship test for voter registration. Despite opposition by the States Rights Party, downstate black voters had begun to increase their rate of registration, which also reflected the growth of their middle classes. In 1960 the state established the Louisiana State Sovereignty Commission, to investigate civil rights activists and maintain segregation. Despite this, gradually black voter registration and turnout increased to 20% and more, and it was 32% by 1964, when the first national civil rights legislation of the era was passed. The percentage of black voters ranged widely in the state during these years, from 93.8% in Evangeline Parish to 1.7% in Tensas Parish, for instance, where there were white efforts to suppress the vote in the black-majority parish. Violent attacks on civil rights activists in two mill towns were catalysts to the founding of the first two chapters of the Deacons for Defense and Justice in late 1964 and early 1965, in Jonesboro and Bogalusa, respectively. Made up of veterans of World War II and the Korean War, they were armed self-defense groups established to protect activists and their families. Continued violent white resistance in Bogalusa to blacks trying to use public facilities in 1965, following passage of the Civil Rights Act of 1964, caused the federal government to order local police to protect the activists. Other chapters were formed in Louisiana, Mississippi, and Alabama. By 1960 the proportion of African Americans in Louisiana had dropped to 32%. The 1,039,207 black citizens were still suppressed by segregation and disfranchisement. African Americans continued to suffer disproportionate discriminatory application of the state's voter registration rules. Because of better opportunities elsewhere, from 1965 to 1970, blacks continued to migrate out of Louisiana, for a net loss of more than 37,000 people. Based on official census figures, the African American population in 1970 stood at 1,085,109, a net gain of more than 46,000 people compared to 1960. During the latter period, some people began to migrate to cities of the New South for opportunities. Since that period, blacks entered the political system and began to be elected to office, as well as having other opportunities. On May 21, 1919, the Nineteenth Amendment to the United States Constitution, giving women full rights to vote, was passed at a national level, and was made the law throughout the United States on August 18, 1920. Louisiana finally ratified the amendment on June 11, 1970. Due to its location on the Gulf Coast, Louisiana has regularly suffered the effects of tropical storms and damaging hurricanes. On August 29, 2005, New Orleans and many other low-lying parts of the state along the Gulf of Mexico were hit by the catastrophic Hurricane Katrina. It caused widespread damage due to breaching of levees and large-scale flooding of more than 80% of the city. Officials had issued warnings to evacuate the city and nearby areas, but tens of thousands of people, mostly African Americans, stayed behind, many of them stranded. Many people died and survivors suffered through the damage of the widespread floodwaters. In July 2016 the shooting of Alton Sterling sparked protests throughout the state capital of Baton Rouge. In August 2016, an unnamed storm dumped trillions of gallons of rain on southern Louisiana, including the cities of Denham Springs, Baton Rouge, Gonzales, St. Amant and Lafayette, causing catastrophic flooding. An estimated 110,000 homes were damaged and thousands of residents were displaced. In 2019, three Louisiana black churches were set on fire. The suspect used gasoline, destroying each church completely. Holden Matthews, 21 years old, was charged with the destruction of the churches. The first case of COVID-19 in Louisiana was announced on March 9, 2020. Since the first confirmed case as of October 27, 2020, there had been 180,069 confirmed cases; 5,854 people have died of COVID-19. Louisiana entered phase one of re-opening the state on May 15. On June 4, Governor John Bel Edwards signed an order moving to phase two. Gov. Edwards extended phase two until September 11, and phase three began with speculation on October 9. Geography Louisiana is bordered to the west by Texas; to the north by Arkansas; to the east by Mississippi; and to the south by the Gulf of Mexico. The state may properly be divided into two parts, the uplands of the north (the region of North Louisiana), and the alluvial along the coast (the Central Louisiana, Acadiana, Florida Parishes, and Greater New Orleans regions). The alluvial region includes low swamp lands, coastal marshlands and beaches, and barrier islands that cover about . This area lies principally along the Gulf of Mexico and the Mississippi River, which traverses the state from north to south for a distance of about and empties into the Gulf of Mexico; also in the state are the Red River; the Ouachita River and its branches; and other minor streams (some of which are called bayous). The breadth of the alluvial region along the Mississippi is 10–60 miles (15–100 km), and along the other rivers, the alluvial region averages about 10 miles (15 km) across. The Mississippi River flows along a ridge formed by its natural deposits (known as a levee), from which the lands decline toward a river beyond at an average fall of six feet per mile (3m/km). The alluvial lands along other streams present similar features. The higher and contiguous hill lands of the north and northwestern part of the state have an area of more than . They consist of prairie and woodlands. The elevations above sea level range from 10 feet (3m) at the coast and swamp lands to 50–60 feet (15–18m) at the prairie and alluvial lands. In the uplands and hills, the elevations rise to Driskill Mountain, the highest point in the state only 535 feet (163m) above sea level. From 1932 to 2010 the state lost 1,800 square miles due to rises in sea level and erosion. The Louisiana Coastal Protection and Restoration Authority (CPRA) spends around $1billion per year to help shore up and protect Louisiana shoreline and land in both federal and state funding. Besides the waterways named, there are the Sabine, forming the western boundary; and the Pearl, the eastern boundary; the Calcasieu, the Mermentau, the Vermilion, Bayou Teche, the Atchafalaya, the Boeuf, Bayou Lafourche, the Courtableau River, Bayou D'Arbonne, the Macon River, the Tensas, Amite River, the Tchefuncte, the Tickfaw, the Natalbany River, and a number of other smaller streams, constituting a natural system of navigable waterways, aggregating over long. The state also has political jurisdiction over the approximately -wide portion of subsea land of the inner continental shelf in the Gulf of Mexico. Through a peculiarity of the political geography of the United States, this is substantially less than the -wide jurisdiction of nearby states Texas and Florida, which, like Louisiana, have extensive Gulf coastlines. The southern coast of Louisiana in the United States is among the fastest-disappearing areas in the world. This has largely resulted from human mismanagement of the coast (see Wetlands of Louisiana). At one time, the land was added to when spring floods from the Mississippi River added sediment and stimulated marsh growth; the land is now shrinking. There are multiple causes. Artificial levees block spring flood water that would bring fresh water and sediment to marshes. Swamps have been extensively logged, leaving canals and ditches that allow salt water to move inland. Canals dug for the oil and gas industry also allow storms to move sea water inland, where it damages swamps and marshes. Rising sea waters have exacerbated the problem. Some researchers estimate that the state is losing a landmass equivalent to 30 football fields every day. There are many proposals to save coastal areas by reducing human damage, including restoring natural floods from the Mississippi. Without such restoration, coastal communities will continue to disappear. And as the communities disappear, more and more people are leaving the region. Since the coastal wetlands support an economically important coastal fishery, the loss of wetlands is adversely affecting this industry. The Gulf of Mexico 'dead zone' off the coast of Louisiana is the largest recurring hypoxic zone in the United States. It was in 2017, the largest ever recorded. Geology The Gulf of Mexico did not exist 250 million years ago when there was but one supercontinent, Pangea. As Pangea split apart, the Atlantic Ocean and Gulf of Mexico opened. Louisiana slowly developed, over millions of years, from water into land, and from north to south. The oldest rocks are exposed in the north, in areas such as the Kisatchie National Forest. The oldest rocks date back to the early Cenozoic Era, some 60 million years ago. The history of the formation of these rocks can be found in D. Spearing's Roadside Geology of Louisiana. The youngest parts of the state were formed during the last 12,000 years as successive deltas of the Mississippi River: the Maringouin, Teche, St. Bernard, Lafourche, the modern Mississippi, and now the Atchafalaya. The sediments were carried from north to south by the Mississippi River. In between the tertiary rocks of the north, and the relatively new sediments along the coast, is a vast belt known as the Pleistocene Terraces. Their age and distribution can be largely related to the rise and fall of sea levels during past ice ages. In general, the northern terraces have had sufficient time for rivers to cut deep channels, while the newer terraces tend to be much flatter. Salt domes are also found in Louisiana. Their origin can be traced back to the early Gulf of Mexico when the shallow ocean had high rates of evaporation. There are several hundred salt domes in the state; one of the most familiar is Avery Island, Louisiana. Salt domes are important not only as a source of salt; they also serve as underground traps for oil and gas. Climate Louisiana has a humid subtropical climate (Köppen climate classification Cfa), with long, hot, humid summers and short, mild winters. The subtropical characteristics of the state are due to its low latitude, low lying topography, and the influence of the Gulf of Mexico, which at its farthest point is no more than away. Rain is frequent throughout the year, although from April to September is slightly wetter than the rest of the year, which is the state's wet season. There is a dip in precipitation in October. In summer, thunderstorms build during the heat of the day and bring intense but brief, tropical downpours. In winter, rainfall is more frontal and less intense. Summers in southern Louisiana have high temperatures from June through September averaging or more, and overnight lows averaging above . At times, temperatures in the 90s°F(), combined with dew points in the upper 70s°F(), create sensible temperatures over . The humid, thick, jungle-like heat in southern Louisiana is a famous subject of countless stories and movies. Temperatures are generally warm in the winter in the southern part of the state, with highs around New Orleans, Baton Rouge, the rest of southern Louisiana, and the Gulf of Mexico averaging . The northern part of the state is mildly cool in the winter, with highs averaging . The overnight lows in the winter average well above freezing throughout the state, with the average near the Gulf and an average low of in the winter in the northern part of the state. On occasion, cold fronts from low-pressure centers to the north, reach Louisiana in winter. Low temperatures near occur on occasion in the northern part of the state but rarely do so in the southern part of the state. Snow is rare near the Gulf of Mexico, although residents in the northern parts of the state might receive a dusting of snow a few times each decade. Louisiana's highest recorded temperature is in Plain Dealing on August 10, 1936, while the coldest recorded temperature is at Minden on February 13, 1899. Louisiana is often affected by tropical cyclones and is very vulnerable to strikes by major hurricanes, particularly the lowlands around and in the New Orleans area. The unique geography of the region, with the many bayous, marshes and inlets, can result in water damage across a wide area from major hurricanes. The area is also prone to frequent thunderstorms, especially in the summer. The entire state averages over 60 days of thunderstorms a year, more than any other state except Florida. Louisiana averages 27 tornadoes annually. The entire state is vulnerable to a tornado strike, with the extreme southern portion of the state slightly less so than the rest of the state. Tornadoes are more common from January to March in the southern part of the state, and from February through March in the northern part of the state. Publicly owned land Owing to its location and geology, the state has high biological diversity. Some vital areas, such as southwestern prairie, have experienced a loss in excess of
|
Following the American Civil War and emancipation of slaves, violence rose in the southern U.S. as the war was carried on by insurgent private and paramilitary groups. During the initial period afer the war, there was a massive rise in Black participation in terms of voting and holding political office. Louisiana saw the United States' first and second Black governors with Oscar Dunn and P.B.S. Pinchback, both taking the office after serving as Lieutenant Governors (Dunn having been elected to the post of Lieutenant Governor while Pinchback was appointed after being elected as a member of the state Sentate and President Pro Tempore of that body), with 125 Black members of the state legislature being elected during this time, while Charles E. Nash was elected to represent the state's 6 Congressional District in the U.S. House of Representatives. Eventually former Confederates came to dominante the state legislature after the end of Reconstruction and federal occupation in the late 1870s, and black codes were implemented to regulate freedmen and increasinlgy restricted the right to vote. They refused to extend voting rights to African Americans who had been free before the war and had sometimes obtained education and property (as in New Orleans). Following the Memphis riots of 1866 and the New Orleans riot the same year, the Fourteenth Amendment was passed that provided suffrage and full citizenship for freedmen. Congress passed the Reconstruction Act, establishing military districts for those states where conditions were considered the worst, including Louisiana. It was grouped with Texas in what was administered as the Fifth Military District. African Americans began to live as citizens with some measure of equality before the law. Both freedmen and people of color who had been free before the war began to make more advances in education, family stability and jobs. At the same time, there was tremendous social volatility in the aftermath of war, with many whites actively resisting defeat and the free labor market. White insurgents mobilized to enforce white supremacy, first in Ku Klux Klan chapters. By 1877, when federal forces were withdrawn, white Democrats in Louisiana and other states had regained control of state legislatures, often by paramilitary groups such as the White League, which suppressed black voting through intimidation and violence. Following Mississippi's example in 1890, in 1898, the white Democratic, planter-dominated legislature passed a new constitution that effectively disfranchised people of color by raising barriers to voter registration, such as poll taxes, residency requirements and literacy tests. The effect was immediate and long lasting. In 1896, there were 130,334 black voters on the rolls and about the same number of white voters, in proportion to the state population, which was evenly divided. The state population in 1900 was 47% African American: a total of 652,013 citizens. Many in New Orleans were descendants of Creoles of color, the sizeable population of free people of color before the Civil War. By 1900, two years after the new constitution, only 5,320 black voters were registered in the state. Because of disfranchisement, by 1910 there were only 730 black voters (less than 0.5 percent of eligible African-American men), despite advances in education and literacy among blacks and people of color. Blacks were excluded from the political system and also unable to serve on juries. White Democrats had established one-party Democratic rule, which they maintained in the state for decades deep into the 20th century until after congressional passage of the 1965 Voting Rights Act provided federal oversight and enforcement of the constitutional right to vote. In the early decades of the 20th century, thousands of African Americans left Louisiana in the Great Migration north to industrial cities for jobs and education, and to escape Jim Crow society and lynchings. The boll weevil infestation and agricultural problems cost many sharecroppers and farmers their jobs. The mechanization of agriculture also reduced the need for laborers. Beginning in the 1940s, blacks went west to California for jobs in its expanding defense industries. During some of the Great Depression, Louisiana was led by Governor Huey Long. He was elected to office on populist appeal. His public works projects provided thousands of jobs to people in need, and he supported education and increased suffrage for poor whites, but Long was criticized for his allegedly demogogic and autocratic style. He extended patronage control through every branch of Louisiana's state government. Especially controversial were his plans for wealth redistribution in the state. Long's rule ended abruptly when he was assassinated in the state capitol in 1935. Mid–20th century to present Mobilization for World War II created jobs in the state. But thousands of other workers, black and white alike, migrated to California for better jobs in its burgeoning defense industry. Many African Americans left the state in the Second Great Migration, from the 1940s through the 1960s to escape social oppression and seek better jobs. The mechanization of agriculture in the 1930s had sharply cut the need for laborers. They sought skilled jobs in the defense industry in California, better education for their children, and living in communities where they could vote. On November 26, 1958, at Chennault Air Force Base, a USAF B-47 bomber with a nuclear weapon on board developed a fire while on the ground. The aircraft wreckage and the site of the accident were contaminated after a limited explosion of non-nuclear material. In the 1950s the state created new requirements for a citizenship test for voter registration. Despite opposition by the States Rights Party, downstate black voters had begun to increase their rate of registration, which also reflected the growth of their middle classes. In 1960 the state established the Louisiana State Sovereignty Commission, to investigate civil rights activists and maintain segregation. Despite this, gradually black voter registration and turnout increased to 20% and more, and it was 32% by 1964, when the first national civil rights legislation of the era was passed. The percentage of black voters ranged widely in the state during these years, from 93.8% in Evangeline Parish to 1.7% in Tensas Parish, for instance, where there were white efforts to suppress the vote in the black-majority parish. Violent attacks on civil rights activists in two mill towns were catalysts to the founding of the first two chapters of the Deacons for Defense and Justice in late 1964 and early 1965, in Jonesboro and Bogalusa, respectively. Made up of veterans of World War II and the Korean War, they were armed self-defense groups established to protect activists and their families. Continued violent white resistance in Bogalusa to blacks trying to use public facilities in 1965, following passage of the Civil Rights Act of 1964, caused the federal government to order local police to protect the activists. Other chapters were formed in Louisiana, Mississippi, and Alabama. By 1960 the proportion of African Americans in Louisiana had dropped to 32%. The 1,039,207 black citizens were still suppressed by segregation and disfranchisement. African Americans continued to suffer disproportionate discriminatory application of the state's voter registration rules. Because of better opportunities elsewhere, from 1965 to 1970, blacks continued to migrate out of Louisiana, for a net loss of more than 37,000 people. Based on official census figures, the African American population in 1970 stood at 1,085,109, a net gain of more than 46,000 people compared to 1960. During the latter period, some people began to migrate to cities of the New South for opportunities. Since that period, blacks entered the political system and began to be elected to office, as well as having other opportunities. On May 21, 1919, the Nineteenth Amendment to the United States Constitution, giving women full rights to vote, was passed at a national level, and was made the law throughout the United States on August 18, 1920. Louisiana finally ratified the amendment on June 11, 1970. Due to its location on the Gulf Coast, Louisiana has regularly suffered the effects of tropical storms and damaging hurricanes. On August 29, 2005, New Orleans and many other low-lying parts of the state along the Gulf of Mexico were hit by the catastrophic Hurricane Katrina. It caused widespread damage due to breaching of levees and large-scale flooding of more than 80% of the city. Officials had issued warnings to evacuate the city and nearby areas, but tens of thousands of people, mostly African Americans, stayed behind, many of them stranded. Many people died and survivors suffered through the damage of the widespread floodwaters. In July 2016 the shooting of Alton Sterling sparked protests throughout the state capital of Baton Rouge. In August 2016, an unnamed storm dumped trillions of gallons of rain on southern Louisiana, including the cities of Denham Springs, Baton Rouge, Gonzales, St. Amant and Lafayette, causing catastrophic flooding. An estimated 110,000 homes were damaged and thousands of residents were displaced. In 2019, three Louisiana black churches were set on fire. The suspect used gasoline, destroying each church completely. Holden Matthews, 21 years old, was charged with the destruction of the churches. The first case of COVID-19 in Louisiana was announced on March 9, 2020. Since the first confirmed case as of October 27, 2020, there had been 180,069 confirmed cases; 5,854 people have died of COVID-19. Louisiana entered phase one of re-opening the state on May 15. On June 4, Governor John Bel Edwards signed an order moving to phase two. Gov. Edwards extended phase two until September 11, and phase three began with speculation on October 9. Geography Louisiana is bordered to the west by Texas; to the north by Arkansas; to the east by Mississippi; and to the south by the Gulf of Mexico. The state may properly be divided into two parts, the uplands of the north (the region of North Louisiana), and the alluvial along the coast (the Central Louisiana, Acadiana, Florida Parishes, and Greater New Orleans regions). The alluvial region includes low swamp lands, coastal marshlands and beaches, and barrier islands that cover about . This area lies principally along the Gulf of Mexico and the Mississippi River, which traverses the state from north to south for a distance of about and empties into the Gulf of Mexico; also in the state are the Red River; the Ouachita River and its branches; and other minor streams (some of which are called bayous). The breadth of the alluvial region along the Mississippi is 10–60 miles (15–100 km), and along the other rivers, the alluvial region averages about 10 miles (15 km) across. The Mississippi River flows along a ridge formed by its natural deposits (known as a levee), from which the lands decline toward a river beyond at an average fall of six feet per mile (3m/km). The alluvial lands along other streams present similar features. The higher and contiguous hill lands of the north and northwestern part of the state have an area of more than . They consist of prairie and woodlands. The elevations above sea level range from 10 feet (3m) at the coast and swamp lands to 50–60 feet (15–18m) at the prairie and alluvial lands. In the uplands and hills, the elevations rise to Driskill Mountain, the highest point in the state only 535 feet (163m) above sea level. From 1932 to 2010 the state lost 1,800 square miles due to rises in sea level and erosion. The Louisiana Coastal Protection and Restoration Authority (CPRA) spends around $1billion per year to help shore up and protect Louisiana shoreline and land in both federal and state funding. Besides the waterways named, there are the Sabine, forming the western boundary; and the Pearl, the eastern boundary; the Calcasieu, the Mermentau, the Vermilion, Bayou Teche, the Atchafalaya, the Boeuf, Bayou Lafourche, the Courtableau River, Bayou D'Arbonne, the Macon River, the Tensas, Amite River, the Tchefuncte, the Tickfaw, the Natalbany River, and a number of other smaller streams, constituting a natural system of navigable waterways, aggregating over long. The state also has political jurisdiction over the approximately -wide portion of subsea land of the inner continental shelf in the Gulf of Mexico. Through a peculiarity of the political geography of the United States, this is substantially less than the -wide jurisdiction of nearby states Texas and Florida, which, like Louisiana, have extensive Gulf coastlines. The southern coast of Louisiana in the United States is among the fastest-disappearing areas in the world. This has largely resulted from human mismanagement of the coast (see Wetlands of Louisiana). At one time, the land was added to when spring floods from the Mississippi River added sediment and stimulated marsh growth; the land is now shrinking. There are multiple causes. Artificial levees block spring flood water that would bring fresh water and sediment to marshes. Swamps have been extensively logged, leaving canals and ditches that allow salt water to move inland. Canals dug for the oil and gas industry also allow storms to move sea water inland, where it damages swamps and marshes. Rising sea waters have exacerbated the problem. Some researchers estimate that the state is losing a landmass equivalent to 30 football fields every day. There are many proposals to save coastal areas by reducing human damage, including restoring natural floods from the Mississippi. Without such restoration, coastal communities will continue to disappear. And as the communities disappear, more and more people are leaving the region. Since the coastal wetlands support an economically important coastal fishery, the loss of wetlands is adversely affecting this industry. The Gulf of Mexico 'dead zone' off the coast of Louisiana is the largest recurring hypoxic zone in the United States. It was in 2017, the largest ever recorded. Geology The Gulf of Mexico did not exist 250 million years ago when there was but one supercontinent, Pangea. As Pangea split apart, the Atlantic Ocean and Gulf of Mexico opened. Louisiana slowly developed, over millions of years, from water into land, and from north to south. The oldest rocks are exposed in the north, in areas such as the Kisatchie National Forest. The oldest rocks date back to the early Cenozoic Era, some 60 million years ago. The history of the formation of these rocks can be found in D. Spearing's Roadside Geology of Louisiana. The youngest parts of the state were formed during the last 12,000 years as successive deltas of the Mississippi River: the Maringouin, Teche, St. Bernard, Lafourche, the modern Mississippi, and now the Atchafalaya. The sediments were carried from north to south by the Mississippi River. In between the tertiary rocks of the north, and the relatively new sediments along the coast, is a vast belt known as the Pleistocene Terraces. Their age and distribution can be largely related to the rise and fall of sea levels during past ice ages. In general, the northern terraces have had sufficient time for rivers to cut deep channels, while the newer terraces tend to be much flatter. Salt domes are also found in Louisiana. Their origin can be traced back to the early Gulf of Mexico when the shallow ocean had high rates of evaporation. There are several hundred salt domes in the state; one of the most familiar is Avery Island, Louisiana. Salt domes are important not only as a source of salt; they also serve as underground traps for oil and gas. Climate Louisiana has a humid subtropical climate (Köppen climate classification Cfa), with long, hot, humid summers and short, mild winters. The subtropical characteristics of the state are due to its low latitude, low lying topography, and the influence of the Gulf of Mexico, which at its farthest point is no more than away. Rain is frequent throughout the year, although from April to September is slightly wetter than the rest of the year, which is the state's wet season. There is a dip in precipitation in October. In summer, thunderstorms build during the heat of the day and bring intense but brief, tropical downpours. In winter, rainfall is more frontal and less intense. Summers in southern Louisiana have high temperatures from June through September averaging or more, and overnight lows averaging above . At times, temperatures in the 90s°F(), combined with dew points in the upper 70s°F(), create sensible temperatures over . The humid, thick, jungle-like heat in southern Louisiana is a famous subject of countless stories and movies. Temperatures are generally warm in the winter in the southern part of the state, with highs around New Orleans, Baton Rouge, the rest of southern Louisiana, and the Gulf of Mexico averaging . The northern part of the state is mildly cool in the winter, with highs averaging . The overnight lows in the winter average well above freezing throughout the state, with the average near the Gulf and an average low of in the winter in the northern part of the state. On occasion, cold fronts from low-pressure centers to the north, reach Louisiana in winter. Low temperatures near occur on occasion in the northern part of the state but rarely do so in the southern part of the state. Snow is rare near the Gulf of Mexico, although residents in the northern parts of the state might receive a dusting of snow a few times each decade. Louisiana's highest recorded temperature is in Plain Dealing on August 10, 1936, while the coldest recorded temperature is at Minden on February 13, 1899. Louisiana is often affected by tropical cyclones and is very vulnerable to strikes by major hurricanes, particularly the lowlands around and in the New Orleans area. The unique geography of the region, with the many bayous, marshes and inlets, can result in water damage across a wide area from major hurricanes. The area is also prone to frequent thunderstorms, especially in the summer. The entire state averages over 60 days of thunderstorms a year, more than any other state except Florida. Louisiana averages 27 tornadoes annually. The entire state is vulnerable to a tornado strike, with the extreme southern portion of the state slightly less so than the rest of the state. Tornadoes are more common from January to March in the southern part of the state, and from February through March in the northern part of the state. Publicly owned land Owing to its location and geology, the state has high biological diversity. Some vital areas, such as southwestern prairie, have experienced a loss in excess of 98 percent. The pine flatwoods are also at great risk, mostly from fire suppression and urban sprawl. There is not yet a properly organized system of natural areas to represent and protect Louisiana's biological diversity. Such a system would consist of a protected system of core areas linked by biological corridors, such as Florida is planning. Louisiana contains a number of areas which, to varying degrees, prevent people from using them. In addition to National Park Service areas and a United States National Forest, Louisiana operates a system of state parks, state historic sites, one state preservation area, one state forest, and many Wildlife Management Areas. One of Louisiana's largest government-owned areas is Kisatchie National Forest. It is some 600,000 acres in area, more than half of which is flatwoods vegetation, which supports many rare plant and animal species. These include the Louisiana pinesnake and red-cockaded woodpecker. The system of government-owned cypress swamps around Lake Pontchartrain is another large area, with southern wetland species including egrets, alligators, and sturgeon. At least 12 core areas would be needed to build a "protected areas system" for the state; these would range from southwestern prairies, to the Pearl River Floodplain in the east, to the Mississippi River alluvial swamps in the north. Additionally, the state operates a system of 22 state parks, 17 state historic sites and one state preservation area; in these lands, Louisiana maintains a diversity of fauna and flora. National Park Service Historic or scenic areas managed, protected, or otherwise recognized by the National Park Service include: Atchafalaya National Heritage Area in Ascension Parish; Cane River National Heritage Area near Natchitoches; Cane River Creole National Historical Park near Natchitoches; Jean Lafitte National Historical Park and Preserve, headquartered in New Orleans, with units in St. Bernard Parish, Barataria (Crown Point), and Acadiana (Lafayette); Poverty Point National Monument at Delhi, Louisiana; and Saline Bayou, a designated National Wild and Scenic River near Winn Parish in northern Louisiana. U.S. Forest Service Kisatchie National Forest is Louisiana's only national forest. It includes more than 600,000 acres in central and northern Louisiana with large areas of flatwoods and longleaf pine forest. Major cities Louisiana contains 308 incorporated municipalities, consisting of four consolidated city-parishes, and 304 cities, towns, and villages. Louisiana's municipalities cover only 7.9% of the state's land mass but are home to 45.3% of its population. The majority of urban Louisianians live along the coast or in northern Louisiana. The oldest permanent settlement in the state is Nachitoches. Baton Rouge, the state capital, is the second-largest city in the state. The most populous city is New Orleans. As defined by the U.S. Census Bureau, Louisiana contains nine metropolitan statistical areas. Major areas include Greater New Orleans, Greater Baton Rouge, Lafayette, and Shreveport–Bossier City. Demographics Louisiana is the second-most populous of the South Central United States after Texas. The majority of the state's growing population lives in southern Louisiana, spread throughout Greater New Orleans, the Florida Parishes, and Acadiana, while Central and North Louisiana have been losing population. At the 2020 United States census, Louisiana had an apportioned population of 4,661,468. Its resident population was 4,657,757 as of 2020. The United States Census Bureau estimated that the population of Louisiana was 4,648,794 on July 1, 2019, a 2.55% increase since the 2010 United States census. In 2010, the state of Louisiana had a population of 4,533,372, up from 76,556 in 1810. According to immigration statistics in 2018, approximately four percent of Louisianians were immigrants, while another four percent were native-born U.S. citizens with at least one immigrant parent. The majority of Louisianian immigrants came from Mexico (16%), Honduras (15%), Vietnam (10%), the Philippines (5%), and Guatemala (4%). Among the immigrant population in 2014, an estimated 64,500 were undocumented; Louisiana's undocumented immigrant population earned more than a billion U.S. dollars and paid $136million in taxes. The undocumented immigrant population increased to 70,000 in 2016 and comprised two percent of the state population. New Orleans has been defined as a sanctuary city. The population density of the state is 104.9 people per square mile. The center of population of Louisiana is located in Pointe Coupee Parish, in the city of New Roads. According to the 2010 United States census, 5.4% of the population age5 and older spoke Spanish at home, up from 3.5% in 2000; and 4.5% spoke French (including Louisiana French and Louisiana Creole), down from 4.8% in 2000. Race and ethnicity Several American Indian tribes such as the Atakapa and Caddo were the primary residents of Louisiana before European colonization, concentrated along the Red River and Gulf of Mexico. At the beginning of French and Spanish colonization of Louisiana, white and black Americans began to move into the area. From French and Spanish rule in Louisiana, they were joined by Filipinos and Germans, both slave and free, who settled in enclaves within the Greater New Orleans region and Acadiana. By the 19th and 20th centuries, the state's population fluctuated between white and black Americans; 47% of the population was Black or African American in 1900. The Black or African American population declined following migration to states including New York and California in efforts to flee Jim Crow regulations. At the end of the 20th century, Louisiana's population has experienced diversification again, and its non-Hispanic or Latino American white population has been declining. Since 2020, the Black or African American population have made up the largest non-white share of youths. Hispanic and Latino Americans have also increased as the second-largest racial and ethnic composition in the state, making up nearly 7% of Louisiana's population at the 2020 census. As of 2018, the largest single Hispanic and Latino American ethnicity were Mexican Americans (2.0%), followed by Puerto Ricans (0.3%) and Cuban Americans (0.2%). Other Hispanic and Latino Americans altogether made up 2.6% of Louisiana's Hispanic or Latino American population. The Asian American and multiracial communities have also experienced rapid growth, with many of Louisiana's multiracial population identifying as Cajun or Louisiana Creole. At the 2019 American Community Survey, the largest ancestry groups of Louisiana were African American (31.4%), French (9.6%), German (6.2%), English (4.6%), Italian (4.2%), and Scottish (0.9%). African American and French heritage have been dominant since colonial Louisiana. As of 2011, 49.0% of Louisiana's population younger than age1 were minorities. Religion Christians made up 84% of the adult population in 2014, making Louisiana one of the most predominantly-Christian states in the United States; at the 2020 Public Religion Research Institute study, 76.5% of the total adult population were Christian. In 2010, the largest Christian denominations by number of adherents were the Catholic Church with 1,200,900; Southern Baptist Convention with 709,650; and the United Methodist Church with 146,848. Non-denominational Evangelical Protestant churches had 195,903 members. As in other southern U.S. states, the majority of Louisianians, particularly in the north of the state, belong to various Protestant denominations, with Protestants comprising 57% of the state's adult population at the 2014 Pew Research Center study, and 53% at the 2020 Public Religion Research Institute's study. Protestants are concentrated in North Louisiana, Central Louisiana, and the northern tier of the Florida Parishes. According to the 2014 study, Louisiana's largest Protestant Christian denominations were the Southern Baptist Convention, National Baptist Convention USA, National Baptist Convention of America, Progressive National Baptist Convention, American Baptist Churches USA, non/interdenominational Evangelicals and mainline Protestants, the Assemblies of God USA, Church of God in Christ, African Methodist Episcopal and Christian Methodist Episcopal churches, and the United Methodist Church. Because of French and Spanish heritage, and their descendants the Creoles, and later Irish, Italian, Portuguese and German immigrants, southern Louisiana and the Greater New Orleans area are predominantly Catholic; according to the 2020 study, 22% of the population were Catholic. Since Creoles were the first settlers, planters and leaders of the territory, they have traditionally been well represented in politics. For instance, most of the early governors were Creole Catholics. Because Catholics still constitute a significant fraction of Louisiana's population, they have continued to be influential in state politics. The high proportion and influence of the Catholic population makes Louisiana distinct among southern states. The Roman Catholic Archdiocese of New Orleans, Diocese of Baton Rouge, and Diocese of Lafayette in Louisiana are the largest Catholic jurisdictions in the state, located within the Greater New Orleans, Greater Baton Rouge, and Lafayette metropolitan statistical areas. Jewish communities are established in the state's larger cities, notably New Orleans and Baton Rouge. The most significant of these is the Jewish community of the New Orleans area. In 2000, before the 2005 Hurricane Katrina, its population was about 12,000. Louisiana was among the southern states with a significant Jewish population before the 20th century; Virginia, South Carolina, and Georgia also had influential Jewish populations in some of their major cities from the 18th and 19th centuries. The earliest Jewish colonists were Sephardic Jews who immigrated to the Thirteen Colonies. Later in the 19th century, German Jews began to immigrate, followed by those from eastern Europe and the Russian Empire in the late 19th and early 20th centuries. Dominant Jewish movements in the state include Orthodox and Reform Judaism. Prominent Jews in Louisiana's political leadership have included Whig (later Democrat) Judah P. Benjamin (1811–1884), who represented Louisiana in the U.S. Senate before the American Civil War and then became the Confederate secretary of state; Democrat-turned-Republican Michael Hahn who was elected as governor, serving 1864–1865 when Louisiana was occupied by the Union Army, and later elected in 1884 as a U.S. congressman; Democrat Adolph Meyer (1842–1908), Confederate Army officer who represented the state in the U.S. House of Representatives from 1891 until his death in 1908; Republican secretary of state Jay Dardenne (1954–), and Republican (Democrat before 2011) attorney general Buddy Caldwell (1946–). Other non-Christian religions are also primarily established in the metropolitan areas of Louisiana, including Islam, Buddhism and Hinduism. In the Shreveport–Bossier City metropolitan area, Muslims made up an estimated 14% of Louisiana's total Muslim population as of 2014. The largest Islamic denominations in the major metropolises of Louisiana were Sunni Islam, non-denominational Islam and Quranism, Shia Islam, and the Nation of Islam. In the state's irreligious community, 2% affiliated with Atheism and 13% claimed no religion as of 2014; an estimated 10% of the state's population practiced nothing in particular at the 2014 study. Economy Louisiana's population, agricultural products, abundance of oil and natural gas, and southern Louisiana's medical and technology corridors have contributed to its growing and diversifying economy. In 2014, Louisiana was ranked as one of the most small business friendly states, based on a study drawing upon data from more than 12,000 small business owners. The state's principal agricultural products include seafood (it is the biggest producer of crawfish in the world, supplying approximately 90%), cotton, soybeans, cattle, sugarcane, poultry and eggs, dairy products, and rice. Among its energy and other industries, chemical products, petroleum and coal products, processed foods, transportation equipment, and paper products have contributed to a significant portion of the state's GSP. Tourism and gaming are also important elements in the economy, especially in Greater New Orleans. The Port of South Louisiana, located on the Mississippi River between New Orleans and Baton Rouge, was the largest volume shipping port in the Western hemisphere and 4th largest in the world, as well as the largest bulk cargo port in the U.S. in 2004. The Port of South Louisiana continued to be the busiest port by tonnage in the U.S. through 2018. South Louisiana was number 15 among world ports in 2016. New Orleans, Shreveport, and Baton Rouge are home to a thriving film industry. State financial incentives since 2002 and aggressive promotion have given Louisiana the nickname "Hollywood South." Because of its distinctive culture within the United States, only Alaska is Louisiana's rival in popularity as a setting for reality television programs. In late 2007 and early 2008, a film studio was scheduled to open in Tremé, with state-of-the-art production facilities, and a film training institute. Tabasco sauce, which is marketed by one of the United States' biggest producers of hot sauce, the McIlhenny Company, originated on Avery Island. From 2010 to 2020, Louisiana's gross state product increased from $213.6billion to $253.3billion, the 26th highest in the United States at the time. As of 2020, its GSP is greater than the GDPs of Greece, Peru, and New Zealand. Ranking 41st in the United States with a per capita personal income of $30,952 in 2014, its residents per capita income decreased to $28,662 in 2019. The median household income was $51,073, while the national average was $65,712 at the 2019 American Community Survey. In July 2017, the state's unemployment rate was 5.3%; it decreased to 4.4% in 2019. Louisiana has three personal income tax brackets, ranging from 2% to 6%. The state sales tax rate is 4.45%, and parishes can levy additional sales tax on top of this. The state also has a use tax, which includes 4% to be distributed to local governments. Property taxes are assessed and collected at the local level. Louisiana is a subsidized state, and Louisiana taxpayers receive more federal funding per dollar of federal taxes paid compared to the average state. Per dollar of federal tax collected in
|
every LAX terminal in a counter-clockwise direction, starting at terminal 1. The service hours vary based on the line, with most leaving on or near the top of the hour. Buses use the regional system of high-occupancy vehicle lanes and high-occupancy toll lanes (Metro ExpressLanes) to expedite their trips. Metro Rail LAX does not currently have any direct service from the Los Angeles Metro Rail system, however there is a bus connection to a nearby station. LAX Shuttle route G offers free connections between the Central Terminal Area and the Aviation/LAX station on the C Line, away. In 2023, Aviation/Century station on the K Line is expected to open about away from the Central Terminal Area and will the LAX Shuttle will be rerouted. In 2024, Aviation/96th Street station on the K Line is expected to open and will have a direct connection to the LAX Automated People Mover system to the Central Terminal Area. LAX Automated People Mover The LAX Automated People Mover (APM) is an electric train system currently under construction by LAWA. The APM will travel and will have three stations serving the Central Terminal Area (Terminals 1–8 and the Tom Bradley International Terminal). Leaving the Central Terminal Area stations, heading east, the first station will be the Intermodal Transportation Facility–West, a large long-term parking structure, located near employee parking and hotels. The next station will be the Intermodal Transportation Facility–East, which is being built on top of Metro Rail's Aviation/96th Street station and will also have a transit bus terminal. The last stop on the APM will be Consolidated Rent-A-Car facility, which will house of the car rental companies. The APM project is estimated to cost $5.5 billion and be completed in 2023. Freeways and roads LAX's terminals are immediately west of the interchange between Century Boulevard and Sepulveda Boulevard (State Route 1). Interstate 405 can be reached to the east via Century Boulevard. Interstate 105 is to the south via Sepulveda Boulevard, through the Airport Tunnel that crosses under the airport runways. Taxis, ride-share and private shuttles Arriving passengers take a shuttle or walk to the LAXit waiting area east of Terminal 1 for taxi or ride-share pickups. Taxicab services are operated by nine city-authorized taxi companies and regulated by Authorized Taxicab Supervision Inc. (ATS). ATS queues up taxis at the LAXit waiting area. A number of private shuttle companies also offer limousine and bus services to LAX, including from suburban areas such as Lancaster, Palmdale, and Santa Clarita. Bakersfield had a similar service to LAX, but it suspended operations during the 2020 pandemic. Other facilities The airport has the administrative offices of Los Angeles World Airports. Continental Airlines once had its corporate headquarters on the airport property. At a 1962 press conference in the office of Mayor of Los Angeles Sam Yorty, Continental Airlines announced that it planned to move its headquarters to Los Angeles in July 1963. In 1963 Continental Airlines headquarters moved to a two-story, $2.3 million building on the grounds of the airport. The July 2009 Continental Magazine issue stated that the move "underlined Continental Airlines western and Pacific orientation". On July 1, 1983 the airline's headquarters were relocated to the America Tower in the Neartown area of Houston. In addition to Continental Airlines, Western Airlines and Flying Tiger Line also had their headquarters at LAX. Flight Path Learning Center & Museum The Flight Path Learning Center is a museum located at 6661 Imperial Highway and was formerly known as the "West Imperial Terminal". This building used to house some charter flights. It sat empty for 10 years until it was re-opened as a learning center for LAX. The center contains information on the history of aviation, several pictures of the airport, as well as aircraft scale models, flight attendant uniforms, and general airline memorabilia such as playing cards, china, magazines, signs, a TWA gate information sign. The museum's library contains an extensive collection of rare items such as aircraft manufacturer company newsletters/magazines, technical manuals for both military and civilian aircraft, industry magazines dating back to World War II and before, historic photographs and other invaluable references on aircraft operation and manufacturing. The museum has on display "The Spirit of Seventy-Six," a DC-3 that flew in commercial airline service, before serving as a corporate aircraft for Union 76 Oil Company for 32 years. The plane was built in the Douglas Aircraft Company plant in Santa Monica in January 1941, which was a major producer of both commercial and military aircraft. Accidents and incidents During its history there have been numerous incidents, but only the most notable are summarized below: 1930s On January 23, 1939, the sole prototype Douglas 7B twin-engine attack bomber, designed and built as a company project, suffered a loss of the vertical fin and rudder during a demonstration flight over Mines Field, flat spun into the parking lot of North American Aviation, and burned. Another source states that the test pilot, in an attempt to impress the Gallic passenger, attempted a snap roll at low altitude with one engine feathered, resulting in the fatal spin. Douglas test pilot Johnny Cable bailed out at 300 feet, his chute unfurled but did not have time to deploy, he was killed on impact, the flight engineer John Parks rode in the airframe and died, but 33-year-old French Air Force Capt. Paul Chemidlin, riding in the aft fuselage near the top turret, survived with a broken leg, severe back injuries, and a slight concussion. The presence of Chemidlin, a representative of a foreign purchasing mission, caused a furor in Congress by isolationists over neutrality and export laws. The type was developed as the Douglas DB-7. 1940s On June 1, 1940, the first Douglas R3D-1 for the U.S. Navy, BuNo 1901, crashed at Mines Field, before delivery. The Navy later acquired the privately owned DC-5 prototype, from William E. Boeing as a replacement. On November 20, 1940, the prototype NA-73X Mustang, NX19998, first flown October 26, 1940, by test pilot Vance Breese, crashed this date. According to P-51 designer Edgar Schmued, the NA-73 was lost because test pilot Paul Balfour refused, before a high-speed test run, to go through the takeoff and flight test procedure with Schmued while the aircraft was on the ground, claiming "one airplane was like another". After making two high speed passes over Mines Field, he forgot to put the fuel valve on "reserve" and during the third pass ran out of fuel. An emergency landing in a freshly plowed field caused the wheels to dig in, the aircraft flipped over, the airframe was not rebuilt, the second aircraft being used for subsequent testing. On October 26, 1944, WASP pilot Gertrude Tompkins Silver of the 601st Ferrying Squadron, 5th Ferrying Group, Love Field, Dallas, Texas, departed Los Angeles Airport, in a North American P-51D Mustang, 44-15669, at 1600 hrs PWT, headed for the East Coast. She took off into the wind, into an offshore fog bank, and was expected that night at Palm Springs. She never arrived. Owing to a paperwork foul-up, a search did not get under way for several days, and while the eventual search of land and sea was massive, it failed to find a trace of Silver or her plane. She is the only missing WASP pilot. She had married Sgt. Henry Silver one month before her disappearance. 1950s On June 30, 1956, United Airlines Flight 718 collided with TWA Flight 2 over the Grand Canyon, killing 128 people. Both aircraft departed LAX, with fight 718 bound for Chicago Midway, and flight 2 bound for Kansas City. The cause was found to be issues within the US air traffic control system and aviation law. 1960s On January 13, 1969, Scandinavian Airlines System Flight 933 Douglas DC-8-62, crashed into Santa Monica Bay, approximately west of LAX at 7:21 pm, local time. The aircraft was operating as flight SK933, nearing the completion of a flight from Seattle. Of nine crewmembers, three lost their lives to drowning, while 12 of the 36 passengers also drowned. On January 18, 1969, United Airlines Flight 266 a Boeing 727-100 bearing the registration number N7434U, crashed into Santa Monica Bay approximately west of LAX at 6:21 pm local time. The aircraft was destroyed, resulting in the death of all 32 passengers and six crew members aboard. 1970s On the evening of June 6, 1971, Hughes Airwest Flight 706, a Douglas DC-9 jetliner that had departed LAX on a flight to Salt Lake City, Utah, was struck nine minutes after takeoff by a U.S. Marine Corps McDonnell Douglas F-4 Phantom II fighter jet over the San Gabriel Mountains. The midair collision killed all 44 passengers and five crew members aboard the DC-9 airliner and one of two crewmen aboard the military jet. On August 4, 1971, Continental Airlines Flight 712, a Boeing 707, collided in midair with a Cessna 150 over Compton. There were no fatalities. On August 6, 1974, a bomb exploded near the Pan Am ticketing area at Terminal 2; three people were killed and 35 were injured. On March 1, 1978, two tires burst in succession on a McDonnell Douglas DC-10-10 on Continental Airlines Flight 603 during its takeoff roll at LAX and the plane, bound for Honolulu, veered off the runway. A third tire burst and the DC-10's left landing gear collapsed, causing a fuel tank to rupture. Following the aborted takeoff, spilled fuel ignited and enveloped the center portion of the aircraft in flames. During the ensuing emergency evacuation, a husband and wife died when they exited the passenger cabin onto the wing and dropped down directly into the flames. Two additional passengers died of their injuries approximately three months after the accident; 74 others aboard the plane were injured, as were 11 firemen battling the fire. On the evening of March 10, 1979, Swift Aire Flight 235, a twin-engine Aerospatiale Nord 262A-33 turboprop en route to Santa Maria, was forced to ditch in Santa Monica Bay after experiencing engine problems upon takeoff from LAX. The pilot, co-pilot, and a female passenger drowned when they were unable to exit the aircraft after the ditching. The female flight attendant and the three remaining passengers—two men and a pregnant woman—survived and were rescued by several pleasure boats and other watercraft in the vicinity. 1980s On August 31, 1986, Aeroméxico Flight 498, a DC-9 en route from Mexico City, Mexico to Los Angeles, began its descent into LAX when a Piper Cherokee collided with the DC-9's left horizontal stabilizer over Cerritos, causing the DC-9 to crash into a residential neighborhood. All 67 people on the two aircraft were killed, in addition to 15 people on the ground. 5 homes were destroyed and an additional 7 were damaged by the crash and resulting fire. The Piper went down in
|
crosses under the airport runways. Taxis, ride-share and private shuttles Arriving passengers take a shuttle or walk to the LAXit waiting area east of Terminal 1 for taxi or ride-share pickups. Taxicab services are operated by nine city-authorized taxi companies and regulated by Authorized Taxicab Supervision Inc. (ATS). ATS queues up taxis at the LAXit waiting area. A number of private shuttle companies also offer limousine and bus services to LAX, including from suburban areas such as Lancaster, Palmdale, and Santa Clarita. Bakersfield had a similar service to LAX, but it suspended operations during the 2020 pandemic. Other facilities The airport has the administrative offices of Los Angeles World Airports. Continental Airlines once had its corporate headquarters on the airport property. At a 1962 press conference in the office of Mayor of Los Angeles Sam Yorty, Continental Airlines announced that it planned to move its headquarters to Los Angeles in July 1963. In 1963 Continental Airlines headquarters moved to a two-story, $2.3 million building on the grounds of the airport. The July 2009 Continental Magazine issue stated that the move "underlined Continental Airlines western and Pacific orientation". On July 1, 1983 the airline's headquarters were relocated to the America Tower in the Neartown area of Houston. In addition to Continental Airlines, Western Airlines and Flying Tiger Line also had their headquarters at LAX. Flight Path Learning Center & Museum The Flight Path Learning Center is a museum located at 6661 Imperial Highway and was formerly known as the "West Imperial Terminal". This building used to house some charter flights. It sat empty for 10 years until it was re-opened as a learning center for LAX. The center contains information on the history of aviation, several pictures of the airport, as well as aircraft scale models, flight attendant uniforms, and general airline memorabilia such as playing cards, china, magazines, signs, a TWA gate information sign. The museum's library contains an extensive collection of rare items such as aircraft manufacturer company newsletters/magazines, technical manuals for both military and civilian aircraft, industry magazines dating back to World War II and before, historic photographs and other invaluable references on aircraft operation and manufacturing. The museum has on display "The Spirit of Seventy-Six," a DC-3 that flew in commercial airline service, before serving as a corporate aircraft for Union 76 Oil Company for 32 years. The plane was built in the Douglas Aircraft Company plant in Santa Monica in January 1941, which was a major producer of both commercial and military aircraft. Accidents and incidents During its history there have been numerous incidents, but only the most notable are summarized below: 1930s On January 23, 1939, the sole prototype Douglas 7B twin-engine attack bomber, designed and built as a company project, suffered a loss of the vertical fin and rudder during a demonstration flight over Mines Field, flat spun into the parking lot of North American Aviation, and burned. Another source states that the test pilot, in an attempt to impress the Gallic passenger, attempted a snap roll at low altitude with one engine feathered, resulting in the fatal spin. Douglas test pilot Johnny Cable bailed out at 300 feet, his chute unfurled but did not have time to deploy, he was killed on impact, the flight engineer John Parks rode in the airframe and died, but 33-year-old French Air Force Capt. Paul Chemidlin, riding in the aft fuselage near the top turret, survived with a broken leg, severe back injuries, and a slight concussion. The presence of Chemidlin, a representative of a foreign purchasing mission, caused a furor in Congress by isolationists over neutrality and export laws. The type was developed as the Douglas DB-7. 1940s On June 1, 1940, the first Douglas R3D-1 for the U.S. Navy, BuNo 1901, crashed at Mines Field, before delivery. The Navy later acquired the privately owned DC-5 prototype, from William E. Boeing as a replacement. On November 20, 1940, the prototype NA-73X Mustang, NX19998, first flown October 26, 1940, by test pilot Vance Breese, crashed this date. According to P-51 designer Edgar Schmued, the NA-73 was lost because test pilot Paul Balfour refused, before a high-speed test run, to go through the takeoff and flight test procedure with Schmued while the aircraft was on the ground, claiming "one airplane was like another". After making two high speed passes over Mines Field, he forgot to put the fuel valve on "reserve" and during the third pass ran out of fuel. An emergency landing in a freshly plowed field caused the wheels to dig in, the aircraft flipped over, the airframe was not rebuilt, the second aircraft being used for subsequent testing. On October 26, 1944, WASP pilot Gertrude Tompkins Silver of the 601st Ferrying Squadron, 5th Ferrying Group, Love Field, Dallas, Texas, departed Los Angeles Airport, in a North American P-51D Mustang, 44-15669, at 1600 hrs PWT, headed for the East Coast. She took off into the wind, into an offshore fog bank, and was expected that night at Palm Springs. She never arrived. Owing to a paperwork foul-up, a search did not get under way for several days, and while the eventual search of land and sea was massive, it failed to find a trace of Silver or her plane. She is the only missing WASP pilot. She had married Sgt. Henry Silver one month before her disappearance. 1950s On June 30, 1956, United Airlines Flight 718 collided with TWA Flight 2 over the Grand Canyon, killing 128 people. Both aircraft departed LAX, with fight 718 bound for Chicago Midway, and flight 2 bound for Kansas City. The cause was found to be issues within the US air traffic control system and aviation law. 1960s On January 13, 1969, Scandinavian Airlines System Flight 933 Douglas DC-8-62, crashed into Santa Monica Bay, approximately west of LAX at 7:21 pm, local time. The aircraft was operating as flight SK933, nearing the completion of a flight from Seattle. Of nine crewmembers, three lost their lives to drowning, while 12 of the 36 passengers also drowned. On January 18, 1969, United Airlines Flight 266 a Boeing 727-100 bearing the registration number N7434U, crashed into Santa Monica Bay approximately west of LAX at 6:21 pm local time. The aircraft was destroyed, resulting in the death of all 32 passengers and six crew members aboard. 1970s On the evening of June 6, 1971, Hughes Airwest Flight 706, a Douglas DC-9 jetliner that had departed LAX on a flight to Salt Lake City, Utah, was struck nine minutes after takeoff by a U.S. Marine Corps McDonnell Douglas F-4 Phantom II fighter jet over the San Gabriel Mountains. The midair collision killed all 44 passengers and five crew members aboard the DC-9 airliner and one of two crewmen aboard the military jet. On August 4, 1971, Continental Airlines Flight 712, a Boeing 707, collided in midair with a Cessna 150 over Compton. There were no fatalities. On August 6, 1974, a bomb exploded near the Pan Am ticketing area at Terminal 2; three people were killed and 35 were injured. On March 1, 1978, two tires burst in succession on a McDonnell Douglas DC-10-10 on Continental Airlines Flight 603 during its takeoff roll at LAX and the plane, bound for Honolulu, veered off the runway. A third tire burst and the DC-10's left landing gear collapsed, causing a fuel tank to rupture. Following the aborted takeoff, spilled fuel ignited and enveloped the center portion of the aircraft in flames. During the ensuing emergency evacuation, a husband and wife died when they exited the passenger cabin onto the wing and dropped down directly into the flames. Two additional passengers died of their injuries approximately three months after the accident; 74 others aboard the plane were injured, as were 11 firemen battling the fire. On the evening of March 10, 1979, Swift Aire Flight 235, a twin-engine Aerospatiale Nord 262A-33 turboprop en route to Santa Maria, was forced to ditch in Santa Monica Bay after experiencing engine problems upon takeoff from LAX. The pilot, co-pilot, and a female passenger drowned when they were unable to exit the aircraft after the ditching. The female flight attendant and the three remaining passengers—two men and a pregnant woman—survived and were rescued by several pleasure boats and other watercraft in the vicinity. 1980s On August 31, 1986, Aeroméxico Flight 498, a DC-9 en route from Mexico City, Mexico to Los Angeles, began its descent into LAX when a Piper Cherokee collided with the DC-9's left horizontal stabilizer over Cerritos, causing the DC-9 to crash into a residential neighborhood. All 67 people on the two aircraft were killed, in addition to 15 people on the ground. 5 homes were destroyed and an additional 7 were damaged by the crash and resulting fire. The Piper went down in a nearby schoolyard and caused no further injuries on the ground. As a result of this incident, the FAA required all commercial aircraft to be equipped with Traffic Collision Avoidance System (TCAS). 1990s On February 1, 1991, USAir Flight 1493 (arriving from Columbus, Ohio), a Boeing 737-300, landing on runway 24L at LAX, collided on touchdown with a SkyWest Airlines Fairchild Metroliner, Flight 5569 departing to Palmdale. The Skywest plane was given clearance to wait on the runway for takeoff. The same controller then gave the USAir plane clearance to land on the same runway, forgetting that the SkyWest plane was there. The collision killed all 12 occupants of the SkyWest plane and 23 people aboard the USAir 737. On September 6, 1993, Air New Zealand Flight 55, a Boeing 767-200, suffered a right rear undercarriage failure while boarding for Honolulu. The aircraft was at Gate 104 in the Tom Bradley Terminal. There were 9 crew and 195 passengers onboard. Mud from a runway excursion was slammed for causing the corrosion and stress cracking which caused the failure. 2000s Al-Qaeda attempted to bomb LAX on New Year's Eve 1999/2000. The bomber, Algerian Ahmed Ressam, was captured in Port Angeles, Washington, the U.S. port of entry, with a cache of explosives that could have produced a blast 40 times greater than that of a car bomb hidden in the trunk of the rented car in which he had traveled from Canada. He had planned to leave one or two suitcases filled with explosives in an LAX passenger waiting area. He was initially sentenced to 22 years in prison, but in February 2010 an appellate court ordered that his sentence be extended. On January 31, 2000, Alaska Airlines Flight 261, a McDonnell Douglas MD-83 jetliner flying from Puerto Vallarta, Mexico to San Francisco and Seattle, requested an emergency landing at LAX after experiencing problems with its tail-mounted horizontal stabilizer. Before the plane could divert to Los Angeles, it suddenly plummeted into the Pacific Ocean approximately north of Anacapa Island off the California coast, killing all 88 people aboard. On September 11, 2001, American Airlines Flight 11, United Airlines Flight 175 and American Airlines Flight 77 were bound for LAX and they were hijacked mid-flight. The hijackers flew the aircraft themselves and then crashing the planes into the World Trade Center and The Pentagon. American flags flies over the gates of the three flights at Logan International Airport and Washington Dulles International Airport. In the 2002 Los Angeles International Airport shooting of July 4, 2002, Hesham Mohamed Hadayet killed two Israelis at the ticket counter of El Al Airlines at LAX. Although the gunman was not linked to any terrorist group, the man was upset at U.S. support for
|
therefore common to also talk of the "La Tène period" in the context of those regions even though they were never part of the La Tène culture proper, but connected to its core area via trade. Ethnology The bearers of the La Tène culture were the people known as Celts or Gauls to ancient ethnographers. Ancient Celtic culture had no written literature of its own, but rare examples of epigraphy in the Greek or Latin alphabets exist allowing the fragmentary reconstruction of Continental Celtic. Current knowledge of this cultural area is derived from three sources comprising archaeological evidence, Greek and Latin literary records, and ethnographical evidence suggesting some La Tène artistic and cultural survivals in traditionally Celtic regions of far western Europe. Some of the societies that are archaeologically identified with La Tène material culture were identified by Greek and Roman authors from the 5th century onwards as Keltoi ("Celts") and Galli ("Gauls"). Herodotus (iv.49) correctly placed Keltoi at the source of the Ister/Danube, in the heartland of La Tène material culture: "The Ister flows right across Europe, rising in the country of the Celts". Whether the usage of classical sources means that the whole of La Tène culture can be attributed to a unified Celtic people is difficult to assess; archaeologists have repeatedly concluded that language, material culture, and political affiliation do not necessarily run parallel. Frey (2004) notes that in the 5th century, "burial customs in the Celtic world were not uniform; rather, localised groups had their own beliefs, which, in consequence, also gave rise to distinct artistic expressions". Type site The La Tène type site is on the northern shore of Lake Neuchâtel, Switzerland, where the small river Thielle, connecting to another lake, enters the Lake Neuchâtel. In 1857, prolonged drought lowered the waters of the lake by about 2 m. On the northernmost tip of the lake, between the river and a point south of the village of Epagnier (), Hansli Kopp, looking for antiquities for Colonel Frédéric Schwab, discovered several rows of wooden piles that still reached up about 50 cm into the water. From among these, Kopp collected about forty iron swords. The Swiss archaeologist Ferdinand Keller published his findings in 1868 in his influential first report on the Swiss pile dwellings (Pfahlbaubericht). In 1863 he interpreted the remains as a Celtic village built on piles. Eduard Desor, a geologist from Neuchâtel, started excavations on the lakeshore soon afterwards. He interpreted the site as an armory, erected on platforms on piles over the lake and later destroyed by enemy action. Another interpretation accounting for the presence of cast iron swords that had not been sharpened, was of a site for ritual depositions. With the first systematic lowering of the Swiss lakes from 1868 to 1883, the site fell completely dry. In 1880, Emile Vouga, a teacher from Marin-Epagnier, uncovered the wooden remains of two bridges (designated "Pont Desor" and "Pont Vouga") originally over 100 m long, that crossed the little Thielle River (today a nature reserve) and the remains of five houses on the shore. After Vouga had finished, F. Borel, curator of the Marin museum, began to excavate as well. In 1885 the canton asked the Société d'Histoire of Neuchâtel to continue the excavations, the results of which were published by Vouga in the same year. All in all, over 2500 objects, mainly made from metal, have been excavated in La Tène. Weapons predominate, there being 166 swords (most without traces of wear), 270 lanceheads, and 22 shield bosses, along with 385 brooches, tools, and parts of chariots. Numerous human and animal bones were found as well. The site was used from the 3rd century, with a peak of activity around 200 BCE and abandonment by about 60 BCE. Interpretations of the site vary. Some scholars believe the bridge was destroyed by high water, while others see it as a place of sacrifice after a successful battle (there are almost no female ornaments). An exhibition marking the 150th anniversary of the discovery of the La Tène site opened in 2007 at the Musée Schwab in Biel/Bienne, Switzerland, moving to move to Zürich in 2008 and Mont Beuvray in Burgundy in 2009. Genetics A genetic study published in PLOS One in December 2018 examined 45 individuals buried at a La Téne necropolis in Urville-Nacqueville, France. The people buried there were identified as Gauls. The mtDNA of the examined individuals belonged primarily to haplotypes of H and U. They were found to be carrying a large amount of steppe ancestry, and to have been closely related to peoples of the preceding Bell Beaker culture, suggesting genetic continuity between Bronze Age and Iron Age France. Significant gene flow with Great Britain and Iberia was detected. The results of the study partially supported the notion that French people are largely descended from the Gauls. A genetic study published in the Journal of Archaeological Science in October 2019 examined 43 maternal and 17 paternal lineages for the La Téne necropolis in Urville-Nacqueville, France, and 27 maternal and 19 paternal lineages for La Téne tumulus of Gurgy Les Noisats near modern
|
be linguistically linked is debated. The art history of La Tène culture has various schemes of periodization. The archaeological period is now mostly divided into four sub-periods, following Paul Reinecke. History The preceding final phase of the Hallstatt culture, HaD, c. 650–450 BC, was also widespread across Central Europe, and the transition over this area was gradual, being mainly detected through La Tène style elite artefacts, which first appear on the western edge of the old Hallstatt region.Though there is no agreement on the precise region in which La Tène culture first developed, there is a broad consensus that the centre of the culture lay on the northwest edges of Hallstatt culture, north of the Alps, within the region between in the West the valleys of the Marne and Moselle, and the part of the Rhineland nearby. In the east the western end of the old Hallstatt core area in modern Bavaria, Czechia, Austria and Switzerland formed a somewhat separate "eastern style Province" in the early La Tène, joining with the western area in Alsace. In 1994 a prototypical ensemble of elite grave sites of the early 5th century BCE was excavated at Glauberg in Hesse, northeast of Frankfurt-am-Main, in a region that had formerly been considered peripheral to the La Tène sphere. The site at La Tène itself was therefore near the southern edge of the original "core" area (as is also the case for the Hallstatt site for its core). The establishment of a Greek colony, soon very successful, at Massalia (modern Marseilles) on the Mediterranean coast of France led to great trade with the Hallstatt areas up the Rhone and Saone river systems, and early La Tène elite burials like the Vix Grave in Burgundy contain imported luxury goods along with artifacts produced locally. Most areas were probably controlled by tribal chiefs living in hilltop forts, while the bulk of the population lived in small villages or farmsteads in the countryside. By 500 BCE the Etruscans expanded to border Celts in north Italy, and trade across the Alps began to overhaul trade with the Greeks, and the Rhone route declined. Booming areas included the middle Rhine, with large iron ore deposits, the Marne and Champagne regions, and also Bohemia, although here trade with the Mediterranean area was much less important. Trading connections and wealth no doubt played a part in the origin of the La Tène style, though how large a part remains much discussed; specific Mediterranean-derived motifs are evident, but the new style does not depend on them. Barry Cunliffe notes localization of La Tène culture during the 5th century BCE when there arose "two zones of power and innovation: a Marne – Moselle zone in the west with trading links to the Po Valley via the central Alpine passes and the Golasecca culture, and a Bohemian zone in the east with separate links to the Adriatic via the eastern Alpine routes and the Venetic culture". From their homeland, La Tène culture expanded in the 4th century BCE to more of modern France, Germany, and Central Europe, and beyond to Hispania, northern and central Italy, the Balkans, and even as far as Asia Minor, in the course of several major migrations. La Tène style artefacts start to appear in Britain around the same time, and Ireland rather later. The style of "Insular La Tène" art is somewhat different and the artefacts are initially found in some parts of the islands but not others. Migratory movements seem at best only partly responsible for the diffusion of La Tène culture there, and perhaps other parts of Europe. By about 400 BCE, the evidence for Mediterranean trade becomes sparse; this may be because the expanding Celtic populations began to migrate south and west, coming into violent conflict with the established populations, including the Etruscans and Romans. The settled life in much of the La Tène homelands also seems to have become much more unstable and prone to wars. In about 387 BCE, the Celts under Brennus defeated the Romans and then sacked Rome, establishing themselves as the most prominent threats to the Roman homeland, a status they would retain through a series of Roman-Gallic wars until Julius Caesar's final conquest of Gaul in 58-50 BCE. The Romans prevented the Celts from reaching very far south of Rome, but on the other side of the Adriatic Sea groups passed through the Balkans to reach Greece, where Delphi was attacked in 279 BCE, and Asia, where Galatia was established as a Celtic area of Anatolia. By this time, the La Tène style was spreading to the British Isles, though apparently without any significant movements in population. After about 275 BCE, Roman expansion into the La Tène area began, at first with the conquest of Gallia Cisalpina. The conquest of Celtic Gaul began in 121 BCE and was complete with the Gallic Wars of the 50s BCE. Gaulish culture now quickly assimilated to Roman culture, giving rise to the hybrid Gallo-Roman culture of Late Antiquity. Material culture La Tène metalwork in bronze, iron and gold, developing technologically out of Hallstatt culture, is stylistically characterized by inscribed and inlaid intricate spirals and interlace, on fine bronze vessels, helmets and shields, horse trappings and elite jewelry, especially the neck rings called torcs and elaborate clasps called fibulae. It is characterized by elegant, stylized curvilinear animal and vegetal forms, allied with the Hallstatt traditions of geometric patterning. The Early Style of La Tène art and culture mainly featured static, geometric decoration, while the transition to the Developed Style constituted a shift to movement-based forms, such as triskeles. Some subsets within the Developed Style contain more specific design trends, such as the recurrent serpentine scroll of the Waldalgesheim Style. Initially La Tène people lived in open settlements that were dominated by the chieftains' hill forts. The development of towns—oppida—appears in mid-La Tène culture. La Tène dwellings were carpenter-built rather than of masonry. La Tène peoples also dug ritual shafts, in which votive offerings and even human sacrifices were cast. Severed heads appear to have held great power and were often represented in carvings. Burial sites included weapons, carts, and both elite and household goods, evoking a strong continuity with an afterlife. Elaborate burials also reveal a wide network of trade. In Vix, France, an elite woman of the 6th century BCE was buried with a very large bronze "wine-mixer" made in Greece. Exports from La Tène cultural areas to the Mediterranean cultures were based on salt, tin, copper, amber, wool, leather, furs and gold. Artefacts typical of the La Tène culture were also discovered in stray finds as far afield as Scandinavia, Northern Germany, Poland and in the Balkans. It is therefore common to also talk of the "La Tène period" in the context of those regions even though they were never part of the La Tène culture proper, but connected to its core area via trade. Ethnology The bearers of the La Tène culture were the people known as Celts or Gauls to ancient ethnographers. Ancient Celtic culture had no written literature of its own, but rare examples of epigraphy in the Greek or Latin alphabets exist allowing the fragmentary reconstruction of Continental Celtic. Current knowledge of this cultural area is derived from three sources comprising archaeological evidence, Greek and Latin literary records, and ethnographical evidence suggesting some La Tène artistic and cultural survivals in traditionally Celtic regions of far western Europe. Some of the societies that are archaeologically identified with La Tène material culture were identified by Greek and Roman authors from the 5th century onwards as Keltoi ("Celts") and Galli ("Gauls"). Herodotus (iv.49) correctly placed Keltoi at the source of the Ister/Danube, in the heartland of La Tène material culture: "The Ister flows right across Europe, rising in the country of the Celts". Whether the usage of classical sources means that the whole of La Tène culture can be attributed to a unified Celtic people is difficult to assess; archaeologists have repeatedly concluded that language, material culture, and political affiliation do not necessarily run parallel. Frey (2004) notes that in the 5th century, "burial customs in the Celtic world were not uniform; rather, localised groups had their own beliefs, which, in consequence, also gave rise to distinct artistic expressions". Type site The La Tène type site is on the northern shore of Lake Neuchâtel, Switzerland, where the small river Thielle, connecting to another lake, enters the Lake Neuchâtel. In 1857, prolonged drought lowered the waters of the lake by about 2 m. On the northernmost tip of the lake, between the river and a point south of the village of Epagnier (), Hansli Kopp, looking for antiquities for Colonel Frédéric Schwab, discovered several rows of wooden piles that still reached up about 50 cm into the water. From among these, Kopp collected about forty iron swords. The Swiss archaeologist Ferdinand Keller published his findings in 1868 in
|
in the diagram. Definition and calculation The Lorenz curve is a probability plot (a P–P plot) comparing the distribution of a variable against a hypothetical uniform distribution of that variable. It can usually be represented by a function L(F), where F, the cumulative portion of the population, is represented by the horizontal axis, and L, the cumulative portion of the total wealth or income, is represented by the vertical axis. For a discrete distribution of Y given by values y1,...,yn in non-decreasing order ( yi ≤ yi+1) and their probabilities the Lorenz curve is the continuous piecewise linear function connecting the points ( Fi, Li ), i = 0 to n, where F0 = 0, L0 = 0, and for i = 1 to n: When all yi are equally probable with probabilities 1/n this simplifies to For a continuous distribution with the probability density function f and the cumulative distribution function F, the Lorenz curve L is given by: where denotes the average. The Lorenz curve L(F) may then be plotted as a function parametric in x: L(x) vs. F(x). In other contexts, the quantity computed here is known as the length biased (or size biased) distribution; it also has an important role in renewal theory. Alternatively, for a cumulative distribution function F(x) with inverse x(F), the Lorenz curve L(F) is directly given by: The inverse x(F) may not exist because the cumulative distribution function has intervals of constant values. However, the previous formula can still apply by generalizing the definition of x(F): x(F1) = inf {y : F(y) ≥ F1} For an example of a Lorenz curve, see Pareto distribution. Properties A Lorenz curve always starts at (0,0) and ends at (1,1). The Lorenz curve is not defined if the mean of the probability distribution is zero or infinite. The Lorenz curve for a probability distribution is a continuous function. However, Lorenz curves representing discontinuous functions can be constructed as the limit of Lorenz curves of probability distributions, the line of perfect inequality being an example. The information in a Lorenz curve may be summarized by the Gini coefficient and the Lorenz asymmetry coefficient. The Lorenz curve cannot rise above the line of perfect equality. A Lorenz curve that never falls beneath a second Lorenz curve and at least once runs above it, has Lorenz dominance over the second one. If the variable being measured cannot take negative values, the Lorenz curve: cannot sink below the line of perfect inequality, is increasing. Note however that a Lorenz curve for net worth would start out by going negative due to the fact that some people have a negative net worth because of debt. The Lorenz curve is invariant under positive scaling. If X is a random variable, for any positive number c the random variable c X has the same Lorenz curve as X. The Lorenz curve is flipped twice, once about F = 0.5 and once about L = 0.5, by negation. If X is a random variable with Lorenz curve LX(F), then −X has the Lorenz curve: L − X = 1 − L X (1 − F) The Lorenz curve is changed by translations so that the equality gap F − L(F) changes in proportion to the ratio of the original and translated means. If X is a random variable with a Lorenz curve L X (F) and mean μ X , then for any constant c ≠ −μ X , X + c has a Lorenz curve defined by: For a cumulative distribution function F(x) with mean μ and (generalized) inverse x(F), then for any F with 0 < F < 1 : If the Lorenz
|
worst risk scores. Explanation Data from 2005. Points on the Lorenz curve represent statements such as, "the bottom 20% of all households have 10% of the total income." A perfectly equal income distribution would be one in which every person has the same income. In this case, the bottom N% of society would always have N% of the income. This can be depicted by the straight line y = x; called the "line of perfect equality." By contrast, a perfectly unequal distribution would be one in which one person has all the income and everyone else has none. In that case, the curve would be at y = 0% for all x < 100%, and y = 100% when x = 100%. This curve is called the "line of perfect inequality." The Gini coefficient is the ratio of the area between the line of perfect equality and the observed Lorenz curve to the area between the line of perfect equality and the line of perfect inequality. The higher the coefficient, the more unequal the distribution is. In the diagram on the right, this is given by the ratio A/(A+B), where A and B are the areas of regions as marked in the diagram. Definition and calculation The Lorenz curve is a probability plot (a P–P plot) comparing the distribution of a variable against a hypothetical uniform distribution of that variable. It can usually be represented by a function L(F), where F, the cumulative portion of the population, is represented by the horizontal axis, and L, the cumulative portion of the total wealth or income, is represented by the vertical axis. For a discrete distribution of Y given by values y1,...,yn in non-decreasing order ( yi ≤ yi+1) and their probabilities the Lorenz curve is the continuous piecewise linear function connecting the points ( Fi, Li ), i = 0 to n, where F0 = 0, L0 = 0, and for i = 1 to n: When all yi are equally probable with probabilities 1/n this simplifies to For a continuous distribution with the probability density function f and the cumulative distribution function F, the Lorenz curve L is given by: where denotes the average. The Lorenz curve L(F) may then be plotted as a function parametric in x: L(x) vs. F(x). In other contexts, the quantity computed here is known as the length biased (or size biased) distribution; it also has an important role in renewal theory. Alternatively, for a cumulative distribution function F(x) with inverse x(F), the Lorenz curve L(F) is directly given by: The inverse x(F) may not exist because the cumulative distribution function has intervals of constant values. However, the previous formula can still apply by generalizing the definition of x(F): x(F1) = inf {y : F(y) ≥ F1} For an example of a Lorenz curve, see Pareto distribution. Properties A Lorenz curve always starts at (0,0) and ends at (1,1). The Lorenz curve is not defined if the mean of the probability distribution is zero or infinite. The Lorenz curve for a probability distribution is a continuous function. However, Lorenz curves representing discontinuous functions can be constructed as the limit of Lorenz curves of probability distributions, the line of perfect inequality being an example. The information in a Lorenz curve may be summarized by the Gini coefficient and the Lorenz asymmetry coefficient. The Lorenz curve cannot rise above the line of perfect equality. A Lorenz curve that never falls beneath a second Lorenz curve and at least once runs above it, has Lorenz dominance over the second one. If the variable being measured cannot take negative values, the Lorenz curve: cannot sink below the line of perfect inequality, is increasing. Note however that a Lorenz curve for net worth would start out by going negative due to the fact that some people have a negative net worth because of debt. The Lorenz curve is invariant under positive scaling. If X is a random variable, for any positive number c the
|
illustration of the basic elements of literate programming. Creation of macros The following snippet of the wc literate program shows how arbitrary descriptive phrases in a natural language are used in a literate program to create macros, which act as new "operators" in the literate programming language, and hide chunks of code or other macros. The mark-up notation consists of double angle brackets ("<<...>>") that indicate macros, the "@" symbol which indicates the end of the code section in a noweb file. The "<<*>>" symbol stands for the "root", topmost node the literate programming tool will start expanding the web of macros from. Actually, writing out the expanded source code can be done from any section or subsection (i.e. a piece of code designated as "<<name of the chunk>>=", with the equal sign), so one literate program file can contain several files with machine source code. The purpose of wc is to count lines, words, and/or characters in a list of files. The number of lines in a file is ......../more explanations/ Here, then, is an overview of the file wc.c that is defined by the noweb program wc.nw: <<*>>= <<Header files to include>> <<Definitions>> <<Global variables>> <<Functions>> <<The main program>> @ We must include the standard I/O definitions, since we want to send formatted output to stdout and stderr. <<Header files to include>>= #include <stdio.h> @ The unraveling of the chunks can be done in any place in the literate program text file, not necessarily in the order they are sequenced in the enclosing chunk, but as is demanded by the logic reflected in the explanatory text that envelops the whole program. Program as a web—macros are not just section names Macros are not the same as "section names" in standard documentation. Literate programming macros can hide any chunk of code behind themselves, and be used inside any low-level machine language operators, often inside logical operators such as "if", "while" or "case". This is illustrated by the following snippet of the wc literate program. The present chunk, which does the counting, was actually one of the simplest to write. We look at each character and change state if it begins or ends a word. <<Scan file>>= while (1) { <<Fill buffer if it is empty; break at end of file>> c = *ptr++; if (c > ' ' && c < 0177) { /* visible ASCII codes */ if (!in_word) { word_count++; in_word = 1; } continue; } if (c == '\n') line_count++; else if (c != ' ' && c != '\t') continue; in_word = 0; /* c is newline, space, or tab */ } @ In fact, macros can stand for any arbitrary chunk of code or other macros, and are thus more general than top-down or bottom-up "chunking", or than subsectioning. Knuth says that when he realized this, he began to think of a program as a web of various parts. Order of human logic, not that of the compiler In a noweb literate program besides the free order of their exposition, the chunks behind macros, once introduced with "<<...>>=", can be grown later in any place in the file by simply writing "<<name of the chunk>>=" and adding more content to it, as the following snippet illustrates ("plus" is added by the document formatter for readability, and is not in the code). The grand totals must be initialized to zero at the beginning of the program. If we made these variables local to main, we would have to do this initialization explicitly; however, C globals are automatically zeroed. (Or rather,``statically zeroed.'' (Get it?) <<Global variables>>+= long tot_word_count, tot_line_count, tot_char_count; /* total number of words, lines, chars */ @ Record of the train of thought The documentation for a literate program is produced as part of writing the program. Instead of comments provided as side notes to source code a literate program contains the explanation of concepts on each level, with lower level concepts deferred to their appropriate place, which allows for better communication of thought. The snippets of the literate wc above show how an explanation of the program and its source code are interwoven. Such exposition of ideas creates the flow of thought that is like a literary work. Knuth wrote a "novel" which explains the code of the interactive fiction game Colossal Cave Adventure. Remarkable examples Axiom, which is evolved from scratchpad, a computer algebra system developed by IBM. It is now being developed by Tim Daly, one of the developers of scratchpad, Axiom is totally written as a literate program. Literate programming practices The first published literate programming environment was WEB, introduced by Knuth in 1981 for his TeX typesetting system; it uses Pascal as its underlying programming language and TeX for typesetting of the documentation. The complete commented TeX source code was published in Knuth's TeX: The program, volume B of his 5-volume Computers and Typesetting. Knuth had privately used a literate programming system called DOC as early as 1979. He was inspired by the ideas of Pierre-Arnoul de Marneffe. The free CWEB, written by Knuth and Silvio Levy, is WEB adapted for C and C++, runs on most operating systems and can produce TeX and PDF documentation. There are various other implementations of the literate programming concept (some of them don't have macros and hence violate the order of human logic principle): Other useful tools include The Leo text editor is an outlining editor which supports optional noweb and CWEB markup. The author of Leo mixes two different approaches: first, Leo is an outlining editor, which helps with management of large texts; second, Leo incorporates some of the ideas of literate programming, which in its pure form (i.e., the way it is used by Knuth Web tool or tools like "noweb") is possible only with some degree of inventiveness and the use of the editor in a way not exactly envisioned by its author (in modified @root nodes). However, this and other extensions (@file nodes) make outline programming and text management successful and easy and in some ways similar to literate programming. The Haskell programming language has native support for semi-literate programming. The compiler/interpreter supports two file name extensions: .hs and .lhs; the latter stands for literate Haskell. The literate scripts can be full LaTeX source text, at the same time it can be compiled, with no changes, because the interpreter only compiles the text in a code environment, for example: % here text describing the function: \begin{code} fact 0 = 1 fact (n+1) = (n+1) * fact n \end{code} here more text The code can be also marked in the Richard Bird style, starting each line with a greater than symbol and a space, preceding and ending the piece of code with blank lines. The LaTeX listings package provides a lstlisting environment which can be used to embellish the source code. It can be used to define a code environment to use within Haskell to print the symbols in the following manner: \newenvironment{code}{\lstlistings[language=Haskell]}{\endlstlistings} \begin{code} comp :: (beta -> gamma) -> (alpha -> beta) -> (alpha -> gamma) (g `comp` f) x = g(f x) \end{code} which can be configured to yield: Although the package does not provide means to organize chunks of code, one can split the LaTeX source code in different files. See listings manual for an overview. The Web 68 Literate Programming system used Algol 68 as the underlying programming language, although there was nothing in the pre-processor 'tang' to force the use of that language. The customization mechanism of the Text Encoding Initiative which enables the constraining, modification, or extension of the TEI scheme enables users to mix prose documentation with fragments of schema specification in their One Document Does-it-all format. From this prose documentation, schemas, and processing model pipelines can be generated and Knuth's Literate Programming paradigm is cited as the inspiration for this way of working. See also Documentation generator – the inverse on literate programming where documentation is embedded in and generated from source code Notebook interface – virtual
|
are language-agnostic and exist above the programming languages. History and philosophy Literate programming was first introduced by Knuth in 1984. The main intention behind this approach was to treat a program as literature understandable to human beings. This approach was implemented at Stanford University as a part of research on algorithms and digital typography. This implementation was called "WEB" by Knuth since he believed that it was one of the few three-letter words of English that hadn't already been applied to computing. However, it correctly resembles the complicated nature of software delicately pieced together from simple materials. The practice of literate programming has seen an important resurgence in the 2010s with the use of computational notebooks, especially in data science. Concept Literate programming is writing out the program logic in a human language with included (separated by a primitive markup) code snippets and macros. Macros in a literate source file are simply title-like or explanatory phrases in a human language that describe human abstractions created while solving the programming problem, and hiding chunks of code or lower-level macros. These macros are similar to the algorithms in pseudocode typically used in teaching computer science. These arbitrary explanatory phrases become precise new operators, created on the fly by the programmer, forming a meta-language on top of the underlying programming language. A preprocessor is used to substitute arbitrary hierarchies, or rather "interconnected 'webs' of macros", to produce the compilable source code with one command ("tangle"), and documentation with another ("weave"). The preprocessor also provides an ability to write out the content of the macros and to add to already created macros in any place in the text of the literate program source file, thereby disposing of the need to keep in mind the restrictions imposed by traditional programming languages or to interrupt the flow of thought. Advantages According to Knuth, literate programming provides higher-quality programs, since it forces programmers to explicitly state the thoughts behind the program, making poorly thought-out design decisions more obvious. Knuth also claims that literate programming provides a first-rate documentation system, which is not an add-on, but is grown naturally in the process of exposition of one's thoughts during a program's creation. The resulting documentation allows the author to restart his own thought processes at any later time, and allows other programmers to understand the construction of the program more easily. This differs from traditional documentation, in which a programmer is presented with source code that follows a compiler-imposed order, and must decipher the thought process behind the program from the code and its associated comments. The meta-language capabilities of literate programming are also claimed to facilitate thinking, giving a higher "bird's eye view" of the code and increasing the number of concepts the mind can successfully retain and process. Applicability of the concept to programming on a large scale, that of commercial-grade programs, is proven by an edition of TeX code as a literate program. Knuth also claims that literate programming can lead to easy porting of software to multiple environments, and even cites the implementation of TeX as an example. Contrast with documentation generation Literate programming is very often misunderstood to refer only to formatted documentation produced from a common file with both source code and comments – which is properly called documentation generation – or to voluminous commentaries included with code. This is the converse of literate programming: well-documented code or documentation extracted from code follows the structure of the code, with documentation embedded in the code; while in literate programming, code is embedded in documentation, with the code following the structure of the documentation. This misconception has led to claims that comment-extraction tools, such as the Perl Plain Old Documentation or Java Javadoc systems, are "literate programming tools". However, because these tools do not implement the "web of abstract concepts" hiding behind the system of natural-language macros, or provide an ability to change the order of the source code from a machine-imposed sequence to one convenient to the human mind, they cannot properly be called literate programming tools in the sense intended by Knuth. Critique In 1986, Jon Bentley asked Knuth to demonstrate the concept of literate programming for his Programming Pearls column in the Communications of the ACM, by writing a program in WEB. Knuth sent him a program for a problem previously discussed in the column (that of sampling M random numbers in the range 1..N), and also asked for an "assignment". Bentley gave him the problem of finding the K most common words from a text file, for which Knuth wrote a WEB program that was published together with a review by Douglas McIlroy of Bell Labs. McIlroy praised the intricacy of Knuth's solution, his choice of a data structure (a variant of Frank M. Liang's hash trie), and the presentation. He criticized some matters of style, such as the fact that the central idea was described late in the paper, the use of magic constants, and the absence of a diagram to accompany the explanation of the data structure. McIlroy, known for Unix pipelines, also used the review to critique the programming task itself, pointing out that in Unix (developed at Bell Labs), utilities for text processing (tr, sort, uniq and sed) had been written previously that were "staples", and a solution that was easy to implement, debug and reuse could be obtained by combining these utilities in a six-line shell script. In response, Bentley wrote that: McIlroy later admitted that his critique was unfair, since he criticized Knuth's program on engineering grounds, while Knuth's purpose was only to demonstrate the literate programming technique. In 1987, Communications of the ACM published a followup article which illustrated literate programming with a C program that combined artistic approach of Knuth with engineering approach of McIlroy, with a critique by John Gilbert. Workflow Implementing literate programming consists of two steps: Weaving: Generating a comprehensive document about the program and its maintenance. Tangling: Generating machine executable code Weaving and tangling are done on the same source so that they are consistent with each other. Example A classic example of literate programming is the literate implementation of the standard Unix wc word counting program. Knuth presented a CWEB version of this example in Chapter 12 of his Literate Programming book. The same example was later rewritten for the noweb literate programming tool. This example provides a good illustration of the basic elements of literate programming. Creation of macros The following snippet of the wc literate program shows how arbitrary descriptive phrases in a natural language are used in a literate program to create macros, which act as new "operators" in the literate programming language, and hide chunks of code or other macros. The mark-up notation consists of double angle brackets ("<<...>>") that indicate macros, the "@" symbol which indicates the end of the code section in a noweb file. The "<<*>>" symbol stands for the "root", topmost node the literate programming tool will start expanding the web of macros from. Actually, writing out the expanded source code can be done from any section or subsection (i.e. a piece of code designated as "<<name of the chunk>>=", with the equal sign), so one literate program file can contain several files with machine source code. The purpose of wc is to count lines, words, and/or characters in a list of files. The number of lines in a
|
also exhibits chaotic dynamics.) One can also consider values of in the interval , so that remains bounded on . Characteristics of the map Behavior dependent on The image below shows the amplitude and frequency content of some logistic map iterates for parameter values ranging from 2 to 4. By varying the parameter , the following behavior is observed: With between 0 and 1, the population will eventually die, independent of the initial population. With between 1 and 2, the population will quickly approach the value , independent of the initial population. With between 2 and 3, the population will also eventually approach the same value , but first will fluctuate around that value for some time. The rate of convergence is linear, except for , when it is dramatically slow, less than linear (see Bifurcation memory). With between 3 and 1 + ≈ 3.44949 the population will approach permanent oscillations between two values. These two values are dependent on and given by . With between 3.44949 and 3.54409 (approximately), from almost all initial conditions the population will approach permanent oscillations among four values. The latter number is a root of a 12th degree polynomial . With increasing beyond 3.54409, from almost all initial conditions the population will approach oscillations among 8 values, then 16, 32, etc. The lengths of the parameter intervals that yield oscillations of a given length decrease rapidly; the ratio between the lengths of two successive bifurcation intervals approaches the Feigenbaum constant . This behavior is an example of a period-doubling cascade. At is the onset of chaos, at the end of the period-doubling cascade. From almost all initial conditions, we no longer see oscillations of finite period. Slight variations in the initial population yield dramatically different results over time, a prime characteristic of chaos. Most values of beyond 3.56995 exhibit chaotic behaviour, but there are still certain isolated ranges of that show non-chaotic behavior; these are sometimes called islands of stability. For instance, beginning at 1 + (approximately 3.82843) there is a range of parameters that show oscillation among three values, and for slightly higher values of oscillation among 6 values, then 12 etc. The development of the chaotic behavior of the logistic sequence as the parameter varies from approximately 3.56995 to approximately 3.82843 is sometimes called the Pomeau–Manneville scenario, characterized by a periodic (laminar) phase interrupted by bursts of aperiodic behavior. Such a scenario has an application in semiconductor devices. There are other ranges that yield oscillation among 5 values etc.; all oscillation periods occur for some values of . A period-doubling window with parameter is a range of -values consisting of a succession of subranges. The th subrange contains the values of for which there is a stable cycle (a cycle that attracts a set of initial points of unit measure) of period . This sequence of sub-ranges is called a cascade of harmonics. In a sub-range with a stable cycle of period , there are unstable cycles of period for all . The value at the end of the infinite sequence of sub-ranges is called the point of accumulation of the cascade of harmonics. As rises there is a succession of new windows with different values. The first one is for ; all subsequent windows involving odd occur in decreasing order of starting with arbitrarily large . Beyond , almost all initial values eventually leave the interval and diverge. For any value of there is at most one stable cycle. If a stable cycle exists, it is globally stable, attracting almost all points. Some values of with a stable cycle of some period have infinitely many unstable cycles of various periods. The bifurcation diagram at right summarizes this. The horizontal axis shows the possible values of the parameter while the vertical axis shows the set of values of visited asymptotically from almost all initial conditions by the iterates of the logistic equation with that value. The bifurcation diagram is a self-similar: if we zoom in on the above-mentioned value and focus on one arm of the three, the situation nearby looks like a shrunk and slightly distorted version of the whole diagram. The same is true for all other non-chaotic points. This is an example of the deep and ubiquitous connection between chaos and fractals. We can also consider negative values of : For between -2 and -1 the logistic sequence also features chaotic behavior. With between -1 and 1 - and for 0 between 1/ and 1-1/, the population will approach permanent oscillations between two values, as with the case of between 3 and 1 + , and given by the same formula. Chaos and the logistic map The relative simplicity of the logistic map makes it a widely used point of entry into a consideration of the concept of chaos. A rough description of chaos is that chaotic systems exhibit a great sensitivity to initial conditions—a property of the logistic map for most values of between about 3.57 and 4 (as noted above). A common source of such sensitivity to initial conditions is that the map represents a repeated folding and stretching of the space on which it is defined. In the case of the logistic map, the quadratic difference equation describing it may be thought of as a stretching-and-folding operation on the interval . The following figure illustrates the stretching and folding over a sequence of iterates of the map. Figure (a), left, shows a two-dimensional Poincaré plot of the logistic map's state space for , and clearly shows the quadratic curve of the difference equation (). However, we can embed the same sequence in a three-dimensional state space, in order to investigate the deeper structure of the map. Figure (b), right, demonstrates this, showing how initially nearby points begin to diverge, particularly in those regions of corresponding to the steeper sections of the plot. This stretching-and-folding does not just produce a gradual divergence of the sequences of iterates, but an exponential divergence (see Lyapunov exponents), evidenced also by the complexity and unpredictability of the chaotic logistic map. In fact, exponential divergence of sequences of iterates explains the connection between chaos and unpredictability: a small error in the supposed initial state of the system will tend to correspond to a large error later in its evolution. Hence, predictions about future states become progressively (indeed, exponentially) worse when there are even very small errors in our knowledge of the initial state. This quality of unpredictability and apparent randomness led the logistic map equation to be used as a pseudo-random number generator in early computers. Since the map is confined to an interval on the real number line, its dimension is less than or equal to unity. Numerical estimates yield a correlation dimension of (Grassberger, 1983), a Hausdorff dimension of about 0.538 (Grassberger 1981), and an information dimension of approximately 0.5170976 (Grassberger 1983) for (onset of chaos). Note: It can be shown that the correlation dimension is certainly between 0.4926 and 0.5024. It is often possible, however, to
|
parameter while the vertical axis shows the set of values of visited asymptotically from almost all initial conditions by the iterates of the logistic equation with that value. The bifurcation diagram is a self-similar: if we zoom in on the above-mentioned value and focus on one arm of the three, the situation nearby looks like a shrunk and slightly distorted version of the whole diagram. The same is true for all other non-chaotic points. This is an example of the deep and ubiquitous connection between chaos and fractals. We can also consider negative values of : For between -2 and -1 the logistic sequence also features chaotic behavior. With between -1 and 1 - and for 0 between 1/ and 1-1/, the population will approach permanent oscillations between two values, as with the case of between 3 and 1 + , and given by the same formula. Chaos and the logistic map The relative simplicity of the logistic map makes it a widely used point of entry into a consideration of the concept of chaos. A rough description of chaos is that chaotic systems exhibit a great sensitivity to initial conditions—a property of the logistic map for most values of between about 3.57 and 4 (as noted above). A common source of such sensitivity to initial conditions is that the map represents a repeated folding and stretching of the space on which it is defined. In the case of the logistic map, the quadratic difference equation describing it may be thought of as a stretching-and-folding operation on the interval . The following figure illustrates the stretching and folding over a sequence of iterates of the map. Figure (a), left, shows a two-dimensional Poincaré plot of the logistic map's state space for , and clearly shows the quadratic curve of the difference equation (). However, we can embed the same sequence in a three-dimensional state space, in order to investigate the deeper structure of the map. Figure (b), right, demonstrates this, showing how initially nearby points begin to diverge, particularly in those regions of corresponding to the steeper sections of the plot. This stretching-and-folding does not just produce a gradual divergence of the sequences of iterates, but an exponential divergence (see Lyapunov exponents), evidenced also by the complexity and unpredictability of the chaotic logistic map. In fact, exponential divergence of sequences of iterates explains the connection between chaos and unpredictability: a small error in the supposed initial state of the system will tend to correspond to a large error later in its evolution. Hence, predictions about future states become progressively (indeed, exponentially) worse when there are even very small errors in our knowledge of the initial state. This quality of unpredictability and apparent randomness led the logistic map equation to be used as a pseudo-random number generator in early computers. Since the map is confined to an interval on the real number line, its dimension is less than or equal to unity. Numerical estimates yield a correlation dimension of (Grassberger, 1983), a Hausdorff dimension of about 0.538 (Grassberger 1981), and an information dimension of approximately 0.5170976 (Grassberger 1983) for (onset of chaos). Note: It can be shown that the correlation dimension is certainly between 0.4926 and 0.5024. It is often possible, however, to make precise and accurate statements about the likelihood of a future state in a chaotic system. If a (possibly chaotic) dynamical system has an attractor, then there exists a probability measure that gives the long-run proportion of time spent by the system in the various regions of the attractor. In the case of the logistic map with parameter and an initial state in , the attractor is also the interval and the probability measure corresponds to the beta distribution with parameters and . Specifically, the invariant measure is Unpredictability is not randomness, but in some circumstances looks very much like it. Hence, and fortunately, even if we know very little about the initial state of the logistic map (or some other chaotic system), we can still say something about the distribution of states arbitrarily far into the future, and use this knowledge to inform decisions based on the state of the system. Special cases of the map Upper bound when Although exact solutions to the recurrence relation are only available in a small number of cases, a closed-form upper bound on the logistic map is known when . There are two aspects of the behavior of the logistic map that should be captured by an upper bound in this regime: the asymptotic geometric decay with constant , and the fast initial decay when is close to 1, driven by the term in the recurrence relation. The following bound captures both of these effects: Solution when The special case of can in fact be solved exactly, as can the case with ; however, the general case can only be predicted statistically. The solution when is, where the initial condition parameter is given by For rational , after a finite number of iterations maps into a periodic sequence. But almost all are irrational, and, for irrational , never repeats itself – it is non-periodic. This solution equation clearly demonstrates the two key features of chaos – stretching and folding: the factor shows the exponential growth of stretching, which results in sensitive dependence on initial conditions, while the squared sine function keeps folded within the range . For an equivalent solution in terms of complex numbers instead of trigonometric functions is where is either of the complex numbers with modulus equal to 1. Just as the squared sine function in the trigonometric solution leads to neither shrinkage nor expansion of the set of points visited, in the latter solution this effect is accomplished by the unit modulus of . By contrast, the solution when is for . Since for any value of other than the unstable fixed point 0, the term goes to 0 as goes to infinity, so goes to the stable fixed point . Finding cycles of any length when For the case, from almost all initial conditions the iterate sequence is chaotic. Nevertheless,
|
used by the organization known as ISIL, ISIS, and other names, though there is disagreement as to whether this translation is accurate. In archaeology: a definition In The Oxford Handbook of the Archaeology of the Levant: c. 8000–332 BCE (OHAL; 2013), the definition of the Levant for the specific purposes of the book is synonymous to that of the Arabic "bilad al-sham, 'the land of sham [Syria]'", translating in Western parlance to greater Syria. OHAL defines the boundaries of the Levant as follows. To the north: the Taurus Mountains or the Plain of 'Amuq To the east: the eastern deserts, i.e. (from north to south) the Euphrates and the Jebel el-Bishrī area for the northern Levant, followed by the Syrian Desert east of the eastern hinterland of the Anti-Lebanon range (whose southernmost part is Mount Hermon), and Transjordan's highlands and eastern desert (also discussed at Syrian Desert, also known as the Badia region). In other words, Mesopotamia and the North Arabian Desert. To the south: Wadi al-Arish in Sinai To the west: the Mediterranean Sea Subregions A distinction is made between the main subregions of the Levant, the northern and the southern: The Litani River marks the division between the Northern Levant and the Southern Levant. The island of Cyprus is also included as a third subregion in the archaeological region of the Levant: Cyprus, geographically distinct from the Levant, is included due to its proximity and natural resources (copper in particular), which induced close cultural ties. History Demographics and religion The largest religious group in the Levant are the Muslims and the largest cultural-linguistic group are Arabs. Muslim Arabs became the majority due to the Muslim conquest of the Levant in the 7th century and subsequent Arabization of the region. The majority of Muslim Levantines are Sunni with Alawi and Shia minorities. Other large ethnic groups in the Levant include Jews, Maronites, Kurds, Turks, Turkmens, Antiochian Greeks, Assyrians, Yazidi Kurds, Druze and Armenians. There are many Levantine Christian groups such as Greek, Oriental Orthodox (mainly Syriac Orthodox, Coptic, Georgian, and Maronite), Roman Catholic, Nestorian, and Protestant. Armenians mostly belong to the Armenian Apostolic Church. There are Levantines or Franco-Levantines who are mostly Roman Catholic. There are also Circassians, Turks, Samaritans, and Nawars. There are Assyrian peoples belonging to the Assyrian Church of the East (autonomous) and the Chaldean Catholic Church (Catholic). In addition, this region has a number of sites that are of religious significance, such as Al-Aqsa Mosque, Antioch in Hatay, the Church of the Holy Sepulchre, and the Western Wall in Jerusalem. Language Most populations in the Levant speak Levantine Arabic (, ), usually classified as the varieties North Levantine Arabic in Lebanon, Syria, and parts of Turkey, and South Levantine Arabic in Palestine and Jordan. Each of these encompasses a spectrum of regional or urban/rural variations. In addition to the varieties normally grouped together as "Levantine", a number of other varieties and dialects of Arabic are spoken in the Levant area, such as Levantine Bedawi Arabic and Mesopotamian Arabic. Among the languages of Israel, the official language is Hebrew; Arabic was until July 19, 2018, also an official language. The Arab minority, in 2018 about 21% of the population of Israel, speaks a dialect of Levantine Arabic essentially indistinguishable from the forms spoken in the Palestinian territories.
|
the Mediterranean in the 1570s, and the English merchant company signed its agreement ("capitulations") with the Ottoman Sultan in 1579. The English Levant Company was founded in 1581 to trade with the Ottoman Empire, and in 1670 the French Compagnie du Levant was founded for the same purpose. At this time, the Far East was known as the "Upper Levant". In early 19th-century travel writing, the term sometimes incorporated certain Mediterranean provinces of the Ottoman empire, as well as independent Greece (and especially the Greek islands). In 19th-century archaeology, it referred to overlapping cultures in this region during and after prehistoric times, intending to reference the place instead of any one culture. The French mandate of Syria and Lebanon (1920–1946) was called the Levant states. Geography and modern-day use of the term Today, "Levant" is the term typically used by archaeologists and historians with reference to the history of the region. Scholars have adopted the term Levant to identify the region due to it being a "wider, yet relevant, cultural corpus" that does not have the "political overtones" of Syria-Palestine. The term is also used for modern events, peoples, states or parts of states in the same region, namely Cyprus, Egypt, Iraq, Israel, Jordan, Lebanon, Palestine, Syria, and Turkey are sometimes considered Levant countries (compare with Near East, Middle East, Eastern Mediterranean and Western Asia). Several researchers include the island of Cyprus in Levantine studies, including the Council for British Research in the Levant, the UCLA Near Eastern Languages and Cultures department, Journal of Levantine Studies and the UCL Institute of Archaeology, the last of which has dated the connection between Cyprus and mainland Levant to the early Iron Age. Archaeologists seeking a neutral orientation that is neither biblical nor national have used terms such as Levantine archaeology and archaeology of the Southern Levant. While the usage of the term "Levant" in academia has been restricted to the fields of archeology and literature, there is a recent attempt to reclaim the notion of the Levant as a category of analysis in political and social sciences. Two academic journals were launched in the early 2010s using the word: the Journal of Levantine Studies, published by the Van Leer Jerusalem Institute and The Levantine Review, published by Boston College. The word Levant has been used in some translations of the term ash-Shām as used by the organization known as ISIL, ISIS, and other names, though there is disagreement as to whether this translation is accurate. In archaeology: a definition In The Oxford Handbook of the Archaeology of the Levant: c. 8000–332 BCE (OHAL; 2013), the definition of the Levant for the specific purposes of the book is synonymous to that of the Arabic "bilad al-sham, 'the land of sham [Syria]'", translating in Western parlance to greater Syria. OHAL defines the boundaries of the Levant as follows. To the north: the Taurus Mountains or the Plain of 'Amuq To the east: the eastern deserts, i.e. (from north to south) the Euphrates and the Jebel el-Bishrī area for the northern Levant, followed by the Syrian Desert east of the eastern hinterland of the Anti-Lebanon range (whose southernmost part is Mount Hermon), and Transjordan's highlands and eastern desert (also discussed at Syrian Desert, also known as the Badia region). In other words, Mesopotamia and the North Arabian Desert. To the south: Wadi al-Arish in Sinai To the west: the Mediterranean Sea Subregions A distinction is made between the main subregions of the Levant, the northern and the southern: The Litani River marks the division between the Northern Levant and the Southern Levant. The island of Cyprus is also included as a third subregion in the archaeological region of the Levant: Cyprus, geographically distinct from the Levant, is included due to its proximity and natural resources (copper in particular), which induced close cultural ties. History Demographics and religion The largest religious group in the Levant are the Muslims and the largest cultural-linguistic group are Arabs. Muslim Arabs became the majority due
|
as (protectorates or territories), which were deemed to require a greater level of control by the mandatory power: "...the Mandatory must be responsible for the administration of the territory under conditions which will guarantee freedom of conscience and religion." The mandatory power was forbidden to construct military or naval bases within the mandates. The Class C mandates, including South West Africa and certain of the South Pacific Islands, were considered to be "best administered under the laws of the Mandatory as integral portions of its territory" List of mandates Column header abbreviations: C = Class, sov. = sovereignty Rules of establishment According to the Council of the League of Nations, meeting of August 1920: "draft mandates adopted by the Allied and Associated Powers would not be definitive until they had been considered and approved by the League ... the legal title held by the mandatory Power must be a double one: one conferred by the Principal Powers and the other conferred by the League of Nations," Three steps were required to establish a Mandate under international law: (1) The Principal Allied and Associated Powers confer a mandate on one of their number or on a third power; (2) the principal powers officially notify the council of the League of Nations that a certain power has been appointed mandatory for such a certain defined territory; and (3) the council of the League of Nations takes official cognisance of the appointment of the mandatory power and informs the latter that it [the council] considers it as invested with the mandate, and at the same time notifies it of the terms of the mandate, after ascertaining whether they are in conformance with the provisions of the covenant." The U.S. State Department Digest of International Law says that the terms of the Treaty of Lausanne provided for the application of the principles of state succession to the "A" Mandates. The Treaty of Versailles (1920) provisionally recognised the former Ottoman communities as independent nations. It also required Germany to recognise the disposition of the former Ottoman territories and to recognise the new states laid down within their boundaries. The terms of the Treaty of Lausanne (1923) required the newly created states that acquired the territory detached from the Ottoman Empire to pay annuities on the Ottoman public debt and to assume responsibility for the administration of concessions that had been granted by the Ottomans. The treaty also let the States acquire, without payment, all the property and possessions of the Ottoman Empire situated within their territory. The treaty provided that the League of Nations was responsible for establishing an arbitral court to resolve disputes that might arise and stipulated that its decisions were final. A disagreement regarding the legal status and the portion of the annuities to be paid by the "A" mandates was settled when an Arbitrator ruled that some of the mandates contained more than one State:The difficulty arises here how one is to regard the Asiatic countries under the British and French mandates. Iraq is a Kingdom in regard to which Great Britain has undertaken responsibilities equivalent to those of a Mandatory Power. Under the British mandate, Palestine and Transjordan have each an entirely
|
C mandates, including South West Africa and certain of the South Pacific Islands, were considered to be "best administered under the laws of the Mandatory as integral portions of its territory" List of mandates Column header abbreviations: C = Class, sov. = sovereignty Rules of establishment According to the Council of the League of Nations, meeting of August 1920: "draft mandates adopted by the Allied and Associated Powers would not be definitive until they had been considered and approved by the League ... the legal title held by the mandatory Power must be a double one: one conferred by the Principal Powers and the other conferred by the League of Nations," Three steps were required to establish a Mandate under international law: (1) The Principal Allied and Associated Powers confer a mandate on one of their number or on a third power; (2) the principal powers officially notify the council of the League of Nations that a certain power has been appointed mandatory for such a certain defined territory; and (3) the council of the League of Nations takes official cognisance of the appointment of the mandatory power and informs the latter that it [the council] considers it as invested with the mandate, and at the same time notifies it of the terms of the mandate, after ascertaining whether they are in conformance with the provisions of the covenant." The U.S. State Department Digest of International Law says that the terms of the Treaty of Lausanne provided for the application of the principles of state succession to the "A" Mandates. The Treaty of Versailles (1920) provisionally recognised the former Ottoman communities as independent nations. It also required Germany to recognise the disposition of the former Ottoman territories and to recognise the new states laid down within their boundaries. The terms of the Treaty of Lausanne (1923) required the newly created states that acquired the territory detached from the Ottoman Empire to pay annuities on the Ottoman public debt and to assume responsibility for the administration of concessions that had been granted by the Ottomans. The treaty also let the States acquire, without payment, all the property and possessions of the Ottoman Empire situated within their territory. The treaty provided that the League of Nations was responsible for establishing an arbitral court to resolve disputes that might arise and stipulated that its decisions were final. A disagreement regarding the legal status and the portion of the annuities to be paid by the "A" mandates was settled when an Arbitrator ruled that some of the mandates contained more than one State:The difficulty arises here how one is to regard the Asiatic countries under the British and French mandates. Iraq is a Kingdom in regard to which Great Britain has undertaken responsibilities equivalent to those of a Mandatory Power. Under the British mandate, Palestine and Transjordan have each an entirely separate organization. We are, therefore, in the presence of three States sufficiently separate to be considered as distinct Parties. France has received a single mandate from the Council of the League of Nations, but in the countries subject to that mandate, one can distinguish two distinct States: Syria and the Lebanon, each State possessing its own constitution and a nationality clearly different from the other. Later history After the United Nations was founded in
|
is popularly known as Laconia, the location of the race was moved from Belknap Recreation Area to Loudon in 1964. References Motorsport
|
Hampshire International Speedway) is the longest running motorcycle race in the United States, and is held every year on Father's Day. While it is
|
is home to the New Hampshire Highland Games and to a portion of Franconia Notch State Park. Set in the White Mountains, large portions of the town are within the White Mountain National Forest. The Appalachian Trail crosses the western and northeastern parts of the town. Lincoln is the location of Loon Mountain Ski Resort and associated recreation-centered development. The primary settlement in town, where 969 people resided at the 2020 census, is defined as the Lincoln census-designated place (CDP) and is located along New Hampshire Route 112 east of Interstate 93. The town also includes the former village sites of Stillwater and Zealand (sometimes known as Pullman) in the town's remote eastern and northern sections respectively, which are now within the White Mountain National Forest. History In 1764, colonial Governor Benning Wentworth granted to a group of approximately 70 land investors from Connecticut. Lincoln was named after Henry Fiennes Pelham-Clinton, 2nd Duke of Newcastle, 9th Earl of Lincoln – a cousin of the Wentworth governors. He held the position of comptroller of customs for the port of London under King George II and George III, which was important to trade between America and England. The town was settled about 1782. The 1790 census indicates that it had 22 inhabitants. Rocky soil yielded poor farming, but the area's abundant timber, combined with water power to run sawmills on the Pemigewasset River and its East Branch, helped Lincoln develop into a center for logging. By 1853, the Merrimack River Lumber Company was operating. The railroad transported freight, and increasingly brought tourists to the beautiful mountain region. In 1892, James Everell Henry (1831–1912) bought approximately of virgin timber and established a logging enterprise at what is today the center of Lincoln. In 1902, he built a pulp and paper mill. He erected the Lincoln House hotel in 1903, although a 1907 fire would nearly raze the community. Until he died in 1912, Henry controlled his company town, installing relatives in positions of civic authority. In 1917, Henry's heirs sold the business to the Parker Young Company, which in turn sold it to the Marcalus Manufacturing Company in 1946. Franconia Paper took over in 1950, producing 150 tons of paper a day until bankruptcy in 1971, at which time new river classification standards discouraged further papermaking in Lincoln. Tourism is today the principal business. Nearby Loon Mountain has long drawn skiers, and in recent years has attempted to convert itself into a four-season attraction. The Flume is one of the most visited attractions in the state. Discovered in 1808, it is a natural canyon extending at the base of Mount Liberty. Walls of Conway granite rise to a height of and are only apart. Geography According to the
|
today the center of Lincoln. In 1902, he built a pulp and paper mill. He erected the Lincoln House hotel in 1903, although a 1907 fire would nearly raze the community. Until he died in 1912, Henry controlled his company town, installing relatives in positions of civic authority. In 1917, Henry's heirs sold the business to the Parker Young Company, which in turn sold it to the Marcalus Manufacturing Company in 1946. Franconia Paper took over in 1950, producing 150 tons of paper a day until bankruptcy in 1971, at which time new river classification standards discouraged further papermaking in Lincoln. Tourism is today the principal business. Nearby Loon Mountain has long drawn skiers, and in recent years has attempted to convert itself into a four-season attraction. The Flume is one of the most visited attractions in the state. Discovered in 1808, it is a natural canyon extending at the base of Mount Liberty. Walls of Conway granite rise to a height of and are only apart. Geography According to the United States Census Bureau, the town has a total area of , of which are land and are water, comprising 0.43% of the town. It is the second-largest town in area in New Hampshire, after Pittsburg. Lincoln is drained by the Pemigewasset River and its East Branch. Lincoln lies almost fully within the Merrimack River watershed, with the western edge of town in the Connecticut River watershed. Kancamagus Pass, elevation , is on the Kancamagus Highway at the eastern boundary. The highest point in Lincoln is the summit of Mount Bond at above sea level. Demographics As of the census of 2010, there were 1,662 people, 794 households, and 439 families residing in the town. There were 2,988 housing units, of which 2,194, or 73.4%, were vacant. 2,083 of the vacant units were for seasonal or recreational use. The
|
infantry. Lasers used for this purpose are usually infrared lasers, so the enemy cannot easily detect the guiding laser light. Firearms Laser sight The laser has in most firearms applications been used as a tool to enhance the targeting of other weapon systems. For example, a laser sight'' is a small, usually visible-light laser placed on a handgun or a rifle and aligned to emit a beam parallel to the barrel. Since a laser beam has low divergence, the laser light appears as a small spot even at long distances; the user places the spot on the desired target and the barrel of the gun is aligned (but not necessarily allowing for bullet drop, windage, distance between the direction of the beam and the axis of the barrel, and the target mobility while the bullet travels). Most laser sights use a red laser diode. Others use an infrared diode to produce a dot invisible to the naked human eye but detectable with night vision devices. The firearms adaptive target acquisition module LLM01 laser light module combines visible and infrared laser diodes. In the late 1990s, green diode pumped solid state laser (DPSS) laser sights (532 nm) became available. Eye-targeted lasers A non-lethal laser weapon was developed by the U.S. Air Force to temporarily impair an adversary's ability to fire a weapon or to otherwise threaten enemy forces. This unit illuminates an opponent with harmless low-power laser light and can have the effect of dazzling or disorienting the subject or causing them to flee. Several types of dazzlers are now available, and some have been used in combat. There remains the possibility of using lasers to blind, since this requires relatively low power levels and is easily achievable in a man-portable unit. However, most nations regard the deliberate permanent blinding of the enemy as forbidden by the rules of war (see Protocol on Blinding Laser Weapons). Although several nations have developed blinding laser weapons, such as China's ZM-87, none of these are believed to have made it past the prototype stage. In addition to the applications that cross over with military applications, a widely known law enforcement use of lasers is for lidar to measure the speed of vehicles. Holographic weapon sight A holographic weapon sight uses a laser diode to illuminate a hologram of a reticle built into a flat glass optical window of the sight. The user looks through the optical window and sees a cross hair reticle image superimposed at a distance on the field of view. Medical Cosmetic surgery (removing tattoos, scars, stretch marks, sunspots, wrinkles, birthmarks, and hairs): see laser hair removal. Laser types used in dermatology include ruby (694 nm), alexandrite (755 nm), pulsed diode array (810 nm), Nd:YAG (1064 nm), Ho:YAG (2090 nm), and Er:YAG (2940 nm). Eye surgery and refractive surgery Soft tissue surgery: CO2, Er:YAG laser Laser scalpel (General surgery, gynecological, urology, laparoscopic) Photobiomodulation (i.e. laser therapy) "No-Touch" removal of tumors, especially of the brain and spinal cord. In dentistry for caries removal, endodontic/periodontic procedures, tooth whitening, and oral surgery Cancer treatment Burn and surgical scar management: scar contracture CO2 (especially the newer fractionated CO2 lasers), redness and itch (Pulsed Dye laser - PDL), post-inflammatory hyper-pigmentation (Q-switched lasers :Ruby, Alexandrite), burn scar unwanted hair growth and trapped hairs (Ruby, IPL and numerous hair removal lasers) Industrial and commercial Industrial laser applications can be divided into two categories depending on the power of the laser: material processing and micro-material processing. In material processing, lasers with average optical power above 1 kilowatt are used mainly for industrial materials processing applications. Beyond this power threshold there are thermal issues related to the optics that separate these lasers from their lower-power counterparts. Laser systems in the 50-300W range are used primarily for pumping, plastic welding and soldering applications. Lasers above 300W are used in brazing, thin metal welding, and sheet metal cutting applications. The required brightness (as measured in by the beam parameter product) is higher for cutting applications than for brazing and thin metal welding. High power applications, such as hardening, cladding, and deep penetrating welding, require multiple kW of optical power, and are used in a broad range of industrial processes. Micro material processing is a category that includes all laser material processing applications under 1 kilowatt. The use of lasers in Micro Materials Processing has found broad application in the development and manufacturing of screens for smartphones, tablet computers, and LED TVs. A detailed list of industrial and commercial laser applications includes: Laser cutting Laser welding Laser drilling Laser marking Laser cleaning Laser cladding, a surface engineering process applied to mechanical components for reconditioning, repair work or hardfacing Photolithography Optical communications over optical fiber or in free space Laser peening Guidance systems (e.g., ring laser gyroscopes) Laser rangefinder / surveying, Lidar / pollution monitoring, Digital minilabs Barcode readers Laser engraving of printing plate Laser bonding of additive marking materials for decoration and identification, Laser pointers Laser mice Laser accelerometers OLED display manufacturing Holography Bubblegrams Optical tweezers Writing subtitles onto motion picture films. Power beaming, which is a possible solution to transfer energy to the climber of a Space elevator 3D laser scanners for accurate 3D measurement Laser line levels are used in surveying and construction. Lasers are also used for guidance for aircraft. Extensively in both consumer and industrial imaging equipment. In laser printers: gas and diode lasers play a key role in manufacturing high resolution printing plates and in image scanning equipment. Diode lasers are used as a lightswitch in industry, with a laser beam and a receiver which will switch on or off when the beam is interrupted, and because a laser can keep the light intensity over larger distances than a normal light, and is more precise than a normal light it can be used for product detection in automated production. Laser alignment Additive manufacturing Plastic welding Metrology - handheld and robotic laser systems for Aerospace, Automotive and Rail applications To store and retrieve data in optical discs, such as CDs and DVDs Blu-ray Entertainment and recreation Laser lighting displays accompany many music concerts Laser tag Laser harp: a musical instrument were
|
are used in many ways, including: A wide variety of interferometric techniques Raman spectroscopy Laser induced breakdown spectroscopy Atmospheric remote sensing Investigating nonlinear optics phenomena Holographic techniques employing lasers also contribute to a number of measurement techniques. Laser based lidar (LIght raDAR) technology has application in geology, seismology, remote sensing and atmospheric physics. Lasers have been used aboard spacecraft such as in the Cassini-Huygens mission. In astronomy, lasers have been used to create artificial laser guide stars, used as reference objects for adaptive optics telescopes. Lasers may also be indirectly used in spectroscopy as a micro-sampling system, a technique termed Laser ablation (LA), which is typically applied to ICP-MS apparatus resulting in the powerful LA-ICP-MS. The principles of laser spectroscopy are discussed by Demtröder. Spectroscopy Most types of laser are an inherently pure source of light; they emit near-monochromatic light with a very well defined range of wavelengths. By careful design of the laser components, the purity of the laser light (measured as the "linewidth") can be improved more than the purity of any other light source. This makes the laser a very useful source for spectroscopy. The high intensity of light that can be achieved in a small, well collimated beam can also be used to induce a nonlinear optical effect in a sample, which makes techniques such as Raman spectroscopy possible. Other spectroscopic techniques based on lasers can be used to make extremely sensitive detectors of various molecules, able to measure molecular concentrations in the parts-per-1012 (ppt) level. Due to the high power densities achievable by lasers, beam-induced atomic emission is possible: this technique is termed Laser induced breakdown spectroscopy (LIBS). Heat treatment Heat treating with the lasers allows selective surface hardening against wear with little or no distortion of the component. Because this eliminates much part reworking that is currently done, the laser system's capital cost is recovered in a short time. An inert, absorbent coating for laser heat treatment has also been developed that eliminates the fumes generated by conventional paint coatings during the heat-treating process with CO2 laser beams. One consideration crucial to the success of a heat treatment operation is control of the laser beam irradiance on the part surface. The optimal irradiance distribution is driven by the thermodynamics of the laser-material interaction and by the part geometry. Typically, irradiances between 500-5000 W/cm^2 satisfy the thermodynamic constraints and allow the rapid surface heating and minimal total heat input required. For general heat treatment, a uniform square or rectangular beam is one of the best options. For some special applications or applications where the heat treatment is done on an edge or corner of the part, it may be better to have the irradiance decrease near the edge to prevent melting. Weather Research shows that scientists may one day be able to induce rain and lightning storms (as well as micro-manipulating some other weather phenomena) using high energy lasers. Such a breakthrough could potentially eradicate droughts, help alleviate weather related catastrophes, and allocate weather resources to areas in need. Lunar laser ranging When the Apollo astronauts visited the moon, they planted retroreflector arrays to make possible the Lunar Laser Ranging Experiment. Laser beams are focused through large telescopes on Earth aimed toward the arrays, and the time taken for the beam to be reflected back to Earth measured to determine the distance between the Earth and Moon with high accuracy. Photochemistry Some laser systems, through the process of mode locking, can produce extremely brief pulses of light - as short as picoseconds or femtoseconds (10−12 - 10−15 seconds). Such pulses can be used to initiate and analyze chemical reactions, a technique known as photochemistry. The short pulses can be used to probe the process of the reaction at a very high temporal resolution, allowing the detection of short-lived intermediate molecules. This method is particularly useful in biochemistry, where it is used to analyse details of protein folding and function. Laser scanner Laser barcode scanners are ideal for applications that require high speed reading of linear codes or stacked symbols. Laser cooling A technique that has recent success is laser cooling. This involves atom trapping, a method where a number of atoms are confined in a specially shaped arrangement of electric and magnetic fields. Shining particular wavelengths of light at the ions or atoms slows them down, thus cooling them. As this process is continued, they all are slowed and have the same energy level, forming an unusual arrangement of matter known as a Bose–Einstein condensate. Nuclear fusion Some of the world's most powerful and complex arrangements of multiple lasers and optical amplifiers are used to produce extremely high intensity pulses of light of extremely short duration, e.g. laboratory for laser energetics, National Ignition Facility, GEKKO XII, Nike laser, Laser Mégajoule, HiPER. These pulses are arranged such that they impact pellets of tritium–deuterium simultaneously from all directions, hoping that the squeezing effect of the impacts will induce atomic fusion in the pellets. This technique, known as "inertial confinement fusion", so far has not been able to achieve "breakeven", that is, so far the fusion reaction generates less power than is used to power the lasers, but research continues. Microscopy Confocal laser scanning microscopy and Two-photon excitation microscopy make use of lasers to obtain blur-free images of thick specimens at various depths. Laser capture microdissection use lasers to procure specific cell populations from a tissue section under microscopic visualization. Additional laser microscopy techniques include harmonic microscopy, four-wave mixing microscopy and interferometric microscopy. Military Directly as an energy weapon A laser weapon is directed-energy weapon based on lasers. Defensive countermeasures Defensive countermeasure applications can range from compact, low power infrared countermeasures to high power, airborne laser systems. IR countermeasure systems use lasers to confuse the seeker heads on infrared homing missiles. Disorientation Some weapons simply use a laser to disorient a person. One such weapon is the Thales Green Laser Optical Warner. Guidance Laser guidance is a technique of guiding a missile or other projectile or vehicle to a target by means of a laser beam. Target designator Another military use of lasers is as a laser target designator. This is a low-power laser pointer used to indicate a target for a precision-guided munition, typically launched from an aircraft. The guided munition adjusts its flight-path to home in to the laser light reflected by the target, enabling a great precision in aiming. The beam of the laser target designator is set to a pulse rate that matches that set on the guided munition to ensure munitions strike their designated targets and do not follow other laser beams which may be in use in the area. The laser designator can
|
the topspinner (which turns less and bounces higher in the cricket pitch), the arm ball (which does not turn at all, drifts into a right-handed batsman in the direction of the bowler's arm movement; also called a 'floater') and the left-arm spinner's version of a doosra (which turns the other way). Notable slow left arm orthodox spin bowlers Players listed below have been included as they meet specific criteria which the general cricketing public would recognise as having achieved significant success in the art of left-arm orthodox spin bowling. For example, leading wicket-takers, and inventors of new deliveries. Rangana Herath – 433 Test wickets Daniel Vettori – 362 Test wickets and 305 ODI wickets Derek Underwood – 297 Test wickets Bishan Singh Bedi – 266 Test wickets Ravindra Jadeja – 223 Test wickets and 188 ODI wickets Shakib Al Hasan - 215 Test wickets, 115 T20I wickets and 277 ODI wickets Ravi
|
not turn at all, drifts into a right-handed batsman in the direction of the bowler's arm movement; also called a 'floater') and the left-arm spinner's version of a doosra (which turns the other way). Notable slow left arm orthodox spin bowlers Players listed below have been included as they meet specific criteria which the general cricketing public would recognise as having achieved significant success in the art of left-arm orthodox spin bowling. For example, leading wicket-takers, and inventors of new deliveries. Rangana Herath – 433 Test wickets Daniel Vettori – 362 Test wickets and 305 ODI wickets Derek Underwood – 297 Test wickets Bishan Singh Bedi – 266 Test wickets Ravindra Jadeja – 223 Test wickets and 188 ODI wickets Shakib Al Hasan - 215 Test wickets, 115 T20I wickets and 277 ODI wickets Ravi Shastri – 151 Test wickets Keshav Maharaj - 129 Test Wickets Ashley Giles- 143 Test wickets Taijul Islam- 134 Test wickets Jess Jonassen – 109 WODI wickets and 71 WT20I wickets Sophie Ecclestone - 64 WT20I wickets Ajaz Patel - Only left
|
hundreds if not thousands of different gain media in which laser operation has been achieved (see list of laser types for a list of the most important ones). The gain medium is excited by the pump source to produce a population inversion, and it is in the gain medium where spontaneous and stimulated emission of photons takes place, leading to the phenomenon of optical gain, or amplification. Examples of different gain media include: Liquids, such as dye lasers. These are usually organic chemical solvents, such as methanol, ethanol or ethylene glycol, to which are added chemical dyes such as coumarin, rhodamine, and fluorescein. The exact chemical configuration of the dye molecules determines the operation wavelength of the dye laser. Gases, such as carbon dioxide, argon, krypton and mixtures such as helium–neon. These lasers are often pumped by electrical discharge. Solids, such as crystals and glasses. The solid host materials are usually doped with an impurity such as chromium, neodymium, erbium or titanium ions. Typical hosts include YAG (yttrium aluminium garnet), YLF (yttrium lithium fluoride), sapphire (aluminium oxide) and various glasses. Examples of solid-state laser media include Nd:YAG, Ti:sapphire, Cr:sapphire (usually known as ruby), Cr:LiSAF (chromium-doped lithium strontium aluminium fluoride), Er:YLF, Nd:glass, and Er:glass. Solid-state lasers are usually pumped by flashlamps or light from another laser. Semiconductors, a type of solid, crystal with uniform dopant distribution or material with differing dopant levels in which the movement of electrons can cause laser action. Semiconductor lasers are typically very small, and can be pumped with a simple electric current, enabling them to be used in consumer devices such as compact disc players. See laser diode. Optical resonator The optical resonator, or optical cavity, in its simplest form is two parallel mirrors placed around the gain medium, which provide feedback of the light. The mirrors are given optical coatings which determine their reflective properties. Typically, one will be a high reflector, and the other will be a partial reflector. The latter is called the output coupler, because it allows some of the light to leave the cavity to produce the laser's output beam. Light from the medium, produced by spontaneous emission, is reflected by the mirrors back into the medium, where it may be amplified by
|
lasers. These are usually organic chemical solvents, such as methanol, ethanol or ethylene glycol, to which are added chemical dyes such as coumarin, rhodamine, and fluorescein. The exact chemical configuration of the dye molecules determines the operation wavelength of the dye laser. Gases, such as carbon dioxide, argon, krypton and mixtures such as helium–neon. These lasers are often pumped by electrical discharge. Solids, such as crystals and glasses. The solid host materials are usually doped with an impurity such as chromium, neodymium, erbium or titanium ions. Typical hosts include YAG (yttrium aluminium garnet), YLF (yttrium lithium fluoride), sapphire (aluminium oxide) and various glasses. Examples of solid-state laser media include Nd:YAG, Ti:sapphire, Cr:sapphire (usually known as ruby), Cr:LiSAF (chromium-doped lithium strontium aluminium fluoride), Er:YLF, Nd:glass, and Er:glass. Solid-state lasers are usually pumped by flashlamps or light from another laser. Semiconductors, a type of solid, crystal with uniform dopant distribution or material with differing dopant levels in which the movement of electrons can cause laser action. Semiconductor lasers are typically very small, and can be pumped with a simple electric current, enabling them to be used in consumer devices such as compact disc players. See laser diode. Optical resonator The optical resonator, or optical cavity, in its simplest form is two parallel mirrors placed around the gain medium, which provide feedback of the light. The mirrors are given optical coatings which determine their reflective properties. Typically, one will be a high reflector, and the other will be a partial reflector. The latter is called the output coupler, because it allows some of the light to leave the cavity to produce the laser's output beam. Light from the medium, produced by spontaneous emission, is reflected by the mirrors back into the medium, where it may be amplified by stimulated emission. The light may reflect from the mirrors and thus pass through the gain medium many hundreds of times before exiting the cavity. In more complex lasers, configurations with four or more mirrors forming the cavity are used. The design and alignment of the mirrors with respect to the medium is crucial for determining the exact operating wavelength and other attributes of the laser system. Other optical devices, such as spinning mirrors, modulators, filters, and absorbers,
|
valid, simple argument form. Intuitively, it permits the inference from any conjunction of either element of that conjunction. A and B. Therefore, A. ...or alternatively, A and B. Therefore, B. In logical operator notation: ...or alternatively, Negation Definition A conjunction is proven false by establishing either or . In terms of the object language, this reads This formula can be seen as a special case of when is a false proposition. Other proof strategies If implies , then both as well as prove the conjunction false: In other words, a conjunction can actually be proven false just by knowing about the relation of its conjuncts, and not necessary about their truth values. This formula can be seen as a special case of when is a false proposition. Either of the above are constructively valid proofs by contradiction. Properties commutativity: yes associativity: yes distributivity: with various operations, especially with or idempotency: yes monotonicity: yes truth-preserving: yesWhen all inputs are true, the output is true. falsehood-preserving: yesWhen all inputs are false, the output is false. Walsh spectrum: (1,-1,-1,1) Nonlinearity: 1 (the function is bent) If using binary values for true (1) and false (0), then logical conjunction works exactly like normal arithmetic multiplication. Applications in computer engineering In high-level computer programming and digital electronics, logical conjunction is commonly represented by an infix operator, usually as a keyword such as "AND", an algebraic multiplication, or the ampersand symbol & (sometimes doubled as in &&). Many languages also provide short-circuit control structures corresponding to logical conjunction. Logical conjunction is often used for bitwise operations, where 0 corresponds to false and 1 to true: 0 AND 0 = 0, 0 AND 1 = 0, 1 AND 0 = 0, 1 AND 1 = 1. The operation can also be applied to two binary words viewed as bitstrings of equal length, by taking the bitwise AND of each pair of bits at corresponding positions. For example: 11000110 AND 10100011 = 10000010. This
|
rule of inference, conjunction introduction is a classically valid, simple argument form. The argument form has two premises, A and B. Intuitively, it permits the inference of their conjunction. A, B. Therefore, A and B. or in logical operator notation: Here is an example of an argument that fits the form conjunction introduction: Bob likes apples. Bob likes oranges. Therefore, Bob likes apples and Bob likes oranges. Conjunction elimination is another classically valid, simple argument form. Intuitively, it permits the inference from any conjunction of either element of that conjunction. A and B. Therefore, A. ...or alternatively, A and B. Therefore, B. In logical operator notation: ...or alternatively, Negation Definition A conjunction is proven false by establishing either or . In terms of the object language, this reads This formula can be seen as a special case of when is a false proposition. Other proof strategies If implies , then both as well as prove the conjunction false: In other words, a conjunction can actually be proven false just by knowing about the relation of its conjuncts, and not necessary about their truth values. This formula can be seen as a special case of when is a false proposition. Either of the above are constructively valid proofs by contradiction. Properties commutativity: yes associativity: yes distributivity: with various operations, especially with or idempotency: yes monotonicity: yes truth-preserving: yesWhen all inputs are true, the output is true. falsehood-preserving: yesWhen all inputs are false, the output is false. Walsh spectrum: (1,-1,-1,1) Nonlinearity: 1 (the function is bent) If using binary values for true (1) and false (0), then logical conjunction works exactly like normal arithmetic multiplication. Applications in computer engineering In high-level computer programming and digital electronics, logical conjunction is commonly represented by an infix operator, usually as a keyword such as "AND", an algebraic multiplication, or the ampersand symbol & (sometimes doubled as in &&). Many languages also provide short-circuit control structures corresponding to logical conjunction. Logical conjunction is often used for bitwise operations, where 0 corresponds to false and 1 to true: 0 AND 0 = 0, 0 AND 1 = 0, 1 AND 0 = 0, 1 AND 1 = 1. The operation can also be applied to two binary words viewed as bitstrings of equal length, by taking the bitwise AND of each pair of bits at corresponding positions. For example: 11000110 AND 10100011 = 10000010. This can be used to select part of a bitstring using a bit mask. For example, 10011101 AND 00001000 = 00001000 extracts the fifth bit of an 8-bit
|
in 1908; ↔ was used at least by Tarski in 1940; ⇔ was used in Vax; other symbols appeared punctually in the history, such as ⊃⊂ in Gentzen, ~ in Schönfinkel or ⊂⊃ in Chazal. True: the symbol 1 comes from Boole's interpretation of logic as an elementary algebra over the two-element Boolean algebra; other notations include (to be found in Peano). False: the symbol 0 comes also from Boole's interpretation of logic as a ring; other notations include (to be found in Peano). Some authors used letters for connectives at some time of the history: u. for conjunction (German's "und" for "and") and o. for disjunction (German's "oder" for "or") in earlier works by Hilbert (1904); Np for negation, Kpq for conjunction, Dpq for alternative denial, Apq for disjunction, Xpq for joint denial, Cpq for implication, Epq for biconditional in Łukasiewicz (1929); cf. Polish notation. Redundancy Such a logical connective as converse implication "←" is actually the same as material conditional with swapped arguments; thus, the symbol for converse implication is redundant. In some logical calculi (notably, in classical logic), certain essentially different compound statements are logically equivalent. A less trivial example of a redundancy is the classical equivalence between and . Therefore, a classical-based logical system does not need the conditional operator "→" if "¬" (not) and "∨" (or) are already in use, or may use the "→" only as a syntactic sugar for a compound having one negation and one disjunction. There are sixteen Boolean functions associating the input truth values and with four-digit binary outputs. These correspond to possible choices of binary logical connectives for classical logic. Different implementations of classical logic can choose different functionally complete subsets of connectives. One approach is to choose a minimal set, and define other connectives by some logical form, as in the example with the material conditional above. The following are the minimal functionally complete sets of operators in classical logic whose arities do not exceed 2: One element {↑}, {↓}. Two elements , , , , , , , , , , , , , , , , , . Three elements , , , , , . Another approach is to use with equal rights connectives of a certain convenient and functionally complete, but not minimal set. This approach requires more propositional axioms, and each equivalence between logical forms must be either an axiom or provable as a theorem. The situation, however, is more complicated in intuitionistic logic. Of its five connectives, {∧, ∨, →, ¬, ⊥}, only negation "¬" can be reduced to other connectives (see for more). Neither conjunction, disjunction, nor material conditional has an equivalent form constructed from the other four logical connectives. Natural language The standard logical connectives of classical logic have rough equivalents in the grammars of natural languages. In English, as in many languages, such expressions are typically grammatical conjunctions. However, they can also take the form of complementizers, verb suffixes, and particles. The denotations of natural language connectives is a major topic of research in formal semantics, a field that studies the logical structure of natural languages. The meanings of natural language connectives are not precisely identical to their nearest equivalents in classical logic. In particular, disjunction can receive an exclusive interpretation in many languages. Some researchers have taken this fact as evidence that natural language semantics is nonclassical. However, others maintain classical semantics by positing pragmatic accounts of exclusivity which create the illusion of nonclassicality. In such accounts, exclusivity is typically treated as a scalar implicature. Related puzzles involving disjunction include free choice inferences, Hurford's Constraint, and the contribution of disjunction in alternative questions. Other apparent discrepancies between natural language and classical logic include the paradoxes of material implication, donkey anaphora and the problem of counterfactual conditionals. These phenomena have been taken as motivation for identifying the denotations of natural language conditionals with logical operators including the strict conditional, the variably strict conditional, as well as various dynamic operators. The following table shows the standard classically definable approximations for the English connectives. Properties Some logical connectives possess properties that may be expressed in the theorems containing the connective. Some of those properties that a logical connective may have
|
above. The following are the minimal functionally complete sets of operators in classical logic whose arities do not exceed 2: One element {↑}, {↓}. Two elements , , , , , , , , , , , , , , , , , . Three elements , , , , , . Another approach is to use with equal rights connectives of a certain convenient and functionally complete, but not minimal set. This approach requires more propositional axioms, and each equivalence between logical forms must be either an axiom or provable as a theorem. The situation, however, is more complicated in intuitionistic logic. Of its five connectives, {∧, ∨, →, ¬, ⊥}, only negation "¬" can be reduced to other connectives (see for more). Neither conjunction, disjunction, nor material conditional has an equivalent form constructed from the other four logical connectives. Natural language The standard logical connectives of classical logic have rough equivalents in the grammars of natural languages. In English, as in many languages, such expressions are typically grammatical conjunctions. However, they can also take the form of complementizers, verb suffixes, and particles. The denotations of natural language connectives is a major topic of research in formal semantics, a field that studies the logical structure of natural languages. The meanings of natural language connectives are not precisely identical to their nearest equivalents in classical logic. In particular, disjunction can receive an exclusive interpretation in many languages. Some researchers have taken this fact as evidence that natural language semantics is nonclassical. However, others maintain classical semantics by positing pragmatic accounts of exclusivity which create the illusion of nonclassicality. In such accounts, exclusivity is typically treated as a scalar implicature. Related puzzles involving disjunction include free choice inferences, Hurford's Constraint, and the contribution of disjunction in alternative questions. Other apparent discrepancies between natural language and classical logic include the paradoxes of material implication, donkey anaphora and the problem of counterfactual conditionals. These phenomena have been taken as motivation for identifying the denotations of natural language conditionals with logical operators including the strict conditional, the variably strict conditional, as well as various dynamic operators. The following table shows the standard classically definable approximations for the English connectives. Properties Some logical connectives possess properties that may be expressed in the theorems containing the connective. Some of those properties that a logical connective may have are: Associativity Within an expression containing two or more of the same associative connectives in a row, the order of the operations does not matter as long as the sequence of the operands is not changed. CommutativityThe operands of the connective may be swapped, preserving logical equivalence to the original expression. Distributivity A connective denoted by · distributes over another connective denoted by +, if for all operands , , . Idempotence Whenever the operands of the operation are the same, the compound is logically equivalent to the operand. Absorption A pair of connectives ∧, ∨ satisfies the absorption law if for all operands , . Monotonicity If f(a1, ..., an) ≤ f(b1, ..., bn) for all a1, ..., an, b1, ..., bn ∈ {0,1} such that a1 ≤ b1, a2 ≤ b2, ..., an ≤ bn. E.g., ∨, ∧, ⊤, ⊥. Affinity Each variable always makes a difference in the truth-value of the operation or it never makes a difference. E.g., ¬, ↔, , ⊤, ⊥. Duality To read the truth-value assignments for the operation from top to bottom on its truth table is the same as taking the complement of reading the table of the same or another connective from bottom to top. Without resorting to truth tables it may be formulated as . E.g., ¬. Truth-preserving The compound all those arguments are tautologies is a tautology itself. E.g., ∨, ∧, ⊤, →, ↔, ⊂ (see validity). Falsehood-preserving The compound all those argument are contradictions is a contradiction itself. E.g., ∨, ∧, , ⊥, ⊄, ⊅ (see validity). Involutivity (for unary connectives) . E.g. negation in classical logic. For classical and intuitionistic logic, the "=" symbol means that corresponding implications "...→..." and "...←..." for logical compounds can be both proved as theorems, and the "≤" symbol means that "...→..." for logical compounds is a consequence of corresponding "...→..." connectives for propositional variables. Some many-valued logics may have incompatible definitions of equivalence and order (entailment). Both conjunction and disjunction are associative, commutative and idempotent in classical logic, most varieties of many-valued logic and intuitionistic logic. The same is true about distributivity of conjunction over disjunction and disjunction over conjunction, as well as for the absorption law. In classical logic and some
|
conclusion are propositions. The premises are taken for granted, and with the application of modus ponens (an inference rule), the conclusion follows. As propositional logic is not concerned with the structure of propositions beyond the point where they can't be decomposed any more by logical connectives, this inference can be restated replacing those atomic statements with statement letters, which are interpreted as variables representing statements: Premise 1: Premise 2: Conclusion: The same can be stated succinctly in the following way: When is interpreted as "It's raining" and as "it's cloudy" the above symbolic expressions can be seen to correspond exactly with the original expression in natural language. Not only that, but they will also correspond with any other inference of this form, which will be valid on the same basis this inference is. Propositional logic may be studied through a formal system in which formulas of a formal language may be interpreted to represent propositions. A system of axioms and inference rules allows certain formulas to be derived. These derived formulas are called theorems and may be interpreted to be true propositions. A constructed sequence of such formulas is known as a derivation or proof and the last formula of the sequence is the theorem. The derivation may be interpreted as proof of the proposition represented by the theorem. When a formal system is used to represent formal logic, only statement letters (usually capital roman letters such as , and ) are represented directly. The natural language propositions that arise when they're interpreted are outside the scope of the system, and the relation between the formal system and its interpretation is likewise outside the formal system itself. In classical truth-functional propositional logic, formulas are interpreted as having precisely one of two possible truth values, the truth value of true or the truth value of false. The principle of bivalence and the law of excluded middle are upheld. Truth-functional propositional logic defined as such and systems isomorphic to it are considered to be zeroth-order logic. However, alternative propositional logics are also possible. For more, see Other logical calculi below. History Although propositional logic (which is interchangeable with propositional calculus) had been hinted by earlier philosophers, it was developed into a formal logic (Stoic logic) by Chrysippus in the 3rd century BC and expanded by his successor Stoics. The logic was focused on propositions. This advancement was different from the traditional syllogistic logic, which was focused on terms. However, most of the original writings were lost and the propositional logic developed by the Stoics was no longer understood later in antiquity. Consequently, the system was essentially reinvented by Peter Abelard in the 12th century. Propositional logic was eventually refined using symbolic logic. The 17th/18th-century mathematician Gottfried Leibniz has been credited with being the founder of symbolic logic for his work with the calculus ratiocinator. Although his work was the first of its kind, it was unknown to the larger logical community. Consequently, many of the advances achieved by Leibniz were recreated by logicians like George Boole and Augustus De Morgan—completely independent of Leibniz. Just as propositional logic can be considered an advancement from the earlier syllogistic logic, Gottlob Frege's predicate logic can be also considered an advancement from the earlier propositional logic. One author describes predicate logic as combining "the distinctive features of syllogistic logic and propositional logic." Consequently, predicate logic ushered in a new era in logic's history; however, advances in propositional logic were still made after Frege, including natural deduction, truth trees and truth tables. Natural deduction was invented by Gerhard Gentzen and Jan Łukasiewicz. Truth trees were invented by Evert Willem Beth. The invention of truth tables, however, is of uncertain attribution. Within works by Frege and Bertrand Russell, are ideas influential to the invention of truth tables. The actual tabular structure (being formatted as a table), itself, is generally credited to either Ludwig Wittgenstein or Emil Post (or both, independently). Besides Frege and Russell, others credited with having ideas preceding truth tables include Philo, Boole, Charles Sanders Peirce, and Ernst Schröder. Others credited with the tabular structure include Jan Łukasiewicz, Alfred North Whitehead, William Stanley Jevons, John Venn, and Clarence Irving Lewis. Ultimately, some have concluded, like John Shosky, that "It is far from clear that any one person should be given the title of 'inventor' of truth-tables.". Terminology In general terms, a calculus is a formal system that consists of a set of syntactic expressions (well-formed formulas), a distinguished subset of these expressions (axioms), plus a set of formal rules that define a specific binary relation, intended to be interpreted as logical equivalence, on the space of expressions. When the formal system is intended to be a logical system, the expressions are meant to be interpreted as statements, and the rules, known to be inference rules, are typically intended to be truth-preserving. In this setting, the rules, which may include axioms, can then be used to derive ("infer") formulas representing true statements—from given formulas representing true statements. The set of axioms may be empty, a nonempty finite set, or a countably infinite set (see axiom schema). A formal grammar recursively defines the expressions and well-formed formulas of the language. In addition a semantics may be given which defines truth and valuations (or interpretations). The language of a propositional calculus consists of a set of primitive symbols, variously referred to as atomic formulas, placeholders, proposition letters, or variables, and a set of operator symbols, variously interpreted as logical operators or logical connectives. A well-formed formula is any atomic formula, or any formula that can be built up from atomic formulas by means of operator symbols according to the rules of the grammar. Mathematicians sometimes distinguish between propositional constants, propositional variables, and schemata. Propositional constants represent some particular proposition, while propositional variables range over the set of all atomic propositions. Schemata, however, range over all propositions. It is common to represent propositional constants by , , and , propositional variables by , , and , and schematic letters are often Greek letters, most often , , and . Basic concepts The following outlines a standard propositional calculus. Many different formulations exist which are all more or less equivalent, but differ in the details of: their language (i.e., the particular collection of primitive symbols and operator symbols), the set of axioms, or distinguished formulas, and the set of inference rules. Any given proposition may be represented with a letter called a 'propositional constant', analogous to representing a number by a letter in mathematics (e.g., ). All propositions require exactly one of two truth-values: true or false. For example, let be the proposition that it is raining outside. This will be true () if it is raining outside, and false otherwise (). We then define truth-functional operators, beginning with negation. represents the negation of , which can be thought of as the denial of . In the example above, expresses that it is not raining outside, or by a more standard reading: "It is not the case that it is raining outside." When is true, is false; and when is false, is true. As a result, always has the same truth-value as . Conjunction is a truth-functional connective which forms a proposition out of two simpler propositions, for example, and . The conjunction of and is written , and expresses that each are true. We read as " and ". For any two propositions, there are four possible assignments of truth values: is true and is true is true and is false is false and is true is false and is false The conjunction of and is true in case 1, and is false otherwise. Where is the proposition that it is raining outside and is the proposition that a cold-front is over Kansas, is true when it is raining outside and there is a cold-front over Kansas. If it is not raining outside, then is false; and if there is no cold-front over Kansas, then is also false. Disjunction resembles conjunction in that it forms a proposition out of two simpler propositions. We write it , and it is read " or ". It expresses that either or is true. Thus, in the cases listed above, the disjunction of with is true in all cases—except case 4. Using the example above, the disjunction expresses that it is either raining outside, or there is a cold front over Kansas. (Note, this use of disjunction is supposed to resemble the use of the English word "or". However, it is most like the English inclusive "or", which can be used to express the truth of at least one of two propositions. It is not like the English exclusive "or", which expresses the truth of exactly one of two propositions. In other words, the exclusive "or" is false when both and are true (case 1). An example of the exclusive or is: You may have a bagel or a pastry, but not both. Often in natural language, given the appropriate context, the addendum "but not both" is omitted—but implied. In mathematics, however, "or" is always inclusive or; if exclusive or is meant it will be specified, possibly by "xor".) Material conditional also joins two simpler propositions, and we write , which is read "if then ". The proposition to the left of the arrow is called the antecedent, and the proposition to the right is called the consequent. (There is no such designation for conjunction or disjunction, since they are commutative operations.) It expresses that is true whenever is true. Thus is true in every case above except case 2, because this is the only case when is true but is not. Using the example, if then expresses that if it is raining outside, then there is a cold-front over Kansas. The material conditional is often confused with physical causation. The material conditional, however, only relates two propositions by their truth-values—which is not the relation of cause and effect. It is contentious in the literature whether the material implication represents logical causation. Biconditional joins two simpler propositions, and we write , which is read " if and only if ". It expresses that and have the same truth-value, and in cases 1 and 4. ' is true if and only if ' is true, and is false otherwise. It is very helpful to look at the truth tables for these different operators, as well as the method of analytic tableaux. Closure under operations Propositional logic is closed under truth-functional connectives. That is to say, for any proposition , is also a proposition. Likewise, for any propositions and , is a proposition, and similarly for disjunction, conditional, and biconditional. This implies that, for instance, is a proposition, and so it can be conjoined with another proposition. In order to represent this, we need to use parentheses to indicate which proposition is conjoined with which. For instance, is not a well-formed formula, because we do not know if we are conjoining with or if we are conjoining with . Thus we must write either to represent the former, or to represent the latter. By evaluating the truth conditions, we see that both expressions have the same truth conditions (will be true in the same cases), and moreover that any proposition formed by arbitrary conjunctions will have the same truth conditions, regardless of the location of the parentheses. This means that conjunction is associative, however, one should not assume that parentheses never serve a purpose. For instance, the sentence does not have the same truth conditions of , so they are different sentences distinguished only by the parentheses. One can verify this by the truth-table method referenced above. Note: For any arbitrary number of propositional constants, we can form a finite number of cases which list their possible truth-values. A simple way to generate this is by truth-tables, in which one writes , , ..., , for any list of propositional constants—that is to say, any list of propositional constants with entries. Below this list, one writes rows, and below one fills in the first half of the rows with true (or T) and the second half with false (or F). Below one fills in one-quarter of the rows with T, then one-quarter with F, then one-quarter with T and the last quarter with F. The next column alternates between true and false for each eighth of the rows, then sixteenths, and so on, until the last propositional constant varies between T and F for each row. This will give a complete listing of cases or truth-value assignments possible for those propositional constants. Argument The propositional calculus then defines an argument to be a list of propositions. A valid argument is a list of propositions, the last of which follows from—or is implied by—the rest. All other arguments are invalid. The simplest valid argument is modus ponens, one instance of which is the following list of propositions: This is a list of three propositions, each line is a proposition, and the last follows from the rest. The first two lines are called premises, and the last line the conclusion. We say that any proposition follows from any set of propositions , if must be true whenever every member of the set is true. In the argument above, for any and , whenever and are true, necessarily is true. Notice that, when is true, we cannot consider cases 3 and 4 (from the truth table). When is true, we cannot consider case 2. This leaves only case 1, in which is also true. Thus is implied by the premises. This generalizes schematically. Thus, where and may be any propositions at all, Other argument forms are convenient, but not necessary. Given a complete set of axioms (see below for one such set), modus ponens is sufficient to prove all other argument forms in propositional logic, thus they may be considered to be a derivative. Note, this is
|
are found in natural languages. In English for example, some examples are "and" (conjunction), "or" (disjunction), "not" (negation) and "if" (but only when used to denote material conditional). The following is an example of a very simple inference within the scope of propositional logic: Premise 1: If it's raining then it's cloudy. Premise 2: It's raining. Conclusion: It's cloudy. Both premises and the conclusion are propositions. The premises are taken for granted, and with the application of modus ponens (an inference rule), the conclusion follows. As propositional logic is not concerned with the structure of propositions beyond the point where they can't be decomposed any more by logical connectives, this inference can be restated replacing those atomic statements with statement letters, which are interpreted as variables representing statements: Premise 1: Premise 2: Conclusion: The same can be stated succinctly in the following way: When is interpreted as "It's raining" and as "it's cloudy" the above symbolic expressions can be seen to correspond exactly with the original expression in natural language. Not only that, but they will also correspond with any other inference of this form, which will be valid on the same basis this inference is. Propositional logic may be studied through a formal system in which formulas of a formal language may be interpreted to represent propositions. A system of axioms and inference rules allows certain formulas to be derived. These derived formulas are called theorems and may be interpreted to be true propositions. A constructed sequence of such formulas is known as a derivation or proof and the last formula of the sequence is the theorem. The derivation may be interpreted as proof of the proposition represented by the theorem. When a formal system is used to represent formal logic, only statement letters (usually capital roman letters such as , and ) are represented directly. The natural language propositions that arise when they're interpreted are outside the scope of the system, and the relation between the formal system and its interpretation is likewise outside the formal system itself. In classical truth-functional propositional logic, formulas are interpreted as having precisely one of two possible truth values, the truth value of true or the truth value of false. The principle of bivalence and the law of excluded middle are upheld. Truth-functional propositional logic defined as such and systems isomorphic to it are considered to be zeroth-order logic. However, alternative propositional logics are also possible. For more, see Other logical calculi below. History Although propositional logic (which is interchangeable with propositional calculus) had been hinted by earlier philosophers, it was developed into a formal logic (Stoic logic) by Chrysippus in the 3rd century BC and expanded by his successor Stoics. The logic was focused on propositions. This advancement was different from the traditional syllogistic logic, which was focused on terms. However, most of the original writings were lost and the propositional logic developed by the Stoics was no longer understood later in antiquity. Consequently, the system was essentially reinvented by Peter Abelard in the 12th century. Propositional logic was eventually refined using symbolic logic. The 17th/18th-century mathematician Gottfried Leibniz has been credited with being the founder of symbolic logic for his work with the calculus ratiocinator. Although his work was the first of its kind, it was unknown to the larger logical community. Consequently, many of the advances achieved by Leibniz were recreated by logicians like George Boole and Augustus De Morgan—completely independent of Leibniz. Just as propositional logic can be considered an advancement from the earlier syllogistic logic, Gottlob Frege's predicate logic can be also considered an advancement from the earlier propositional logic. One author describes predicate logic as combining "the distinctive features of syllogistic logic and propositional logic." Consequently, predicate logic ushered in a new era in logic's history; however, advances in propositional logic were still made after Frege, including natural deduction, truth trees and truth tables. Natural deduction was invented by Gerhard Gentzen and Jan Łukasiewicz. Truth trees were invented by Evert Willem Beth. The invention of truth tables, however, is of uncertain attribution. Within works by Frege and Bertrand Russell, are ideas influential to the invention of truth tables. The actual tabular structure (being formatted as a table), itself, is generally credited to either Ludwig Wittgenstein or Emil Post (or both, independently). Besides Frege and Russell, others credited with having ideas preceding truth tables include Philo, Boole, Charles Sanders Peirce, and Ernst Schröder. Others credited with the tabular structure include Jan Łukasiewicz, Alfred North Whitehead, William Stanley Jevons, John Venn, and Clarence Irving Lewis. Ultimately, some have concluded, like John Shosky, that "It is far from clear that any one person should be given the title of 'inventor' of truth-tables.". Terminology In general terms, a calculus is a formal system that consists of a set of syntactic expressions (well-formed formulas), a distinguished subset of these expressions (axioms), plus a set of formal rules that define a specific binary relation, intended to be interpreted as logical equivalence, on the space of expressions. When the formal system is intended to be a logical system, the expressions are meant to be interpreted as statements, and the rules, known to be inference rules, are typically intended to be truth-preserving. In this setting, the rules, which may include axioms, can then be used to derive ("infer") formulas representing true statements—from given formulas representing true statements. The set of axioms may be empty, a nonempty finite set, or a countably infinite set (see axiom schema). A formal grammar recursively defines the expressions and well-formed formulas of the language. In addition a semantics may be given which defines truth and valuations (or interpretations). The language of a propositional calculus consists of a set of primitive symbols, variously referred to as atomic formulas, placeholders, proposition letters, or variables, and a set of operator symbols, variously interpreted as logical operators or logical connectives. A well-formed formula is any atomic formula, or any formula that can be built up from atomic formulas by means of operator symbols according to the rules of the grammar. Mathematicians sometimes distinguish between propositional constants, propositional variables, and schemata. Propositional constants represent some particular proposition, while propositional variables range over the set of all atomic propositions. Schemata, however, range over all propositions. It is common to represent propositional constants by , , and , propositional variables by , , and , and schematic letters are often Greek letters, most often , , and . Basic concepts The following outlines a standard propositional calculus. Many different formulations exist which are all more or less equivalent, but differ in the details of: their language (i.e., the particular collection of primitive symbols and operator symbols), the set of axioms, or distinguished formulas, and the set of inference rules. Any given proposition may be represented with a letter called a 'propositional constant', analogous to representing a number by a letter in mathematics (e.g., ). All propositions require exactly one of two truth-values: true or false. For example, let be the proposition that it is raining outside. This will be true () if it is raining outside, and false otherwise (). We then define truth-functional operators, beginning with negation. represents the negation of , which can be thought of as the denial of . In the example above, expresses that it is not raining outside, or by a more standard reading: "It is not the case that it is raining outside." When is true, is false; and when is false, is true. As a result, always has the same truth-value as . Conjunction is a truth-functional connective which forms a proposition out of two simpler propositions, for example, and . The conjunction of and is written , and expresses that each are true. We read as " and ". For any two propositions, there are four possible assignments of truth values: is true and is true is true and is false is false and is true is false and is false The conjunction of and is true in case 1, and is false otherwise. Where is the proposition that it is raining outside and is the proposition that a cold-front is over Kansas, is true when it is raining outside and there is a cold-front over Kansas. If it is not raining outside, then is false; and if there is no cold-front over Kansas, then is also false. Disjunction resembles conjunction in that it forms a proposition out of two simpler propositions. We write it , and it is read " or ". It expresses that either or is true. Thus, in the cases listed above, the disjunction of with is true in all cases—except case 4. Using the example above, the disjunction expresses that it is either raining outside, or there is a cold front over Kansas. (Note, this use of disjunction is supposed to resemble the use of the English word "or". However, it is most like the English inclusive "or", which can be used to express the truth of at least one of two propositions. It is not like the English exclusive "or", which expresses the truth of exactly one of two propositions. In other words, the exclusive "or" is false when both and are true (case 1). An example of the exclusive or is: You may have a bagel or a pastry, but not both. Often in natural language, given the appropriate context, the addendum "but not both" is omitted—but implied. In mathematics, however, "or" is always inclusive or; if exclusive or is meant it will be specified, possibly by "xor".) Material conditional also joins two simpler propositions, and we write , which is read "if then ". The proposition to the left of the arrow is called the antecedent, and the proposition to the right is called the consequent. (There is no such designation for conjunction or disjunction, since they are commutative operations.) It expresses that is true whenever is true. Thus is true in every case above except case 2, because this is the only case when is true but is not. Using the example, if then expresses that if it is raining outside, then there is a cold-front over Kansas. The material conditional is often confused with physical causation. The material conditional, however, only relates two propositions by their truth-values—which is not the relation of cause and effect. It is contentious in the literature whether the material implication represents logical causation. Biconditional joins two simpler propositions, and we write , which is read " if and only if ". It expresses that and have the same truth-value, and in cases 1 and 4. ' is true if and only if ' is true, and is false otherwise. It is very helpful to look at the truth tables for these different operators, as well as the method of analytic tableaux. Closure under operations Propositional logic is closed under truth-functional connectives. That is to say, for any proposition , is also a proposition. Likewise, for any propositions and , is a proposition, and similarly for disjunction, conditional, and biconditional. This implies that, for instance, is a proposition, and so it can be conjoined with another proposition. In order to represent this, we need to use parentheses to indicate which proposition is conjoined with which. For instance, is not a well-formed formula, because we do not know if we are conjoining with or if we are conjoining with . Thus we must write either to represent the former, or to represent the latter. By evaluating the truth conditions, we see that both expressions have the same truth conditions (will be true in the same cases), and moreover that any proposition formed by arbitrary conjunctions will have the same truth conditions, regardless of the location of the parentheses. This means that conjunction is associative, however, one should not assume that parentheses never serve a purpose. For instance, the sentence does not have the same truth conditions of , so they are different sentences distinguished only by the parentheses. One can verify this by the truth-table method referenced above. Note: For any arbitrary number of propositional constants, we can form a finite number of cases which list their possible truth-values. A simple way to generate this is by truth-tables, in which one writes , , ..., , for any list of propositional constants—that is to say, any list of propositional constants with entries. Below this list, one writes rows, and below one fills in the first half of the rows with true (or T) and the second half with false (or F). Below one fills in one-quarter of the rows with T, then one-quarter with F, then one-quarter with T and the last quarter with F. The next column alternates between true and false for each eighth of the rows, then sixteenths, and so on, until the last propositional constant varies between T and F for each row. This will give a complete listing of cases or truth-value assignments possible for those propositional constants. Argument The propositional calculus then defines an argument to be a list of propositions. A valid argument is a list of propositions, the last of which follows from—or is implied by—the rest. All other arguments are invalid. The simplest valid argument is modus ponens, one instance of which is the following list of propositions: This is a list of three propositions, each line is a proposition, and the last follows from the rest. The first two lines are called premises, and the last line the conclusion. We say that any proposition follows from any set of propositions , if must be true whenever every member of the set is true. In the argument above, for any and , whenever and are true, necessarily is true. Notice that, when is true, we cannot consider cases 3 and 4 (from the truth table). When is true, we cannot consider case 2. This leaves only case 1, in which is also true. Thus is implied by the premises. This generalizes schematically. Thus, where and may be any propositions at all, Other argument forms are convenient, but not necessary. Given a complete set of axioms (see below for one such set), modus ponens is sufficient to prove all other argument forms in propositional logic, thus they may be considered to be a derivative. Note, this is not true of the extension of propositional logic to other logics like first-order logic. First-order logic requires at least one additional rule of inference in order to obtain completeness. The significance of argument in formal logic is that one may obtain new truths from established truths. In the first example above, given the two premises, the truth of is not yet known or stated. After the argument is made, is deduced. In this way, we define a deduction system to be a set of all propositions that may be deduced from another set of propositions. For instance, given the set of propositions , we can define a deduction system, , which is the set of all propositions which follow from . Reiteration is always assumed, so . Also, from the first element of , last element, as well as modus ponens, is a consequence, and so . Because we have not included sufficiently complete axioms, though, nothing else may be deduced. Thus, even though most deduction systems studied in propositional logic are able to deduce , this one is too weak to prove such a proposition. Generic description of a propositional calculus A propositional calculus is a formal system , where: The language of , also known as its set of formulas, well-formed formulas, is inductively defined by the following rules: Base: Any element of the alpha set is a formula of . If are formulas and is in , then is a formula. Closed: Nothing else is a formula of . Repeated applications of these rules permits the construction of complex formulas. For example: By rule 1, is a formula. By rule 2, is a formula. By rule 1, is a formula. By rule 2, is a formula. Example 1. Simple axiom system Let , where , , , are defined as follows: The set , the countably infinite set of symbols that serve to represent logical propositions: The functionally complete set of logical operators (logical connectives and negation) is as follows. Of the three connectives for conjunction, disjunction, and implication (, and ), one can be taken as primitive and the other two can be defined in terms of it and negation (). Alternatively, all of the logical operators may be defined in terms of a sole sufficient operator, such as the Sheffer stroke. The biconditional () can of course be defined in terms of conjunction and implication as . Adopting negation and implication as the two primitive operations of a propositional calculus is tantamount to having the omega set partition as follows: The set (the set of initial points of logical deduction, i.e., logical axioms) is the axiom system proposed by Jan Łukasiewicz, and used as the propositional-calculus part of a Hilbert system. The axioms are all substitution instances of: The set of transformation rules (rules of inference) is the sole rule modus ponens
|
and James H. Morris and by Daniel P. Friedman and David S. Wise. Applications Delayed evaluation is used particularly in functional programming languages. When using delayed evaluation, an expression is not evaluated as soon as it gets bound to a variable, but when the evaluator is forced to produce the expression's value. That is, a statement such as x = expression; (i.e. the assignment of the result of an expression to a variable) clearly calls for the expression to be evaluated and the result placed in x, but what actually is in x is irrelevant until there is a need for its value via a reference to x in some later expression whose evaluation could itself be deferred, though eventually the rapidly growing tree of dependencies would be pruned to produce some symbol rather than another for the outside world to see. Control structures Lazy evaluation allows control structures to be defined normally, and not as primitives or compile-time techniques. For example one can define if-then-else and short-circuit evaluation operators: ifThenElse True b c = b ifThenElse False b c = c -- or True || b = True False || b = b -- and True && b = b False && b = False These have the usual semantics, i.e. evaluates (a), then if and only if (a) evaluates to true does it evaluate (b), otherwise it evaluates (c). That is, exactly one of (b) or (c) will be evaluated. Similarly for , if the easy part gives True the lots of work expression could be avoided. Finally, when evaluating , if SafeToTry is false there will be no attempt at evaluating the Expression. Conversely, in an eager language the above definition for would evaluate (a), (b), and (c) regardless of the value of (a). This is not the desired behavior, as (b) or (c) may have side effects, take a long time to compute, or throw errors. It is usually possible to introduce user-defined lazy control structures in eager languages as functions, though they may depart from the language's syntax for eager evaluation: Often the involved code bodies need to be wrapped in a function value, so that they are executed only when called. Working with infinite data structures Delayed evaluation has the advantage of being able to create calculable infinite lists without infinite loops or size matters interfering in computation. The actual values are only computed when needed. For example, one could create a function that creates an infinite list (often called a stream) of Fibonacci numbers. The calculation of the n-th Fibonacci number would be merely the extraction of that element from the infinite list, forcing the evaluation of only the first n members of the list. Take for example this trivial program in Haskell: numberFromInfiniteList :: Int -> Int numberFromInfiniteList n = infinity !! n - 1 where infinity = [1..] main = print $ numberFromInfiniteList 4 In the function , the value of is an infinite range, but until an actual value (or more specifically, a specific value at a certain index) is needed, the list is not evaluated, and even then it is only evaluated as needed (that is, until the desired index.) Provided the programmer is careful, the program completes normally. However, certain calculations may result in the program attempting to evaluate an infinite number of elements; for example, requesting the length of the list or trying to sum the elements of the list with a fold operation would result in the program either failing to terminate or running out of memory. As another example, the list of all Fibonacci numbers can be written in the Haskell programming language as: fibs = 0 : 1 : zipWith (+) fibs (tail fibs) In Haskell syntax, ":" prepends an element to a list, tail returns a list without its first element, and zipWith uses a specified function (in this case addition) to combine corresponding elements of two lists to produce a third. List-of-successes pattern Other uses In computer windowing systems, the painting of information to the screen is driven by expose events which drive the display code at the last possible moment. By doing this, windowing systems avoid computing unnecessary display content updates. Another example of laziness in modern computer systems is copy-on-write page allocation or demand paging, where memory is allocated only when a value stored in that memory is changed. Laziness can be useful for high performance scenarios. An example is the Unix mmap function, which provides demand driven loading of pages from disk, so that only those pages actually touched are loaded into memory, and unneeded memory is not allocated. MATLAB implements copy on edit, where arrays which are copied have their actual memory storage replicated only when their content is changed, possibly leading to an out of memory error when updating an element afterwards instead of during the copy operation. Performance The number of beta reductions to reduce a lambda term with call-by-need is no larger than the number needed by call-by-value or call-by-name reduction. And with certain programs the number of steps
|
pages from disk, so that only those pages actually touched are loaded into memory, and unneeded memory is not allocated. MATLAB implements copy on edit, where arrays which are copied have their actual memory storage replicated only when their content is changed, possibly leading to an out of memory error when updating an element afterwards instead of during the copy operation. Performance The number of beta reductions to reduce a lambda term with call-by-need is no larger than the number needed by call-by-value or call-by-name reduction. And with certain programs the number of steps may be much smaller, for example a specific family of lambda terms using Church numerals take an infinite amount of steps with call-by-value (i.e. never complete), an exponential number of steps with call-by-name, but only a polynomial number with call-by-need. Call-by-need embodies two optimizations - never repeat work (similar to call-by-value), and never perform unnecessary work (similar to call-by-name). Lazy evaluation can also lead to reduction in memory footprint, since values are created when needed. In practice, lazy evaluation may cause significant performance issues compared to eager evaluation. For example, on modern computer architectures, delaying a computation and performing it later is slower than performing it immediately. This can be alleviated through strictness analysis. Lazy evaluation can also introduce memory leaks due to unevaluated expressions. Implementation Some programming languages delay evaluation of expressions by default, and some others provide functions or special syntax to delay evaluation. In Miranda and Haskell, evaluation of function arguments is delayed by default. In many other languages, evaluation can be delayed by explicitly suspending the computation using special syntax (as with Scheme's "delay" and "force" and OCaml's "lazy" and "Lazy.force") or, more generally, by wrapping the expression in a thunk. The object representing such an explicitly delayed evaluation is called a lazy future. Raku uses lazy evaluation of lists, so one can assign infinite lists to variables and use them as arguments to functions, but unlike Haskell and Miranda, Raku does not use lazy evaluation of arithmetic operators and functions by default. Laziness and eagerness Controlling eagerness in lazy languages In lazy programming languages such as Haskell, although the default is to evaluate expressions only when they are demanded, it is possible in some cases to make code more eager—or conversely, to make it more lazy again after it has been made more eager. This can be done by explicitly coding something which forces evaluation (which may make the code more eager) or avoiding such code (which may make the code more lazy). Strict evaluation usually implies eagerness, but they are technically different concepts. However, there is an optimisation implemented in some compilers called strictness analysis, which, in some cases, allows the compiler to infer that a value will always be used. In such cases, this may render the programmer's choice of whether to force that particular value or not, irrelevant, because strictness analysis will force strict evaluation. In Haskell, marking constructor fields strict means that their values will always be demanded immediately. The seq function can also be used to demand a value immediately and then pass it on, which is useful if a constructor field should generally be lazy. However, neither of these techniques implements recursive strictness—for that, a function called deepSeq was invented. Also, pattern matching in Haskell 98 is strict by default, so the ~ qualifier has to be used to make it lazy. Simulating laziness in eager languages Java In Java, lazy evaluation can be done by using objects that have a method to evaluate them when the value is needed. The body of this method must contain the code required to perform this evaluation. Since the introduction of lambda expressions in Java SE8, Java has supported a compact notation for this. The following example generic interface provides a framework for lazy evaluation: interface Lazy<T> { T eval(); } The Lazy interface with its eval() method is equivalent to the Supplier interface with its get() method in the java.util.function library. Each class that implements the Lazy interface must provide an eval method, and instances of the class may carry whatever values the method needs to accomplish lazy evaluation. For example, consider the following code to lazily compute and print 210: Lazy<Integer> a = ()-> 1; for (int i = 1; i <= 10; i++) { final Lazy<Integer> b = a; a = ()-> b.eval() + b.eval(); } System.out.println( "a = " + a.eval() ); In the above, the variable initially refers to a lazy integer object created by the lambda expression ()->1. Evaluating this lambda expression is equivalent to constructing a new instance of an anonymous class that implements Lazy<Integer> with an method returning . Each iteration of the loop links to a new object created by evaluating the lambda expression inside the loop. Each of these objects holds a reference to another lazy object, , and has an method that calls b.eval() twice and returns the sum. The variable is needed here to meet Java's requirement that variables referenced from within a lambda expression be final. This is an inefficient program because this implementation of lazy integers does not memoize the result of previous calls to . It also involves considerable autoboxing and unboxing. What may not be obvious is that, at the end of the loop, the program has constructed a linked list of 11 objects and that all of the actual additions involved in computing the result are done in response to the call to a.eval() on the final line of code. This call recursively traverses the list to perform the necessary additions. We can build a
|
They have long, bushy tails and soft, woolly fur of varying coloration. The hindlegs are slightly longer than the forelegs, although not enough to hamper fully quadrupedal movement (unlike the sportive lemurs). Most species are highly agile, and regularly leap several metres between trees. They have a good sense of smell and binocular vision. Unlike most other lemurs, all but one species of lemurid (the ring-tailed lemur) lack a tapetum lucidum, a reflective layer in the eye that improves night vision. Historically among mammals, activity cycles are either strictly diurnal or nocturnal, however, these can widely vary across species. Lemur activity has in general evolved from nocturnal to diurnal. Some lemurs are also cathemeral, an activity pattern where an animal is neither strictly diurnal nor nocturnal. Lemurids are herbivorous, eating fruit, leaves, and, in some cases, nectar. For the most part, they have the dental formula: . A lemur's diet is one that is not restricted since their diet consists of frugivory, granivory, folivory, insectivory, omnivory, and gumnivory foods. Some Subfossil records have contributed to the knowledge of the currently extant lemurs from the Holocene by showing the changes in their dental records in habitats near human activity. This demonstrates that lemur species such as the lemur catta and the common brown lemur were forced to switch their primary diet to a group of secondary food sources. With most lemurids, the mother gives birth to one or two young after a gestation
|
families commonly known as lemurs. These animals were once thought to be the evolutionary predecessors of monkeys and apes, but this is no longer considered correct. They are formally referred to as lemurids. Classification The family Lemuridae contains 21 extant species in five genera. Family Lemuridae Genus Lemur Ring-tailed lemur, Lemur catta Genus Eulemur, true lemursCommon brown lemur, Eulemur fulvusSanford's brown lemur, Eulemur sanfordiWhite-headed lemur, Eulemur albifronsRed lemur, Eulemur rufusRed-fronted lemur, Eulemur rufifronsCollared brown lemur, Eulemur collarisGray-headed lemur, Eulemur cinereicepsBlack lemur, Eulemur macacoBlue-eyed black lemur, Eulemur flavifronsCrowned lemur, Eulemur coronatusRed-bellied lemur, Eulemur rubriventerMongoose lemur, Eulemur mongozGenus Varecia, ruffed lemurs Black-and-white ruffed lemur, Varecia variegataRed ruffed lemur, Varecia rubraGenus Hapalemur, bamboo lemurs Eastern lesser bamboo lemur (a.k.a. gray gentle bamboo lemur), Hapalemur griseusSouthern lesser bamboo lemur, Hapalemur meridionalisWestern lesser bamboo lemur, Hapalemur occidentalisLac Alaotra gentle lemur (a.k.a. bandro), Hapalemur alaotrensisGolden bamboo lemur, Hapalemur aureusGenus ProlemurGreater bamboo lemur, Prolemur simusGenus †Pachylemur†Pachylemur insignis†Pachylemur jullyi'' This family was once broken into two subfamilies, Hapalemurinae (bamboo lemurs and the greater bamboo lemur) and Lemurinae (the rest of the family), but molecular evidence and the similarity of the scent glands have since placed the ring-tailed lemur with the bamboo lemurs and the greater bamboo lemur. Characteristics Lemurids are medium-sized arboreal primates, ranging from 32 to 56 cm in length, excluding the tail, and weighing from 0.7 to 5 kg. They have long, bushy tails and soft, woolly fur of varying coloration. The hindlegs are slightly longer than the forelegs, although not enough to hamper fully quadrupedal movement (unlike the sportive lemurs). Most species are highly agile, and regularly leap several metres between trees. They have a good sense of smell and binocular vision. Unlike most other lemurs, all but one species of lemurid (the ring-tailed lemur) lack a tapetum lucidum, a reflective layer in the eye that improves night vision. Historically among mammals, activity cycles are either strictly diurnal or nocturnal, however, these can widely vary across species. Lemur activity has in general evolved from nocturnal to diurnal. Some lemurs are also cathemeral, an activity pattern where an animal is neither strictly diurnal nor nocturnal. Lemurids are herbivorous, eating fruit, leaves, and, in some cases, nectar. For the most part, they have the dental formula: . A lemur's diet is one that is not restricted since their diet consists
|
them. This continues the Dante theme, although moving away from his Divine Comedy to the poem La Vita Nuova. Logo The Lucent logo, the Innovation Ring, was designed by Landor Associates, a prominent San Francisco-based branding consultancy. One source inside Lucent says that the logo is a Zen Buddhist symbol for "eternal truth", the Enso, turned 90 degrees and modified. Another source says it represents the mythic ouroboros, a snake holding its tail in its mouth. Lucent's logo also has been said to represent constant re-creating and re-thinking. Carly Fiorina picked the logo because her mother was a painter and she rejected the sterile geometric logos of most high tech companies. After the logo was compared in the media to the ring a coffee mug leaves on paper, a Dilbert comic strip showed Dogbert as an overpaid consultant designing a new company logo; he takes a piece of paper that his coffee cup was sitting on and calls it the "Brown Ring of Quality". A telecommunication commentator referred to the logo as "a big red zero" and predicted financial losses. History One of the primary reasons AT&T Corporation chose to spin off its equipment manufacturing business was to permit it to profit from sales to competing telecommunications providers; these customers had previously shown reluctance to purchase from a direct competitor. Bell Labs brought prestige to the new company, as well as the revenue from thousands of patents. At the time of its spinoff, Lucent was placed under the leadership of Henry Schacht, who was brought in to oversee its transition from an arm of AT&T into an independent corporation. Richard McGinn, who was serving as President and COO, succeeded Schacht as CEO in 1997 while Schacht remained chairman of the board. Lucent became a "darling" stock of the investment community in the late 1990s, and its split-adjusted spinoff price of $7.56/share rose to a high of $84. Its market capitalization reached a high of $258 billion, and it was at the time the most widely held company with 5.3 million shareholders. In 1997, Lucent acquired Milpitas-based voicemail market leader Octel Communications Corporation for $2.1 billion, a move which immediately rendered the Business Systems Group profitable. By 1999 Lucent stock continued to soar and in that year Lucent acquired Ascend Communications, an Alameda, California–based manufacturer of communications equipment for US$24 billion. Lucent held discussions to acquire Juniper Networks but decided instead to build its own routers. In 1997, Lucent acquired Livingston Enterprises Inc. for $650 million in stock. Livingston was known most for the creation of the RADIUS protocol and their PortMaster product that was used widely by dial-up internet service providers. In 1995, Carly Fiorina led corporate operations. In that capacity, she reported to Lucent chief executive Henry B. Schacht. She played a key role in planning and implementing the 1996 initial public offering of a successful stock and company launch strategy. Under her guidance, the spin-off raised 3 billion. Later in 1996, Fiorina was appointed president of Lucent's consumer products sector, reporting to president and chief operating officer Rich McGinn. In 1997, she was named group president for Lucent's 19 billion global service-provider business, overseeing marketing and sales for the company's largest customer segment. That year, Fiorina chaired a 2.5 billion joint venture between Lucent's consumer communications and Royal Philips Electronics, under the name Philips Consumer Communications (PCC). The focus of the venture was to bring both companies to the top three in technology, distribution, and brand recognition. Ultimately, the project struggled and dissolved a year later after it garnered only 2% market share in mobile phones. Losses were at $500 million on sales of $2.5 billion. As a result of the failed joint venture, Philips announced the closure of one-quarter of the company's 230 factories worldwide, and Lucent closed down its wireless handset portion of the venture. Analysts suggested that the joint venture's failure was due to a combination of technology and management problems. Upon the end of the joint venture, PCC sent 5,000 employees back to Philips, many of which were laid off, and 8,400 employees back to Lucent. Under Fiorina, the company added 22,000 jobs and revenues seemed to grow from 19 billion to 38 billion. However, the real cause of Lucent spurring sales under Fiorina was by lending money to their own customers. According to Fortune magazine, "In a neat bit of accounting magic, money from the loans began to appear on Lucent’s income statement as new revenue while the dicey debt got stashed on its balance sheet as an allegedly solid asset". Lucent's
|
sterile geometric logos of most high tech companies. After the logo was compared in the media to the ring a coffee mug leaves on paper, a Dilbert comic strip showed Dogbert as an overpaid consultant designing a new company logo; he takes a piece of paper that his coffee cup was sitting on and calls it the "Brown Ring of Quality". A telecommunication commentator referred to the logo as "a big red zero" and predicted financial losses. History One of the primary reasons AT&T Corporation chose to spin off its equipment manufacturing business was to permit it to profit from sales to competing telecommunications providers; these customers had previously shown reluctance to purchase from a direct competitor. Bell Labs brought prestige to the new company, as well as the revenue from thousands of patents. At the time of its spinoff, Lucent was placed under the leadership of Henry Schacht, who was brought in to oversee its transition from an arm of AT&T into an independent corporation. Richard McGinn, who was serving as President and COO, succeeded Schacht as CEO in 1997 while Schacht remained chairman of the board. Lucent became a "darling" stock of the investment community in the late 1990s, and its split-adjusted spinoff price of $7.56/share rose to a high of $84. Its market capitalization reached a high of $258 billion, and it was at the time the most widely held company with 5.3 million shareholders. In 1997, Lucent acquired Milpitas-based voicemail market leader Octel Communications Corporation for $2.1 billion, a move which immediately rendered the Business Systems Group profitable. By 1999 Lucent stock continued to soar and in that year Lucent acquired Ascend Communications, an Alameda, California–based manufacturer of communications equipment for US$24 billion. Lucent held discussions to acquire Juniper Networks but decided instead to build its own routers. In 1997, Lucent acquired Livingston Enterprises Inc. for $650 million in stock. Livingston was known most for the creation of the RADIUS protocol and their PortMaster product that was used widely by dial-up internet service providers. In 1995, Carly Fiorina led corporate operations. In that capacity, she reported to Lucent chief executive Henry B. Schacht. She played a key role in planning and implementing the 1996 initial public offering of a successful stock and company launch strategy. Under her guidance, the spin-off raised 3 billion. Later in 1996, Fiorina was appointed president of Lucent's consumer products sector, reporting to president and chief operating officer Rich McGinn. In 1997, she was named group president for Lucent's 19 billion global service-provider business, overseeing marketing and sales for the company's largest customer segment. That year, Fiorina chaired a 2.5 billion joint venture between Lucent's consumer communications and Royal Philips Electronics, under the name Philips Consumer Communications (PCC). The focus of the venture was to bring both companies to the top three in technology, distribution, and brand recognition. Ultimately, the project struggled and dissolved a year later after it garnered only 2% market share in mobile phones. Losses were at $500 million on sales of $2.5 billion. As a result of the failed joint venture, Philips announced the closure of one-quarter of the company's 230 factories worldwide, and Lucent closed down its wireless handset portion of the venture. Analysts suggested that the joint venture's failure was due to a combination of technology and management problems. Upon the end of the joint venture, PCC sent 5,000 employees back to Philips, many of which were laid off, and 8,400 employees back to Lucent. Under Fiorina, the company added 22,000 jobs and revenues seemed to grow from 19 billion to 38 billion. However, the real cause of Lucent spurring sales under Fiorina was by lending money to their own customers. According to Fortune magazine, "In a neat bit of accounting magic, money from the loans began to appear on Lucent’s income statement as new revenue while the dicey debt got stashed on its balance sheet as an allegedly solid asset". Lucent's stock price grew 10-fold. At the start of 2000, Lucent's "private bubble" burst, while competitors like Nortel Networks and Alcatel were still going strong; it would be many months before the rest of the telecom industry bubble collapsed. Previously Lucent had 14 straight quarters where it exceeded analysts' expectations, leading to high expectations for the 15th quarter, ending Dec. 31, 1999. On January 6, 2000, Lucent made the first of a string of announcements that it had missed its quarterly estimates, as CEO Rich McGinn grimly announced that Lucent had run into special problems during that quarter—including disruptions in its optical networking business—and
|
goats) and a dog were sacrificed by one or another of the Luperci, under the supervision of the Flamen dialis, Jupiter's chief priest. An offering was also made of salted mealcakes, prepared by the Vestal Virgins. After the blood sacrifice, two Luperci approached the altar. Their foreheads were anointed with blood from the sacrificial knife, then wiped clean with wool soaked in milk, after which they were expected to laugh. The sacrificial feast followed, after which the Luperci cut thongs (known as ) from the flayed skin of the animal, and ran with these, naked or near-naked, along the old Palatine boundary, in an anticlockwise direction around the hill. In Plutarch's description of the Lupercalia, written during the early Empire, ...many of the noble youths and of the magistrates run up and down through the city naked, for sport and laughter striking those they meet with shaggy thongs. And many women of rank also purposely get in their way, and like children at school present their hands to be struck, believing that the pregnant will thus be helped in delivery, and the barren to pregnancy. The Luperci completed their circuit of the Palatine, then returned to the Lupercal cave. History The Februa was of ancient and possibly Sabine origin. After February was added to the Roman calendar, Februa occurred on its fifteenth day (). Of its various rituals, the most important came to be those of the Lupercalia. The Romans themselves attributed the instigation of the Lupercalia to Evander, a culture hero from Arcadia who was credited with bringing the Olympic pantheon, Greek laws and alphabet to Italy, where he founded the city of Pallantium on the future site of Rome, 60 years before the Trojan War. Lupercalia was celebrated in parts of Italy and Gaul; Luperci are attested by inscriptions at Velitrae, Praeneste, Nemausus (modern Nîmes) and elsewhere. The ancient cult of the Hirpi Sorani ("wolves of Soranus", from Sabine hirpus "wolf"), who practiced at Mt. Soracte, north of Rome, had elements in common with the Roman Lupercalia. Descriptions of the Lupercalia festival of 44 BC attest to its continuity; Julius Caesar used it as the backdrop for his public refusal of a golden crown offered to him by Mark Antony. The Lupercal cave was restored or rebuilt by Augustus, and has been speculated to be identical with a grotto discovered in 2007, below the remains of Augustus' residence; according to scholarly consensus, the grotto is a nymphaeum, not the Lupercal. The Lupercalia festival is marked on a calendar of 354 alongside traditional and Christian festivals. Despite the banning in 391 of all non-Christian cults and festivals, the Lupercalia was celebrated by the nominally Christian populace on a regular basis into the reign of the emperor Anastasius. Pope Gelasius I (494–96) claimed that only the "vile rabble" were involved in the festival and sought its forceful abolition; the Roman Senate protested that the Lupercalia was essential to Rome's safety and well-being. This prompted Gelasius' scornful suggestion that "If you assert that this rite has salutary force, celebrate it yourselves in the ancestral fashion; run nude yourselves that you may properly carry out the mockery". There is no contemporary evidence to support the popular notions that Gelasius abolished the Lupercalia, or that he, or any other prelate, replaced it with the Feast of the Purification of the Blessed Virgin Mary.
|
in delivery, and the barren to pregnancy. The Luperci completed their circuit of the Palatine, then returned to the Lupercal cave. History The Februa was of ancient and possibly Sabine origin. After February was added to the Roman calendar, Februa occurred on its fifteenth day (). Of its various rituals, the most important came to be those of the Lupercalia. The Romans themselves attributed the instigation of the Lupercalia to Evander, a culture hero from Arcadia who was credited with bringing the Olympic pantheon, Greek laws and alphabet to Italy, where he founded the city of Pallantium on the future site of Rome, 60 years before the Trojan War. Lupercalia was celebrated in parts of Italy and Gaul; Luperci are attested by inscriptions at Velitrae, Praeneste, Nemausus (modern Nîmes) and elsewhere. The ancient cult of the Hirpi Sorani ("wolves of Soranus", from Sabine hirpus "wolf"), who practiced at Mt. Soracte, north of Rome, had elements in common with the Roman Lupercalia. Descriptions of the Lupercalia festival of 44 BC attest to its continuity; Julius Caesar used it as the backdrop for his public refusal of a golden crown offered to him by Mark Antony. The Lupercal cave was restored or rebuilt by Augustus, and has been speculated to be identical with a grotto discovered in 2007, below the remains of Augustus' residence; according to scholarly consensus, the grotto is a nymphaeum, not the Lupercal. The Lupercalia festival is marked on a calendar of 354 alongside traditional and Christian festivals. Despite the banning in 391 of all non-Christian cults and festivals, the Lupercalia was celebrated by the nominally Christian populace on a regular basis into the reign of the emperor Anastasius. Pope Gelasius I (494–96) claimed that only the "vile rabble" were involved in the festival and sought its forceful abolition; the Roman Senate protested that the Lupercalia was essential to Rome's safety and well-being. This prompted Gelasius' scornful suggestion that "If you assert that this rite has salutary force, celebrate it yourselves in the ancestral fashion; run nude yourselves that you may properly carry out the mockery". There is no contemporary evidence to support the popular notions that Gelasius abolished the Lupercalia, or that he, or any other prelate, replaced it with the Feast of the Purification of the Blessed Virgin Mary. A literary association between the Lupercalia and the romantic elements of Saint Valentine's Day dates back to Chaucer and poetic traditions of courtly love. Legacy Horace's Ode III, 18 alludes to the Lupercalia. The festival or its associated rituals gave its name to the Roman month of February () and thence to the modern month. The Roman god Februus personified both the month and purification, but seems to postdate both. William Shakespeare's play Julius Caesar begins during the Lupercalia. Mark Antony is instructed by Caesar to strike his wife Calpurnia, in the hope that she will be able to conceive. Research published in 2019 suggests that the word Leprechaun derives from Lupercus. In the second season of the Netflix series Chilling Adventures of Sabrina the witches celebrate Lupercalia. Today, the Satanic Temple celebrates Lupercalia among its official holidays. References Citations Bibliography A. M. Franklin, The Lupercalia (doctoral dissertation, 1921, 102pp.) Liebler, Naomi Conn (1988). The Ritual Ground of Julius Caesar. Further reading Beard, Mary; North, John; Price, Simon. Religions of Rome: A History. Cambridge University Press, 1998, vol. 1, limited preview online; search "Lupercalia". Lincoln, Bruce. Authority: Construction and Corrosion. University of Chicago
|
have publicly identified themselves as atheists. Lists by country, territory, or people List of atheist Americans List of atheist Armenians List of Dutch atheists List of Jewish atheists and agnostics List of South African atheists Lists by profession List of atheist activists and educators List of atheist authors List of atheist philosophers List of atheists in film, radio, television and theater List of atheists in music List of atheists in politics and law List of atheists in science and technology List of atheists (miscellaneous) Lists by surname List of atheists
|
atheists (surnames H to K) List of atheists (surnames L to M) List of atheists (surnames N to Q) List of atheists (surnames R to S) List of atheists (surnames T to Z) See also List of nonreligious Nobel laureates List of fictitious atheists and agnostics Lists of people by belief (including non-beliefs) List of agnostics List of converts to nontheism List of deists List of former atheists and agnostics List of humanists List of Jewish atheists and agnostics
|
President of the Soka Gakkai International Sangharakshita (1925–2018) Edward Salim Michael (1921—2006) Nakamura Hajime (1911–1999) Nishida Kitaro (1870–1945) Gudo Wafu Nishijima (1919–2014) Nishitani Keiji (1900–1990) Henry Steel Olcott (1832–1907), major revivalist of Buddhism in Sri Lanka and a Buddhist modernist for his efforts in interpreting Buddhism through a Westernized len Shunryū Suzuki (1904–1971), Sōtō Zen monk and teacher who helped popularize Zen Buddhism in the United States Sharon Salzberg (1953–), teacher of Buddhist meditation practices in the West, and also a New York Times Best selling author Sheng-yen (1930–2009), religious scholar, one of the most respected teachers of Chinese Ch'an (Zen) Buddhism, and founder of spiritual and educational organization Dharma Drum Mountain Taixu (1890–1947), activist and thinker who advocated the reform and renewal of Chinese Buddhism Yin Shun (1906–2005), bring forth the ideal of "Humanistic" (human-realm) Buddhism and regenerated the interests in the long-ignored Āgamas among Chinese Buddhists Tanaka Chigaku (1861–1939) Tsunesaburo Makiguchi (1871–1944), Japanese educator and founder of the Soka Gakkai Robert Thurman (1941–), American author, editor and translator of books on Tibetan Buddhism, Je Tsongkhapa professor of Indo-Tibetan Buddhist Studies at Columbia University and co-founder and president of Tibet House U.S. Brad Warner (1964–) Alan Watts (1915–1973) Robert Wright (1957–) Noah Levine (1971–) is an American Buddhist teacher and the author Politicians and activists Indian B. R. Ambedkar (1891–1956), Indian nationalist, jurist, scholar, political leader, anthropologist, economist and architect of the Constitution of India Prakash(Balasaheb) Ambedkar, Indian Politician, Grandson of Dr. Babasaheb Ambedkar Kiren Rijiju, Indian politician Ramdas Athawale, Indian politician Udit Raj, is an Indian politician and member of Indian National Congress. Raj, a Dalit, converted from Hinduism to Buddhism in 2001. Malaysian Tan Cheng Lock (1883-1960), Malaysian nationalist, businessmen and founder of Malaysian Chinese Association, key figure in the independence of Malaysia. Burmese Aung San Suu Kyi, Burmese opposition politician and chairperson of the National League for Democracy (NLD) in Burma; received the Rafto Prize and the Sakharov Prize in 1990 and the Nobel Peace Prize in 1991 (Theravada) U Thant (1909–1974), Burmese diplomat and third Secretary-General of the United Nations (1961–1971) (Theravada) U Nu (1997 - 1995), Prime Minister of Burma and facilitator of Sixth Buddhist Council American Bill Clinton, 42nd U.S. president from (1993-2001) David Ige is an american politician. He is the 8th Governor of Hawaii. A Democrat, he served in the Hawaii State Senate from 2003 to 2014 and the Hawaii House of Representatives from 1985 to 2003. In the 2014 gubernatorial election, he defeated incumbent Governor Neil Abercrombie in the Democratic primary, and won the general election over Republican nominee Duke Aiona. Ige was reelected in 2018. Colleen Hanabusa, U.S. Congresswoman (2011–), Democrat and lawyer from Hawaii Mazie Hirono, U.S. Senator (2013–), U.S. Congresswoman (2007–2013) and Democrat from Hawaii; first elected female Senator from Hawaii, first Asian-American woman elected to the Senate, first U.S. Senator born in Japan and the nation's first Buddhist Senator Hank Johnson, U.S. Congressman (2007–) and Democrat from Georgia; one of the first two Buddhists to serve in the United States Congress (Soka Gakkai International) English Eric Lubbock, 4th Baron Avebury (1928–2016), English politician and Liberal Democrat; served as the Liberal Member of Parliament for Orpington from 1962 to 1970 and served in the House of Lords, having inherited the title of Baron Avebury in 1971 (Secular Buddhism) South Korean Jiyul, a Buddhist nun from South Korea who fasted to stop destruction of Korean salamander lands (Korean Seon) Pomnyun, South Korean Buddhist monk, Zen master, and peace activist who received the Ramon Magsaysay Award for Peace and International Understanding in 2002 for his peace activism on the issue of Korean peninsula. (Korean Seon) Vietnamese Thích Huyền Quang (1919–2008), Vietnamese Buddhist monk, dissident and activist; formerly the patriarch of the Unified Buddhist Sangha of Vietnam; in 2002, he was awarded the Homo Homini Award for his human rights activism by the Czech group People in Need Thích Quảng Độ, Vietnamese Buddhist monk, current patriarch of the Unified Buddhist Sangha of Vietnam; awarded the Homo Homini Award for human rights activism by the Czech group People in Need in 2002; nine-time Nobel Peace Prize nominee Thích Quảng Đức (1897–1963), Vietnamese Mahayana monk and self-martyr for freedom of religion; burned himself to death at a busy Saigon road intersection on 11 June 1963 (Mahayana) Sri Lankan D. S. Senanayake (1883-1952), Prime Minister of Ceylon S. W. R. D. Bandaranaike (1899-1959), Prime Minister of Ceylon Sirimavo Bandaranaike (1916-2000), Prime Minister of Sri Lanka and first female Prime Minister in the world. Actors American Anthony Lee, (1981-2000), was an American Buddhist actor and playwright. (Soka Gakkai International) Keanu Reeves (1964- ), American- Canadian Actor and became Lord Buddha in Little Buddha (1993) and Neo in The Matrix film series . (Theravada) Robert Downey Junior (1965-), American jewish buddhist who is well-known as Iron Man. He has said many times that Buddhism has helped him with his drug and alcohol addiction.He was honored by Time Magazine's "Time 100" in 2008, an annual list of the 100 most influential people in the world. His laurels include two Academy Award nominations, three Golden Globe wins, numerous other award nominations and wins, and tremendous popular and commercial success, particularly in his roles as Sherlock Holmes and Tony Stark (the latter of which he has so far played in Iron Man (2008), Iron Man 2 (2010), The Avengers (2012), Iron Man 3 (2013), and Avengers: Age of Ultron (2015). For three consecutive years, from 2012 to 2015, Downey has topped the Forbes list of Hollywood's highest-paid actors, making an estimated $80 million in earnings between June 2014 and June 2015.(Theravada) Ron Glass (1945-2016), is an american devout buddhist actor and comedian. Steven Seagal, American actor and aikido expert (Tibetan Buddhism) Chris Evans (1981- ), is an American buddhist actor. He is well-known as Captain America. He is a student of Indian Buddism. He spent three weeks in Rishikesh in 2005 or 2006 at a Buddhist retreat and that he attends a Buddhism class in LA.(Theravada) Pattrick Duffy (1949- ), is an American actor and director widely known for his role on the CBS primetime soap opera Dallas, where he played Bobby Ewing, the youngest son of Miss Ellie, and the nicest brother of J.R. Ewing from 1978 to 1985 and from 1986 to 1991. The actor was brought closer to the teachings of Buddhism by his late wife, the ballet dancer Carlyn Rosser (1939-2017). He has now been practicing religion for almost 50 years and describes it as an "Essential part" of his life. (Soka Gakkai International) Peter Coyote (1941–), American actor and author Jeff Bridges (1949- ), is an American actor. One of the most acclaimed actors of his generation, he is the recipient of numerous accolades, including a Screen Actors Guild Award, two Golden Globe Awards, and an Academy Award from seven nominations. Critic Pauline Kael wrote that Bridges "May be the most natural and least self-conscious screen actor that has ever lived." The actor elaborated that his Buddhism is more like a general calmness. (Zen) Michael Imperioli (1966- ), is an American actor, writer, director and musician, best known for his role as Christopher Moltisanti in the HBO crime drama The Sopranos (1999–2007), which earned him the Primetime Emmy Award for Outstanding Supporting Actor in a Drama Series in 2004. In 2008, Imperioli became a Buddhist. John Astin is an American actor best known for playing Gomez Addams on The Addams Family Martin Starr (1983- ), is an American Buddhist actor and comedian. He is known for the television roles of Bill Haverchuck on the short-lived comedy-drama Freaks and Geeks (1999–2000), Roman De Beers on the comedy series Party Down (2009–2010), Bertram Gilfoyle on the HBO series Silicon Valley (2014–2019), for his film roles in Knocked Up (2007) and Adventureland (2009), and as Roger Harrington in the Marvel Cinematic Universe films The Incredible Hulk (2008), Spider-Man: Homecoming (2017), Spider-Man: Far From Home (2019), and Spider-Man: No Way Home (2021). (Theravada) David Labrava is an actor, writer, tattoo artist, former member of the Hells Angels, and motorcycle enthusiast best known for playing Happy Lowman in the FX series Sons of Anarchy and its spinoff Mayans M.C.(Zen) Garry Shandling (1949-2016), was an american actor and comedian. (Zen) Drew Carey, is an american buddhist actor, comedian, game show host and photographer.(Theravada) British Adewale Akinnuoye-Agbaje (1967 ) British-Nigerian actor best known for his roles on television, including Lost, Oz, and Game of Thrones (Soka Gakkai International) Benedict Cumberbatch (1976- ) is a British buddhist actor.He is famous for Dr.Strange (2021), The Imitation Game (2014) and Spider-man:No Way Home (2021).(Theravada). Chris Gascoyne (1968-) is an english buddhist actor, who is known for his role as the seventh Peter Barlow in the soap opera Coronation Street from 2000 . Gascoyne has been nominated for several accolades at the British Soap Awards for his portrayal of Peter Barlow.(Theravada) Orlando Bloom (1977- ), English actor. Well-known for Will turner in Pirates of the Carrebean flim series, Elf Legolas in Lord of Rings movie series. (Soka Gakkai International) Peter Dean (1939-), is a British buddhist actor.Best known for his roles as Pete Beale in EastEnders, Jeff Bateman in Coronation Street and Sergeant Jack Wilding in Woodentop (Zen) Russell Brand (1975- ), is a british comedian, actor, and radio host. After beginning his career as a comedian and later becoming an MTV presenter, Brand first achieved renown in 2004 as the host of Big Brother's Big Mouth, and Big Brother spin-off.(Tibetan Buddhism) Indian Gagan Malik (1976- ), Indian actor.(Theravada) Tusshar Kapoor (1976- ), Most celebrated Bollywood actor and producer of India. He is famous for Golmal flim series. ( Nichiren Buddhism) Ayushman Khurrana (1984- ), is an Indian flim actor and activists. Ayushmann Khurrana and his wife Tahira Kashyap are followers of Nichiren Buddhism, which has provided the fuel to fight their battles against cancer. Buddhism has also helped Khurrana articulate his journey as an actor better. “I practice Nichren Buddhism. It has taught me that you have to be mentally strong. It has an impact on your physical being. It (cancer) was a minor frustration for me. But I accepted it truly. I decided that I will not live in denial and hide it from the world,” says Tahira, who was detected with DCIS (ductal carcinoma in situ) with high grade malignant cells last year. ( Niciren Buddhism) Ravi Dubey (1983- ), is an indian buddhist actor,model and producer. He is a Nichiren Buddhist. He said, "I started following Buddhism when I was going through a very rough patch in my life and I wanted some understanding of the chaos that was going on in one's life. I wanted to align myself and feel better about myself. So, when things went out of control, I started chanting at that time."(Nichiren Buddhism) Italian Manuel de pepe (1970-), italian actor,producer and singer. He converted to Buddhism in 2011. (Secular Buddhism) Marco Columbro (1950- ), is an Italian actor and television host.(Tibetan Buddhism) Singer American David Bowie (8 January 1947 – 10 January 2016), was an English singer-songwriter and actor. Duncan Sheik American singer-songwriter and composer(Soka Gakkai International ) Steven Sater American playwright, lyricist and screenwriter best known for Spring Awakenings(Soka Gakkai International) Australian Jimmy Barnes , is an australian singer. British Howard Jones English musician, singer and songwriter Canadian Beverly Glenn-Copeland U.S.-born Canadian musician, songwriter and singer(Soka Gakkai International) k.d. lang, Canadian singer (Tibetan Buddhism) Chinese French Hong Konger Daniel Chan, is a popular Hong Kong singer, songwriter, and actor. He is most notable as one of the young talents in the 1990s music scene.Chan is a Buddhist.(Chan Buddhism) Indian Shibani Kashyap, Indian singer Italian Carmen Consoli Italian singer and songwriter Vietnamese Sport players Footballer Brett Kirk (1976–), is a former Australian rules football player of the Sydney Swans and was the AFL's International Ambassador. Kirk is currently serving as an assistant coach with the Sydney Swans.Kirk is known as a Buddhist and has a tattoo of a Buddhist symbol on his back. Fabien Barthez, French goalkeeper (1994–2006) of 1998 FIFA World Cup and Euro 2000-winning French national football team (Zen) Shunsuke Nakamura Japanese soccer player, midfielder for the Scottish team Celtic F.C. Sébastien Frey, is a French former professional footballer who played as a goalkeeper. His club career began in France with Cannes in 1997, but later went on to spend most of his career in the Italian Serie A, playing for Inter Milan, Hellas Verona, Parma, Fiorentina, and Genoa; he ended his career in 2015, after two seasons with Turkish side Bursaspor.Frey is a Buddhist and credited former Fiorentina legend Roberto Baggio as one of his spiritual mentors.(Soka Gakkai International) Roberto Baggio, Italian (1988–2004) footballer; in 1993, he was named FIFA World Player of the Year and won the Ballon d'Or (Soka Gakkai International) Mario Balotelli Barwuah, is an Italian buddhist professional footballer who plays as a striker for Süper Lig club Adana Demirspor. Balotelli started his professional football career at Lumezzane and played for the first team twice before having an unsuccessful trial at Barcelona, and subsequently joining Inter Milan in 2007. He is studying Buddhism in a bid to find inner peace.He has also bought several copies of the dharma, the religion’s teachings, and set up a quiet area with a statue of Buddha where he can meditate. (Pure Land Buddhism) Mehmet Scholl, is a German football manager and former player. He played most of his career as an attacking midfielder for Bayern Munich. During his career he won the UEFA Cup in 1996, the Euro 1996, and the UEFA Champions League in 2001, as well as eight German Championships.(Theravada) Cricketer Kumar Sangakkara (1977-) is a Sri Lankan cricket commentator, former professional cricketer, businessman, ICC Hall of Fame inductee, and the former president of Marylebone Cricket Club. He is widely regarded as one of the greatest wicket-keeper-batters in the history of the sport. (Theravada) Lasith Malinga (1981- ) is a Sri Lankan professional cricket player and Captain of T20 International cricket of Sri Lanka. he is considered as one of the greatest limited-overs bowlers of all time. He has got a lot of popularity for his ability to take Hat-trick in all three formats of the game. In addition to this, Malinga is the first player to take two world cup Hat-trick and three Hat-tricks in the ODIs.(Theravada) Tillakaratne Dilshan (1976–), Sri Lankan cricket player who converted from Islam to Buddhism at the age of 16, previously known as Tuwan Muhammad Dilshan. (Theravada) Tillakaratne Sampath (1982–), Sri Lankan cricket player who was previously known as Tuwan Mohammad Nishan Sampath Suraj Randiv (1985–), Sri Lankan cricket player.(Theravada) Swimer Anthony Ervin, american gold medilist swimer.(Zen) Rugby Jonny Wilkinson (1979- ), is an english former rugby union player. He is particularly known for scoring the winning drop goal in the 2003 Rugby World Cup Final and is widely acknowledged as one of the best rugby union players of all time. (Thravada) Golfer Tiger Woods, American golfer(Theravada) Military leaders Ellison Onizuka (1946–1986), U.S. Air Force Colonel and first Asian American astronaut of NASA (Pure Land Buddhism) Buddhist practitioners notable in other fields Kate Bosworth, American actress (Soka Gakkai International) John Cage, American composer (Zen Buddhism) Jennifer Aniston (1965- ) , American actress and producer. She famous for Freinds. (Zen) Robert Wright (1957–) American journalist and author.(Zen) Belinda Carlisle, American singer (Soka Gakkai International) Anne Louise Hassing Danish actress(Soka Gakkai International) Tisca Chopra, Indian actress (Soka Gakkai International) Edson Celulari, Brazilian actor Chow Yun-fat, Chinese actor Leonard Cohen, Canadian singer-songwriter/poet (Zen) Penélope Cruz, Spanish actress and model Shraddha Das, is an Indian actress and model who predominantly appears in Telugu, Hindi, and Kannada language films.(Theravada) George Dvorsky, Transhumanist, Futurist and one of directors of Humanity+ (Secular Buddhism) Richard Gere, American actor (Tibetan Buddhism) Allen Ginsberg, poet (Tibetan Buddhism) Philip Glass, American composer (Tibetan Buddhist) Herbie Hancock, American pianist and composer (Soka Gakkai International) Steve Jobs, American businessman, entrepreneur, marketer, inventor and the CEO of Apple Inc (Zen) Jack Kerouac, American novelist (Zen and Tibetan Buddhism; also the Catholic Church) Celeste Lecesne, American actor, author, screenwriter, LGBT rights activist, founder of The Trevor Project (Soka Gakkai International) Jet Li, Chinese martial artist, Hollywood actor (Tibetan Buddhist) Courtney Love, American singer-songwriter (Soka Gakkai International) Naima Mora, fashion model, winner of America's Next Top Model (Soka Gakkai International) Hansika Motwani, is an Indian actress who predominantly appears in Tamil and Telugu films. She is Buddhist. She said in an interview, “The best way to effectively de-stress for me is to chant- Nam Myo Ho Renge Kyo, as I strongly follow Buddhism.” (Tibetan Buddhism) Kenneth Pai, Chinese-American writer Maya Soetoro-Ng, Indonesian American writer, university instructor and maternal half-sister of Barack Obama, the 44th President of the United States Oliver Stone, American film director Sharon Stone, American actress, producer, and former fashion model Earl Sweatshirt, American rapper, songwriter, and record producer. (Nichiren Buddhism) George Takei, American actor and author (Theravada) Tina Turner, American singer-songwriter (Soka Gakkai International) Marcia Wallace, American actress, voice artist, comedian (Soka Gakkai International) Naomi Watts, British-Australian actress and film producer Faye Wong, Chinese singer and actress (Tibetan Buddhism) Michelle Yeoh, Malaysian actress Priscilla Chan, pediatrician and philanthropist, wife of Facebook founder Mark Zuckerberg Fictional Buddhists Anime and Manga Gautama Buddha, protagonist from Saint Young Men The cast from Ah My Buddha Ikkyū, protagonist from Ikkyū-san The cast from Oseam Seishin Muroi, character from Shiki Yoh Asakura, protagonist of the anime/manga Shaman King Hanamaru Kunikida, character from Love Live! Sunshine!! Miroku, character from Japanese Anime Inuyasha Krillin, character from the Dragonball series Kaname Asahina, Chiaki and Yūsei, characters from Brothers Conflict Chichiri, character from Fushigi Yūgi Yakumo Kokonoe, character from The Irregular at Magic High School Mayura Sōda, Miyuki Sagara, and Yukimasa Sagara, characters from RDG: Red Data Girl Keisei Tagami and Akasha Shishidō, characters from the Corpse Princess series Anji Yūkyūzan, character from Rurouni Kenshin
|
Zen master of the Rinzai school Dōgen Zenji (1200–1253), founder of the Sōtō school of Zen, based upon the Caodong school Eisai (1141–1215), travelled to China and returned to found the Rinzai school of Zen] Hakuin Ekaku (1686–1769), Rinzai school of Zen] Hōnen (1133–1212), founder of the Jōdo-shū school of Pure Land Buddhism Ikkyū (1374–1481), Zen Buddhist monk and poet Ippen (1234–1289), founder of the Ji-shū sect of Pure Land Buddhism Kūkai (774–835), founder of Shingon Buddhism Myōe (1173–1232), monk of Kegon and Shingon Buddhism, known for his propagation of the Mantra of Light Nakahara Nantenbō (1839–1925), Zen master and artist Nichiren (1222–1282), founder of Nichiren Buddhism Nikkō (1246–1333), founder of Nichiren Shōshū Rōben (689–773), invited Simsang to Japan and founded the Kegon tradition based upon the Korean Hwaeom school Ryōkan (1758–1831), Zen monk and poet Saichō (767–822), founded Tendai school in Japan, also known by the posthumous title Dengyō Daishi Shinran (1173–1263), founder of the Jōdo Shinshū school of Pure Land Buddhism and disciple of Hōnen Takuan Sōhō (1573–1645), Zen teacher, and, according to legend, mentor of the swordsman Miyamoto Musashi Gempō Yamamoto (1866–1961), Zen master Shinjō Itō (1906–1989), founder of Shinnyo-en Korean Gihwa (1376–1433), Korean Seon monk; wrote commentaries on the Diamond Sutra and Sutra of Perfect Enlightenment Jinul, Korean Seon monk (1158–1210); founder of modern Korean gong'an meditation system Uisang (7th century), Korean monk, founder of Hwaeom tradition, based upon the Chinese Huayan school Woncheuk Wonhyo (617–668), Korean monk; prolific commentator on Mahayana sutras Burmese Shin Arahan, primate of Pagan Kingdom, 1056–1115 Ledi Sayadaw, propagator of Vipassanā Mahasi Sayadaw, propagator of Vipassanā Sayadaw U Tejaniya, propagator of Vipassanā Mogok Sayadaw, propagator of Vipassanā Webu Sayadaw, propagator of Vipassanā Panditarama Sayadaw, propagator of Vipassanā Mingun Sayadaw, first monk in Myanmar to be awarded the title of Tipitakadhara, meaning Keeper and Guardian of the Tipitaka Taunggwin Sayadaw, the last Buddhist monk to hold the office as Thathanabaing of Burma Maha Bodhi Ta Htaung Sayadaw, founder of Maha Bodhi Tahtaung Thamanya Sayadaw, best known for his doctrinal emphasis on metta Sunlun Sayadaw, a popular meditation teacher among the monks and Vipassanā meditation master Sitagu Sayadaw, founder and Supreme Head of the Sitagu Buddhist Academies Ashin Nandamalabhivamsa, rector of International Theravada Buddhist Missionary University Chanmyay Sayadaw, well-known monk and editor of the Buddhist Scriptures in Pali for reciting Buddhist scriptures at the Sixth Buddhist Council in Myanmar Taung Galay Sayadaw, Karen Theravadin Buddhist monk, and also known as a prolific writer and a historian Sayadaw U Narada, planted many thousands of Bodhi trees, built thousands of pagodas and Buddha statues Sayadaw U Pannavamsa, prominent Buddhist monk, known for his missionary work, particularly in Sri Lanka and Malaysia Ashin Sandadika, well-known monk Sayagyi U Ba Khin, propagator of vipassana meditation in the Ledi tradition Thai Somdet Phra Buddhacarya (1788–1872), monk who was the preceptor and teacher of King Rama IV Ajahn Sao Kantasīlo (1861–1941), one of the pioneers of the Dhammayuttika Nikaya, mentor of Ajahn Mun Ajahn Mun Bhūridatta (1870–1949), monk who established the Thai Forest Tradition or "Kammaṭṭhāna tradition" Khruba Siwichai (1878–1939), best known for the building of many temples during his time, his charismatic and personalistic character Luang Pu Sodh Candasaro (1884–1959), monk who founded the Dhammakaya Movement in the early 20th century Luang Pu Waen Suciṇṇo (1887–1985), first generation student of the Thai Forest Tradition Somdet Phra Sangharaja Chao Krommaluang Jinavajiralongkorn (1897–1988), the 18th Supreme Patriarch of Thailand Phra Ajaan Thate Desaransi (1902–1994), first generation student of the Thai Forest Tradition and one of the founding teachers of the lineage Buddhādasa Bhikkhu (1906–1993), famous and influential Thai ascetic-philosopher of the 20th century Ajahn Lee Dhammadharo (1907–1961), regarded as one of the great teacher and meditation master of the Thai Forest Tradition Ajahn Maha Bua (1913–2011), well-known monk in the Thai Forest Tradition Somdet Phra Sangharaja Chao Krommaluang Vajirañāṇasaṃvara (1913–2013), the 19th Supreme Patriarch of Thailand Ajahn Fuang Jotiko (1915–1986), student of Ajahn Lee, well-known monk in the Thai Forest Tradition Ajahn Chah (1918–1992), monk well known for his students from all over the world Ajahn Suwat Suvaco (1919–2002), student of Ajahn Funn and established four monasteries in the United States Phra Chanda Thawaro (1922–2012), student of Ajahn Mun, one of the best known Thai Buddhist monks of the late 20th and early 21st centuries Somdet Phra Ariyavongsagatanana IX (1927–), the 20th and current Supreme Patriarch of Thailand, practitioner of the Thai Forest Tradition Rulers and monarchs Anawrahta (1015–1078), founder of the Pagan Kingdom and credited with introducing Theravada Buddhism there and reintroducing it in Ceylon Ashoka (304–232 BC), Mauryan Emperor of ancient India, and the first Buddhist ruler to send Buddhist missionaries outside of India throughout the Old World (阿育王) Brihadratha Maurya, last ruler of the Maurya Empire Bayinnaung Kyawhtin Nawrahta (1516-1581), king of the Toungoo Dynasty, assembled the largest empire in the history of Southeast Asia, viewed himself as the protector of Theravada Buddhism, and had long tried to promote and protect the religion in Ceylon, introduced more orthodox Theravada Buddhism to Upper Burma and the Shan states, prohibited all human and animal sacrifices throughout the kingdom Harsha (606–648), Indian emperor who converted to Buddhism Jayavarman VII (1181–1219), king of Cambodia Kanishka the Great, ruler of the Kushan Empire Kublai Khan, Mongol khagan and founder of the Yuan dynasty of China Hulagu Khan, Mongol ruler who conquered much of Southwest Asia, he converted to Buddhism on his deathbed, spending most of his life as a Nestorian Christian Menander I (Pali: Milinda), 2nd century BCE, a king of the Indo-Greek Kingdom of Northwestern India who questioned Nāgasena about Buddhism in the Milinda Pañha and is said to have become an arhat Mindon Min (1808–1878), penultimate King of Burma and facilitator of the Fifth Buddhist council Emperor Ming of Han Mongkut, king of Thailand and founder of the Dhammayuttika Nikaya Prince Shōtoku (574–622), mythologized crown prince and regent of Japan Theodorus (1st century BCE), Indo-Greek governor, author of a Buddhist dedication Wu Zetian (625–705), only female Empress Regnant in Chinese history Emperor Wu of Liang (梁武帝) (502–549) Devanampiya Tissa of Anuradhapura (307 BCE–267 BCE), King of Anuradhapura Dutugamunu of Anuradhapura (161 BCE-131 BCE), King of Sri Lanka Bimbisar (544-492 BC) founder of Haryanka dynasty Ajatshatru (492 460 BC ) second emperor of Haryanka dynasty Udayin (460-444 BC) third emperor of Haryanka dynasty Pasenadi king of kosala Mahinda Rajapaksa Prime minister of Sri Lanka and Modern Day leader of Buddhist’s World Modern teachers Theravada teachers Ajahn Amaro (1956–) Ajahn Buddhadasa Bhikkhu (1906–1993) Ajahn Brahm (1951–) Ajahn Candasiri (1947–) Ajahn Chah (1918–1992) Ajahn Jayasaro (1958–) Ajahn Khemadhammo (1944–) Ajahn Mun Bhuridatta (1870–1949) Ajahn Pasanno (1949–) Ajahn Sucitto (1949–) Ajahn Sumedho (1934–) Ajahn Sundara (1946–) Ajahn Viradhammo (1947–) Ayya Khema (1923–1997) Balangoda Ananda Maitreya Thero (1896–1998) Bhante Sujato (1966–) Bhikkhu Anālayo (1962–) Bhikkhu Bodhi (1944–) Bhikkhu Kiribathgoda Gnanananda (1961–) Bour Kry (1945–) Charles Henry Allan Bennett (1872–1923) Dipa Ma (1911–1989) Godwin Samararatne (1932–2000) Hammalawa Saddhatissa (1914–1990) Henepola Gunaratana (1927–) Jack Kornfield (1945–) K. L. Dhammajoti (1949–) K. Sri Dhammananda (1919–2006) Kirinde Sri Dhammaratana (1948–) Ledi Sayadaw (1846–1923) Luangpor Thong (1939–) Mahasi Sayadaw (1904–1982) Mother Sayamagyi (1925–2017) Ñāṇamoli Bhikkhu (1905–1960) Nyānaponika Mahāthera (1901–1994) Nyānatiloka Mahāthera (1878–1957) Ñāṇavīra Thera (1920–1965) Narada Maha Thera Phra Paisal Visalo Piyadassi Maha Thera Preah Maha Ghosananda (1929–2007) Sayagyi U Ba Khin (1899–1971) S. N. Goenka (1924–2013) Sharon Salzberg (1952–) Sujiva (1951–) Thanissaro Bhikkhu (1949–) Yuttadhammo Bhikkhu (1979–) In Thailand, Ajahn means monk teachers (have to been a monk more than 10-years) For Theravada, Bhikkhu (male) and Bhikkhuni (female) mean monastic members in Pali (Theravada use Pali language for studying Tripitaka) Tibetan Buddhist teachers Anagarika Govinda (1898–1985) B. Alan Wallace (1950–) Chagdud Tulku Rinpoche (1930–2002) Chögyam Trungpa Rinpoche (1940–1987) Chökyi Nyima Rinpoche (1951–) Dhardo Rimpoche (1917–1990) Dilgo Khyentse (1910–1991) Dudjom Jigdral Yeshe Dorje (1904–1987) Gyaincain Norbu, the 11th Panchen Lama (controversial; born 1990) Kalu Rinpoche (1905–1989) Karma Thinley Rinpoche (1931–) Kelsang Gyatso Matthieu Ricard (1946–) Ole Nydahl (1941–) Rangjung Rigpe Dorje, 16th Karmapa (1924–1981) Sakyong Mipham 14th Dalai Lama (1935–) Tenzin Palmo (1943–) Thubten Yeshe (known as Lama Yeshe) (1935–1984), Tibetan lama who, while exiled in Nepal, co-founded Kopan Monastery (1969) and the Foundation for the Preservation of the Mahayana Tradition (1975). He followed the Gelug tradition. Thubten Zopa Rinpoche Trijang Lobsang Yeshe Tenzin Gyatso(1901–1981) Tsoknyi Rinpoche (1966–) Tulku Urgyen Rinpoche (1920–1996), Dzogchen, Mahamudra and the Chokling Tersar Yongey Mingyur Rinpoche (1975–) Gelek Rimpoche Tsem Tulku Rinpoche (1965–) Dagyab Kyabgoen Rinpoche Yongey Mingyur Rinpoche Sakya Trizin Thubten Chodron Pema Chödrön Robina Courtin Robert Thurman Mark Epstein Dzogchen and Bon Teachers Namkhai Norbu (1938–2018) Tenzin Wangyal Rinpoche (1961–) Zen teachers American Adyashanti Robert Baker Aitken (1917–2010) Anne Hopkins Aitken (1911–1994) Reb Anderson (1943–) Zentatsu Richard Baker (1936–) Joko Beck (1917–2011) Sherry Chayat (1943–) Issan Dorsey (1933–1990) Zoketsu Norman Fischer (1946–) James Ishmael Ford (1948–) Tetsugen Bernard Glassman (1939–2018) Paul Haller Cheri Huber (1944) Sozui Schubert (1965) hvzc.org Soenghyang (Barbara Rhodes, 1948–) Philip Kapleau (1912–2004) Houn Jiyu-Kennett (1924–1996) Bodhin Kjolhede (1948–) Jakusho Kwong (1935–) Taigen Dan Leighton (1950–) John Daido Loori (1931–2009) Dai Bai Zan Cho Bo Zen Ji (1954–) Heng Sure (1949–) Bonnie Myotai Treace (1956–) Brad Warner (1964–) Chinese Fayun (1933–2003) Hsu Yun (1840–1959) Hsuan Hua (1918–1995) Nan Huai-Chin (1918–2012) European John Crook (1930–2011) U Dhammaloka (1856?–1914?) John Garrie (1923–1998) Muhō Noelke (1968–) Japanese Kōbun Chino Otogawa (1938–2002) Taisen Deshimaru (1914–1982) Hakuin Ekaku (1686–1769) Keido Fukushima Jakushitsu Genkō (1290–1367) Shodo Harada (1940–) Harada Daiun Sogaku (1871–1961) Dainin Katagiri (1928–1990) Musō Soseki (1275–1351) Imakita Kosen (1816–1892) Yamada Koun (1907–1989) Taizan Maezumi (1931–1995) Sōyū Matsuoka (?–1998) Sōkō Morinaga (1925–1995) Soen Nakagawa (1907–1984) Gudō Wafu Nishijima (1919–2014) Shōhaku Okumura Kōdō Sawaki (1880–1965) Nyogen Senzaki (1876–1958) Oda Sessō (1901–1966) Soyen Shaku (1859–1919) Zenkei Shibayama (1894–1974) Eido Tai Shimano (1932–2018) Omori Sogen (1904–1994) D. T. Suzuki (1870–1966) Shunryū Suzuki (1904–1971) Dai Bai Zan Cho Bo Zen Ji (1933–) Bassui Tokushō (1327–1387) Sesshū Tōyō (1420–1506) Sobin Yamada Hakuun Yasutani (1885–1973) Bankei Yōtaku (1622–1693) Sesson Yūbai (1290–1348) Korean Seongcheol (1912–1993) Seungsahn (1927–2004) Pomnyun (1953–) Malaysian Chi Chern (1955–) Taiwanese Guang Qin (廣欽) (1892–1986), founder of Cheng Tian Temple (承天禪寺) in Taiwan Yin Shun (印順) (1906–2005), founder of Humanistic Buddhism (人間佛教) Sheng-yen (聖嚴) (1931–2009), founder of Dharma Drum Mountain (法鼓山) in Taiwan Cheng Yen (證嚴) (1937–), founder of Tzu Chi Foundation (慈濟基金會) in Taiwan Hsing Yun (星雲) (1927–), founder of Fo Guang Shan (佛光山) in Taiwan Wei Chueh (惟覺) (1928–), founder of Chung Tai Shan (中台禪寺) in Taiwan Vietnamese Thích Nhất Hạnh (1926–2022) Thích Chân Không (1938–) Thích Thiên-Ân (1926–1980) Thích Thanh Từ (1924–) Writers Nyanatiloka Mahathera, (1878–1957), translated several important Theravadin Pali texts into German, also wrote a Pali grammar, an anthology, and a Buddhist dictionary Nyanaponika Thera (1901–1994), co-founder of the Buddhist Publication Society, contemporary author of numerous seminal Theravada books Ñāṇamoli Bhikkhu (1905–1960), is remembered for his reliable translations from the Pali into English, remarkable command of the Pali language and a wide knowledge of the canonical scriptures Bhikkhu Bodhi (1944–), second president of the Buddhist Publication Society and has edited and authored several publications grounded in the Theravada Buddhist tradition Ṭhānissaro Bhikkhu (1949–), known for his translations of almost 1000 Sutta in all and providing the majority of the sutta translations in a website known as "Access to Insight" Bhikkhu Analayo (1962–), known for his comparative studies of Early Buddhist Texts as preserved by the various early Buddhist traditions Buddhādasa Bhikkhu, his works literally take up an entire room in the National Library of Thailand, and inspired a group of Thai social activists and artists of the 20th century Jack Kornfield (1945–), American book writer, student of renowned forest monk Ajahn Chah, and teacher of Theravada Buddhism Joseph Goldstein (1944–), one of the first American Vipassana teachers, contemporary author of numerous popular books on Buddhism Ven. K. Sri Dhammananda (1919–2006), Buddhist monk and scholar. in Malaysia, wrote approximately 60 Buddhist works, ranging from small pamphlets to texts of over 700 pages Achan Sobin S. Namto (1931–), taught Vipassana meditation and Buddhist psychology in Southeast Asia and North America for over 50 years Phra Dhammavisuddhikavi (1936–), Ex-Vice Rector for Academic Affairs at Mahamakut Buddhist University and has written 70 books on Buddhism P.A. Payutto (1937–), lectured and written extensively about a variety of topics related to Buddhism, awarded the 1994 UNESCO Prize for Peace Education Phra Paisal Visalo, writing and editing books on environment and Buddhism, co-founder of Sekiyadhamma, a network of socially engaged monks in Thailand Yuttadhammo Bhikkhu, (1979–), facilitates a meditation website for groups and individuals, maintains a YouTube channel where hosts both live chatrooms and pre-recorded videos answering viewers' questions about Theravada Buddhism Tara Brach (1953–) John Crook (1930–2011), British ecologist, sociologist, and practitioner of both Ch'an and Tibetan Buddhism tradition Josei Toda (1900–1958), peace activist and second president of the Soka Gakkai Han Yong-un (1879–1944) Chittadhar Hridaya (1906–1982) Hsuan Hua (1918–1995), Tripitaka Master; extensive English commentaries on the major Mahayana Sutras: Avatamsaka Sutra, Shurangama Sutra, Shurangama Mantra, Lotus Sutra, Diamond Sutra, and many others Christmas Humphreys (1901–1983) Daisaku Ikeda (1928–), prolific writer of Nichiren Buddhism, society, peace
|
did not believe in God, and that he was mostly agnostic Sidney Poitier (1927–2022): Bahamian American actor, film director, author, and diplomat; his views are closer to deism Hugo Riemann (1949–1919): German music theorist and composer Joe Rogan (born 1967): American comedian, podcaster, social critic and UFC color commentator Andy Rooney (1919–2011): American broadcast personality; specified that he was an agnostic and not an atheist, but also called himself an atheist Tim Rice (born 1944): Wrote the rock opera Jesus Christ Superstar about Jesus. The opera was controversial with conservative Christians. Larry Sanger (born 1968): American co-founder of Wikipedia. Franz Schubert (1797–1828): Austrian composer Robert Schumann (1810–1856): German composer and influential music critic; widely regarded as one of the greatest composers of the Romantic era Ridley Scott (born 1937): English film director and producer; Alien (1979), Blade Runner Adrienne Shelly (1966–2006), American actor, screenwriter and director Richard Strauss (1864–1949): German composer of the late Romantic and early modern eras Howard Stern (born 1954): American radio personality, television host, author, actor, and photographer Sting (born 1951): English musician and lead singer of The Police Matt Stone (born 1971): American co-creator of the cartoon series South Park; considers himself an agnostic Jew (his mother is Jewish), though he has also denied the existence of God Osamu Tezuka (1928–1989): Japanese cartoonist, manga artist, animator, producer, activist and medical doctor; creator of Astro Boy, Kimba the White Lion and Black Jack; often credited as the "godfather of anime", and is often considered the Japanese equivalent to Walt Disney Jhonen Vasquez (born 1974): American comic book writer, and cartoonist; known for the animated series Invader Zim Giuseppe Verdi (1813–1901): Italian composer, one of the most influential of the 19th century Robert Jastrow (1925–2008): American astronomer, physicist and cosmologist. Edwin Thompson Jaynes (1922–1998): American physicist and statistician. He wrote extensively on statistical mechanics and on foundations of probability and statistical inference. He also pioneered the field of Digital physics. James Hopwood Jeans (1877–1946): English physicist, astronomer and mathematician. Jerome Karle (1918–2013): American physical chemist. Jointly with Herbert A. Hauptman, he was awarded the Nobel Prize in Chemistry in 1985, for the direct analysis of crystal structures using X-ray scattering techniques. August Kekulé (1829–1896): German organic chemist. He was one of the most prominent chemists in Europe, especially in theoretical chemistry. He was the principal founder of the theory of chemical structure. John Kendrew (1917–1997): English biochemist and crystallographer who shared the 1962 Nobel Prize in Chemistry with Max Perutz; their group in the Cavendish Laboratory investigated the structure of heme-containing proteins. John Maynard Keynes (1883–1946): British economist. His ideas are the basis for the school of thought known as Keynesian economics, as well as its various offshoots. Michio Kaku (born 1947): American theoretical physicist. Alfred Kastler (1902–1984): French physicist. He won the Nobel Prize in Physics in 1966. Joseph-Louis Lagrange (1736–1813): Italian-French mathematician and astronomer. He made significant contributions to all fields of analysis, number theory, and classical and celestial mechanics. Irving Langmuir (1881–1957): American chemist and physicist. He was awarded the 1932 Nobel Prize in Chemistry for his work in surface chemistry. Anthony James Leggett (born 1938): English-American physicist. Professor Leggett is widely recognized as a world leader in the theory of low-temperature physics, and his pioneering work on superfluidity was recognized by the 2003 Nobel Prize in Physics. Joseph Leidy (1823–1891): American paleontologist. Mario Livio (born 1945): Israeli-American astrophysicist. Seth Lloyd (born 1960): American mechanical engineer. He is a professor of mechanical engineering at the Massachusetts Institute of Technology. James Lovelock (born 1919): British scientist, environmentalist and futurologist. He is best known for proposing the Gaia hypothesis. Percival Lowell (1855–1916): American businessman, author, mathematician, and astronomer who fueled speculation that there were canals on Mars, founded the Lowell Observatory in Flagstaff, Arizona, and formed the beginning of the effort that led to the discovery of Pluto 14 years after his death. Frank Malina (1912–1981): American aeronautical engineer and painter, especially known for becoming both a pioneer in the art world and the realm of scientific engineering. Rudolph A. Marcus (born 1923): Canadian-born chemist who received the 1992 Nobel Prize in Chemistry for his theory of electron transfer. Lynn Margulis (1938–2011): American biologist. She is best known for her theory on the origin of eukaryotic organelles, and her contributions to the endosymbiotic theory, which is now generally accepted for how certain organelles were formed. She is also associated with the Gaia hypothesis, based on an idea developed by the English environmental scientist James Lovelock. Dan McKenzie (geophysicist) (born 1942): British geophysicist. Simon van der Meer (1925–2011): Dutch particle accelerator physicist who shared the Nobel Prize in Physics in 1984 with Carlo Rubbia for contributions to the CERN project which led to the discovery of the W and Z particles, two of the most fundamental constituents of matter. Albert Abraham Michelson (1852–1931): American physicist known for his work on the measurement of the speed of light and especially for the Michelson–Morley experiment. In 1907 he received the Nobel Prize in Physics. Ludwig von Mises (1881–1973): Austrian Economist and Philosopher. He was a prominent figure in the Austrian School of economic thought. Ludwig Mond (1839–1909): German-born British chemist and industrialist. Robert S. Mulliken (1896–1986): American physicist and chemist, primarily responsible for the early development of molecular orbital theory, i. e. the elaboration of the molecular orbital method of computing the structure of molecules. Dr. Mulliken received the Nobel Prize for chemistry in 1966. Nathan Myhrvold (born 1959): American computer scientist, technologist, mathematician, physicist, entrepreneur, nature and wildlife photographer, master chef. David Nalin (born 1941): American physiologist. Nalin had the key insight that Oral rehydration therapy (ORT) would work if the volume of solution patients drank matched the volume of their fluid losses, and that this would drastically reduce or completely replace the only current treatment for cholera, intravenous therapy. Nalin's discoveries have been estimated to have saved over 50 million lives worldwide. Fridtjof Nansen (1861–1930): Norwegian explorer, scientist, diplomat, humanitarian and Nobel Peace Prize laureate. In 1922, he was awarded the Nobel Peace Prize for his work on behalf of the displaced victims of the First World War and related conflicts. Erwin Neher (born 1944): German biophysicist. Along with Bert Sakmann, he was awarded the Nobel Prize in Physiology or Medicine in 1991. Ronald George Wreyford Norrish (1897–1978): British chemist. As a result of the development of flash photolysis, he was awarded the Nobel Prize in Chemistry in 1967 along with Manfred Eigen and George Porter for their study of extremely fast chemical reactions. Robert Noyce (1927–1990): American physicist, businessman, and inventor. He co-founded Fairchild Semiconductor in 1957 and Intel Corporation in 1968. He is also credited (along with Jack Kilby) with the invention of the integrated circuit or microchip which fueled the personal computer revolution. Sherwin B. Nuland (1930–2014): American surgeon and author of How We Die. Paul Nurse (born 1949): 2001 Nobel Laureate in Physiology or Medicine, called himself an atheist, but specified that "sceptical agnostic" was a more "philosophically correct" term. Bill Nye (born 1955): American science educator, comedian, television host, actor, mechanical engineer and scientist. Popularly known as "Bill Nye the Science Guy". George Olah (1927–2017): 1994 Nobel Laureate in Chemistry, discoverer of superacids, Mark Oliphant (1901–2000): Australian physicist and humanitarian. He played a fundamental role in the first experimental demonstration of nuclear fusion and also the development of the atomic bomb. Karl Pearson (1857–1936): English mathematician who has been credited for establishing the discipline of mathematical statistics. Saul Perlmutter (born 1959): American astrophysicist. He shared both the 2006 Shaw Prize in Astronomy and the 2011 Nobel Prize in Physics with Brian P. Schmidt and Adam Riess for providing evidence that the expansion of the universe is accelerating. Henri Poincaré (1854–1912): French mathematician, theoretical physicist, engineer, and a philosopher of science. He is often described as a polymath, and in mathematics as The Last Universalist, since he excelled in all fields of the discipline as it existed during his lifetime. Siméon Denis Poisson (1781–1840): French mathematician, geometer, and physicist. George Pólya (1888–1985): Hungarian Jewish mathematician. He was a professor of mathematics from 1914 to 1940 at ETH Zürich and from 1940 to 1953 at Stanford University. He made fundamental contributions to combinatorics, number theory, numerical analysis and probability theory. He is also noted for his work in heuristics and mathematics education. Carolyn Porco (born 1953): American planetary scientist. She is best known for her work in the exploration of the outer Solar System, beginning with her imaging work on the Voyager missions to Jupiter, Saturn, Uranus and Neptune in the 1980s. Vladimir Prelog (1906–1998): Croatian organic chemist. He won the Nobel Prize in Chemistry in 1975. Vilayanur S. Ramachandran (born 1951): Indian-American neuroscientist. Best known for his work in the fields of behavioral neurology and visual psychophysics. C. V. Raman (1888–1970): Indian physicist whose work was influential in the growth of science in India. He was the recipient of the Nobel Prize for Physics in 1930 for the discovery that when light traverses a transparent material, some of the light that is deflected changes in wavelength. This phenomenon is now called Raman scattering and is the result of the Raman effect. Lisa Randall (born 1962): American theoretical physicist and a student of particle physics and cosmology. She works on several of the competing models of string theory in the quest to explain the fabric of the universe. Her best known contribution to the field is the Randall–Sundrum model, first published in 1999 with Raman Sundrum. John Strutt, 3rd Baron Rayleigh (1842–1919): English physicist who, with William Ramsay, discovered the element argon, an achievement for which he earned the Nobel Prize for Physics in 1904. He also discovered the phenomenon now called Rayleigh scattering, explaining why the sky is blue, and predicted the existence of the surface waves now known as Rayleigh waves. Rayleigh's textbook, The Theory of Sound, is still referred to by acoustic engineers today. Grote Reber (1911–2002): American amateur astronomer and pioneer of radio astronomy. He was instrumental in investigating and extending Karl Jansky's pioneering work, and conducted the first sky survey in the radio frequencies. His 1937 radio antenna was the second ever to be used for astronomical purposes and the first parabolic reflecting antenna to be used as a "radio telescope". Robert Coleman Richardson (1937–2013):
|
Conan Doyle (1859–1930): Scottish physician and writer; known for his stories about the detective Sherlock Holmes; a prolific writer whose other works include science fiction stories, plays, romances, poetry, non-fiction and historical novels. W.E.B. Du Bois (1868–1963): American sociologist, historian, civil rights activist, Pan-Africanist, author and editor; co-founder of the National Association for the Advancement of Colored People (NAACP) in 1909. Bart D. Ehrman (born 1955): American New Testament scholar and "a happy agnostic". Edward FitzGerald (1809–1883): English poet and writer, best known as the poet of the first and most famous English translation of The Rubaiyat of Omar Khayyam Betty Friedan (1921–2006): American writer, activist and feminist; a leading figure in the women's movement in the United States; her 1963 book, The Feminine Mystique, is often credited with sparking the "second wave" of American feminism in the 20th century. Frederick James Furnivall (1825–1910): English second editor of the Oxford English Dictionary. John Galsworthy (1867–1933): English novelist and playwright; The Forsyte Saga (1906–1921) and its sequels, A Modern Comedy and End of the Chapter; won the Nobel Prize in Literature in 1932 Neil Gaiman (born 1960): English author of short fiction, novels, comic books, graphic novels, audio theatre and films including the comic book series The Sandman and novels Stardust, American Gods, Coraline, and The Graveyard Book. Maxim Gorky (1868–1936): Russian and Soviet author who brought Socialist Realism to literature. Thomas Hardy (1840–1928): English novelist and poet; while his works typically belong to the Naturalism movement, several poems display elements of the previous Romantic and Enlightenment periods of literature, such as his fascination with the supernatural. Sadegh Hedayat (1903–1951): Iranian author and writer. Robert A. Heinlein (1907–1988): American science fiction writer. Joseph Heller (1923–1999): American satirical novelist, short story writer, and playwright; Catch-22. Alexander Herzen (1812–1870): Russian writer and thinker; the "father of Russian socialism"; one of the main fathers of agrarian populism. Aldous Huxley (1894–1963): English writer of novels, such as Brave New World, and wide-ranging essays. A.J. Jacobs (born 1968): American author. James Joyce (1882–1941): Irish novelist and poet, considered to be one of the most influential writers in the modernist avant-garde movement of the early 20th century; best known for his novel Ulysses. Franz Kafka (1883–1924): Czech-born Jewish writer. John Keats (1795–1821): English Romantic poet. Janusz Korczak (1878 or 1879–1942): Polish Jewish educator, children's author and pediatrician. After spending many years working as director of an orphanage in Warsaw, Korczak refused freedom and remained with the orphans as they were sent to Treblinka extermination camp during the Grossaktion Warsaw of 1942. Stanislaw Lem (1921–2006): Polish science fiction novelist and essayist. H. P. Lovecraft (1890–1937): American writer of strange fiction and horror. Lucretius (99 BC–55 BC): Roman poet and philosopher. Bernard Malamud (1914–1986): American author of novels and short stories; one of the great American Jewish authors of the 20th century. H. L. Mencken (1880–1956): German-American journalist, satirist, social critic, cynic and freethinker, known as the "Sage of Baltimore". Thomas Mann (1875–1955): German novelist, short story writer, social critic, philanthropist, essayist, and 1929 Nobel Prize laureate, known for his series of highly symbolic and ironic epic novels and novellas, noted for their insight into the psychology of the artist and the intellectual. Vladimir Nabokov (1899–1977): Russian novelist, poet and short story writer; known for his novel Lolita. Eugene O'Neill (1888–1953), American playwright; won the Nobel Prize in Literature in 1936. Larry Niven (born 1938): American science fiction author; Ringworld (1970). Fernando Pessoa (1888–1935): Portuguese poet, writer, literary critic and translator, described as one of the most significant literary figures of the 20th century and one of the greatest poets in Portuguese. Marcel Proust (1871–1922): French novelist, critic and essayist, known for his work In Search of Lost Time. Philip Pullman (born 1946): English children's author of the trilogy His Dark Materials; has said that he is technically an agnostic, though he also calls himself an atheist. Alexander Pushkin (1799–1837): Russian author of the Romantic era, considered by many to be the greatest Russian poet and the founder of modern Russian literature. Edward Said (1935–2003): Palestinian-American literary theorist and advocate for Palestinian rights; university professor of English and Comparative Literature at Columbia University; a founding figure in postcolonialism. Arthur M. Schlesinger Jr. (1917–2007): American historian and Pulitzer Prize–winning writer. Mary Shelley (1797–1851): English novelist, short story writer, dramatist, essayist, biographer, and travel writer, best known for her Gothic novel Frankenstein (1818). Edward Snowden (born 1983): American computer specialist, privacy activist and former CIA employee and NSA contractor; disclosed classified details of several top-secret United States and British government mass surveillance programs. Elizabeth Cady Stanton (1815–1902): American social activist, abolitionist, and leading figure of the early woman's movement. Her Declaration of Sentiments, presented at the Seneca Falls Convention held in 1848 in Seneca Falls, New York, is often credited with initiating the first organized woman's rights and woman's suffrage movements in the United States. Late in life she led the effort to write the Woman's Bible to correct the injustices she perceived against women in the Bible. Olaf Stapledon (1886–1950): English philosopher and author of several influential works of science fiction. John Steinbeck (1902–1968): American writer known for novels such as The Grapes of Wrath and East of Eden; won the Nobel Prize in Literature in 1962 Stendhal (1783–1842) (a.k.a. Marie-Henri Beyle): French writer. Boris Strugatsky (1925–2012): Soviet-Russian science fiction author who collaborated with his brother, Arkady Strugatsky, on various works; their novel Piknik na obochine was translated into English as Roadside Picnic in 1977 and was filmed by Andrei Tarkovsky under the title Stalker. Charles Templeton (1915–2001): Canadian evangelist; author of A Farewell to God. Thucydides (c. 460–c. 395): Greek historian and author from Alimos. His History of the Peloponnesian War recounts the 5th-century BC war between Sparta and Athens to the year 411 BC. Thucydides has been dubbed the father of "scientific history", because of his strict standards of evidence-gathering and analysis in terms of cause and effect without reference to intervention by the gods, as outlined in his introduction to his work. Ivan Turgenev (1818–1883): Russian novelist, short story writer and playwright; A Sportsman's Sketches, Fathers and Sons. Mark Twain (1835–1910): American humorist, satirist, lecturer and writer, most noted for his novels Adventures of Huckleberry Finn and The Adventures of Tom Sawyer; has also been identified a deist. Adam Bruno Ulam (1922–2000): Polish and American historian and political scientist at Harvard University; one of the world's foremost authorities on Russia and the Soviet Union, and the author of twenty books and many articles. Ibn Warraq (born 1946): known for his books critical of Islam. Hale White (1831–1913): British writer and civil servant. Robert Anton Wilson (1932–2007): American author and futurologist Mary Wollstonecraft (1759–1797): English writer, philosopher, and advocate of women's rights. During her brief career, she wrote novels, treatises, a travel narrative, a history of the French Revolution, a conduct book, and a children's book. Wollstonecraft is best known for A Vindication of the Rights of Woman (1792), in which she argues that women are not naturally inferior to men, but appear to be only because they lack education. She suggests that both men and women should be treated as rational beings and imagines a social order founded on reason. David Yallop (born 1937): English true crime author. Émile Zola (1840–1902): French writer; prominent figure in the literary school of naturalism; important contributor to the development of theatrical naturalism. Business Leslie Alexander (born 1943): American sports owner, owner of the Houston Rockets Warren Buffett (born 1930): American investor; identified himself as agnostic in response to Warren Allen Smith, who had asked him whether he believed in God Henry Dunant (1828–1910): Swiss businessman and social activist; founder of International Committee of the Red Cross; in 1901 he received the first Nobel Peace Prize, together with Frédéric Passy Elon Musk (born 1971): South African American inventor and entrepreneur best known for founding SpaceX and co-founding Tesla Motors and PayPal (originally X.com) Ted Turner (born 1938): American founder of Turner Broadcasting System, now part of Time Warner Media and arts John Adams (born 1947): American composer Hideaki Anno (born 1960): Japanese animation and film director; known for his work on the popular anime series Neon Genesis Evangelion Simon Baker (born 1969): Australian television and movie actor David Bazan (born 1976): American singer, songwriter, musician and former frontman of Pedro The Lion, an indie rock outfit associated with Christian rock that was controversial among Christians for their language and off-kilter views about religion; his solo career has been focused around his newfound agnosticism. Monica Bellucci (born 1964): Italian actress and fashion model Tom Bergeron (born 1955): American television personality and game show host; host of America's Funniest Home Videos, Hollywood Squares and Dancing with the Stars Ingmar Bergman (1918–2007): Swedish director, writer and producer for film, stage and television Irving Berlin (1888–1989): American composer and lyricist of Jewish heritage, widely considered one of the greatest songwriters in American history Hector Berlioz (1803–1869): French Romantic composer Gael García Bernal (born 1978): Mexican actor and director; claims to be "culturally Catholic" and "spiritually agnostic" Lewis Black (born 1948): American stand-up comedian, author, playwright, social critic and actor Johannes Brahms (1833–1897): German composer and pianist Georges Brassens (1921–1981): French singer-songwriter and poet Benjamin Britten (1913–1976): English composer, conductor, and pianist; a central figure of 20th-century British classical music Gavin Bryars (born 1943): English composer and double bassist Rose Byrne (born 1979), Australian actress Dick Cavett (born 1936): American television talk show host Charlie Chaplin (1889–1977): English comic actor, film director and composer best known for his work in the United States during the silent film era Aaron Copland (1900–1990): American composer Salvador Dalí (1904–1989): Spanish surrealist painter born in Figueres, Spain. Dalí, a skilled draftsman, became best known for the striking and bizarre images in his surrealist work. His painterly skills are often attributed to the influence of Renaissance masters. His arguably best-known work, The Persistence of Memory, was completed in 1931. Dalí's expansive artistic repertoire included film, sculpture, and photography, in collaboration with a range of artists in a variety of media. He allegedly claimed to be both an agnostic and a Roman Catholic. Miles Davis (1926–1991): American trumpeter, bandleader, and composer. Daniel Day-Lewis (born 1957): English-Irish actor, three-time Academy Award for Best Actor winner Leonardo DiCaprio (born 1974): American actor Ronnie James Dio (1942–2010): American heavy metal singer (Elf, Rainbow, Black Sabbath, Dio, Heaven & Hell) Richard Dreyfuss (born 1947): American actor Thomas Eakins (1844–1916): American realist painter, photographer, sculptor, and fine arts educator; widely acknowledged to be one of the most important artists in American art history Christopher Eccleston (born 1964): English actor Zac Efron (born 1987): American actor, star of movies such as High School Musical and 17 Again; was raised agnostic (his paternal grandfather was Jewish) Carrie Fisher (1956–2016): American actress, screenwriter and novelist Gabriel Fauré (1845–1924): French composer, organist, pianist and teacher; one of the foremost French composers of his generation; his musical style influenced many 20th-century composers Henry Fonda (1905–1982): American film and stage actor Emilia Fox (born 1974): English actress William Friedkin (born 1935): American film and television director, producer and screenwriter, known for directing the action thriller film The French Connection and the supernatural horror film The Exorcist. Gilberto Gil (born 1942): Brazilian singer, guitarist, and songwriter, known for both his musical innovation
|
Newell, Cliff Shaw and Herbert A. Simon at RAND Corporation as the primary data structure for their Information Processing Language. IPL was used by the authors to develop several early artificial intelligence programs, including the Logic Theory Machine, the General Problem Solver, and a computer chess program. Reports on their work appeared in IRE Transactions on Information Theory in 1956, and several conference proceedings from 1957 to 1959, including Proceedings of the Western Joint Computer Conference in 1957 and 1958, and Information Processing (Proceedings of the first UNESCO International Conference on Information Processing) in 1959. The now-classic diagram consisting of blocks representing list nodes with arrows pointing to successive list nodes appears in "Programming the Logic Theory Machine" by Newell and Shaw in Proc. WJCC, February 1957. Newell and Simon were recognized with the ACM Turing Award in 1975 for having "made basic contributions to artificial intelligence, the psychology of human cognition, and list processing". The problem of machine translation for natural language processing led Victor Yngve at Massachusetts Institute of Technology (MIT) to use linked lists as data structures in his COMIT programming language for computer research in the field of linguistics. A report on this language entitled "A programming language for mechanical translation" appeared in Mechanical Translation in 1958. Another early appearance of linked lists was by Hans Peter Luhn who wrote an internal IBM memorandum in January 1953 that suggested the use of linked lists in chained hash tables. LISP, standing for list processor, was created by John McCarthy in 1958 while he was at MIT and in 1960 he published its design in a paper in the Communications of the ACM, entitled "Recursive Functions of Symbolic Expressions and Their Computation by Machine, Part I". One of LISP's major data structures is the linked list. By the early 1960s, the utility of both linked lists and languages which use these structures as their primary data representation was well established. Bert Green of the MIT Lincoln Laboratory published a review article entitled "Computer languages for symbol manipulation" in IRE Transactions on Human Factors in Electronics in March 1961 which summarized the advantages of the linked list approach. A later review article, "A Comparison of list-processing computer languages" by Bobrow and Raphael, appeared in Communications of the ACM in April 1964. Several operating systems developed by Technical Systems Consultants (originally of West Lafayette Indiana, and later of Chapel Hill, North Carolina) used singly linked lists as file structures. A directory entry pointed to the first sector of a file, and succeeding portions of the file were located by traversing pointers. Systems using this technique included Flex (for the Motorola 6800 CPU), mini-Flex (same CPU), and Flex9 (for the Motorola 6809 CPU). A variant developed by TSC for and marketed by Smoke Signal Broadcasting in California, used doubly linked lists in the same manner. The TSS/360 operating system, developed by IBM for the System 360/370 machines, used a double linked list for their file system catalog. The directory structure was similar to Unix, where a directory could contain files and other directories and extend to any depth. Basic concepts and nomenclature Each record of a linked list is often called an 'element' or 'node'. The field of each node that contains the address of the next node is usually called the 'next link' or 'next pointer'. The remaining fields are known as the 'data', 'information', 'value', 'cargo', or 'payload' fields. The 'head' of a list is its first node. The 'tail' of a list may refer either to the rest of the list after the head, or to the last node in the list. In Lisp and some derived languages, the next node may be called the 'cdr' (pronounced could-er) of the list, while the payload of the head node may be called the 'car'. Singly linked list Singly linked lists contain nodes which have a data field as well as 'next' field, which points to the next node in line of nodes. Operations that can be performed on singly linked lists include insertion, deletion and traversal. The following code demonstrates how to add a new node with data "value" to the end of a singly linked list:node addNode(node head, int value) { node temp, p; // declare two nodes temp and p temp = createNode(); // assume createNode creates a new node with data = 0 and next pointing to NULL. temp->data = value; // add element's value to data part of node if (head == NULL) { head = temp; // when linked list is empty } else { p = head; // assign head to p while (p->next != NULL) { p = p->next; // traverse the list until p is the last node. The last node always points to NULL. } p->next = temp; // Point the previous last node to the new node created. } return head; } Doubly linked list In a 'doubly linked list', each node contains, besides the next-node link, a second link field pointing to the 'previous' node in the sequence. The two links may be called 'forward('s') and 'backwards', or 'next' and 'prev'('previous'). A technique known as XOR-linking allows a doubly linked list to be implemented using a single link field in each node. However, this technique requires the ability to do bit operations on addresses, and therefore may not be available in some high-level languages. Many modern operating systems use doubly linked lists to maintain references to active processes, threads, and other dynamic objects. A common strategy for rootkits to evade detection is to unlink themselves from these lists. Multiply linked list In a 'multiply linked list', each node contains two or more link fields, each field being used to connect the same set of data records in a different order of same set (e.g., by name, by department, by date of birth, etc.). While doubly linked lists can be seen as special cases of multiply linked list, the fact that the two and more orders are opposite to each other leads to simpler and more efficient algorithms, so they are usually treated as a separate case. Circular linked list In the last node of a list, the link field often contains a null reference, a special value is used to indicate the lack of further nodes. A less common convention is to make it point to the first node of the list; in that case, the list is said to be 'circular' or 'circularly linked'; otherwise, it is said to be 'open' or 'linear'. It is a list where the last pointer points to the first node. In the case of a circular doubly linked list, the first node also points to the last node of the list. Sentinel nodes In some implementations an extra 'sentinel' or 'dummy' node may be added before the first data record or after the last one. This convention simplifies and accelerates some list-handling algorithms, by ensuring that all links can be safely dereferenced and that every list (even one that contains no data elements) always has a "first" and "last" node. Empty lists An empty list is a list that contains no data records. This is usually the same as saying that it has zero nodes. If sentinel nodes are being used, the list is usually said to be empty when it has only sentinel nodes. Hash linking The link fields need not be physically part of the nodes. If the data records are stored in an array and referenced by their indices, the link field may be stored in a separate array with the same indices as the data records. List handles Since a reference to the first node gives access to the whole list, that reference is often called the 'address', 'pointer', or 'handle' of the list. Algorithms that manipulate linked lists usually get such handles to the input lists and return the handles to the resulting lists. In fact, in the context of such algorithms, the word "list" often means "list handle". In some situations, however, it may be convenient to refer to a list by a handle that consists of two links, pointing to its first and last nodes. Combining alternatives The alternatives listed above may be arbitrarily combined in almost every way, so one may have circular doubly linked lists without sentinels, circular singly linked lists with sentinels, etc. Tradeoffs As with most choices in computer programming and design, no method is well suited to all circumstances. A linked list data structure might work well in one case, but cause problems in another. This is a list of some of the common tradeoffs involving linked list structures. Linked lists vs. dynamic arrays A dynamic array is a data structure that allocates all elements contiguously in memory, and keeps a count of the current number of elements. If the space reserved for the dynamic array is exceeded, it is reallocated and (possibly) copied, which is an expensive operation. Linked lists have several advantages over dynamic arrays. Insertion or deletion of an element at a specific point of a list, assuming that we have indexed a pointer to the node (before the one to be removed, or before the insertion point) already, is a constant-time operation (otherwise without this reference it is O(n)), whereas insertion in a dynamic array at random locations will require moving half of the elements on average, and all the elements in the worst case. While one can "delete" an element from an array in constant time by somehow marking its slot as "vacant", this causes fragmentation that impedes the performance of iteration. Moreover, arbitrarily many elements may be inserted into a linked list, limited only by the total memory available; while a dynamic array will eventually fill up its underlying array data structure and will have to reallocate—an expensive operation, one that may not even be possible if memory is fragmented, although the cost of reallocation can be averaged over insertions, and the cost of an insertion due to reallocation would still be amortized O(1). This helps with appending elements at the array's end, but inserting into (or removing from) middle positions still carries prohibitive costs due to data moving to maintain contiguity. An array from which many elements are removed may also have to be resized in order to avoid wasting too much space. On the other hand, dynamic arrays (as well as fixed-size array data structures) allow constant-time random access, while linked lists allow only sequential access to elements. Singly linked lists, in fact, can be easily traversed in only one direction. This makes linked lists unsuitable for applications where it's useful to look up an element by its index quickly, such as heapsort. Sequential access on arrays and dynamic arrays is also faster than on linked lists on many machines, because they have optimal locality of reference and thus make good use of data caching. Another disadvantage of linked lists is the extra storage needed for references, which often makes them impractical for lists of small data items such as characters or boolean values, because the storage overhead for the links may exceed by a factor of two or more the size of the data. In contrast, a dynamic array requires only the space for the data itself (and a very small amount of control data). It can also be slow, and with a naïve allocator, wasteful, to allocate memory separately for each new element, a problem generally solved using memory pools. Some hybrid solutions try to combine the advantages of the two representations. Unrolled linked lists store several elements in each list node, increasing cache performance while decreasing memory overhead for references. CDR coding does both these as well, by replacing references with the actual data referenced, which extends off the end of the referencing record. A good example that highlights the pros and cons of using dynamic arrays vs. linked lists is by implementing a program that resolves the Josephus problem. The Josephus problem is an election method that works by having a group of people stand in a circle. Starting at a predetermined person, one may count around the circle n times. Once the nth person is reached, one should remove them from the circle and have the members close the circle. The process is repeated until only one person is left. That person wins the election. This shows the strengths and weaknesses of a linked list vs. a dynamic array, because if the people are viewed as connected nodes in a circular linked list, then it shows how easily the linked list is able to delete nodes (as it only has to rearrange the links to the different nodes). However, the linked list will be poor at finding the next person to remove and will need to search through the list until it finds that person. A dynamic array, on the other hand, will be poor at deleting nodes (or elements) as it cannot remove one node without individually shifting all the elements up the list by one. However, it is exceptionally easy to find the nth person in the circle by directly referencing them by their position in the array. The list ranking problem concerns the efficient conversion of a linked list representation into an array. Although trivial for a conventional computer, solving this problem by a parallel algorithm is complicated and has been the subject of much research. A balanced tree has similar memory access patterns and space overhead to a linked list while permitting much more efficient indexing, taking O(log n) time instead of O(n) for a random access. However, insertion and deletion operations are more expensive due to the overhead of tree manipulations to maintain balance. Schemes exist for trees to automatically maintain themselves in a balanced state: AVL trees or red–black trees. Singly linked linear lists vs. other lists While doubly linked and circular lists have advantages over singly linked linear lists, linear lists offer some advantages that make them preferable in some situations. A singly linked linear list is a recursive data structure, because it contains a pointer to a smaller object of the same type. For that reason, many operations on singly linked linear lists (such as merging two lists, or enumerating the elements in reverse order) often have very simple recursive algorithms, much simpler than any solution using iterative commands. While those recursive solutions can be adapted for doubly linked and circularly linked lists, the procedures generally need extra arguments and more complicated base cases. Linear singly linked lists also allow tail-sharing, the use of a common final portion of sub-list as the terminal portion of two different lists. In particular, if a new node is added at the beginning of a list, the former list remains available as the tail of the new one—a simple example of a persistent data structure. Again, this is not true with the other variants: a node may never belong to two different circular or doubly linked lists. In particular, end-sentinel nodes can be shared among singly linked non-circular lists. The same end-sentinel node may be used for every such list. In Lisp, for example, every proper list ends with a link to a special node, denoted by nil or (), whose CAR and CDR links point to itself. Thus a Lisp procedure can safely take the CAR or CDR of any list. The advantages of the fancy variants are often limited to the complexity of the algorithms, not in their efficiency. A circular list, in particular, can usually be emulated by a linear list together with two variables that point to the first and last nodes, at no extra cost. Doubly linked vs. singly linked Double-linked lists require more space per node (unless one uses XOR-linking), and their elementary operations are more expensive; but they are often easier to manipulate because they allow fast and easy sequential access to the list in both directions. In a doubly linked list, one can insert or delete a node in a constant number of operations given only that node's address. To do the same in a singly linked list, one must have the address of the pointer to that node, which is either the handle for the whole list (in case of the first node) or the link field in the previous node. Some algorithms require access in both directions. On the other hand, doubly linked lists do not allow tail-sharing and cannot be used as persistent data structures. Circularly linked vs. linearly linked A circularly linked list may be a natural option to represent arrays that are naturally circular, e.g. the corners of a polygon, a pool of buffers that are used and released in FIFO ("first in, first out") order, or a set of processes that should be time-shared in round-robin order. In these applications, a pointer to any node serves as a handle to the whole list. With a circular list, a pointer to the last node gives easy access also to the first node, by following one link. Thus, in applications that require access to both ends of the list (e.g., in the implementation of a queue), a circular structure allows one to handle the structure by a single pointer, instead of two. A circular list can be split into two circular lists, in constant time, by giving the addresses of the last node of each piece. The operation consists in swapping the contents of the link fields of those two nodes. Applying the same operation to any two nodes in two distinct lists joins the two list into one. This property greatly simplifies some algorithms and data structures, such as the quad-edge and face-edge. The simplest representation for an empty circular list (when such a thing makes sense) is a null pointer, indicating that the list has no nodes. Without this choice, many algorithms have to test for this special case, and handle it separately. By contrast, the use of null to denote an empty linear list is more natural and often creates fewer special cases. For some applications, it can be useful to use singly linked lists that can vary between being circular and being linear, or even circular with a linear initial segment. Algorithms for searching or otherwise operating on these have to take precautions to avoid accidentally entering an endless loop. One usual method is to have a second pointer walking the list at half or double the speed, and if both pointers meet at the same node, you know you found a cycle. Using sentinel nodes Sentinel node may simplify certain list operations, by ensuring that the next or previous nodes exist for every element, and that even empty lists have at least one node. One may also use a sentinel node at the end of the list, with an appropriate data field, to eliminate some end-of-list tests. For example, when scanning the list looking for a node with a given value x, setting the sentinel's data field to x makes it unnecessary to test for end-of-list inside the loop. Another example is the merging two sorted lists: if their sentinels have data fields set to +∞, the choice of the next output node does not need special handling for empty lists. However, sentinel nodes use up extra space (especially in applications that use many short lists), and they may complicate other operations (such as the creation of a new empty list). However, if the circular list is used merely to simulate
|
be adapted for doubly linked and circularly linked lists, the procedures generally need extra arguments and more complicated base cases. Linear singly linked lists also allow tail-sharing, the use of a common final portion of sub-list as the terminal portion of two different lists. In particular, if a new node is added at the beginning of a list, the former list remains available as the tail of the new one—a simple example of a persistent data structure. Again, this is not true with the other variants: a node may never belong to two different circular or doubly linked lists. In particular, end-sentinel nodes can be shared among singly linked non-circular lists. The same end-sentinel node may be used for every such list. In Lisp, for example, every proper list ends with a link to a special node, denoted by nil or (), whose CAR and CDR links point to itself. Thus a Lisp procedure can safely take the CAR or CDR of any list. The advantages of the fancy variants are often limited to the complexity of the algorithms, not in their efficiency. A circular list, in particular, can usually be emulated by a linear list together with two variables that point to the first and last nodes, at no extra cost. Doubly linked vs. singly linked Double-linked lists require more space per node (unless one uses XOR-linking), and their elementary operations are more expensive; but they are often easier to manipulate because they allow fast and easy sequential access to the list in both directions. In a doubly linked list, one can insert or delete a node in a constant number of operations given only that node's address. To do the same in a singly linked list, one must have the address of the pointer to that node, which is either the handle for the whole list (in case of the first node) or the link field in the previous node. Some algorithms require access in both directions. On the other hand, doubly linked lists do not allow tail-sharing and cannot be used as persistent data structures. Circularly linked vs. linearly linked A circularly linked list may be a natural option to represent arrays that are naturally circular, e.g. the corners of a polygon, a pool of buffers that are used and released in FIFO ("first in, first out") order, or a set of processes that should be time-shared in round-robin order. In these applications, a pointer to any node serves as a handle to the whole list. With a circular list, a pointer to the last node gives easy access also to the first node, by following one link. Thus, in applications that require access to both ends of the list (e.g., in the implementation of a queue), a circular structure allows one to handle the structure by a single pointer, instead of two. A circular list can be split into two circular lists, in constant time, by giving the addresses of the last node of each piece. The operation consists in swapping the contents of the link fields of those two nodes. Applying the same operation to any two nodes in two distinct lists joins the two list into one. This property greatly simplifies some algorithms and data structures, such as the quad-edge and face-edge. The simplest representation for an empty circular list (when such a thing makes sense) is a null pointer, indicating that the list has no nodes. Without this choice, many algorithms have to test for this special case, and handle it separately. By contrast, the use of null to denote an empty linear list is more natural and often creates fewer special cases. For some applications, it can be useful to use singly linked lists that can vary between being circular and being linear, or even circular with a linear initial segment. Algorithms for searching or otherwise operating on these have to take precautions to avoid accidentally entering an endless loop. One usual method is to have a second pointer walking the list at half or double the speed, and if both pointers meet at the same node, you know you found a cycle. Using sentinel nodes Sentinel node may simplify certain list operations, by ensuring that the next or previous nodes exist for every element, and that even empty lists have at least one node. One may also use a sentinel node at the end of the list, with an appropriate data field, to eliminate some end-of-list tests. For example, when scanning the list looking for a node with a given value x, setting the sentinel's data field to x makes it unnecessary to test for end-of-list inside the loop. Another example is the merging two sorted lists: if their sentinels have data fields set to +∞, the choice of the next output node does not need special handling for empty lists. However, sentinel nodes use up extra space (especially in applications that use many short lists), and they may complicate other operations (such as the creation of a new empty list). However, if the circular list is used merely to simulate a linear list, one may avoid some of this complexity by adding a single sentinel node to every list, between the last and the first data nodes. With this convention, an empty list consists of the sentinel node alone, pointing to itself via the next-node link. The list handle should then be a pointer to the last data node, before the sentinel, if the list is not empty; or to the sentinel itself, if the list is empty. The same trick can be used to simplify the handling of a doubly linked linear list, by turning it into a circular doubly linked list with a single sentinel node. However, in this case, the handle should be a single pointer to the dummy node itself. Linked list operations When manipulating linked lists in-place, care must be taken to not use values that you have invalidated in previous assignments. This makes algorithms for inserting or deleting linked list nodes somewhat subtle. This section gives pseudocode for adding or removing nodes from singly, doubly, and circularly linked lists in-place. Throughout we will use null to refer to an end-of-list marker or sentinel, which may be implemented in a number of ways. Linearly linked lists Singly linked lists Our node data structure will have two fields. We also keep a variable firstNode which always points to the first node in the list, or is null for an empty list. record Node { data; // The data being stored in the node Node next // A reference to the next node, null for last node } record List { Node firstNode // points to first node of list; null for empty list } Traversal of a singly linked list is simple, beginning at the first node and following each next link until we come to the end: node := list.firstNode while node not null (do something with node.data) node := node.next The following code inserts a node after an existing node in a singly linked list. The diagram shows how it works. Inserting a node before an existing one cannot be done directly; instead, one must keep track of the previous node and insert a node after it. function insertAfter(Node node, Node newNode) // insert newNode after node newNode.next := node.next node.next := newNode Inserting at the beginning of the list requires a separate function. This requires updating firstNode. function insertBeginning(List list, Node newNode) // insert node before current first node newNode.next := list.firstNode list.firstNode := newNode Similarly, we have functions for removing the node after a given node, and for removing a node from the beginning of the list. The diagram demonstrates the former. To find and remove a particular node, one must again keep track of the previous element. function removeAfter(Node node) // remove node past this one obsoleteNode := node.next node.next := node.next.next destroy obsoleteNode function removeBeginning(List list) // remove first node obsoleteNode := list.firstNode list.firstNode := list.firstNode.next // point past deleted node destroy obsoleteNode Notice that removeBeginning() sets list.firstNode to null when removing the last node in the list. Since we can't iterate backwards, efficient insertBefore or removeBefore operations are not possible. Inserting to a list before a specific node requires traversing the list, which would have a worst case running time of O(n). Appending one linked list to another can be inefficient unless a reference to the tail is kept as part of the List structure, because we must traverse the entire first list in order to find the tail, and then append the second list to this. Thus, if two linearly linked lists are each of length , list appending has asymptotic time complexity of . In the Lisp family of languages, list appending is provided by the append procedure. Many of the special cases of linked list operations can be eliminated by including a dummy element at the front of the list. This ensures that there are no special cases for the beginning of the list and renders both insertBeginning() and removeBeginning() unnecessary. In this case, the first useful data in the list will be found at list.firstNode.next. Circularly linked list In a circularly linked list, all nodes are linked in a continuous circle, without using null. For lists with a front and a back (such as a queue), one stores a reference to the last node in the list. The next node after the last node is the first node. Elements can be added to the back of the list and removed from the front in constant time. Circularly linked lists can be either singly or doubly linked. Both types of circularly linked lists benefit from the ability to traverse the full list beginning at any given node. This often allows us to avoid storing firstNode and lastNode, although if the list may be empty we need a special representation for the empty list, such as a lastNode variable which points to some node in the list or is null if it's empty; we use such a lastNode here. This representation significantly simplifies adding and removing nodes with a non-empty list, but empty lists are then a special case. Algorithms Assuming that someNode is some node in a non-empty circular singly linked list, this code iterates through that list starting with someNode: function iterate(someNode) if someNode ≠ null node := someNode do do something with node.value node := node.next while node ≠ someNode Notice that the test "while node ≠ someNode" must be at the end of the loop. If the
|
(DTL). Transistor–transistor logic (TTL) then supplanted DTL. As integrated circuits became more complex, bipolar transistors were replaced with smaller field-effect transistors (MOSFETs); see PMOS and NMOS. To reduce power consumption still further, most contemporary chip implementations of digital systems now use CMOS logic. CMOS uses complementary (both n-channel and p-channel) MOSFET devices to achieve a high speed with low power dissipation. For small-scale logic, designers now use prefabricated logic gates from families of devices such as the TTL 7400 series by Texas Instruments, the CMOS 4000 series by RCA, and their more recent descendants. Increasingly, these fixed-function logic gates are being replaced by programmable logic devices, which allow designers to pack many mixed logic gates into a single integrated circuit. The field-programmable nature of programmable logic devices such as FPGAs has reduced the 'hard' property of hardware; it is now possible to change the logic design of a hardware system by reprogramming some of its components, thus allowing the features or function of a hardware implementation of a logic system to be changed. Other types of logic gates include, but are not limited to: Electronic logic gates differ significantly from their relay-and-switch equivalents. They are much faster, consume much less power, and are much smaller (all by a factor of a million or more in most cases). Also, there is a fundamental structural difference. The switch circuit creates a continuous metallic path for current to flow (in either direction) between its input and its output. The semiconductor logic gate, on the other hand, acts as a high-gain voltage amplifier, which sinks a tiny current at its input and produces a low-impedance voltage at its output. It is not possible for current to flow between the output and the input of a semiconductor logic gate. Another important advantage of standardized integrated circuit logic families, such as the 7400 and 4000 families, is that they can be cascaded. This means that the output of one gate can be wired to the inputs of one or several other gates, and so on. Systems with varying degrees of complexity can be built without great concern of the designer for the internal workings of the gates, provided the limitations of each integrated circuit are considered. The output of one gate can only drive a finite number of inputs to other gates, a number called the 'fan-out limit'. Also, there is always a delay, called the 'propagation delay', from a change in input of a gate to the corresponding change in its output. When gates are cascaded, the total propagation delay is approximately the sum of the individual delays, an effect which can become a problem in high-speed circuits. Additional delay can be caused when many inputs are connected to an output, due to the distributed capacitance of all the inputs and wiring and the finite amount of current that each output can provide. History and development The binary number system was refined by Gottfried Wilhelm Leibniz (published in 1705), influenced by the ancient I Chings binary system. Leibniz established that using the binary system combined the principles of arithmetic and logic. In an 1886 letter, Charles Sanders Peirce described how logical operations could be carried out by electrical switching circuits. Eventually, vacuum tubes replaced relays for logic operations. Lee De Forest's modification, in 1907, of the Fleming valve can be used as a logic gate. Ludwig Wittgenstein introduced a version of the 16-row truth table as proposition 5.101 of Tractatus Logico-Philosophicus (1921). Walther Bothe, inventor of the coincidence circuit, got part of the 1954 Nobel Prize in physics, for the first modern electronic AND gate in 1924. Konrad Zuse designed and built electromechanical logic gates for his computer Z1 (from 1935 to 1938). From 1934 to 1936, NEC engineer Akira Nakashima, Claude Shannon and Viktor Shetakov introduced switching circuit theory in a series of papers showing that two-valued Boolean algebra, which they discovered independently, can describe the operation of switching circuits. Using this property of electrical switches to implement logic is the fundamental concept that underlies all electronic digital computers. Switching circuit theory became the foundation of digital circuit design, as it became widely known in the electrical engineering community during and after World War II, with theoretical rigor superseding the ad hoc methods that had prevailed previously. Metal-oxide-semiconductor (MOS) devices in the forms of PMOS and NMOS were demonstrated by Bell Labs engineers Mohamed M. Atalla and Dawon Kahng in 1960. Both types were later combined and adapted into complementary MOS (CMOS) logic by Chih-Tang Sah and Frank Wanlass at Fairchild Semiconductor in 1963. Active research is taking place in molecular logic gates. Symbols There are two sets of symbols for elementary logic gates in common use, both defined in ANSI/IEEE Std 91-1984 and its supplement ANSI/IEEE Std 91a-1991. The "distinctive shape" set, based on traditional schematics, is used for simple drawings and derives from United States Military Standard MIL-STD-806 of the 1950s and 1960s. It is sometimes unofficially described as "military", reflecting its origin. The "rectangular shape" set, based on ANSI Y32.14 and other early industry standards as later refined by IEEE and IEC, has rectangular outlines for all types of gate and allows representation of a much wider range of devices than is possible with the traditional symbols. The IEC standard, IEC 60617-12, has been adopted by other standards, such as EN 60617-12:1999 in Europe, BS EN 60617-12:1999 in the United Kingdom, and DIN EN 60617-12:1998 in Germany. The mutual goal of IEEE Std 91-1984 and IEC 60617-12 was to provide a uniform method of describing the complex logic functions of digital circuits with schematic symbols. These functions were more complex than simple AND and OR gates. They could be medium scale circuits such as a 4-bit counter to a large scale circuit such as a microprocessor. IEC 617-12 and its successor IEC 60617-12 do not explicitly show the "distinctive shape" symbols, but do not prohibit them. These are, however, shown in ANSI/IEEE 91 (and 91a) with this note: "The distinctive-shape symbol is, according to IEC Publication 617, Part 12, not preferred, but is not considered to be in contradiction to that standard." IEC 60617-12 correspondingly contains the note (Section 2.1) "Although non-preferred, the use of other symbols recognized by official national standards, that is distinctive shapes in place of symbols [list of basic gates], shall not be considered to be in contradiction with this standard. Usage of these
|
Bell Labs engineers Mohamed M. Atalla and Dawon Kahng in 1960. Both types were later combined and adapted into complementary MOS (CMOS) logic by Chih-Tang Sah and Frank Wanlass at Fairchild Semiconductor in 1963. Active research is taking place in molecular logic gates. Symbols There are two sets of symbols for elementary logic gates in common use, both defined in ANSI/IEEE Std 91-1984 and its supplement ANSI/IEEE Std 91a-1991. The "distinctive shape" set, based on traditional schematics, is used for simple drawings and derives from United States Military Standard MIL-STD-806 of the 1950s and 1960s. It is sometimes unofficially described as "military", reflecting its origin. The "rectangular shape" set, based on ANSI Y32.14 and other early industry standards as later refined by IEEE and IEC, has rectangular outlines for all types of gate and allows representation of a much wider range of devices than is possible with the traditional symbols. The IEC standard, IEC 60617-12, has been adopted by other standards, such as EN 60617-12:1999 in Europe, BS EN 60617-12:1999 in the United Kingdom, and DIN EN 60617-12:1998 in Germany. The mutual goal of IEEE Std 91-1984 and IEC 60617-12 was to provide a uniform method of describing the complex logic functions of digital circuits with schematic symbols. These functions were more complex than simple AND and OR gates. They could be medium scale circuits such as a 4-bit counter to a large scale circuit such as a microprocessor. IEC 617-12 and its successor IEC 60617-12 do not explicitly show the "distinctive shape" symbols, but do not prohibit them. These are, however, shown in ANSI/IEEE 91 (and 91a) with this note: "The distinctive-shape symbol is, according to IEC Publication 617, Part 12, not preferred, but is not considered to be in contradiction to that standard." IEC 60617-12 correspondingly contains the note (Section 2.1) "Although non-preferred, the use of other symbols recognized by official national standards, that is distinctive shapes in place of symbols [list of basic gates], shall not be considered to be in contradiction with this standard. Usage of these other symbols in combination to form complex symbols (for example, use as embedded symbols) is discouraged." This compromise was reached between the respective IEEE and IEC working groups to permit the IEEE and IEC standards to be in mutual compliance with one another. A third style of symbols, DIN 40700 (1976), was in use in Europe and is still widely used in European academia, see the logic table in German Wikipedia. In the 1980s, schematics were the predominant method to design both circuit boards and custom ICs known as gate arrays. Today custom ICs and the field-programmable gate array are typically designed with Hardware Description Languages (HDL) such as Verilog or VHDL. Truth tables Output comparison of 1-input logic gates. Output comparison of 2-input logic gates. Universal logic gates Charles Sanders Peirce (during 1880–81) showed that NOR gates alone (or alternatively NAND gates alone) can be used to reproduce the functions of all the other logic gates, but his work on it was unpublished until 1933. The first published proof was by Henry M. Sheffer in 1913, so the NAND logical operation is sometimes called Sheffer stroke; the logical NOR is sometimes called Peirce's arrow. Consequently, these gates are sometimes called universal logic gates. De Morgan equivalent symbols By use of De Morgan's laws, an AND function is identical to an OR function with negated inputs and outputs. Likewise, an OR function is identical to an AND function with negated inputs and outputs. A NAND gate is equivalent to an OR gate with negated inputs, and a NOR gate is equivalent to an AND gate with negated inputs. This leads to an alternative set of symbols for basic gates that use the opposite core symbol (AND or OR) but with the inputs and outputs negated. Use of these alternative symbols can make logic circuit diagrams much clearer and help to show accidental connection of an active high output to an active low input or vice versa. Any connection that has logic negations at both ends can be replaced by a negationless connection and a suitable change of gate or vice versa. Any connection that has a negation at one end and no negation at the other can be made easier to interpret by instead using the De Morgan equivalent symbol at either of the two ends. When negation or polarity indicators on both ends of a connection match, there is no logic negation in that path (effectively, bubbles "cancel"), making it easier to follow logic states from one symbol to the next. This is commonly seen in real logic diagrams – thus the reader must not get into the habit of associating the shapes exclusively as OR or AND shapes, but also take into account the bubbles at both inputs and outputs in order to determine the "true" logic function indicated. A De Morgan symbol can show more clearly a gate's primary logical purpose and the polarity of its nodes that are considered in the "signaled" (active, on) state. Consider the simplified case where a two-input NAND gate is used to drive a motor when either of its inputs are brought low by a switch. The "signaled" state (motor on) occurs when either one OR the other switch is on. Unlike a regular NAND symbol, which suggests AND logic, the De Morgan version, a two negative-input OR gate, correctly shows that OR is of interest. The regular NAND symbol has a bubble at the output and none at the inputs (the opposite of the states that will turn the motor on), but the De Morgan symbol shows both inputs and output in the polarity that will drive the motor. De Morgan's theorem is most commonly used to implement logic gates as combinations of only NAND gates, or as combinations of only NOR gates, for economic reasons. Data storage Logic gates can also be used to store
|
the end of the list), in which case n comparisons are needed. If the value being sought occurs k times in the list, and all orderings of the list are equally likely, the expected number of comparisons is For example, if the value being sought occurs once in the list, and all orderings of the list are equally likely, the expected number of comparisons is . However, if it is known that it occurs once, then at most n - 1 comparisons are needed, and the expected number of comparisons is (for example, for n = 2 this is 1, corresponding to a single if-then-else construct). Either way, asymptotically the worst-case cost and the expected cost of linear search are both O(n). Non-uniform probabilities The performance of linear search improves if the desired value is more likely to be near the beginning of the list than to its end. Therefore, if some values are much more likely to be searched than others, it is desirable to place them at the beginning of the list. In particular, when the list items are arranged in order of decreasing probability, and these probabilities are geometrically distributed, the cost of linear search is only O(1). Application Linear search is usually very simple to implement, and is practical when the list has only a few elements, or when performing a single search in an un-ordered list. When many values have to be searched in the same list, it often pays to pre-process the list in order to use a faster method. For example, one may sort the list and use binary search, or build an efficient search data structure from it. Should the content of the list change frequently, repeated re-organization may be more trouble than it is worth. As a result, even though in theory other search algorithms may be faster than linear search (for instance
|
the end of the list, the search terminates unsuccessfully. Basic algorithm Given a list of elements with values or records , and target value , the following subroutine uses linear search to find the index of the target in . Set to 0. If , the search terminates successfully; return . Increase by 1. If , go to step 2. Otherwise, the search terminates unsuccessfully. With a sentinel The basic algorithm above makes two comparisons per iteration: one to check if equals T, and the other to check if still points to a valid index of the list. By adding an extra record to the list (a sentinel value) that equals the target, the second comparison can be eliminated until the end of the search, making the algorithm faster. The search will reach the sentinel if the target is not contained within the list. Set to 0. If , go to step 4. Increase by 1 and go to step 2. If , the search terminates successfully; return . Else, the search terminates unsuccessfully. In an ordered table If the list is ordered such that , the search can establish the absence of the target more quickly by concluding the search once exceeds the target. This variation requires a sentinel that is greater than the target. Set to 0. If , go to step 4. Increase by 1 and go to step 2. If , the search terminates successfully; return . Else, the search terminates unsuccessfully. Analysis For a list with n items, the best case is when the value is equal to the first element of the list, in which case only one comparison is needed. The worst case is when the value is not in the list (or occurs only once at the end of the list), in which case n comparisons are needed. If the value being sought occurs k times in the list, and all orderings of the list are equally likely, the expected number of comparisons is For example, if the value
|
the 1997 Convention on the Prohibition of the Use, Stockpiling, Production and Transfer of Anti-Personnel Mines and on their Destruction, also known as the Ottawa Treaty. To date, 164 nations have signed the treaty, but these do not include China, the Russian Federation, or the United States. Definition In the Anti-Personnel Mine Ban Convention (also known as the "Ottawa Treaty") and the "Protocol on Mines, Booby-Traps and Other Devices", a mine is defined as a "munition designed to be placed under, on or near the ground or other surface area and to be exploded by the presence, proximity or contact of a person or vehicle". Similar in function is the booby-trap, which the protocol defines as "any device or material which is designed, constructed or adapted to kill or injure and which functions unexpectedly when a person disturbs or approaches an apparently harmless object or performs an apparently safe act". Such actions might include opening a door or picking up an object. Normally, mines are mass-produced and placed in groups, while booby traps are improvised and deployed one at a time. Also, booby traps can be non-explosive devices such as punji sticks. Overlapping both categories is the improvised explosive device (IED), which is "a device placed or fabricated in an improvised manner incorporating explosive material, destructive, lethal, noxious, incendiary, pyrotechnic materials or chemicals designed to destroy, disfigure, distract or harass. They may incorporate military stores, but are normally devised from non-military components." Some meet the definition of mines or booby traps and are also referred to as "improvised", "artisanal" or "locally manufactured" mines. Other types of IED are remotely activated, so are not considered mines. Remotely delivered mines are dropped from aircraft or carried by devices such as artillery shells or rockets. Another type of remotely delivered explosive is the cluster munition, a device that releases several sub munitions ("bomblets") over a large area. The use, transfer, production, and stockpiling of cluster munitions is prohibited by the international CCM treaty. If bomblets do not explode, they are referred to as unexploded ordnance (UXO), along with unexploded artillery shells and other explosive devices that were not manually placed (that is, mines and booby traps are not UXOs). Explosive remnants of war (ERW) include UXOs and abandoned explosive ordnance (AXO), devices that were never used and were left behind after a conflict. Land mines are divided into two types: anti-tank mines, which are designed to disable tanks or other vehicles; and anti-personnel mines, which are designed to injure or kill people. History The history of land mines can be divided into three main phases: In the ancient world, buried spikes provided many of the same functions as modern mines. Mines using gunpowder as the explosive were used from the Ming dynasty to the American Civil War. Subsequently, high explosives were developed and used in land mines. Before explosives Some fortifications in the Roman Empire were surrounded by a series of hazards buried in the ground. These included goads, foot-long pieces of wood with iron hooks on their ends; lilia (lilies, so named after their appearance), which were pits in which sharpened logs were arranged in a five-point pattern; and abatis, fallen trees with sharpened branches facing outwards. As with modern land mines, they were "victim-operated", often concealed, and formed zones that were wide enough so that the enemy could not do much harm from outside, but were under fire (from spear throws, in this case) if they attempted to remove the obstacles. A notable use of these defenses was by Julius Caesar in the Battle of Alesia. His forces were besieging Vercingetorix, the leader of the Gauls, but Vercingetorix managed to send for reinforcements. To maintain the siege and defend against the reinforcements, Caesar formed a line of fortifications on both sides, and they played an important role in his victory. Lilies were also used by Scots against the English at the Battle of Bannockburn in 1314, and by Germans at the Battle of Passchendaele in the First World War. A more easily deployed defense used by the Romans was the caltrop, a weapon 12–15 cm across with four sharp spikes that are oriented so that when it is thrown on the ground, one spike always points up. As with modern antipersonnel mines, caltrops are designed to disable soldiers rather than kill them; they are also more effective in stopping mounted forces, who lack the advantage of being able to carefully scrutinize each step they take (though forcing foot-mounted forces to take the time to do so has benefits in and of itself). They were used by the Jin dynasty in China at the Battle of Zhongdu to slow down the advance of Genghis Khan's army; Joan of Arc was wounded by one in the Siege of Orléans; in Japan they are known as tetsu-bishu and were used by ninjas from the fourteenth century onward. Caltrops are still strung together and used as roadblocks in some modern conflicts. Gunpowder East Asia Starting in the ninth century, the Chinese began centuries of experiments that resulted in gunpowder, an explosive mixture of sulfur, charcoal and potassium nitrate. Gunpowder was first used in battle in the thirteenth century. An "enormous bomb", credited to Lou Qianxia, was used in 1277 by the Chinese at the Battle of Zhongdu, although it probably had little effect. Gunpowder was difficult to use in mines because it is hygroscopic, easily absorbing water from the atmosphere, and when wet it is no longer explosive. A 14th-century military treatise, the Huolongjing (fire dragon manual), describes hollow cast iron cannonball shells filled with gunpowder. The wad of the mine was made of hard wood, carrying three different fuses in case of defective connection to the touch hole. These fuses were long and lit by hand, so they required carefully timed calculations of enemy movements. The Huolongjing also describes land mines that were set off by enemy movement. A nine-foot length of bamboo was waterproofed by wrapping it in cowhide and covering it with oil. It was filled with compressed gunpowder and lead or iron pellets, sealed with wax and concealed in a trench. The triggering mechanism was not fully described until the early 17th century. When the enemy stepped onto hidden boards, they dislodged a pin, causing a weight to fall. A cord attached to the weight was wrapped around a drum attached to two steel wheels; when the weight fell, the wheels struck sparks against flint, igniting a set of fuses leading to multiple mines. A similar mechanism was used in the first wheellock musket in Europe as sketched by Leonardo da Vinci around 1500 AD. Another victim-operated device was the "underground sky-soaring thunder", which lured bounty hunters with halberds, pikes, and lances planted in the ground. If they pulled on one of these weapons, the butt end disturbed a bowl underneath and a slow-burning incandescent material in the bowl ignited the fuses. The fuse mechanisms for the above devices were cumbersome and unreliable. By the time Europeans arrived in China, landmines were largely forgotten. Europe and the United States At Augsburg in 1573, three centuries after the Chinese invented the first pressure-operated mine, a German military engineer by the name of Samuel Zimmermann invented the Fladdermine (flying mine). It consisted of a few pounds of black powder buried near the surface and was activated by stepping on it or tripping a wire that made a flintlock fire. Such mines were deployed on the slope in front of a fort. They were used during the Franco-Prussian War, but were probably not very effective because a flintlock does not work for long when left untended. Another device, the fougasse, was not victim-operated or mass-produced, but it was a precursor of modern fragmentation mines and the claymore mine. It consisted of a cone-shape hole with gunpowder at the bottom, covered either by rocks and scrap iron (stone fougasse) or mortar shells, similar to large black powder hand grenades (shell fougasse). It was triggered by a flintlock connected to a tripwire on the surface. It could sometimes cause heavy casualties but required high maintenance due to the susceptibility of black powder to dampness. Consequently, it was mainly employed in the defenses of major fortifications, in which role it used in several European wars of the eighteenth century and the American Revolution. One of the greatest limitations of early land mines was the unreliable fuses and their susceptibility to dampness. This changed with the invention of the safety fuse. Later, command initiation, the ability to detonate a charge immediately instead of waiting several minutes for a fuse to burn, became possible after electricity was developed. An electrical current sent down a wire could ignite the charge with a spark. The Russians claim first use of this technology in the Russo-Turkish War of 1828–1829, and with it the fougasse remained useful until it was superseded by the claymore in the 1960s. Victim-activated mines were also unreliable because they relied on a flintlock to ignite the explosive. The percussion cap, developed in the early 19th century, made them much more reliable, and pressure-operated mines were deployed on land and sea in the Crimean War (1853–1856). During the American Civil War, the Confederate brigadier general Gabriel J. Rains deployed thousands of "torpedoes" consisting of artillery shells with pressure caps, beginning with the Battle of Yorktown in 1862. As a captain, Rains had earlier employed explosive booby traps during the Seminole Wars in Florida in 1840. Over the course of the war, mines only caused a few hundred casualties, but they had a large effect on morale and slowed down the advance of Union troops. Many on both sides considered the use of mines barbaric, and in response, generals in the Union Army forced Confederate prisoners to remove the mines. High explosives Starting in the 19th century, more powerful explosives than gunpowder were developed, often for non-military reasons such as blasting train tunnels in the Alps and Rockies. Guncotton, up to four times more powerful than gunpowder, was invented by Christian Schonbein in 1846. It was dangerous to make until Frederick Augustus Abel developed a safe method in 1865. From the 1870s to the First World War, it was the standard explosive used by the British military. In 1847, Ascanio Sobrero invented nitroglycerine to treat angina pectoris and it turned out to be a much more powerful explosive than guncotton. It was very dangerous to use until Alfred Nobel found a way to incorporate it in a solid mixture called dynamite and developed a safe detonator. Even then, dynamite needed to be stored carefully or it could form crystals that detonated easily. Thus, the military still preferred guncotton. In 1863, the German chemical industry developed trinitrotoluene (TNT). This had the advantage that it was difficult to detonate, so it could withstand the shock of firing by artillery pieces. It was also advantageous for land mines for several reasons: it was not detonated by the shock of shells landing nearby; it was lightweight, unaffected by damp, and stable under a wide range of conditions; it could be melted to fill a container of any shape, and it was cheap to make. Thus, it became the standard explosive in mines after the First World War. Between the American Civil War and the First World War The British used mines in the Siege of Khartoum to hold off a much larger Sudanese Mahdist force for ten months. In the end, however, the town was taken and the British massacred. In the Boer War (1899–1903), they succeeded in holding Mafeking against Boer forces with the help of a mixture of real and fake minefields; and they laid mines alongside railroad tracks to discourage sabotage. In the Russo-Japanese War of 1904–1905, both sides used land and sea mines, although the effect on land mainly affected morale. The naval mines were far more effective, destroying several battleships. First World War One sign of the increasing power of explosives used in land mines was that, by the First World War, they burst into about 1,000 high-velocity fragments; in the Franco-Prussian War (1870), it had only been 20 to 30 fragments. Nevertheless, antipersonnel mines were not a big factor in the war because machine guns, barbed wire and rapid-fire artillery were far more effective defenses. An exception was in Africa (now Tanzania and Namibia) where the warfare was much more mobile. Towards the end of the war, the British started to use tanks to break through trench defenses. The Germans responded with anti-tank guns and mines. Improvised mines gave way to mass-produced mines consisting of wooden boxes filled with guncotton, and minefields were standardized to stop masses of tanks from advancing. Between world wars, the future Allies did little work on land mines, but the Germans developed a series of anti-tank mines, the Tellermines (plate mines). They also developed the Schrapnell mine (also known as the S-mine), the first bounding mine. When triggered, this jumped up to about waist height and exploded, sending thousands of steel balls in all directions. Triggered by pressure, trip wires or electronics, it could harm soldiers within an area of about 2,800 square feet. Second World War Tens of millions of mines were laid in the Second World War, particularly in the deserts of North Africa and the steppes of Eastern Europe, where the open ground favored tanks. However, the first country to use them was Finland. They were defending against a much larger Soviet force with over 6,000 tanks, twenty times the number the Finns had; but they had terrain that was broken up by lakes and forests, so tank movement was restricted to roads and tracks. Their defensive line, the Mannerheim Line, integrated these natural defenses with mines, including simple fragmentation mines mounted on stakes. While the Germans were advancing rapidly using blitzkrieg tactics, they did not make much use of mines. After 1942, however, they were on the defensive and became the most inventive and systematic users of mines. Their production shot up and they began inventing new types of mines as the Allies found ways to counter the existing ones. To make it more difficult to remove antitank mines, they surrounded them with S-mines and added anti-handling devices that would explode when soldiers tried to lift them. They also took a formal approach to laying mines and they kept detailed records of the locations of mines. In the Second Battle of El Alamein in 1942, the Germans prepared for an Allied attack by laying about half a million mines in two fields running across the entire battlefield and five miles deep. Nicknamed the "Devil's gardens", they were covered by 88 mm anti-tank guns and small-arms fire. The Allies prevailed, but at the cost of over half their tanks; 20 percent of the losses were caused by mines. The Soviets learned the value of mines from their war with Finland, and when Germany invaded, they made heavy use of them, manufacturing over 67 million. At the Battle of Kursk, which put an end to the German advance, they laid over a million mines in eight belts with an overall depth of 35 kilometres. Mines forced tanks to slow down and wait for soldiers to go ahead and remove the mines. The main method of breaching minefields involved prodding the dirt with a bayonet or stick at an angle of 30 degrees (to avoid putting pressure on the top of the mine and detonating it). Since all mines at the beginning of the war had metal casings, metal detectors could be used to speed up the locating of mines. A Polish officer, Józef Kosacki, developed a portable mine detector known as the Polish mine detector. To counter the detector, Germans developed mines with wooden casings, the Schu-mine 42 (antipersonnel) and Holzmine 42 (anti-tank). Effective, cheap and easy to make, the schu mine became the most common mine in the war. Mine casings were also made of glass, concrete and clay. The Russians developed a mine with a pressed-cardboard casing, the PMK40, and the Italians made an anti-tank mine out of bakelite. In 1944, the Germans created the Topfmine, an entirely non-metallic mine. They ensured that they could detect their own mines by covering them with radioactive sand, but the Allies did not find this out until after the war. Several mechanical methods for clearing mines were tried. Heavy rollers attached to tanks or cargo trucks, but they did not last long and their weight made the tanks considerably slower. Tanks and bulldozers pushed ploughs that in turn pushed aside any mines to a depth of 30 cm. The Bangalore torpedo, a long thin tube filled with explosives, was invented in 1912 and used to clear barbed wire. Larger versions such as the Snake and the Conger were developed but were not very effective. One of the best options was the flail, which chains with weights on the end attached to rotating drums. The first version, the Scorpion, was attached to the Matilda tank and used in the Second Battle of El Alamein. The Crab, attached to the Sherman tank, was faster (2 kilometers per hour); it was used during D-Day and the aftermath. Cold War During the Cold War, the members of NATO were concerned about massive armored attacks by the Soviet Union. They planned for a minefield stretching across the entire West German border, and developed new types of mine. The British designed an anti-tank mine, the Mark 7, to defeat rollers by detonating the second time it was pressed. It also had a 0.7-second delay so the tank would be directly over the mine. They also developed the first scatterable mine, the No. 7 ("Dingbat"). The Americans used the M6 antitank mine and tripwire-operated bounding antipersonnel mines such as the M2 and M16. In the Korean War, land mine use was dictated by the steep terrain, narrow valleys, forest cover and lack of developed roads. This made tanks less effective and more easily stopped by mines. However, mines laid near roads were often easy to spot. In response to this problem, the US developed the M24, a mine that was placed off to the side of the road. When triggered by a tripwire, it fired a rocket. However, the mine was not available until after the war. The Chinese had a lot of success with massed infantry attacks. The extensive forest cover limited the range of machine guns, but anti-personnel mines were effective. However, mines were poorly recorded and marked, often becoming as much a hazard to allies as enemies. Tripwire-operated mines were not defended by pressure mines; the Chinese were often able to disable them and reuse them against UN forces. Looking for more destructive mines, the Americans developed the Claymore, a directional fragmentation mine that hurls steel balls in a 60-degree arc at a lethal speed of 1,200 metres per second. They also developed a pressure-operated mine, the M14 ("toe-popper"). These, too, were ready too late for the Korean war. In 1948, the British developed the No. 6 antipersonnel mine, a minimum-metal mine with a narrow diameter, making it difficult to detect with metal detectors or prodding. Its three-pronged pressure piece inspired the nickname "carrot mine". However, it was unreliable in wet conditions. In the 1960s the Canadians developed a similar, but more reliable mine, the C3A1 ("Elsie") and the British army adopted it. The British also developed the L9 bar mine, a wide anti-tank mine with a rectangular shape, which covered more area, allowing a minefield to be laid four times as fast as previous mines. They also upgraded the Dingbat to the Ranger, a plastic mine that was fired from a truck-mounted discharger that could fire 72 mines at a time. In the 1950s, the US Operation Doan Brook studied the feasibility of delivering mines by air. This led to three types of air-delivered mine. Wide area anti-personnel mines (WAAPMs) were small steel spheres that discharged tripwires when they hit the ground; each dispenser held 540 mines. The BLU-43 Dragontooth was small and had a flattened W shape to slow its descent, while the gravel mine was larger. Both were packed by the thousand into bombs. All three were designed to inactivate after a period of time, but any that failed to activate presented a safety challenge. Over 37 million Gravel mines were produced between 1967 and 1968, and when they were dropped in places like Vietnam their locations were unmarked and unrecorded. A similar problem was presented by unexploded cluster munitions. The next generation of scatterable mines arose in response to the increasing mobility of war. The Germans developed the Skorpion system, which scattered AT2 mines from a tracked vehicle. The Italians developed a helicopter delivery system that could rapidly switch between SB-33 anti-personnel mines and SB-81 anti-tank mines. The US developed a range of systems called the Family of Scatterable Mines (FASCAM) that could deliver mines by fast jet, artillery, helicopter and ground launcher. Middle eastern conflicts The Iraq-Iran War, the Gulf War, and the Islamic State have all contributed to land mine saturation in Iraq from the 1980s through 2020. Iraq is now the most saturated country in the world with landmines. Countries that provided land mines during the Iran-Iraq War included Belgium, Canada, Chile, China, Egypt, France, Italy, Romania, Singapore, the former Soviet Union and the U.S., and were concentrated in the Kurdish areas in the northern area of Iraq. During the Gulf War, the U.S. deployed 117,634 mines, with 27,967 being anti-personnel mines and 89,667 being anti-vehicle mines. The U.S. did not use land mines during the Iraq War. Chemical and nuclear In the First World War, the Germans developed a device, nicknamed the "Yperite Mine" by the British, that they left behind in abandoned trenches and bunkers. It was detonated by a delayed charge, spreading mustard gas ("Yperite"). In the Second World War they developed a modern chemical mine, the Sprüh-Büchse 37 (Bounding Gas Mine 37), but never used it. The United States developed the M1 chemical mine , which used mustard gas, in 1939; and the M23 chemical mine, which used the VX nerve agent, in 1960. The Soviets developed the KhF, a "bounding chemical mine". The French had chemical mines and the Iraqis were believed to have them
|
mounted on stakes. While the Germans were advancing rapidly using blitzkrieg tactics, they did not make much use of mines. After 1942, however, they were on the defensive and became the most inventive and systematic users of mines. Their production shot up and they began inventing new types of mines as the Allies found ways to counter the existing ones. To make it more difficult to remove antitank mines, they surrounded them with S-mines and added anti-handling devices that would explode when soldiers tried to lift them. They also took a formal approach to laying mines and they kept detailed records of the locations of mines. In the Second Battle of El Alamein in 1942, the Germans prepared for an Allied attack by laying about half a million mines in two fields running across the entire battlefield and five miles deep. Nicknamed the "Devil's gardens", they were covered by 88 mm anti-tank guns and small-arms fire. The Allies prevailed, but at the cost of over half their tanks; 20 percent of the losses were caused by mines. The Soviets learned the value of mines from their war with Finland, and when Germany invaded, they made heavy use of them, manufacturing over 67 million. At the Battle of Kursk, which put an end to the German advance, they laid over a million mines in eight belts with an overall depth of 35 kilometres. Mines forced tanks to slow down and wait for soldiers to go ahead and remove the mines. The main method of breaching minefields involved prodding the dirt with a bayonet or stick at an angle of 30 degrees (to avoid putting pressure on the top of the mine and detonating it). Since all mines at the beginning of the war had metal casings, metal detectors could be used to speed up the locating of mines. A Polish officer, Józef Kosacki, developed a portable mine detector known as the Polish mine detector. To counter the detector, Germans developed mines with wooden casings, the Schu-mine 42 (antipersonnel) and Holzmine 42 (anti-tank). Effective, cheap and easy to make, the schu mine became the most common mine in the war. Mine casings were also made of glass, concrete and clay. The Russians developed a mine with a pressed-cardboard casing, the PMK40, and the Italians made an anti-tank mine out of bakelite. In 1944, the Germans created the Topfmine, an entirely non-metallic mine. They ensured that they could detect their own mines by covering them with radioactive sand, but the Allies did not find this out until after the war. Several mechanical methods for clearing mines were tried. Heavy rollers attached to tanks or cargo trucks, but they did not last long and their weight made the tanks considerably slower. Tanks and bulldozers pushed ploughs that in turn pushed aside any mines to a depth of 30 cm. The Bangalore torpedo, a long thin tube filled with explosives, was invented in 1912 and used to clear barbed wire. Larger versions such as the Snake and the Conger were developed but were not very effective. One of the best options was the flail, which chains with weights on the end attached to rotating drums. The first version, the Scorpion, was attached to the Matilda tank and used in the Second Battle of El Alamein. The Crab, attached to the Sherman tank, was faster (2 kilometers per hour); it was used during D-Day and the aftermath. Cold War During the Cold War, the members of NATO were concerned about massive armored attacks by the Soviet Union. They planned for a minefield stretching across the entire West German border, and developed new types of mine. The British designed an anti-tank mine, the Mark 7, to defeat rollers by detonating the second time it was pressed. It also had a 0.7-second delay so the tank would be directly over the mine. They also developed the first scatterable mine, the No. 7 ("Dingbat"). The Americans used the M6 antitank mine and tripwire-operated bounding antipersonnel mines such as the M2 and M16. In the Korean War, land mine use was dictated by the steep terrain, narrow valleys, forest cover and lack of developed roads. This made tanks less effective and more easily stopped by mines. However, mines laid near roads were often easy to spot. In response to this problem, the US developed the M24, a mine that was placed off to the side of the road. When triggered by a tripwire, it fired a rocket. However, the mine was not available until after the war. The Chinese had a lot of success with massed infantry attacks. The extensive forest cover limited the range of machine guns, but anti-personnel mines were effective. However, mines were poorly recorded and marked, often becoming as much a hazard to allies as enemies. Tripwire-operated mines were not defended by pressure mines; the Chinese were often able to disable them and reuse them against UN forces. Looking for more destructive mines, the Americans developed the Claymore, a directional fragmentation mine that hurls steel balls in a 60-degree arc at a lethal speed of 1,200 metres per second. They also developed a pressure-operated mine, the M14 ("toe-popper"). These, too, were ready too late for the Korean war. In 1948, the British developed the No. 6 antipersonnel mine, a minimum-metal mine with a narrow diameter, making it difficult to detect with metal detectors or prodding. Its three-pronged pressure piece inspired the nickname "carrot mine". However, it was unreliable in wet conditions. In the 1960s the Canadians developed a similar, but more reliable mine, the C3A1 ("Elsie") and the British army adopted it. The British also developed the L9 bar mine, a wide anti-tank mine with a rectangular shape, which covered more area, allowing a minefield to be laid four times as fast as previous mines. They also upgraded the Dingbat to the Ranger, a plastic mine that was fired from a truck-mounted discharger that could fire 72 mines at a time. In the 1950s, the US Operation Doan Brook studied the feasibility of delivering mines by air. This led to three types of air-delivered mine. Wide area anti-personnel mines (WAAPMs) were small steel spheres that discharged tripwires when they hit the ground; each dispenser held 540 mines. The BLU-43 Dragontooth was small and had a flattened W shape to slow its descent, while the gravel mine was larger. Both were packed by the thousand into bombs. All three were designed to inactivate after a period of time, but any that failed to activate presented a safety challenge. Over 37 million Gravel mines were produced between 1967 and 1968, and when they were dropped in places like Vietnam their locations were unmarked and unrecorded. A similar problem was presented by unexploded cluster munitions. The next generation of scatterable mines arose in response to the increasing mobility of war. The Germans developed the Skorpion system, which scattered AT2 mines from a tracked vehicle. The Italians developed a helicopter delivery system that could rapidly switch between SB-33 anti-personnel mines and SB-81 anti-tank mines. The US developed a range of systems called the Family of Scatterable Mines (FASCAM) that could deliver mines by fast jet, artillery, helicopter and ground launcher. Middle eastern conflicts The Iraq-Iran War, the Gulf War, and the Islamic State have all contributed to land mine saturation in Iraq from the 1980s through 2020. Iraq is now the most saturated country in the world with landmines. Countries that provided land mines during the Iran-Iraq War included Belgium, Canada, Chile, China, Egypt, France, Italy, Romania, Singapore, the former Soviet Union and the U.S., and were concentrated in the Kurdish areas in the northern area of Iraq. During the Gulf War, the U.S. deployed 117,634 mines, with 27,967 being anti-personnel mines and 89,667 being anti-vehicle mines. The U.S. did not use land mines during the Iraq War. Chemical and nuclear In the First World War, the Germans developed a device, nicknamed the "Yperite Mine" by the British, that they left behind in abandoned trenches and bunkers. It was detonated by a delayed charge, spreading mustard gas ("Yperite"). In the Second World War they developed a modern chemical mine, the Sprüh-Büchse 37 (Bounding Gas Mine 37), but never used it. The United States developed the M1 chemical mine , which used mustard gas, in 1939; and the M23 chemical mine, which used the VX nerve agent, in 1960. The Soviets developed the KhF, a "bounding chemical mine". The French had chemical mines and the Iraqis were believed to have them before the invasion of Kuwait. In 1997, the Chemical Weapons Convention came into force, prohibiting the use of chemical weapons and mandating their destruction. As of April 30, 2019, 97% of the declared stockpiles of chemical weapons were destroyed. For a few decades during the Cold War, the U.S. developed atomic demolition munitions, often referred to as nuclear land mines. These were portable nuclear bombs that could be placed by hand, and could be detonated remotely or with a timer. Some of these were deployed in Europe. Governments in West Germany, Turkey and Greece wanted to have nuclear minefields as a defense against attack from the Warsaw Pact. However, such weapons were politically and tactically infeasible, and by 1989 the last of these munitions was retired. The British also had a project, codenamed Blue Peacock, to develop nuclear mines to be buried in Germany; the project was cancelled in 1958. Characteristics and function A conventional land mine consists of a casing that is mostly filled with the main charge. It has a firing mechanism such as a pressure plate; this triggers a detonator or igniter, which in turn sets off a booster charge. There may be additional firing mechanisms in anti-handling devices. Firing mechanisms and initiating actions A land mine can be triggered by a number of things including pressure, movement, sound, magnetism and vibration. Anti-personnel mines commonly use the pressure of a person's foot as a trigger, but tripwires are also frequently employed. Most modern anti-vehicle mines use a magnetic trigger to enable it to detonate even if the tires or tracks did not touch it. Advanced mines are able to sense the difference between friendly and enemy types of vehicles by way of a built-in signature catalog. This will theoretically enable friendly forces to use the mined area while denying the enemy access. Many mines combine the main trigger with a touch or tilt trigger to prevent enemy engineers from defusing it. Land mine designs tend to use as little metal as possible to make searching with a metal detector more difficult; land mines made mostly of plastic have the added advantage of being very inexpensive. Some types of modern mines are designed to self-destruct, or chemically render themselves inert after a period of weeks or months to reduce the likelihood of civilian casualties at the conflict's end. These self-destruct mechanisms are not absolutely reliable, and most land mines laid historically are not equipped in this manner. There is a common misperception that a landmine is armed by stepping on it and only triggered by stepping off, providing tension in movies. In fact the initial pressure trigger will detonate the mine, as they are designed to kill or maim, not to make someone stand very still until it can be disarmed. Anti-handling devices Anti-handling devices detonate the mine if someone attempts to lift, shift or disarm it. The intention is to hinder deminers by discouraging any attempts to clear minefields. There is a degree of overlap between the function of a boobytrap and an anti-handling device insofar as some mines have optional fuze pockets into which standard pull or pressure-release boobytrap firing devices can be screwed. Alternatively, some mines may mimic a standard design, but actually be specifically intended to kill deminers, such as the MC-3 and
|
not all of them support all elements of libertarianism. Most of these political parties are right-libertarians, or are right-leaning for favouring classical liberalism and economic liberalism, as left-libertarians take a different approach, generally opposing electoral politics and political parties themselves; exceptions have been the Libertarian Left in Chile, Libertarian Peru (now Free Peru), and the Radical
|
in Chile, Libertarian Peru (now Free Peru), and the Radical Party in Italy. Active parties by country Defunct parties by country Organizations associated with Libertarian parties See also Liberal parties by country List of libertarian organizations Lists of political parties Outline
|
amid the mixing of different West African traditional religions and the influence of the French colonists' Roman Catholicism. From at least the 19th century, Haitian migrants took their religion to Louisiana, by that point part of the United States, where they contributed to the formation of Louisiana Voodoo, a religion that largely died out in the early 20th century. In the latter part of that century, Voodoo revivalist groups emerged in Louisiana, often incorporating both the lwa spirits of Haitian Vodou and the oricha spirits of Cuban Santería into their practices. Etymology Modern linguists trace the etymology of lwa to a family of Yoruba language words which include (god) and babalawo (diviner or priest). The term lwa is phonetically identical to both a French term for law, loi, and a Haitian Creole term for law, lwa. The early 20th-century writer Jean Price-Mars pondered if the term lwa, used in reference to Vodou spirits, emerged from their popular identification with the laws of the Roman Catholic Church. In the early 21st century, the historian Kate Ramsey agreed that the phonetic similarity between the terms for the law and the Vodou spirits may not be "mere linguistic coincidence" but could reflect the complex interactions of African and French colonial cultures in Haiti. Several spelling for lwa have been used. Early 20th-century writers on Haitian religion, such as Price-Mars, usually spelled the term loi. During that century, writers like the American anthropologist Melville Herskovits favored the spelling loa, although in 2008 the historian Jeffrey E. Anderson wrote that the spelling loa was typically found in older works on the topic, having fallen out of favor with scholarly writers. The spelling lwa has been favored by more recent scholarly writers including Anderson, Ramsey, the anthropologist Karen McCarthy Brown, the scholar of religious studies Leslie Desmangles, and the Hispanic studies scholars Margarite Fernández Olmos and Lizabeth Paravisini-Gebert. Theology Vodou teaches that there are over a thousand lwa. They are regarded as the intermediaries of Bondyé, the supreme creator deity in Vodou. Desmangles argued that by learning about the various lwas, practitioners come to understand the different facets of Bondyé. Much as Vodouists often identify Bondyé with the Christian God, the lwa are sometimes equated with the angels of Christian cosmology. The lwa are also known as the mystères, anges, saints, and les invisibles. The lwa can offer help, protection, and counsel to humans, in return for ritual service. They are thought of as having wisdom that is useful for humans, although they are not seen as moral exemplars which practitioners should imitate. Each lwa has its own personality, and is associated with specific colors, days of the week, and objects. The lwa can be either loyal or capricious in their dealings with their devotees; Vodouists believe that the lwa are easily offended, for instance if offered food that they dislike. When angered, the lwa are believed to remove their protection from their devotees, or to inflict misfortune, illness, or madness on an individual. Although there are exceptions, most lwa names derive from the Fon and Yoruba languages. New lwa are nevertheless added to those brought from Africa; practitioners believe that some Vodou priests and priestesses became lwa after death, or that certain talismans become lwa. Vodouists often refer to the lwa residing in "Guinea", but this is not intended as a precise geographical location. Many lwa are also understood to live under the water, at the bottom of the sea or in rivers. Vodouists believe that the lwa communicate with humans through dreams and through the possession of human beings. During rituals, the lwa are summoned through designs known as veve. These are sketched out on the floor of the ceremonial space using cornmeal, ash, coffee grounds, or powdered eggshells. The lwa are associated with specific Roman Catholic saints. For instance, Azaka, the lwa of agriculture, is associated with Saint Isidore the farmer. Similarly, because he is understood as the "key" to the spirit world, Papa Legba is typically associated with Saint Peter, who is visually depicted holding keys in traditional Roman Catholic imagery. The lwa of love and luxury, Ezili Freda, is associated with Mater Dolorosa. Damballa, who is a serpent, is often equated with Saint Patrick, who is traditionally depicted in a scene with snakes; alternatively he is often associated with Moses. The Marasa, or sacred twins, are typically equated with the twin saints Cosmos and Damian. Nanchon In Haitian Vodou, the lwa are divided into nanchon or "nations". This classificatory system derives from the way in which enslaved West Africans were divided into "nations" upon their arrival in Haiti, usually based on their African port of departure rather than their ethno-cultural identity. The nanchons are nevertheless not groupings based in the geographical origins of specific lwas. The term fanmi (family) is sometimes used synonymously with "nation" or alternatively as a sub-division of the latter category. It is often claimed that there are 17 nanchon, although few Haitians could name all of them. Each is deemed to have its own characteristic
|
and vigor, and these will restore the divine energy of the god." Because Agwé is believed to reside in the sea, rituals devoted to him often take place beside a large body of water such as a lake, river, or sea. His devotees sometimes sail out to Trois Ilets, drumming and singing, where they throw a white sheep overboard as a sacrifice to him. The food is typically offered when it is cool; it remains there for a while before humans can then eat it. The food is often placed within a kwi, a calabash shell bowl. Once selected, the food is placed on special calabashes known as assiettes de Guinée which are located on the altar. Offerings not consumed by the celebrants are then often buried or left at a crossroads. Libations might be poured into the ground. Vodouists believe that the lwa then consume the essence of the food. Certain foods are also offered in the belief that they are intrinsically virtuous, such as grilled maize, peanuts, and cassava. These are sometimes sprinkled over animals that are about to be sacrificed or piled upon the vèvè designs on the floor of the peristil. Possession Possession by the lwa constitutes an important element of Vodou. It lies the heart of many of its rituals; these typically take place in a temple called an ounfò, specifically in a room termed the peristil or peristyle. The person being possessed is referred to as the chwal or chual (horse); the act of possession is called "mounting a horse". Vodou teaches that a lwa can possess an individual regardless of gender; both male and female lwa can possess either men or women. Although children are often present at these ceremonies, they are rarely possessed as it is considered too dangerous. While the specific drums and songs used are designed to encourage a specific lwa to possess someone, sometimes an unexpected lwa appears and takes possession instead. In some instances a succession of lwa possess the same individual, one after the other. The trance of possession is known as the crise de lwa. Vodouists believe that during this process, the lwa enters the head of the chwal and displaces their gwo bon anj, which is one of the two halves of a person's soul. This displacement is believed to cause the chwal to tremble and convulse; Maya Deren described a look of "anguish, ordeal and blind terror" on the faces of those as they became possessed. Because their consciousness has been removed from their head during the possession, Vodouists believe that the chwal will have no memory of what occurs during the incident. The length of the possession varies, often lasting a few hours but sometimes several days. It may end with the chwal collapsing in a semi-conscious state; they are typically left physically exhausted. Some individuals attending the dance will put a certain item, often wax, in their hair or headgear to prevent possession. Once the lwa possesses an individual, the congregation greet it with a burst of song and dance. The chwal will typically bow before the officiating priest or priestess and prostrate before the poto mitan, a central pillar within the temple. The chwal is often escorted into an adjacent room where they are dressed in clothing associated with the possessing lwa. Alternatively, the clothes are brought out and they are dressed in the peristil itself. Once the chwal has been dressed, congregants kiss the floor before them. These costumes and props help the chwal take on the appearance of the lwa. Many ounfo have a large wooden phallus on hand which is used by those possessed by Ghede lwa during their dances. The chwal takes on the behaviour and expressions of the possessing lwa; their performance can be very theatrical. Those believing themselves possessed by the serpent Damballa, for instance, often slither on the floor, dart out their tongue, and climb the posts of the peristil. Those possessed by Zaka, lwa of agriculture, will dress as a peasant in a straw hat with a clay pipe and will often speak in a rustic accent. The chwal will often then join in with the dances, dancing with anyone whom they wish to, or sometimes eating and drinking. Sometimes the lwa, through the chwal, will engage in financial transactions with members of the congregation, for instance by selling them food that has been given as an offering or lending them money. Possession facilitates direct communication between the lwa and its followers; through the chwal, the lwa communicates with their devotees, offering counsel, chastisement, blessings, warnings about the future, and healing. Lwa possession has a healing function, with the possessed individual expected to reveal possible cures to the ailments of those assembled. Clothing that the chwal touches is regarded as bringing luck. The lwa may also offer advice to the individual they are possessing; because the latter is not believed to retain any memory of the events, it is expected that other members of the congregation will pass along the lwa's message. In some instances, practitioners have reported being possessed at other times of ordinary life, such as when someone is in the middle of the market, or when they are
|
into the provision of labour—that is, will work more hours to take advantage of the higher wage rate, or in other words substitute away from leisure because of its higher opportunity cost. This substitution effect is represented by the shift from point C to point B. The net impact of these two effects is shown by the shift from point A to point B. The relative magnitude of the two effects depends on the circumstances. In some cases, such as the one shown, the substitution effect is greater than the income effect (in which case more time will be allocated to working), but in other cases, the income effect will be greater than the substitution effect (in which case less time is allocated to working). The intuition behind this latter case is that the individual decides that the higher earnings on the previous amount of labour can be "spent" by purchasing more leisure. The Labour Supply curve If the substitution effect is greater than the income effect, an individual's supply of labour services will increase as the wage rate rises, which is represented by a positive slope in the labour supply curve (as at point E in the adjacent diagram, which exhibits a positive wage elasticity). This positive relationship is increasing until point F, beyond which the income effect dominates the substitution effect and the individual starts to reduce the number of labour hours he supplies (point G) as wage increases; in other words, the wage elasticity is now negative. The direction of the slope may change more than once for some individuals, and the labour supply curve is different for different individuals. Other variables that affect the labour supply decision, and can be readily incorporated into the model, include taxation, welfare, work environment, and income as a signal of ability or social contribution. Neoclassical microeconomic model – Demand A firm's labour demand is based on its marginal physical product of labour (MPPL). This is defined as the additional output (or physical product) that results from an increase of one unit of labour (or from an infinitesimal increase in labour). (See also Production theory basics.) Labour demand is a derived demand; that is, hiring labour is not desired for its own sake but rather because it aids in producing output, which contributes to an employer's revenue and hence profits. The demand for an additional amount of labour depends on the Marginal Revenue Product (MRP) and the marginal cost (MC) of the worker. With a perfectly competitive goods market, the MRP is calculated by multiplying the price of the end product or service by the Marginal Physical Product of the worker. If the MRP is greater than a firm's Marginal Cost, then the firm will employ the worker since doing so will increase profit. The firm only employs however up to the point where MRP=MC, and not beyond, in neoclassical economic theory. The MRP of the worker is affected by other inputs to production with which the worker can work (e.g. machinery), often aggregated under the term "capital". It is typical in economic models for greater availability of capital for a firm to increase the MRP of the worker, all else equal. Education and training are counted as "human capital". Since the amount of physical capital affects MRP, and since financial capital flows can affect the amount of physical capital available, MRP and thus wages can be affected by financial capital flows within and between countries, and the degree of capital mobility within and between countries. According to neoclassical theory, over the relevant range of outputs, the marginal physical product of labour is declining (law of diminishing returns). That is, as more and more units of labour are employed, their additional output begins to decline. Additionally, although the MRP is a good way of expressing an employer's demand, other factors such as social group formation can the demand, as well as the labour supply. This constantly restructures exactly what a labour market is, and leads way to cause problems for theories of inflation. Neoclassical microeconomic model – Equilibrium A firm's labour demand in the short run (D) and a horizontal supply curve (S) The marginal revenue product of labour can be used as the demand for labour curve for this firm in the short run. In competitive markets, a firm faces a perfectly elastic supply of labour which corresponds with the wage rate and the marginal resource cost of labour (W = SL = MFCL). In imperfect markets, the diagram would have to be adjusted because MFCL would then be equal to the wage rate divided by marginal costs. Because optimum resource allocation requires that marginal factor costs equal marginal revenue product, this firm would demand L units of labour as shown in the diagram. The demand for labour of this firm can be summed with the demand for labour of all other firms in the economy to obtain the aggregate demand for labour. Likewise, the supply curves of all the individual workers (mentioned above) can be summed to obtain the aggregate supply of labour. These supply and demand curves can be analysed in the same way as any other industry demand and supply curves to determine equilibrium wage and employment levels. Wage differences exist, particularly in mixed and fully/partly flexible labour markets. For example, the wages of a doctor and a port cleaner, both employed by the NHS, differ greatly. There are various factors concerning this phenomenon. This includes the MRP of the worker. A doctor's MRP is far greater than that of the port cleaner. In addition, the barriers to becoming a doctor are far greater than that of becoming a port cleaner. To become a doctor takes a lot of education and training which is costly, and only those who excel in academia can succeed in becoming doctors. The port cleaner, however, requires relatively less training. The supply of doctors is therefore significantly less elastic than that of port cleaners. Demand is also inelastic as there is a high demand for doctors and medical care is a necessity, so the NHS will pay higher wage rates to attract the profession. Monopsony Some labour markets have a single employer and thus do not satisfy the perfect competition assumption of the neoclassical model above. The model of a monopsonistic labour market gives a lower quantity of employment and a lower equilibrium wage rate than does the competitive model. Asymmetric information In many real-life situations, the assumption of perfect information is unrealistic. An employer does not necessarily know how hard workers are working or how productive they are. This provides an incentive for workers to shirk from providing their full effort, called moral hazard. Since it is difficult for the employer to identify the hard-working and the shirking employees, there is no incentive to work hard and productivity falls overall, leading to the hiring of more workers and a lower unemployment rate. One solution that is used to avoid a moral hazard is stock options that grant employees the chance to benefit directly from a firm's success. However, this solution has attracted criticism as executives with large stock-option packages have been suspected of acting to over-inflate share values to the detriment of the long-run welfare of the firm. Another solution, foreshadowed by the rise of temporary workers in Japan and the firing of many of these workers in response to the financial crisis of 2008, is more flexible job- contracts and -terms that encourage employees to work less than full-time by partially compensating for the loss of hours, relying on workers to adapt their working time in response to job requirements and economic conditions instead of the employer trying to determine how much work is needed to complete a given task and overestimating. Another aspect of uncertainty results from the firm's imperfect knowledge about worker ability. If a firm is unsure about a worker's ability, it pays a wage assuming that the worker's ability is the average of similar workers. This wage under compensates high-ability workers which may drive them away from the labour market as well as at the same time attracting low-ability workers. Such a phenomenon, called adverse selection, can sometimes lead to market collapse. One way to combat adverse selection, firms will try to use signalling, pioneered by Michael Spence, whereby employers could use various characteristics of applicants differentiate between high-ability or low-ability workers. One common signal used is education, whereby employers assume that high-ability workers will have higher levels of education. Employers can then compensate high-ability workers with higher wages. However, signalling does not always work, and it may appear to an external observer that education has raised the marginal product of labour, without this necessarily being true. Search models One of the major research achievements of the 1990-2010 period was the development of a framework with dynamic search, matching, and bargaining. Personnel economics: hiring and incentives At the micro level, one sub-discipline eliciting increased attention in recent decades is analysis of internal labour markets, that is, within firms (or other organisations), studied in personnel economics from the perspective of personnel management. By contrast, external labour markets "imply that workers move somewhat fluidly between firms and wages are determined by some aggregate process where firms do not have significant discretion over wage setting." The focus is on "how firms establish, maintain, and end employment relationships and on how firms provide incentives to employees," including models and empirical work on incentive systems and as constrained by economic efficiency and risk/incentive tradeoffs relating to personnel compensation. Discrimination and inequality Inequality and discrimination in the workplace can have many effects on workers. In the context of labour economics, inequality is usually referring to the unequal distribution of earning between households. Inequality is commonly measured by economists using the Gini coefficient. This coefficient does not have a concrete meaning but is more used as a way to compare inequality across regions. The higher the Gini coefficient is calculated to be the larger inequality exists in a region. Over time, inequality has, on average, been increasing. This is due to numerous factors including labour supply and demand shifts as well as institutional changes in the labour market. On the shifts in labour supply and demand, factors include demand for skilled workers going up more than the supply of skilled workers and relative to unskilled workers as well as technological changes that increase productivity; all of these things cause wages to go up for skilled labour while unskilled worker wages stay the same or decline. As for the institutional changes, a decrease in union power and a declining real
|
used to show a variety of interesting effects. This is because the absolute value of the slope of the budget constraint is the wage rate. The point of optimisation (point A) reflects the equivalency between the wage rate and the marginal rate of substitution of leisure for income (the absolute value of the slope of the indifference curve). Because the marginal rate of substitution of leisure for income is also the ratio of the marginal utility of leisure (MUL) to the marginal utility of income (MUY), one can conclude: where Y is total income and the right side is the wage rate. Effects of a wage increase If the wage rate increases, this individual's constraint line pivots up from X,Y1 to X,Y2. He/she can now purchase more goods and services. His/her utility will increase from point A on IC1 to point B on IC2. To understand what effect this might have on the decision of how many hours to work, one must look at the income effect and substitution effect. The wage increase shown in the previous diagram can be decomposed into two separate effects. The pure income effect is shown as the movement from point A to point C in the next diagram. Consumption increases from YA to YC and – since the diagram assumes that leisure is a normal good – leisure time increases from XA to XC. (Employment time decreases by the same amount as leisure increases.) The Income and Substitution effects of a wage increase But that is only part of the picture. As the wage rate rises, the worker will substitute away from leisure and into the provision of labour—that is, will work more hours to take advantage of the higher wage rate, or in other words substitute away from leisure because of its higher opportunity cost. This substitution effect is represented by the shift from point C to point B. The net impact of these two effects is shown by the shift from point A to point B. The relative magnitude of the two effects depends on the circumstances. In some cases, such as the one shown, the substitution effect is greater than the income effect (in which case more time will be allocated to working), but in other cases, the income effect will be greater than the substitution effect (in which case less time is allocated to working). The intuition behind this latter case is that the individual decides that the higher earnings on the previous amount of labour can be "spent" by purchasing more leisure. The Labour Supply curve If the substitution effect is greater than the income effect, an individual's supply of labour services will increase as the wage rate rises, which is represented by a positive slope in the labour supply curve (as at point E in the adjacent diagram, which exhibits a positive wage elasticity). This positive relationship is increasing until point F, beyond which the income effect dominates the substitution effect and the individual starts to reduce the number of labour hours he supplies (point G) as wage increases; in other words, the wage elasticity is now negative. The direction of the slope may change more than once for some individuals, and the labour supply curve is different for different individuals. Other variables that affect the labour supply decision, and can be readily incorporated into the model, include taxation, welfare, work environment, and income as a signal of ability or social contribution. Neoclassical microeconomic model – Demand A firm's labour demand is based on its marginal physical product of labour (MPPL). This is defined as the additional output (or physical product) that results from an increase of one unit of labour (or from an infinitesimal increase in labour). (See also Production theory basics.) Labour demand is a derived demand; that is, hiring labour is not desired for its own sake but rather because it aids in producing output, which contributes to an employer's revenue and hence profits. The demand for an additional amount of labour depends on the Marginal Revenue Product (MRP) and the marginal cost (MC) of the worker. With a perfectly competitive goods market, the MRP is calculated by multiplying the price of the end product or service by the Marginal Physical Product of the worker. If the MRP is greater than a firm's Marginal Cost, then the firm will employ the worker since doing so will increase profit. The firm only employs however up to the point where MRP=MC, and not beyond, in neoclassical economic theory. The MRP of the worker is affected by other inputs to production with which the worker can work (e.g. machinery), often aggregated under the term "capital". It is typical in economic models for greater availability of capital for a firm to increase the MRP of the worker, all else equal. Education and training are counted as "human capital". Since the amount of physical capital affects MRP, and since financial capital flows can affect the amount of physical capital available, MRP and thus wages can be affected by financial capital flows within and between countries, and the degree of capital mobility within and between countries. According to neoclassical theory, over the relevant range of outputs, the marginal physical product of labour is declining (law of diminishing returns). That is, as more and more units of labour are employed, their additional output begins to decline. Additionally, although the MRP is a good way of expressing an employer's demand, other factors such as social group formation can the demand, as well as the labour supply. This constantly restructures exactly what a labour market is, and leads way to cause problems for theories of inflation. Neoclassical microeconomic model – Equilibrium A firm's labour demand in the short run (D) and a horizontal supply curve (S) The marginal revenue product of labour can be used as the demand for labour curve for this firm in the short run. In competitive markets, a firm faces a perfectly elastic supply of labour which corresponds with the wage rate and the marginal resource cost of labour (W = SL = MFCL). In imperfect markets, the diagram would have to be adjusted because MFCL would then be equal to the wage rate divided by marginal costs. Because optimum resource allocation requires that marginal factor costs equal marginal revenue product, this firm would demand L units of labour as shown in the diagram. The demand for labour of this firm can be summed with the demand for labour of all other firms in the economy to obtain the aggregate demand for labour. Likewise, the supply curves of all the individual workers (mentioned above) can be summed to obtain the aggregate supply of labour. These supply and demand curves can be analysed in the same way as any other industry demand and supply curves to determine equilibrium wage and employment levels. Wage differences exist, particularly in mixed and fully/partly flexible labour markets. For example, the wages of a doctor and a port cleaner, both employed by the NHS, differ greatly. There are various factors concerning this phenomenon. This includes the MRP of the worker. A doctor's MRP is far greater than that of the port cleaner. In addition, the barriers to becoming a doctor are far greater than that of becoming a port cleaner. To become a doctor takes a lot of education and training which is costly, and only those who excel in academia can succeed in becoming doctors. The port cleaner, however, requires relatively less training. The supply of doctors is therefore significantly less elastic than that of port cleaners. Demand is also inelastic as there is a high demand for doctors and medical care is a necessity, so the NHS will pay higher wage rates to attract the profession. Monopsony Some labour markets have a single employer and thus do not satisfy the perfect competition assumption of the neoclassical model above. The model of a monopsonistic labour market gives a lower quantity of employment and a lower equilibrium wage rate than does the competitive model. Asymmetric information In many real-life situations, the assumption of perfect information is unrealistic. An employer does not necessarily know how hard workers are working or how productive they are. This provides an incentive for workers to shirk from providing their full effort, called moral hazard. Since it is difficult for the employer to identify the hard-working and the shirking employees, there is no incentive to work hard and productivity falls overall, leading to the hiring of more workers and a lower unemployment rate. One solution that is used to avoid a moral hazard is stock options that grant employees the chance to benefit directly from a firm's success. However, this solution has attracted criticism as executives with large stock-option packages have been suspected of acting to over-inflate share values to the detriment of the long-run welfare of the firm. Another solution, foreshadowed by the rise of temporary workers in Japan and the firing of many of these workers in response to the financial crisis of 2008, is more flexible job- contracts and -terms that encourage employees to work less than full-time by partially compensating for the loss of hours, relying on workers to adapt their working time in response to job requirements and economic conditions instead of the employer trying to determine how much work is needed to complete a given task and overestimating. Another aspect of uncertainty results from the firm's imperfect knowledge about worker ability. If a firm is unsure about a worker's ability, it pays a wage assuming that the worker's ability is the average of similar workers. This wage under compensates high-ability workers which may drive them away from the labour market as well as at the same time attracting low-ability workers. Such a phenomenon, called adverse selection, can sometimes lead to market collapse. One way to combat adverse selection, firms will try to use signalling, pioneered by Michael Spence, whereby employers could use various characteristics of applicants differentiate between high-ability or low-ability workers. One common signal used is education, whereby employers assume that high-ability workers will have higher levels of education. Employers can then compensate high-ability workers with higher wages. However, signalling does not always work, and it may appear to an external observer that education has raised the marginal product of labour, without this necessarily being true. Search models One of the major research achievements of the 1990-2010 period was the development of a framework with dynamic search, matching, and bargaining. Personnel economics: hiring and incentives At the micro level, one sub-discipline eliciting increased attention in recent decades is analysis of internal labour markets, that is, within firms (or other organisations), studied in personnel economics from the perspective of personnel management. By contrast, external labour markets "imply that workers move somewhat fluidly between firms and wages are determined by some aggregate process where firms do not have significant discretion over wage setting." The focus is on "how firms establish, maintain, and end employment relationships and on how firms provide incentives to employees," including models and empirical work on incentive systems and as constrained by economic efficiency and risk/incentive tradeoffs relating to personnel compensation. Discrimination and inequality Inequality and discrimination in the workplace can have many effects on workers. In the context of labour economics, inequality is usually referring to the unequal distribution of earning between households. Inequality is commonly measured by economists using the Gini coefficient. This coefficient does not have a concrete meaning but is more used as a way to compare inequality across regions. The higher the Gini coefficient is calculated to be the larger inequality exists in a region. Over time, inequality has, on average, been increasing. This is due to numerous factors including labour supply and demand shifts as well as institutional changes in the labour market. On the shifts in labour supply and demand, factors include demand for skilled workers going up more than the supply of skilled workers and relative to unskilled workers as well as technological changes that increase productivity; all of these things
|
of 1969 the feast of St. Alphonsus Liguori was transferred to this day, the day of St. Alphonsus' death. While Loaf Mass Day is traditionally a Christian holy day, Lughnasadh is celebrated by Neopagans around the same time. History Ann Lewin explains a key practice of the Christian feast of Lammas (Loaf Mass Day) and its importance in the Christian Calendar in relation to other feasts of the Church Year: In the Church of England, the mother church of the Anglican Communion, during the celebration of Holy Communion, "The Lammas loaf, or part of it, may be used as the bread of the Eucharist, or the Lammas loaf and the eucharistic bread may be kept separate." The loaf is blessed and in Anglo-Saxon England it might be employed afterwards in protective rituals: a book of Anglo-Saxon charms directed that the Lammas bread be broken into four parts, which were to be placed at the four corners of the barn, to protect the garnered grain. In many parts of England, tenants were bound to present freshly harvested wheat to their landlords on or before the first day of August. In the Anglo-Saxon Chronicle, where it is referred to frequently, it is called "the feast of first fruits". The blessing of first fruits was performed annually in both the Eastern and Western churches on the 1st or the 6th of August (the latter being the feast of the Transfiguration of Christ). In medieval times the feast was sometimes known in England and Scotland as the "Gule of August", but the meaning of "gule" is unclear. Ronald Hutton suggests following the 18th-century Welsh clerical antiquary John Pettingall that it is merely an anglicisation of , Welsh for "feast of August". The OED and most etymological dictionaries give it a more circuitous origin similar to gullet; from Old French , a diminutive of , "throat, neck," from Latin "throat". Several antiquaries beginning with John Brady offered a back-construction to its being originally known as Lamb-mass, under the undocumented supposition that tenants of the Cathedral of York, dedicated to St. Peter ad Vincula, of which this is the feast, would have been required to bring a live lamb to the church, or, with John Skinner, "because Lambs then grew out of season." This is a folk etymology, of which OED notes that it was "subsequently felt as if from LAMB + MASS". For many villeins, the wheat must have run low in the days before Lammas, and the new harvest began a season of plenty, of hard work and company in the fields, reaping in teams. Thus there was a spirit of celebratory play. In the medieval agricultural year, Lammas also marked the end of the hay harvest that had begun after Midsummer. At the end of hay-making a sheep would be loosed in the meadow among the mowers, for him to keep who could catch it. In Shakespeare's Romeo and Juliet (1.3.19) it is observed of Juliet, "Come Lammas Eve at night shall she [Juliet] be fourteen." Since Juliet was born on Lammas Eve, she came before the harvest festival, which is significant since her life ended before she could reap what she had sown, as blessed by the Friar Francisco, by consummating her marriage: Another well-known cultural reference is the opening of The Battle of Otterburn: "It fell about the Lammas tide when the muir-men win their hay." William Hone speaks in The Every-Day Book (1838) of a later festive Lammas Day sport common among Scottish farmers near Edinburgh. He says that they "build towers ... leaving a hole for a flag-pole in the centre so that they may raise their colours." When the flags over the many peat-constructed towers were raised, farmers would go to others' towers and attempt to "level them to the ground." A successful attempt would bring great praise. However, people were allowed to defend their towers, and so everyone was provided with
|
"throat, neck," from Latin "throat". Several antiquaries beginning with John Brady offered a back-construction to its being originally known as Lamb-mass, under the undocumented supposition that tenants of the Cathedral of York, dedicated to St. Peter ad Vincula, of which this is the feast, would have been required to bring a live lamb to the church, or, with John Skinner, "because Lambs then grew out of season." This is a folk etymology, of which OED notes that it was "subsequently felt as if from LAMB + MASS". For many villeins, the wheat must have run low in the days before Lammas, and the new harvest began a season of plenty, of hard work and company in the fields, reaping in teams. Thus there was a spirit of celebratory play. In the medieval agricultural year, Lammas also marked the end of the hay harvest that had begun after Midsummer. At the end of hay-making a sheep would be loosed in the meadow among the mowers, for him to keep who could catch it. In Shakespeare's Romeo and Juliet (1.3.19) it is observed of Juliet, "Come Lammas Eve at night shall she [Juliet] be fourteen." Since Juliet was born on Lammas Eve, she came before the harvest festival, which is significant since her life ended before she could reap what she had sown, as blessed by the Friar Francisco, by consummating her marriage: Another well-known cultural reference is the opening of The Battle of Otterburn: "It fell about the Lammas tide when the muir-men win their hay." William Hone speaks in The Every-Day Book (1838) of a later festive Lammas Day sport common among Scottish farmers near Edinburgh. He says that they "build towers ... leaving a hole for a flag-pole in the centre so that they may raise their colours." When the flags over the many peat-constructed towers were raised, farmers would go to others' towers and attempt to "level them to the ground." A successful attempt would bring great praise. However, people were allowed to defend their towers, and so everyone was provided with a "tooting-horn" to alert nearby country folk of the impending attack and the battle would turn into a "brawl". According to Hone, more than four people had died at this festival and many more were injured. At the day's end, races were held, with prizes given to the townspeople. Other uses Neopaganism Lughnasadh is the name used for one of the eight sabbats in the Neopagan Wheel of the Year. It is the first of the three autumn harvest festivals, the other two being the autumn equinox (also called Mabon) and Samhain. In the Northern Hemisphere it takes place around 1 August, while in the Southern Hemisphere it is celebrated around 1 February. To the members of the Asatru faith, Lammas is known as Freyfaxi, as it refers to a festival held during Old Norse times when a horse is sacrificed as an offering to Freyr. The name comes from the Old Norse words for "Freyr's horse mane", most likely referring to the deity's steed Blóðughófi. Scottish quarter days Lammas Day was one of the traditional Scottish quarter days (before 1886). Horticulture Lammas leaves or Lammas growth refers to a second crop of leaves produced in high summer by some species of trees in temperate countries to replace those lost to insect damage. They often differ slightly in shape, texture and/or hairiness from the earlier leaves. A low-impact development project at Tir y Gafel, Glandwr, Pembrokeshire, Lammas Ecovillage, is a collective initiative for nine
|
were 5,879 housing units at an average density of . The racial makeup of the town was 95.42% White, 0.69% African American, 0.05% Native American, 2.90% Asian, 0.06% Pacific Islander, 0.26% from other races, and 0.62% from two or more races. Hispanic or Latino of any race were 1.09% of the population. There were 5,734 households, out of which 37.1% had children under the age of 18 living with them, 69.1% were married couples living together, 6.4% had a female householder with no husband present, and 22.7% were non-families. 20.4% of all households were made up of individuals, and 14.0% had someone living alone who was 65 years of age or older. The average household size was 2.66 and the average family size was 3.09. In the town, the population was spread out, with 26.8% under the age of 18, 4.6% from 18 to 24, 22.0% from 25 to 44, 28.7% from 45 to 64, and 17.8% who were 65 years of age or older. The median age was 43 years. For every 100 females, there were 87.7 males. For every 100 females age 18 and over, there were 82.0 males. The median income for a household in the town was $109,586, and the median income for a family was $115,578. Males had a median income of $68,238 versus $40,890 for females. The per capita income for the town was $48,949. About 1.0% of families and 2.1% of the population were below the poverty line, including 0.3% of those under age 18 and 8.3% of those age 65 or over . Government The town is chartered as an Open Town Meeting form of government. The town government also consists of a Select Board with five members, elected by the town. The public school system is governed by the School Committee. The School Committee is made up of seven voting members elected by the town, the superintendent of schools, two assistant-superintendents, a secretary, and a student representative. Education The Longmeadow public school system operates six schools. Blueberry Hill School, Center School, and Wolf Swamp Road School are K−5 elementary schools. Williams Middle School and Glenbrook Middle School serve grades 6–8. Longmeadow High School serves all students in the town between grades 9 and 12. The town's elementary schools have been recently rebuilt, statements of interest for improvements to the two middle schools and Longmeadow High School were filed with the Massachusetts School Building Authority in 2007. In 2010, the voters of Longmeadow approved a 2.5% budget override to support the construction of a new $78 million high school. The town received an estimated $34 million in state funds to be used towards the new construction The new High School was completed and opened to students on February 26, 2013. After students and faculty had moved into the new school, the demolition of the old school was begun. The demolition was completed by June 2013. The school had its grand opening in September 2013 with both the brand new school and renovated business & administration wing open. Longmeadow also hosts two private parochial schools, the Lubavitcher Yeshiva Academy (LYA) and St. Mary's Academy. LYA was established in 1946 in response to the Greater Springfield Jewish community's need for a quality Jewish day school. In 1999, LYA became the first Jewish day school to be accredited by the New England Association of Schools and Colleges (NEASC). The more than 90 students that the school serves each year from across the spectrum of Jewish life include orthodox, conservative, reform, and unaffiliated families. St. Mary's Academy, located behind St. Mary's Church, serves Catholic students grades Pre-K through Grade 8. Approximately 50% of the students at Longmeadow High School participate in the music program. The choruses have won numerous gold medals at the MICCA competition. The jazz
|
the northern border of the town. The private Twin Hills and public Franconia golf courses, plus town athletic fields and conservation land, cover nearly 2/3 of the eastern border of the town. Two large public parks, the Longmeadow Country Club, and three conservation areas account for the bulk of the remaining formal open space. Almost 20% of the houses in town are in proximity to a "dingle", a tree-lined steep-sided sandy ravine with a wetland at the bottom that provides a privacy barrier between yards. Longmeadow has a town common, commonly referred to as "The Green" , located along U.S. Route 5 on the west side of town. It is about long. Roughly 100 houses date back before 1900, most of which are in the historic district, are located near the town green. Longmeadow's Town Green is a historic district on the National Register of Historic Places, and it is surrounded by a number of buildings dating back to the 18th and 19th centuries. Longmeadow is unique as the town green has maintained its residential purpose and has resisted commercial pressure. The current function as listed by the National Register of Historic Places is domestic and landscape. The current sub-function as listed by the National Register of Historic Places is park and single dwelling. Houses along the photogenic main street (Longmeadow Street) are set back farther than in most towns of similar residential density.The town has three recently remodeled elementary schools, two secondary schools, and one high school. The commercial center of town is an area called "The Longmeadow Shops" , including restaurants and clothing stores. According to the United States Census Bureau, the town has a total area of , of which are land and , or 5.34%, are water. Demographics As of the census of 2000, there were 15,633 people, 5,734 households, and 4,432 families residing in the town. The population density was . There were 5,879 housing units at an average density of . The racial makeup of the town was 95.42% White, 0.69% African American, 0.05% Native American, 2.90% Asian, 0.06% Pacific Islander, 0.26% from other races, and 0.62% from two or more races. Hispanic or Latino of any race were 1.09% of the population. There were 5,734 households, out of which 37.1% had children under the age of 18 living with them, 69.1% were married couples living together, 6.4% had a female householder with no husband present, and 22.7% were non-families. 20.4% of all households were made up of individuals, and 14.0% had someone living alone who was 65 years of age or older. The average household size was 2.66 and the average family size was 3.09. In the town, the population was spread out, with 26.8% under the age of 18, 4.6% from 18 to 24, 22.0% from 25 to 44, 28.7% from 45 to 64, and 17.8% who were 65 years of age or older. The median age was 43 years. For every 100 females, there were 87.7 males. For every 100 females age 18 and over, there were 82.0 males. The median income for a household in the town was $109,586, and the median income for a family was $115,578. Males had a median income of $68,238 versus $40,890 for females. The per capita income for the town was $48,949. About 1.0% of families and 2.1% of the population were below the poverty line, including 0.3% of those under age 18 and 8.3% of those age 65 or over . Government The town is chartered as an Open Town Meeting form of government. The town government also consists of a Select Board with five members, elected by the town. The public school system is governed by the School Committee. The School Committee is made up of seven voting members elected by the town, the superintendent of schools, two assistant-superintendents, a secretary, and a student representative. Education The Longmeadow public school
|
Kaiadilt and Thaayorre have no words denoting the egocentric directions in their language; instead, they exclusively refer to cardinal directions, even when describing small-scale spaces. For instance, if they wanted someone to move over on the car seat to make room, they might say "move a bit to the east". To tell someone where exactly they left something in their house, they might say, "I left it on the southern edge of the western table." Or they might warn a person to "look out for that big ant just north of your foot". Other peoples "from Polynesia to Mexico and from Namibia to Bali" similarly have predominantly "geographic languages". American Sign Language makes heavy use of geographical direction through absolute orientation. Left-right discrimination and left-right confusion Left-right discrimination (LRD) refers to a person's ability to differentiate between left and right. The inability to accurately differentiate between left and right is known as left-right confusion (LRC). According to research performed by John R. Clarke of Drexel University, LRC affects approximately 15% of the population. People who suffer from LRC can typically perform daily navigational tasks, such as driving according to road signs or following a map, but may have difficulty performing actions that require a precise understanding of directional commands, such as ballroom dancing. Prevalence Data regarding LRC prevalence is primarily based on behavioral studies, self-assessments, and surveys. Gormley and Brydges found that in a group of 800 adults, 17% of women and 9% of men reported difficulty differentiating between left and right. Such studies suggest that women are more prone to LRC than men, with women reporting higher rates of LRC in both accuracy and speed of response. Sex differences The Bergen Left-Right Discrimination (BLRD) test is designed to measure individual performance in LRD accuracy. However, this test has been criticized for incorporating tasks that require the use of additional strategies, such as mental rotation (MR). Because men have been shown to consistently outperform women in MR tasks, tests involving the use of this particular strategy may present alternative cognitive demands and lead to inaccurate assessment of LRD performance. An extended version of the BLRD test was designed to allow for differential evaluation of LRD and MR abilities, in which subtests were created with either high or low demands on mental rotation. Results from these studies did not find sex differences in LRD performance when mental rotation demands were low. Another study found that sex differences in left-right discrimination existed in terms of self-reported difficulty, but not in actual tested ability. Alternatively, studies focused on LRD as a phenomenon distinct from MR concluded that there are sex differences present in LRD. Scientists controlled for MR demands, potential menstrual cycle effects, and other hormone fluctuations, and determined that the neurocognitive mechanisms that support LRD are different for men and women. This research revealed that inferior parietal and right angular gyrus activation were correlated with LRD performance in both men and women. Women also demonstrated increased prefrontal activation, but did not exhibit greater bilateral activation. Additionally, no correlation was found between LRD accuracy and brain activation, or between brain activation and reaction time, for either sex. These results indicate that there are sex differences in the neurocognitive mechanisms underlying LRD performance; however, findings did not suggest that women are more prone to LRC than men. Acquisition and comparison Humans are constantly making decisions about spatial relations; however, some spatial relations, such as left-right, are commonly confused, while other spatial relations, such as up-down, above-below, and front-back, are seldom, if ever, mistaken. The ability to categorize and compartmentalize space is an essential tool for navigating this 3D world; an ability shown to develop
|
navigational tasks, such as driving according to road signs or following a map, but may have difficulty performing actions that require a precise understanding of directional commands, such as ballroom dancing. Prevalence Data regarding LRC prevalence is primarily based on behavioral studies, self-assessments, and surveys. Gormley and Brydges found that in a group of 800 adults, 17% of women and 9% of men reported difficulty differentiating between left and right. Such studies suggest that women are more prone to LRC than men, with women reporting higher rates of LRC in both accuracy and speed of response. Sex differences The Bergen Left-Right Discrimination (BLRD) test is designed to measure individual performance in LRD accuracy. However, this test has been criticized for incorporating tasks that require the use of additional strategies, such as mental rotation (MR). Because men have been shown to consistently outperform women in MR tasks, tests involving the use of this particular strategy may present alternative cognitive demands and lead to inaccurate assessment of LRD performance. An extended version of the BLRD test was designed to allow for differential evaluation of LRD and MR abilities, in which subtests were created with either high or low demands on mental rotation. Results from these studies did not find sex differences in LRD performance when mental rotation demands were low. Another study found that sex differences in left-right discrimination existed in terms of self-reported difficulty, but not in actual tested ability. Alternatively, studies focused on LRD as a phenomenon distinct from MR concluded that there are sex differences present in LRD. Scientists controlled for MR demands, potential menstrual cycle effects, and other hormone fluctuations, and determined that the neurocognitive mechanisms that support LRD are different for men and women. This research revealed that inferior parietal and right angular gyrus activation were correlated with LRD performance in both men and women. Women also demonstrated increased prefrontal activation, but did not exhibit greater bilateral activation. Additionally, no correlation was found between LRD accuracy and brain activation, or between brain activation and reaction time, for either sex. These results indicate that there are sex differences in the neurocognitive mechanisms underlying LRD performance; however, findings did not suggest that women are more prone to LRC than men. Acquisition and comparison Humans are constantly making decisions about spatial relations; however, some spatial relations, such as left-right, are commonly confused, while other spatial relations, such as up-down, above-below, and front-back, are seldom, if ever, mistaken. The ability to categorize and compartmentalize space is an essential tool for navigating this 3D world; an ability shown to develop in early infancy. Infant ability to visually match above-below and left-right relations appears to diminish in early toddlerhood, as language acquisition may complicate verbal labeling. Children learn to verbally discriminate between above-below relations around the age of three, and learn left-right linguistic labels between the ages of six and
|
that use sit-and-wait hunting strategies. Males establish and maintain territories that contain resources which attract females and which they defend from other males. Important resources include basking, feeding, and nesting sites as well as refuges from predators. The habitat of a species affects the structure of territories, for example, rock lizards have territories atop rocky outcrops. Some species may aggregate in groups, enhancing vigilance and lessening the risk of predation for individuals, particularly for juveniles. Agonistic behaviour typically occurs between sexually mature males over territory or mates and may involve displays, posturing, chasing, grappling and biting. Communication Lizards signal both to attract mates and to intimidate rivals. Visual displays include body postures and inflation, push-ups, bright colours, mouth gapings and tail waggings. Male anoles and iguanas have dewlaps or skin flaps which come in various sizes, colours and patterns and the expansion of the dewlap as well as head-bobs and body movements add to the visual signals. Some species have deep blue dewlaps and communicate with ultraviolet signals. Blue-tongued skinks will flash their tongues as a threat display. Chameleons are known to change their complex colour patterns when communicating, particularly during agonistic encounters. They tend to show brighter colours when displaying aggression and darker colours when they submit or "give up". Several gecko species are brightly coloured; some species tilt their bodies to display their coloration. In certain species, brightly coloured males turn dull when not in the presence of rivals or females. While it is usually males that display, in some species females also use such communication. In the bronze anole, head-bobs are a common form of communication among females, the speed and frequency varying with age and territorial status. Chemical cues or pheromones are also important in communication. Males typically direct signals at rivals, while females direct them at potential mates. Lizards may be able to recognise individuals of the same species by their scent. Acoustic communication is less common in lizards. Hissing, a typical reptilian sound, is mostly produced by larger species as part of a threat display, accompanying gaping jaws. Some groups, particularly geckos, snake-lizards, and some iguanids, can produce more complex sounds and vocal apparatuses have independently evolved in different groups. These sounds are used for courtship, territorial defense and in distress, and include clicks, squeaks, barks and growls. The mating call of the male tokay gecko is heard as "tokay-tokay!". Tactile communication involves individuals rubbing against each other, either in courtship or in aggression. Some chameleon species communicate with one another by vibrating the substrate that they are standing on, such as a tree branch or leaf. Ecology Distribution and habitat Lizards are found worldwide, excluding the far north and Antarctica, and some islands. They can be found in elevations from sea level to . They prefer warmer, tropical climates but are adaptable and can live in all but the most extreme environments. Lizards also exploit a number of habitats; most primarily live on the ground, but others may live in rocks, on trees, underground and even in water. The marine iguana is adapted for life in the sea. Diet The majority of lizard species are predatory and the most common prey items are small, terrestrial invertebrates, particularly insects. Many species are sit-and-wait predators though others may be more active foragers. Chameleons prey on numerous insect species, such as beetles, grasshoppers and winged termites as well as spiders. They rely on persistence and ambush to capture these prey. An individual perches on a branch and stays perfectly still, with only its eyes moving. When an insect lands, the chameleon focuses its eyes on the target and slowly moves towards it before projecting its long sticky tongue which, when hauled back, brings the attach prey with it. Geckos feed on crickets, beetles, termites and moths. Termites are an important part of the diets of some species of Autarchoglossa, since, as social insects, they can be found in large numbers in one spot. Ants may form a prominent part of the diet of some lizards, particularly among the lacertas. Horned lizards are also well known for specializing on ants. Due to their small size and indigestible chitin, ants must be consumed in large amounts, and ant-eating lizards have larger stomachs than even herbivorous ones. Species of skink and alligator lizards eat snails and their power jaws and molar-like teeth are adapted for breaking the shells. Larger species, such as monitor lizards, can feed on larger prey including fish, frogs, birds, mammals and other reptiles. Prey may be swallowed whole and torn into smaller pieces. Both bird and reptile eggs may also be consumed as well. Gila monsters and beaded lizards climb trees to reach both the eggs and young of birds. Despite being venomous, these species rely on their strong jaws to kill prey. Mammalian prey typically consists of rodents and leporids; the Komodo dragon can kill prey as large as water buffalo. Dragons are prolific scavengers, and a single decaying carcass can attract several from away. A dragon is capable of consuming a carcass in 17 minutes. Around 2 percent of lizard species, including many iguanids, are herbivores. Adults of these species eat plant parts like flowers, leaves, stems and fruit, while juveniles eat more insects. Plant parts can be hard to digest, and, as they get closer to adulthood, juvenile iguanas eat faeces from adults to acquire the microflora necessary for their transition to a plant-based diet. Perhaps the most herbivorous species is the marine iguana which dives to forage for algae, kelp and other marine plants. Some non-herbivorous species supplement their insect diet with fruit, which is easily digested. Antipredator adaptations Lizards have a variety of antipredator adaptations, including running and climbing, venom, camouflage, tail autotomy, and reflex bleeding. Camouflage Lizards exploit a variety of different camouflage methods. Many lizards are disruptively patterned. In some species, such as Aegean wall lizards, individuals vary in colour, and select rocks which best match their own colour to minimise the risk of being detected by predators. The Moorish gecko is able to change colour for camouflage: when a light-coloured gecko is placed on a dark surface, it darkens within an hour to match the environment. The chameleons in general use their ability to change their coloration for signalling rather than camouflage, but some species such as Smith's dwarf chameleon do use active colour change for camouflage purposes. The flat-tail horned lizard's body is coloured like its desert background, and is flattened and fringed with white scales to minimise its shadow. Autotomy Many lizards, including geckos and skinks, are capable of shedding their tails (autotomy). The detached tail, sometimes brilliantly coloured, continues to writhe after detaching, distracting the predator's attention from the fleeing prey. Lizards partially regenerate their tails over a period of weeks. Some 326 genes are involved in regenerating lizard tails. The fish-scale gecko Geckolepis megalepis sheds patches of skin and scales if grabbed. Escape, playing dead, reflex bleeding Many lizards attempt to escape from danger by running to a place of safety; for example, wall lizards can run up walls and hide in holes or cracks. Horned lizards adopt differing defences for specific predators. They may play dead to deceive a predator that has caught them; attempt to outrun the rattlesnake, which does not pursue prey; but stay still, relying on their cryptic coloration, for Masticophis whip snakes which can catch even swift prey. If caught, some species such as the greater short-horned lizard puff themselves up, making their bodies hard for a narrow-mouthed predator like a whip snake to swallow. Finally, horned lizards can squirt blood at cat and dog predators from a pouch beneath its eyes, to a distance of about ; the blood tastes foul to these attackers. Evolution Fossil history The earliest known fossil remains of a lizard belong to the iguanian species Tikiguania estesi, found in the Tiki Formation of India, which dates to the Carnian stage of the Triassic period, about 220 million years ago. However, doubt has been raised over the age of Tikiguania because it is almost indistinguishable from modern agamid lizards. The Tikiguania remains may instead be late Tertiary or Quaternary in age, having been washed into much older Triassic sediments. Lizards are most closely related to the Rhynchocephalia, which appeared in the Late Triassic, so the earliest lizards probably appeared at that time. Mitochondrial phylogenetics suggest that the first lizards evolved in the late Permian. It had been thought on the basis of morphological data that iguanid lizards diverged from other squamates very early on, but molecular evidence contradicts this. Mosasaurs probably evolved from an extinct group of aquatic lizards known as aigialosaurs in the Early Cretaceous. Dolichosauridae is a family of Late Cretaceous aquatic varanoid lizards closely related to the mosasaurs. Phylogeny External The position of the lizards and other Squamata among the reptiles was studied using fossil evidence by Rainer Schoch and Hans-Dieter Sues in 2015. Lizards form about 60% of the extant non-avian reptiles. Internal Both the snakes and the Amphisbaenia (worm lizards) are clades deep within the Squamata (the smallest clade that contains all the lizards), so "lizard" is paraphyletic. The cladogram is based on genomic analysis by Wiens and colleagues in 2012 and 2016. Excluded taxa are shown in upper case on the cladogram. Taxonomy In the 13th century, lizards were recognized in Europe as part of a broad category of reptiles that consisted of a miscellany of egg-laying creatures, including "snakes, various fantastic monsters, […], assorted amphibians, and worms", as recorded by Vincent of Beauvais in his Mirror of Nature. The seventeenth century saw changes in this loose description. The name Sauria was coined by James Macartney (1802); it was the Latinisation of the French name Sauriens, coined by Alexandre Brongniart (1800) for an order of reptiles in the classification proposed by the author, containing lizards and crocodilians, later discovered not to be each other's closest relatives. Later authors used the term "Sauria" in a more restricted sense, i.e. as a synonym of Lacertilia, a suborder of Squamata that includes all lizards but excludes snakes. This classification is rarely used today because Sauria so-defined is a paraphyletic group. It was defined as a clade by Jacques Gauthier, Arnold G. Kluge and Timothy Rowe (1988) as the group containing the most recent common ancestor of archosaurs and lepidosaurs (the groups containing crocodiles and lizards, as per Mcartney's original definition) and all its descendants. A different definition was formulated by Michael deBraga and Olivier Rieppel (1997), who defined Sauria as the clade containing the most recent common ancestor of Choristodera, Archosauromorpha, Lepidosauromorpha and all their descendants. However, these uses have not gained wide acceptance among specialists. Suborder Lacertilia (Sauria) – (lizards) Family †Bavarisauridae Family †Eichstaettisauridae Infraorder Iguania Family †Arretosauridae Family †Euposauridae Family Corytophanidae (casquehead lizards) Family Iguanidae (iguanas and spinytail iguanas) Family Phrynosomatidae (earless, spiny, tree, side-blotched and horned lizards) Family Polychrotidae (anoles) Family Leiosauridae (see Polychrotinae) Family Tropiduridae (neotropical ground lizards) Family Liolaemidae (see Tropidurinae) Family Leiocephalidae (see Tropidurinae) Family Crotaphytidae (collared and leopard lizards) Family Opluridae (Madagascar iguanids) Family Hoplocercidae (wood lizards, clubtails) Family †Priscagamidae Family †Isodontosauridae Family Agamidae (agamas, frilled lizards) Family Chamaeleonidae (chameleons) Infraorder Gekkota Family Gekkonidae (geckos) Family Pygopodidae (legless geckos) Family Dibamidae (blind lizards) Infraorder Scincomorpha Family †Paramacellodidae Family †Slavoiidae Family Scincidae (skinks) Family Cordylidae (spinytail lizards) Family Gerrhosauridae (plated lizards) Family Xantusiidae (night lizards) Family Lacertidae (wall lizards or true lizards) Family †Mongolochamopidae Family †Adamisauridae Family Teiidae (tegus and whiptails) Family Gymnophthalmidae (spectacled lizards) Infraorder Diploglossa Family Anguidae (slowworms, glass lizards) Family Anniellidae (American legless lizards) Family Xenosauridae (knob-scaled lizards) Infraorder Platynota (Varanoidea) Family Varanidae (monitor lizards) Family Lanthanotidae (earless monitor lizards) Family Helodermatidae (Gila monsters and beaded lizards) Family †Mosasauridae (marine lizards) Convergence Lizards have frequently evolved convergently, with multiple groups independently developing similar morphology and ecological niches. Anolis ecomorphs have become a model system in evolutionary biology for studying convergence. Limbs have been lost or reduced independently over two dozen times across lizard evolution, including in the Anniellidae, Anguidae, Cordylidae, Dibamidae, Gymnophthalmidae, Pygopodidae, and Scincidae; snakes are just the most famous and species-rich group
|
and to intimidate rivals. Visual displays include body postures and inflation, push-ups, bright colours, mouth gapings and tail waggings. Male anoles and iguanas have dewlaps or skin flaps which come in various sizes, colours and patterns and the expansion of the dewlap as well as head-bobs and body movements add to the visual signals. Some species have deep blue dewlaps and communicate with ultraviolet signals. Blue-tongued skinks will flash their tongues as a threat display. Chameleons are known to change their complex colour patterns when communicating, particularly during agonistic encounters. They tend to show brighter colours when displaying aggression and darker colours when they submit or "give up". Several gecko species are brightly coloured; some species tilt their bodies to display their coloration. In certain species, brightly coloured males turn dull when not in the presence of rivals or females. While it is usually males that display, in some species females also use such communication. In the bronze anole, head-bobs are a common form of communication among females, the speed and frequency varying with age and territorial status. Chemical cues or pheromones are also important in communication. Males typically direct signals at rivals, while females direct them at potential mates. Lizards may be able to recognise individuals of the same species by their scent. Acoustic communication is less common in lizards. Hissing, a typical reptilian sound, is mostly produced by larger species as part of a threat display, accompanying gaping jaws. Some groups, particularly geckos, snake-lizards, and some iguanids, can produce more complex sounds and vocal apparatuses have independently evolved in different groups. These sounds are used for courtship, territorial defense and in distress, and include clicks, squeaks, barks and growls. The mating call of the male tokay gecko is heard as "tokay-tokay!". Tactile communication involves individuals rubbing against each other, either in courtship or in aggression. Some chameleon species communicate with one another by vibrating the substrate that they are standing on, such as a tree branch or leaf. Ecology Distribution and habitat Lizards are found worldwide, excluding the far north and Antarctica, and some islands. They can be found in elevations from sea level to . They prefer warmer, tropical climates but are adaptable and can live in all but the most extreme environments. Lizards also exploit a number of habitats; most primarily live on the ground, but others may live in rocks, on trees, underground and even in water. The marine iguana is adapted for life in the sea. Diet The majority of lizard species are predatory and the most common prey items are small, terrestrial invertebrates, particularly insects. Many species are sit-and-wait predators though others may be more active foragers. Chameleons prey on numerous insect species, such as beetles, grasshoppers and winged termites as well as spiders. They rely on persistence and ambush to capture these prey. An individual perches on a branch and stays perfectly still, with only its eyes moving. When an insect lands, the chameleon focuses its eyes on the target and slowly moves towards it before projecting its long sticky tongue which, when hauled back, brings the attach prey with it. Geckos feed on crickets, beetles, termites and moths. Termites are an important part of the diets of some species of Autarchoglossa, since, as social insects, they can be found in large numbers in one spot. Ants may form a prominent part of the diet of some lizards, particularly among the lacertas. Horned lizards are also well known for specializing on ants. Due to their small size and indigestible chitin, ants must be consumed in large amounts, and ant-eating lizards have larger stomachs than even herbivorous ones. Species of skink and alligator lizards eat snails and their power jaws and molar-like teeth are adapted for breaking the shells. Larger species, such as monitor lizards, can feed on larger prey including fish, frogs, birds, mammals and other reptiles. Prey may be swallowed whole and torn into smaller pieces. Both bird and reptile eggs may also be consumed as well. Gila monsters and beaded lizards climb trees to reach both the eggs and young of birds. Despite being venomous, these species rely on their strong jaws to kill prey. Mammalian prey typically consists of rodents and leporids; the Komodo dragon can kill prey as large as water buffalo. Dragons are prolific scavengers, and a single decaying carcass can attract several from away. A dragon is capable of consuming a carcass in 17 minutes. Around 2 percent of lizard species, including many iguanids, are herbivores. Adults of these species eat plant parts like flowers, leaves, stems and fruit, while juveniles eat more insects. Plant parts can be hard to digest, and, as they get closer to adulthood, juvenile iguanas eat faeces from adults to acquire the microflora necessary for their transition to a plant-based diet. Perhaps the most herbivorous species is the marine iguana which dives to forage for algae, kelp and other marine plants. Some non-herbivorous species supplement their insect diet with fruit, which is easily digested. Antipredator adaptations Lizards have a variety of antipredator adaptations, including running and climbing, venom, camouflage, tail autotomy, and reflex bleeding. Camouflage Lizards exploit a variety of different camouflage methods. Many lizards are disruptively patterned. In some species, such as Aegean wall lizards, individuals vary in colour, and select rocks which best match their own colour to minimise the risk of being detected by predators. The Moorish gecko is able to change colour for camouflage: when a light-coloured gecko is placed on a dark surface, it darkens within an hour to match the environment. The chameleons in general use their ability to change their coloration for signalling rather than camouflage, but some species such as Smith's dwarf chameleon do use active colour change for camouflage purposes. The flat-tail horned lizard's body is coloured like its desert background, and is flattened and fringed with white scales to minimise its shadow. Autotomy Many lizards, including geckos and skinks, are capable of shedding their tails (autotomy). The detached tail, sometimes brilliantly coloured, continues to writhe after detaching, distracting the predator's attention from the fleeing prey. Lizards partially regenerate their tails over a period of weeks. Some 326 genes are involved in regenerating lizard tails. The fish-scale gecko Geckolepis megalepis sheds patches of skin and scales if grabbed. Escape, playing dead, reflex bleeding Many lizards attempt to escape from danger by running to a place of safety; for example, wall lizards can run up walls and hide in holes or cracks. Horned lizards adopt differing defences for specific predators. They may play dead to deceive a predator that has caught them; attempt to outrun the rattlesnake, which does not pursue prey; but stay still, relying on their cryptic coloration, for Masticophis whip snakes which can catch even swift prey. If caught, some species such as the greater short-horned lizard puff themselves up, making their bodies hard for a narrow-mouthed predator like a whip snake to swallow. Finally, horned lizards can squirt blood at cat and dog predators from a pouch beneath its eyes, to a distance of about ; the blood tastes foul to these attackers. Evolution Fossil history The earliest known fossil remains of a lizard belong to the iguanian species Tikiguania estesi, found in the Tiki Formation of India, which dates to the Carnian stage of the Triassic period, about 220 million years ago. However, doubt has been raised over the age of Tikiguania because it is almost indistinguishable from modern agamid lizards. The Tikiguania remains may instead be late Tertiary or Quaternary in age, having been washed into much older Triassic sediments. Lizards are most closely related to the Rhynchocephalia, which appeared in the Late Triassic, so the earliest lizards probably appeared at that time. Mitochondrial phylogenetics suggest that the first lizards evolved in the late Permian. It had been thought on the basis of morphological data that iguanid lizards diverged from other squamates very early on, but molecular evidence contradicts this. Mosasaurs probably evolved from an extinct group of aquatic lizards known as aigialosaurs in the Early Cretaceous. Dolichosauridae is a family of Late Cretaceous aquatic varanoid lizards closely related to the mosasaurs. Phylogeny External The position of the lizards and other Squamata among the reptiles was studied using fossil evidence by Rainer Schoch and Hans-Dieter Sues in 2015. Lizards form about 60% of the extant non-avian reptiles. Internal Both the snakes and the Amphisbaenia (worm lizards) are clades deep within the Squamata (the smallest clade that contains all the lizards), so "lizard" is paraphyletic. The cladogram is based on genomic analysis by Wiens and colleagues in 2012 and 2016. Excluded taxa are shown in upper case on the cladogram. Taxonomy In the 13th century, lizards were recognized in Europe as part of a broad category of reptiles that consisted of a miscellany of egg-laying creatures, including "snakes, various fantastic monsters, […], assorted amphibians, and worms", as recorded by Vincent of Beauvais in his Mirror of Nature. The seventeenth century saw changes in this loose description. The name Sauria was coined by James Macartney (1802); it was the Latinisation of the French name Sauriens, coined by Alexandre Brongniart (1800) for an order of reptiles in the classification proposed by the author, containing lizards and crocodilians, later discovered not to be each other's closest relatives. Later authors used the term "Sauria" in a more restricted sense, i.e. as a synonym of Lacertilia, a suborder of Squamata that includes all lizards but excludes snakes. This classification is rarely used today because Sauria so-defined is a paraphyletic group. It was defined as a clade by Jacques Gauthier, Arnold G. Kluge and Timothy Rowe (1988) as the group containing the most recent common ancestor of archosaurs and lepidosaurs (the groups containing crocodiles and lizards, as per Mcartney's original definition) and all its descendants. A different definition was formulated by Michael deBraga and Olivier Rieppel (1997), who defined Sauria as the clade containing the most recent common ancestor of Choristodera, Archosauromorpha, Lepidosauromorpha and all their descendants. However, these uses have not gained wide acceptance among specialists. Suborder Lacertilia (Sauria) – (lizards) Family †Bavarisauridae Family †Eichstaettisauridae Infraorder Iguania Family †Arretosauridae Family †Euposauridae Family Corytophanidae (casquehead lizards) Family Iguanidae (iguanas and spinytail iguanas) Family Phrynosomatidae (earless, spiny, tree, side-blotched and horned lizards) Family Polychrotidae (anoles) Family Leiosauridae (see Polychrotinae) Family Tropiduridae (neotropical ground lizards) Family Liolaemidae (see Tropidurinae) Family Leiocephalidae (see Tropidurinae) Family Crotaphytidae (collared and leopard lizards) Family Opluridae (Madagascar iguanids) Family Hoplocercidae (wood lizards, clubtails) Family †Priscagamidae Family †Isodontosauridae Family Agamidae (agamas, frilled lizards) Family Chamaeleonidae (chameleons) Infraorder Gekkota Family Gekkonidae (geckos) Family Pygopodidae (legless geckos) Family Dibamidae (blind lizards) Infraorder Scincomorpha Family †Paramacellodidae Family †Slavoiidae Family Scincidae (skinks) Family Cordylidae (spinytail lizards) Family Gerrhosauridae (plated lizards) Family Xantusiidae (night lizards) Family Lacertidae (wall lizards or true lizards) Family †Mongolochamopidae Family †Adamisauridae Family Teiidae (tegus and whiptails) Family Gymnophthalmidae (spectacled lizards) Infraorder Diploglossa Family Anguidae (slowworms, glass lizards) Family Anniellidae (American legless lizards) Family Xenosauridae (knob-scaled lizards) Infraorder Platynota (Varanoidea) Family Varanidae (monitor lizards) Family Lanthanotidae (earless monitor lizards) Family Helodermatidae (Gila monsters and beaded lizards) Family †Mosasauridae (marine lizards) Convergence Lizards
|
band Bad Religion Edward Herbert, 1st Baron Herbert of Cherbury (1583–1648), British soldier, diplomat, historian, poet and religious philosopher Harish-Chandra (1923–1983), Indian mathematician, who did fundamental work in representation theory, especially Harmonic analysis on semisimple Lie groups. James Heckman (1944–), American economist who shared the Nobel Memorial Prize in Economic Sciences in 2000 for his pioneering work in econometrics and microeconomics. Victor Hugo (1802–85), French writer, artist, activist and statesman William Hogarth (1697–1764), English painter, visual artist and pioneering cartoonist James Hutton (1726–1797), Scottish physician, geologist, naturalist, chemical manufacturer and experimental agriculturalist. His work helped to establish the basis of modern geology. His theories of geology and geologic time, also called deep time, came to be included in theories which were called plutonism and uniformitarianism. Thomas Jefferson (1743–1826), author of the Jefferson Bible, an American Founding Father, the principal author of the U.S. Declaration of Independence, and the third President of the United States. Walter Kohn (1923–2016), Austrian-born American theoretical physicist. He was awarded, with John Pople, the Nobel Prize in Chemistry in 1998. Harmony Korine (1973–), American film director, producer, screenwriter, and author. Jean-Baptiste Lamarck (1744–1829), French naturalist. He was a soldier, biologist, academic, and an early proponent of the idea that evolution occurred and proceeded in accordance with natural laws. Abraham Lincoln (1809–1865), sixteenth president of the United States of America. He never joined any church and has been described as a "Christian deist". As a young man, he was religiously skeptical and sometimes ridiculed revivalists. During his early years, Lincoln enjoyed reading the works of deists such as Thomas Paine and Voltaire. He drafted a pamphlet incorporating such ideas but did not publish it. After charges of hostility to Christianity almost cost him a congressional bid, he kept his unorthodox beliefs private. James Adams labelled Lincoln as a deist. In 1834, he reportedly wrote a manuscript essay challenging Christianity modelled on Paine's book The Age of Reason, which a friend supposedly burned to protect him from ridicule. He seemed to believe in an all-powerful God, who shaped events and, by 1865, was expressing those beliefs in major speeches. Gottfried Leibniz (1646–1716), German mathematician and philosopher. He is best known for developing infinitesimal calculus independently of Isaac Newton, and his mathematical notation has been widely used ever since it was published. He has also been labeled a Christian as well. Gotthold Ephraim Lessing (1729–1781), German writer, philosopher, dramatist, publicist, and art critic Mikhail Lomonosov (1711–1765), Russian polymath, scientist and writer, who made important contributions to literature, education, and science. Among his discoveries was the atmosphere of Venus. His spheres of science were natural science, chemistry, physics, mineralogy, history, art, philology, optical devices and others. Lomonosov was also a poet and influenced the formation of the modern Russian literary language. Charles Lyell (1797–1875), British lawyer and the foremost geologist of his day. He is best known as the author of Principles of Geology, which popularised James Hutton's concepts of uniformitarianism. Colin Maclaurin (1698–1746), Scottish mathematician who made important contributions to geometry and algebra. The Maclaurin series, a special case of the Taylor series, are named after him. James Madison (1751–1836), "Father of the United States Constitution", one of the Founding Fathers of the United States, and the 4th President of the United States Alfred M. Mayer (1836–1897), American physicist. Dmitri Mendeleev (1834–1907), Russian chemist and inventor. He is credited as being the creator of the first version of the periodic table of elements. Moses Mendelssohn (1729–1796), German philosopher influential in the Jewish Haskalah Simon Newcomb (1835–1909), Canadian-American astronomer and mathematician. Thomas Paine (1737–1809), English pamphleteer, revolutionary, radical, inventor, and intellectual, and one of the Founding Fathers of the United States Elihu Palmer (1764–1806), American author and advocate of deism Wolfgang Pauli (1900–1958), Austrian theoretical physicist. In 1945, he received the Nobel Prize in Physics. He is best known for his work on Pauli principle and spin theory. Charles Sanders Peirce (1839–1914), American philosopher, logician, mathematician, and scientist, sometimes known as "the father of pragmatism". He was educated as a chemist and employed as a scientist for 30 years. Today he is appreciated largely for his contributions to logic, mathematics, philosophy, scientific methodology, and semiotics, and for his founding of pragmatism. Max Planck (1858–1947), German physicist, regarded as the founder of quantum theory. José Rizal (1861–1896), a Filipino patriot, philosopher, medical doctor, poet, journalist, novelist, political scientist, painter and polyglot. Considered to be one of the Philippines' most important heroes and martyrs whose writings and execution contributed to the igniting of the Philippine Revolution. He is also considered as Asia's first modern non-violent proponent of freedom. Ernest Rutherford (1871–1937), New Zealand chemist and
|
statistical thermodynamics. Max Born (1882–1970), German-British physicist and mathematician who was instrumental in the development of quantum mechanics. He also made contributions to solid-state physics and optics and supervised the work of a number of notable physicists in the 1920s and 30s. Born won the 1954 Nobel Prize in Physics (shared with Walther Bothe). Nick Cave (1957–), Australian musician, songwriter, poet, author and actor. Émilie du Châtelet (1706–1749), French mathematician, physicist, and author during the Age of Enlightenment. Her crowning achievement is considered to be her translation and commentary on Isaac Newton's work Principia Mathematica. Jean le Rond d'Alembert (1717–1783), French mathematician, mechanician, physicist, philosopher, and music theorist. He was also co-editor with Denis Diderot of the Encyclopédie. Leonardo da Vinci (1452–1519), Italian Renaissance polymath: painter, sculptor, architect, musician, scientist, mathematician, engineer, inventor, anatomist, geologist, cartographer, botanist, and writer. described as a deist by some sources. most historians have deemed him a Roman Catholic. Paul Davies (1946–), British physicist and science writer and broadcaster Humphry Davy (1778–1829), British chemist and inventor. Rodrigo Duterte (1945–), 16th President of the Philippines. Thomas Alva Edison (1847–1931), American inventor and businessman. Antony Flew (1923–2010), British analytic philosopher and prominent former atheist; during his last years he openly made an allegiance to Deism and stated to have acknowledged the existence of an Intelligent Creator of the universe, the Aristotelian God. Benjamin Franklin (1706–1790), American polymath; one of the Founding Fathers of the United States Martin Gardner (1914–2010), American popular mathematics and science writer specializing in recreational mathematics, but with interests encompassing micromagic, stage magic, literature (especially the writings of Lewis Carroll and G. K. Chesterton), philosophy, scientific skepticism, and religion. William Lloyd Garrison (1805–1879), American abolitionist, journalist, and social reformer. He is best known as the editor of the abolitionist newspaper The Liberator, and was one of the founders of the American Anti-Slavery Society, he promoted "immediate emancipation" of slaves in the United States. Carl Friedrich Gauss (1777–1855), German mathematician and physical scientist who contributed significantly to many fields, including number theory, statistics, analysis, differential geometry, geodesy, geophysics, electrostatics, astronomy and optics. Brett Gurewitz (1962–), guitarist and songwriter for the American punk rock band Bad Religion Edward Herbert, 1st Baron Herbert of Cherbury (1583–1648), British soldier, diplomat, historian, poet and religious philosopher Harish-Chandra (1923–1983), Indian mathematician, who did fundamental work in representation theory, especially Harmonic analysis on semisimple Lie groups. James Heckman (1944–), American economist who shared the Nobel Memorial Prize in Economic Sciences in 2000 for his pioneering work in econometrics and microeconomics. Victor Hugo (1802–85), French writer, artist, activist and statesman William Hogarth (1697–1764), English painter, visual artist and pioneering cartoonist James Hutton (1726–1797), Scottish physician, geologist, naturalist, chemical manufacturer and experimental agriculturalist. His work helped to establish the basis of modern geology. His theories of geology and geologic time, also called deep time, came to be included in theories which were called plutonism and uniformitarianism. Thomas Jefferson (1743–1826), author of the Jefferson Bible, an American Founding Father, the principal author of the U.S. Declaration of Independence, and the third President of the United States. Walter Kohn (1923–2016), Austrian-born American theoretical physicist. He was awarded, with John Pople, the Nobel Prize in Chemistry in 1998. Harmony Korine (1973–), American film director, producer, screenwriter, and author. Jean-Baptiste Lamarck (1744–1829), French naturalist. He was a soldier, biologist, academic, and an early proponent of the idea that evolution occurred and proceeded in accordance with natural laws. Abraham Lincoln (1809–1865), sixteenth president of the United States of America. He never joined any church and has been described as a "Christian deist". As a young man, he was religiously skeptical and sometimes ridiculed revivalists. During his early years, Lincoln enjoyed reading the works of deists such as Thomas Paine and Voltaire. He drafted a pamphlet incorporating such ideas but did not publish it. After charges of hostility to Christianity almost cost him a congressional bid, he kept his unorthodox beliefs private. James Adams labelled Lincoln as a deist. In 1834, he reportedly wrote a manuscript essay challenging Christianity modelled on Paine's book The Age of Reason, which a friend supposedly burned to protect him from ridicule. He seemed to believe in an all-powerful God, who shaped events and, by 1865, was expressing those beliefs in major speeches. Gottfried Leibniz (1646–1716), German mathematician and philosopher. He is best known for developing infinitesimal calculus independently of Isaac Newton, and his mathematical notation has been widely used ever since it was published. He
|
the Priestly code and actually produced Leviticus as we now have it. Themes Sacrifice and ritual Many scholars argue that the rituals of Leviticus have a theological meaning concerning Israel's relationship with its God. Jacob Milgrom was especially influential in spreading this view. He maintained that the priestly regulations in Leviticus expressed a rational system of theological thought. The writers expected them to be put into practice in Israel's temple, so the rituals would express this theology as well, as well as ethical concern for the poor. Milgrom also argued that the book's purity regulations (chaps. 11–15) have a basis in ethical thinking. Many other interpreters have followed Milgrom in exploring the theological and ethical implications of Leviticus's regulations (e.g. Marx, Balentine), though some have questioned how systematic they really are. Ritual, therefore, is not taking a series of actions for their own sake, but a means of maintaining the relationship between God, the world, and humankind. Kehuna (Jewish priesthood) The main function of the priests is service at the altar, and only the sons of Aaron are priests in the full sense. (Ezekiel also distinguishes between altar-priests and lower Levites, but in Ezekiel the altar-priests are sons of Zadok instead of sons of Aaron; many scholars see this as a remnant of struggles between different priestly factions in First Temple times, finding resolution by the Second Temple into a hierarchy of Aaronite altar-priests and lower-level Levites, including singers, gatekeepers and the like). In chapter 10, God kills Nadab and Abihu, the oldest sons of Aaron, for offering "strange incense". Aaron has two sons left. Commentators have read various messages in the incident: a reflection of struggles between priestly factions in the post–Exilic period (Gerstenberger); or a warning against offering incense outside the Temple, where there might be the risk of invoking strange gods (Milgrom). In any case, there has been a pollution of the sanctuary by the bodies of the two dead priests, leading into the next theme, holiness. Uncleanliness and purity Ritual purity is essential for an Israelite to be able to approach Yahweh and remain part of the community. Uncleanliness threatens holiness; Chapters 11–15 review the various causes of uncleanliness and describe the rituals which will restore cleanliness; one is to maintain cleanliness through observation of the rules on sexual behaviour, family relations, land ownership, worship, sacrifice, and observance of holy days. Yahweh dwells with Israel in the holy of holies. All of the priestly ritual focuses on Yahweh and the construction and maintenance of a holy space, but sin generates impurity, as do everyday events such as childbirth and menstruation; impurity pollutes the holy dwelling place. Failure to ritually purify the sacred space could result in God leaving, which would be disastrous. Infectious diseases in Chapter 13 In Leviticus 13, the Lord God told Moses and Aaron how to identify infectious diseases and deal with them accordingly. The translators and interpreters of the Bible in various languages have never reached a consensus on these infectious diseases or tzaraath (Hebrew צרעת), so that the translation and interpretation of the scriptures are not known for certain. The most translated disease is leprosy, but what is described in the scriptures is not a typical manifestation of leprosy as we know it today. In fact, any modern dermatologist can tell that these are mainly dermatophytoses, which are a group of highly contagious skin diseases. Firstly, the infectious disease of the chin described in Verses 29-37 seems to be Tinea barbae in men or Tinea faciei in women; and, the infectious disease described in Verses 29-37 with hair loss and eventual baldness seems to be Tinea capitis (Favus). Verses 1-17 seem to describe Tinea corporis. The Hebrew word bohaq, alphos in Verses 38-39 is translated as tetter or freckles, likely because translators did not know what it meant at the time, and thus, translated it incorrectly. Later translations believe it is talking about vitiligo, however, vitiligo is not an infectious disease. We can conclude the only infectious disease that can heal itself and leave white patches after infection is pityriasis versicolor (tinea versicolor). Tetter originally meant an outbreak, which later evolved meaning ringworm-like lesions. Therefore, a common name for Tinea pedis (athlete's foot) was Cantlie’s foot tetter. In addition, Verses 18-23 describe infections after scald, and Verses 24-28 describe infections after burn. These two infections are translated into diseases that are unknown in the Chinese version. Atonement Through sacrifice, the priest "makes atonement" for sin and the offeror receives forgiveness (but only if Yahweh accepts the sacrifice). Atonement rituals involve the pouring or sprinkling of blood as the symbol of the life of the victim: the blood has the power to wipe out or absorb the sin. The two-part division of the book structurally reflects the role of atonement: chapters 1–16 call for the establishment of the institution for atonement, and chapters 17–27 call for the life of the atoned community in holiness. Holiness The consistent theme of chapters 17–26 is in the repetition of the phrase, "Be holy, for I the Lord your God am holy." Holiness in ancient Israel and the Bible had a different meaning than in contemporary usage: it might have been regarded as the essence of Yahweh, an invisible but physical and potentially dangerous force. Specific objects, or even days, can be holy, but they derive holiness from being connected with Yahweh—the seventh day, the tabernacle, and the priests all derive their holiness from Him. As a result, Israel had to maintain its own holiness in order to live safely alongside God. The need for holiness is for the possession of the Promised Land (Canaan), where the Jews will become a holy people: "You shall not do as they do in the land of Egypt where you dwelt, and you shall not do as they do in the land of Canaan to which I am bringing you...You shall do my ordinances and keep my statutes...I am the Lord, your God." (Leviticus 18:3). Subsequent tradition Leviticus, as part of the Torah, became the law book of Jerusalem's Second Temple as well as of the Samaritan temple. Evidence of its influence is evident among the Dead Sea Scrolls, which included fragments of seventeen manuscripts of Leviticus dating from the third to the first centuries BC. Many other Qumran scrolls cite the book, especially the Temple Scroll and 4QMMT. Jews and Christians have not observed Leviticus's instructions for animal offerings since the first century AD. Because of the destruction of the temple in Jerusalem in 70 AD, Jewish worship has focused on prayer and the study of Torah. Nevertheless, Leviticus constitutes a major source of Jewish law and is traditionally the first book children learn in the Rabbinic system of education. There are two main Midrashim on Leviticus—the halakhic one (Sifra) and a more aggadic one (Vayikra Rabbah). The New Testament, particularly the Epistle to the Hebrews, uses ideas and images from Leviticus to describe Christ as the high priest who offers his own blood as a sin offering. Therefore, Christians do not make animal offerings, either, as Gordon Wenham summarized: "With the death of Christ the only sufficient 'burnt
|
"life force", usually but not always blood. Leviticus 16 concerns the Day of Atonement. This is the only day on which the High Priest is to enter the holiest part of the sanctuary, the holy of holies. He is to sacrifice a bull for the sins of the priests, and a goat for the sins of the laypeople. The priest is to send a second goat into the desert to "Azazel", bearing the sins of the whole people. Azazel may be a wilderness-demon, but its identity is mysterious. Chapters 17–26 are the Holiness code. It begins with a prohibition on all slaughter of animals outside the Temple, even for food, and then prohibits a long list of sexual contacts and also child sacrifice. The "holiness" injunctions which give the code its name begin with the next section: there are penalties for the worship of Molech, consulting mediums and wizards, cursing one's parents and engaging in unlawful sex. Priests receive instruction on mourning rituals and acceptable bodily defects. The punishment for blasphemy is death, and there is the setting of rules for eating sacrifices; there is an explanation of the calendar, and there are rules for sabbatical and Jubilee years; there are rules for oil lamps and bread in the sanctuary; and there are rules for slavery. The code ends by telling the Israelites they must choose between the law and prosperity on the one hand, or, on the other, horrible punishments, the worst of which will be expulsion from the land. Chapter 27 is a disparate and probably late addition telling about persons and things serving as dedication to the Lord and how one can redeem, instead of fulfill, vows. Composition The majority of scholars have concluded that the Pentateuch received its final form during the Persian period (538–332 BC). Nevertheless, Leviticus had a long period of growth before reaching that form. The entire composition of the book of Leviticus is Priestly literature. Most scholars see chapters 1–16 (the Priestly code) and chapters 17–26 (the Holiness code) as the work of two related schools, but while the Holiness material employs the same technical terms as the Priestly code, it broadens their meaning from pure ritual to the theological and moral, turning the ritual of the Priestly code into a model for the relationship of Israel to Yahweh: as the tabernacle, which is apart from uncleanliness, becomes holy by the presence of Yahweh, so He will dwell among Israel when Israel receives purification (becomes holy) and separates from other peoples. The ritual instructions in the Priestly code apparently grew from priests giving instruction and answering questions about ritual matters; the Holiness code (or H) used to be a separate document, later becoming part of Leviticus, but it seems better to think of the Holiness authors as editors who worked with the Priestly code and actually produced Leviticus as we now have it. Themes Sacrifice and ritual Many scholars argue that the rituals of Leviticus have a theological meaning concerning Israel's relationship with its God. Jacob Milgrom was especially influential in spreading this view. He maintained that the priestly regulations in Leviticus expressed a rational system of theological thought. The writers expected them to be put into practice in Israel's temple, so the rituals would express this theology as well, as well as ethical concern for the poor. Milgrom also argued that the book's purity regulations (chaps. 11–15) have a basis in ethical thinking. Many other interpreters have followed Milgrom in exploring the theological and ethical implications of Leviticus's regulations (e.g. Marx, Balentine), though some have questioned how systematic they really are. Ritual, therefore, is not taking a series of actions for their own sake, but a means of maintaining the relationship between God, the world, and humankind. Kehuna (Jewish priesthood) The main function of the priests is service at the altar, and only the sons of Aaron are priests in the full sense. (Ezekiel also distinguishes between altar-priests and lower Levites, but in Ezekiel the altar-priests are sons of Zadok instead of sons of Aaron; many scholars see this as a remnant of struggles between different priestly factions in First Temple times, finding resolution by the Second Temple into a hierarchy of Aaronite altar-priests and lower-level Levites, including singers, gatekeepers and the like). In chapter 10, God kills Nadab and Abihu, the oldest sons of Aaron, for offering "strange incense". Aaron has two sons left. Commentators have read various messages in the incident: a reflection of struggles between priestly factions in the post–Exilic period (Gerstenberger); or a warning against offering incense outside the Temple, where there might
|
soon as Hamlin got word of his death in 1904. Beginning with the success of the stage version, most subsequent versions of the story, including newer editions of the novel, have been titled "The Wizard of Oz", rather than using the full, original title. In more recent years, restoring the full title has become increasingly common, particularly to distinguish the novel from the Hollywood film. Baum wrote a new Oz book, The Marvelous Land of Oz, with a view to making it into a stage production, which was titled The Woggle-Bug, but Montgomery and Stone balked at appearing when the original was still running. The Scarecrow and Tin Woodman were then omitted from this adaptation, which was seen as a self-rip-off by critics and proved to be a major flop before it could reach Broadway. He also worked for years on a musical version of Ozma of Oz, which eventually became The Tik-Tok Man of Oz. This did fairly well in Los Angeles, but not well enough to convince producer Oliver Morosco to mount a production in New York. He also began a stage version of The Patchwork Girl of Oz, but this was ultimately realized as a film. Later life and work With the success of Wizard on page and stage, Baum and Denslow hoped for further success and published Dot and Tot of Merryland in 1901. The book was one of Baum's weakest, and its failure further strained his faltering relationship with Denslow. It was their last collaboration. Baum worked primarily with John R. Neill on his fantasy work beginning in 1904, but Baum met Neill few times (all before he moved to California) and often found Neill's art not humorous enough for his liking. He was particularly offended when Neill published The Oz Toy Book: Cut-outs for the Kiddies without authorization. Baum reportedly designed the chandeliers in the Crown Room of the Hotel del Coronado; however, that attribution has yet to be corroborated. Several times during the development of the Oz series, Baum declared that he had written his last Oz book and devoted himself to other works of fantasy fiction based in other magical lands, including The Life and Adventures of Santa Claus and Queen Zixi of Ix. However, he returned to the series each time, persuaded by popular demand, letters from children, and the failure of his new books. Even so, his other works remained very popular after his death, with The Master Key appearing on St. Nicholas Magazine's survey of readers' favorite books well into the 1920s. In 1905, Baum declared plans for an Oz amusement park. In an interview, he mentioned buying “Pedloe Island” off the coast of California to turn it into an Oz park. However, there is no evidence that he purchased such an island, and no one has ever been able to find any island whose name even resembles Pedloe in that area. Nevertheless, Baum stated to the press that he had discovered a Pedloe Island off the coast of California and that he had purchased it to be "the Marvelous Land of Oz," intending it to be "a fairy paradise for children." Eleven year old Dorothy Talbot of San Francisco was reported to be ascendant to the throne on March 1, 1906, when the Palace of Oz was expected to be completed. Baum planned to live on the island, with administrative duties handled by the princess and her all-child advisers. Plans included statues of the Scarecrow, Tin Woodman, Jack Pumpkinhead, and H.M. Woggle-Bug, T.E. Baum abandoned his Oz park project after the failure of The Woggle-Bug, which was playing at the Garrick Theatre in 1905. Because of his lifelong love of theatre, he financed elaborate musicals, often to his financial detriment. One of Baum's worst financial endeavors was his The Fairylogue and Radio-Plays (1908), which combined a slideshow, film, and live actors with a lecture by Baum as if he were giving a travelogue to Oz. However, Baum ran into trouble and could not pay his debts to the company who produced the films. He did not get back to a stable financial situation for several years, after he sold the royalty rights to many of his earlier works, including The Wonderful Wizard of Oz. This resulted in the M.A. Donahue Company publishing cheap editions of his early works with advertising which purported that Baum's newer output was inferior to the less expensive books that they were releasing. He claimed bankruptcy in August 1911. However, Baum had shrewdly transferred most of his property into Maud's name, except for his clothing, his typewriter, and his library (mostly of children's books, such as the fairy tales of Andrew Lang, whose portrait he kept in his study)—all of which, he successfully argued, were essential to his occupation. Maud handled the finances anyway, and thus Baum lost much less than he could have. Baum made use of several pseudonyms for some of his other non-Oz books. They include: Edith Van Dyne (the Aunt Jane's Nieces series) Laura Bancroft (The Twinkle Tales, Policeman Bluejay) Floyd Akers (The Boy Fortune Hunters series, continuing the Sam Steele series) Suzanne Metcalf (Annabel) Schuyler Staunton (The Fate of a Crown, Daughters of Destiny) John Estes Cooke (Tamawaca Folks) Capt. Hugh Fitzgerald (the Sam Steele series) Baum also anonymously wrote The Last Egyptian: A Romance of the Nile. He continued theatrical work with Harry Marston Haldeman's men's social group The Uplifters, for which he wrote several plays for various celebrations. He also wrote the group's parodic by-laws. The group also included Will Rogers, but was proud to have had Baum as a member and posthumously revived many of his works despite their ephemeral intent. Many of these play's titles are known, but only The Uplift of Lucifer is known to survive (it was published in a limited edition in the 1960s). Prior to that, his last produced play was The Tik-Tok Man of Oz (based on Ozma of Oz and the basis for Tik-Tok of Oz), a modest success in Hollywood that producer Oliver Morosco decided did not do well enough to take to Broadway. Morosco, incidentally, quickly turned to film production, as did Baum. In 1914, Baum started his own film production company The Oz Film Manufacturing Company, which came as an outgrowth of the Uplifters. He served as its president and principal producer and screenwriter. The rest of the board consisted of Louis F. Gottschalk, Harry Marston Haldeman, and Clarence R. Rundel. The films were directed by J. Farrell MacDonald, with casts that included Violet MacMillan, Vivian Reed, Mildred Harris, Juanita Hansen, Pierre Couderc, Mai Welles, Louise Emmons, J. Charles Haydon, and early appearances by Harold Lloyd and Hal Roach. Silent film actor Richard Rosson appeared in one of the films (Rosson's younger brother Harold Rosson was the cinematographer on The Wizard of Oz, released in 1939). After little success probing the unrealized children's film market, Baum acknowledged his authorship of The Last Egyptian and made a film of it (portions of which are included in Decasia), but the Oz name had become box office poison for the time being, and even a name change to Dramatic Feature Films and transfer of ownership to Frank Joslyn Baum did not help. Baum invested none of his own money in the venture, unlike The Fairylogue and Radio-Plays, but the stress probably took its toll on his health. Death On May 5, 1919, Baum suffered a stroke, slipped into a coma and died the following day, at the age of 62. His last words were spoken to his wife during a brief period of lucidity: "Now we can cross the Shifting Sands." He was buried in Glendale's Forest Lawn Memorial Park Cemetery. His final Oz book, Glinda of Oz, was published on July 10, 1920, a year after his death. The Oz series was continued long after his death by other authors, notably Ruth Plumly Thompson, who wrote an additional twenty-one Oz books. Baum's beliefs Literary Baum's avowed intentions with the Oz books and his other fairy tales was to retell tales such as those which are found in the works of the Brothers Grimm and Hans Christian Andersen, remake them in an American vein, update them, omit stereotypical characters such as dwarfs or genies, and remove the association of violence and moral teachings. His first Oz books contained a fair amount of violence, but the amount of it decreased as the series progressed; in The Emerald City of Oz, Ozma objects to the use of violence, even to the use of violence against the Nomes who threaten Oz with invasion. His introduction is often cited as the beginning of the sanitization of children's stories, although he did not do a great deal more than eliminate harsh moral lessons. Another traditional element that Baum intentionally omitted was the emphasis on romance. He considered romantic love to be uninteresting to young children, as well as largely incomprehensible. In The Wonderful Wizard of Oz, the only elements of romance lay in the background of the Tin Woodman and his love for Nimmie Amee, which explains his condition but does not affect the tale in any other way, and the background of Gayelette and the enchantment of the Winged monkeys. The only other stories with such elements were The Scarecrow of Oz and Tik-Tok of Oz, both of them were based on dramatizations, which Baum regarded warily until his readers accepted them. Political Women's suffrage advocate When Baum lived in Aberdeen, South Dakota, where he was secretary of its Equal Suffrage Club, much of the politics in the Republican Aberdeen Saturday Pioneer dealt with trying to convince the populace to vote for women's suffrage. Susan B. Anthony visited Aberdeen and stayed with the Baums. Nancy Tystad Koupal notes an apparent loss of interest in editorializing after Aberdeen failed to pass the bill for women's enfranchisement. Sally Roesch Wagner of The Matilda Joslyn Gage Foundation published The Wonderful Mother of Oz, describing how Matilda Gage's feminist politics were sympathetically channeled by Baum into his Oz books. Some of Baum's contacts with suffragists of his day seem to have inspired much of The Marvelous Land of Oz. In this story, General Jinjur leads the girls and women of Oz in a revolt, armed with knitting needles; they succeed and make the men do the household chores. Jinjur proves to be an incompetent ruler, but Princess Ozma, who advocates gender equality, is ultimately placed on the throne. Charlotte Perkins Gilman's 1915 classic of feminist science fiction, Herland, bears strong similarities to The Emerald City of Oz(1910); the link between Baum and Gilman is considered to be Gage. Baum's stories outside of Oz also contain feminist or egalitarian themes. His Edith Van Dyne stories depict girls and young women engaging in traditionally masculine activities, including Aunt Jane's Nieces and The Flying Girl and its sequel. The Bluebird Books feature a girl sleuth. Racial views During the period surrounding the 1890 Ghost Dance movement and Wounded Knee Massacre, Baum wrote two editorials asserting that the safety of white settlers depended on the wholesale genocide of American Indians. These editorials were re-published in 1990 by sociologist Robert Venables of Cornell University, who argues that Baum was not using sarcasm. The first piece was published on December 20, 1890, five days after the killing of the Lakota Sioux holy man, Sitting Bull.Rogers, p. 259. The piece opined that with Sitting Bull's death, "the nobility of the Redskin" had been extinguished, and the safety of the frontier would not be established until there was "total annihilation" of the remaining Native Americans, who, he claimed, lived as "miserable wretches." Baum said that their extermination should not be regretted, and their elimination would "do justice to the manly characteristics" of their ancestors. The Wounded Knee Massacre occurred nine days later; the second editorial was published on January 3, 1891. Baum alleged that General Nelson A. Miles' weak rule of the Native Americans had caused American soldiers to suffer a "terrible loss of blood", in a "battle" which had been a disgrace to the Department of War. He found that the "disaster" could have easily been prevented with proper preparations. Baum reiterated that he believed, due to the history of mistreatment of Native Americans, that the extermination of the "untamed and untamable" tribes was necessary to protect American settlers. Baum ended the editorial with the following anecdote: "An eastern contemporary, with a grain of wisdom in its wit, says that 'when the whites win a fight, it is a victory, and when the Indians win it, it is a massacre.'" In 2006, two descendants of Baum apologized to the Sioux nation for any hurt that their ancestor had caused. The short story "The Enchanted Buffalo" claims to be a legend about a tribe of bison, and it states that a key element of it made it into the legends of Native American tribes. Baum mentions his characters' distaste for a Hopi snake dance in Aunt Jane's Nieces and Uncle John, but he also deplores the horrible situation which exists on Indian Reservations. Aunt Jane's Nieces on the Ranch features a hard-working Mexican in order to disprove Anglo stereotypes which portray Mexicans as lazy. Baum's mother-in-law and woman's suffrage leader Matilda Joslyn Gage strongly influenced his views. Gage was initiated into the Wolf Clan and admitted into the Iroquois Council of Matrons in recognition of her outspoken respect and sympathy for Native American people. Political imagery in The Wizard of Oz Numerous political references to the "Wizard" appeared early in the 20th century. Henry Littlefield, an upstate New York high school history teacher, wrote a scholarly article in 1964, the first full-fledged interpretation of the novel as an extended metaphor of the politics and characters of the 1890s. He paid special attention to the Populist metaphors and debates over silver and gold. Baum was a Republican and avid supporter of women's suffrage, and it is thought that he did not support the political ideals of either the Populist movement of 1890–1892 or the Bryanite silver crusade of 1896–1900. He published a poem in support of William McKinley. Since 1964, many scholars, economists, and historians have expanded on Littlefield's interpretation, pointing to multiple similarities between the characters (especially as depicted in Denslow's illustrations) and stock figures from editorial cartoons of the period. Littlefield wrote to The New York Times letters to the editor section spelling out that his theory had no basis in fact, but that his original point was "not to label Baum, or to lessen any of his magic, but rather, as a history teacher at Mount Vernon High School, to invest turn-of-the-century America with the imagery and wonder I have always found in his stories." Baum's newspaper had addressed politics in the 1890s, and Denslow was an editorial cartoonist as well as an illustrator of children's books. A series of political references is included in the 1902 stage version, such as references to the President, to a powerful senator, and to John D. Rockefeller for providing the oil needed by the Tin Woodman. Scholars have found few political references in Baum's Oz books after 1902. Baum was asked whether his stories had hidden meanings, but he always replied that they were written to "please children". Religion Baum was originally a Methodist, but he joined the Episcopal Church in Aberdeen in order to participate in community theatricals. Later, he
|
the basis for Tik-Tok of Oz), a modest success in Hollywood that producer Oliver Morosco decided did not do well enough to take to Broadway. Morosco, incidentally, quickly turned to film production, as did Baum. In 1914, Baum started his own film production company The Oz Film Manufacturing Company, which came as an outgrowth of the Uplifters. He served as its president and principal producer and screenwriter. The rest of the board consisted of Louis F. Gottschalk, Harry Marston Haldeman, and Clarence R. Rundel. The films were directed by J. Farrell MacDonald, with casts that included Violet MacMillan, Vivian Reed, Mildred Harris, Juanita Hansen, Pierre Couderc, Mai Welles, Louise Emmons, J. Charles Haydon, and early appearances by Harold Lloyd and Hal Roach. Silent film actor Richard Rosson appeared in one of the films (Rosson's younger brother Harold Rosson was the cinematographer on The Wizard of Oz, released in 1939). After little success probing the unrealized children's film market, Baum acknowledged his authorship of The Last Egyptian and made a film of it (portions of which are included in Decasia), but the Oz name had become box office poison for the time being, and even a name change to Dramatic Feature Films and transfer of ownership to Frank Joslyn Baum did not help. Baum invested none of his own money in the venture, unlike The Fairylogue and Radio-Plays, but the stress probably took its toll on his health. Death On May 5, 1919, Baum suffered a stroke, slipped into a coma and died the following day, at the age of 62. His last words were spoken to his wife during a brief period of lucidity: "Now we can cross the Shifting Sands." He was buried in Glendale's Forest Lawn Memorial Park Cemetery. His final Oz book, Glinda of Oz, was published on July 10, 1920, a year after his death. The Oz series was continued long after his death by other authors, notably Ruth Plumly Thompson, who wrote an additional twenty-one Oz books. Baum's beliefs Literary Baum's avowed intentions with the Oz books and his other fairy tales was to retell tales such as those which are found in the works of the Brothers Grimm and Hans Christian Andersen, remake them in an American vein, update them, omit stereotypical characters such as dwarfs or genies, and remove the association of violence and moral teachings. His first Oz books contained a fair amount of violence, but the amount of it decreased as the series progressed; in The Emerald City of Oz, Ozma objects to the use of violence, even to the use of violence against the Nomes who threaten Oz with invasion. His introduction is often cited as the beginning of the sanitization of children's stories, although he did not do a great deal more than eliminate harsh moral lessons. Another traditional element that Baum intentionally omitted was the emphasis on romance. He considered romantic love to be uninteresting to young children, as well as largely incomprehensible. In The Wonderful Wizard of Oz, the only elements of romance lay in the background of the Tin Woodman and his love for Nimmie Amee, which explains his condition but does not affect the tale in any other way, and the background of Gayelette and the enchantment of the Winged monkeys. The only other stories with such elements were The Scarecrow of Oz and Tik-Tok of Oz, both of them were based on dramatizations, which Baum regarded warily until his readers accepted them. Political Women's suffrage advocate When Baum lived in Aberdeen, South Dakota, where he was secretary of its Equal Suffrage Club, much of the politics in the Republican Aberdeen Saturday Pioneer dealt with trying to convince the populace to vote for women's suffrage. Susan B. Anthony visited Aberdeen and stayed with the Baums. Nancy Tystad Koupal notes an apparent loss of interest in editorializing after Aberdeen failed to pass the bill for women's enfranchisement. Sally Roesch Wagner of The Matilda Joslyn Gage Foundation published The Wonderful Mother of Oz, describing how Matilda Gage's feminist politics were sympathetically channeled by Baum into his Oz books. Some of Baum's contacts with suffragists of his day seem to have inspired much of The Marvelous Land of Oz. In this story, General Jinjur leads the girls and women of Oz in a revolt, armed with knitting needles; they succeed and make the men do the household chores. Jinjur proves to be an incompetent ruler, but Princess Ozma, who advocates gender equality, is ultimately placed on the throne. Charlotte Perkins Gilman's 1915 classic of feminist science fiction, Herland, bears strong similarities to The Emerald City of Oz(1910); the link between Baum and Gilman is considered to be Gage. Baum's stories outside of Oz also contain feminist or egalitarian themes. His Edith Van Dyne stories depict girls and young women engaging in traditionally masculine activities, including Aunt Jane's Nieces and The Flying Girl and its sequel. The Bluebird Books feature a girl sleuth. Racial views During the period surrounding the 1890 Ghost Dance movement and Wounded Knee Massacre, Baum wrote two editorials asserting that the safety of white settlers depended on the wholesale genocide of American Indians. These editorials were re-published in 1990 by sociologist Robert Venables of Cornell University, who argues that Baum was not using sarcasm. The first piece was published on December 20, 1890, five days after the killing of the Lakota Sioux holy man, Sitting Bull.Rogers, p. 259. The piece opined that with Sitting Bull's death, "the nobility of the Redskin" had been extinguished, and the safety of the frontier would not be established until there was "total annihilation" of the remaining Native Americans, who, he claimed, lived as "miserable wretches." Baum said that their extermination should not be regretted, and their elimination would "do justice to the manly characteristics" of their ancestors. The Wounded Knee Massacre occurred nine days later; the second editorial was published on January 3, 1891. Baum alleged that General Nelson A. Miles' weak rule of the Native Americans had caused American soldiers to suffer a "terrible loss of blood", in a "battle" which had been a disgrace to the Department of War. He found that the "disaster" could have easily been prevented with proper preparations. Baum reiterated that he believed, due to the history of mistreatment of Native Americans, that the extermination of the "untamed and untamable" tribes was necessary to protect American settlers. Baum ended the editorial with the following anecdote: "An eastern contemporary, with a grain of wisdom in its wit, says that 'when the whites win a fight, it is a victory, and when the Indians win it, it is a massacre.'" In 2006, two descendants of Baum apologized to the Sioux nation for any hurt that their ancestor had caused. The short story "The Enchanted Buffalo" claims to be a legend about a tribe of bison, and it states that a key element of it made it into the legends of Native American tribes. Baum mentions his characters' distaste for a Hopi snake dance in Aunt Jane's Nieces and Uncle John, but he also deplores the horrible situation which exists on Indian Reservations. Aunt Jane's Nieces on the Ranch features a hard-working Mexican in order to disprove Anglo stereotypes which portray Mexicans as lazy. Baum's mother-in-law and woman's suffrage leader Matilda Joslyn Gage strongly influenced his views. Gage was initiated into the Wolf Clan and admitted into the Iroquois Council of Matrons in recognition of her outspoken respect and sympathy for Native American people. Political imagery in The Wizard of Oz Numerous political references to the "Wizard" appeared early in the 20th century. Henry Littlefield, an upstate New York high school history teacher, wrote a scholarly article in 1964, the first full-fledged interpretation of the novel as an extended metaphor of the politics and characters of the 1890s. He paid special attention to the Populist metaphors and debates over silver and gold. Baum was a Republican and avid supporter of women's suffrage, and it is thought that he did not support the political ideals of either the Populist movement of 1890–1892 or the Bryanite silver crusade of 1896–1900. He published a poem in support of William McKinley. Since 1964, many scholars, economists, and historians have expanded on Littlefield's interpretation, pointing to multiple similarities between the characters (especially as depicted in Denslow's illustrations) and stock figures from editorial cartoons of the period. Littlefield wrote to The New York Times letters to the editor section spelling out that his theory had no basis in fact, but that his original point was "not to label Baum, or to lessen any of his magic, but rather, as a history teacher at Mount Vernon High School, to invest turn-of-the-century America with the imagery and wonder I have always found in his stories." Baum's newspaper had addressed politics in the 1890s, and Denslow was an editorial cartoonist as well as an illustrator of children's books. A series of political references is included in the 1902 stage version, such as references to the President, to a powerful senator, and to John D. Rockefeller for providing the oil needed by the Tin Woodman. Scholars have found few political references in Baum's Oz books after 1902. Baum was asked whether his stories had hidden meanings, but he always replied that they were written to "please children". Religion Baum was originally a Methodist, but he joined the Episcopal Church in Aberdeen in order to participate in community theatricals. Later, he and his wife were encouraged to become members of the Theosophical Society in 1892 by Matilda Joslyn Gage. Baum's beliefs are frequently reflected in his writings; however, the only mention of a church in his Oz books is the porcelain one which the Cowardly Lion breaks in the Dainty China Country in The Wonderful Wizard of Oz. The Baums sent their older sons to "Ethical Culture Sunday School" in Chicago, which taught morality, not religion.Michael Patrick Hearn. The Annotated Wizard of Oz. 2nd Edition. 2000. pp. 7, 271, 328. Writers including Evan I. Schwartz among others have suggested that Baum intentionally used allegory and symbolism in The Wonderful Wizard of Oz to convey concepts that are central to spiritual teachings such as Theosophy and Buddhism. They postulate that the main characters’ experiences in Oz represent the soul’s journey toward enlightenment. Schwartz specifically states that key plot elements of the book take “the reader on a journey guided by Eastern philosophy” (Schwartz, p. 265). An article in BBC Culture lists several allegorical interpretations of the book including that it may be viewed as a parable of Theosophy. The article cites various symbols and their possible meanings, for example the Yellow Brick Road representing the ‘Golden Path’ in Buddhism, along which the soul travels to a state of spiritual realization. Baum’s own writing suggests he believed the story may have been divinely inspired: “It was pure inspiration. It came to me right out of the blue. I think that sometimes the Great Author had a message to get across and He was to use the instrument at hand”. Bibliography Works Mother Goose in Prose (1897) By the Candelabra's Glare (1898) Father Goose: His Book (1899) A New Wonderland (1900) The Army Alphabet (1900) The Navy Alphabet (1900) American Fairy Tales (1901) The Life and Adventures of Santa Claus (1902) The Boy Fortune Hunters in Egypt (1908) The Boy Fortune Hunters in Panama (1908) Fortune Hunters in China The Boy Fortune Hunters in the South Seas (1911) The Sea Fairies (1911) Sky Island (1912) Queen Zixi of Ix (1905) The Fate of a Crown (1905) Sam Steele's Adventures on Land and Sea (1906) Daughters of Destiny (novel) (1906) The Last Egyptian (1907) Land of Oz worksThe Wonderful Wizard of Oz (1900)The Marvelous Land of Oz (1904)Queer Visitors from the Marvelous Land of Oz (1905, comic strip depicting 27 stories)The Woggle-Bug Book (1905)Ozma of Oz (1907)Dorothy and the Wizard in Oz (1908)The Road to Oz (1909)The Emerald City of Oz (1910)The Patchwork Girl of Oz (1913)Little Wizard Stories of Oz (1913, collection of 6 short stories)Tik-Tok of Oz (1914)The Scarecrow of Oz (1915)Rinkitink in Oz (1916)The Lost Princess of Oz (1917)The Tin Woodman of Oz (1918)The Magic of Oz (1919, posthumously published)Glinda of Oz (1920, posthumously published) 1921's The Royal Book of Oz was posthumously attributed to Baum but was entirely the work of Ruth Plumly Thompson. Popular culture and legacy A 1970 episode of the long-running American Western anthology series Death Valley Days presents a highly romanticized portrayal of Baum's time in South Dakota. The comedic teleplay, titled "The Wizard of Aberdeen", stars Conlan Carter as Baum and Beverlee McKinsey as Maud. Although the 30-minute presentation touches on Baum's family life and his struggles in Aberdeen as a newspaper editor, it focuses principally on his storytelling to local children about characters in a distant land he initially refers to as "Ooz". John Ritter portrayed Baum in the television film The Dreamer of Oz: The L. Frank Baum Story (1990). The theme park Storybook Land, located in Aberdeen, South Dakota, features the Land of Oz, with characters and attractions from the books. In the short-lived 2008 TV series Terminator: The Sarah Connor Chronicles, the show's protagonist John Connor enrolls in high school under the name of "John Baum" (after L. Frank Baum) to keep his true identity a secret. His mother Sarah had mentioned to Cameron that The Wonderful Wizard Of Oz was John's favorite book when he was younger. In 2013, Baum was inducted into the Chicago Literary Hall of Fame. Chittenango, New York holds a three-day annual festival called Oz-Stravaganza! to celebrate the literary works of author L. Frank Baum, who was born in Chittenango on May 15, 1856. The children's novel The Wonderful Wizard of Oz was published on May 17, 1900. The weekend-long festival, usually held during the first Saturday of June and the weekend thereof, includes a parade, which features many community groups. The parade has also featured actors and actresses who played Munchkins in the 1939 film The Wizard of Oz, including Jerry Maren, Karl Slover, Meinhardt Raabe, and Margaret Williams Pellegrini. See also Notes References Algeo, John. "A Notable Theosophist: L. Frank Baum." American Theosophist, Vol. 74 (August–September 1986), pp. 270–3. Attebery, Brian. The Fantasy Tradition in American Literature. Bloomington, IN, Indiana University Press, 1980. Baum, Frank Joslyn, and Russell P. Macfall. To Please a Child. Chicago, Reilly & Lee, 1961. Baum, L. Frank. The Annotated Wizard of Oz. Edited with an Introduction and Notes by Michael Patrick Hearn. New York, Clarkson N. Potter, 1973. Revised 2000. New York, W.W. Norton, 2000. Ford, Alla T. The High-Jinks of L. Frank Baum. Hong Kong, Ford Press, 1969. Ford, Alla T. The Musical Fantasies of L. Frank Baum. Lake Worth, FL, Ford Press, 1969. Gardner, Martin, and Russel B. Nye. The Wizard of Oz and Who He Was. East Lansing, MI, Michigan State University Press, 1957. Revised 1994. Hearn, Michael Patrick. The Critical Heritage Edition of the Wizard of Oz. New York, Schocken, 1986. Koupal, Nancy Tystad. Baum's Road to Oz: The Dakota Years. Pierre, SD, South Dakota State Historical Society, 2000. Koupal, Nancy Tystad. Our Landlady. Lawrence, KS, University of Nebraska Press, 1986. Parker, David B. The Rise and Fall of The Wonderful Wizard of Oz as a "Parable on Populism" Journal of the Georgia Association of Historians, vol. 15 (1994), pp. 49–63. Reneau, Reneau H. "Misanthropology: A Florilegium
|
until the 12th century AD or so. At 9,500 BP, Lake Onega, previously draining into the White Sea, started emptying into Ladoga via the River Svir. Between 9,500 and 9,100 BP, during the transgression of Ancylus Lake, the next freshwater stage of the Baltic, Ladoga certainly became part of it, even if they hadn't been connected immediately before. During the Ancylus Lake subsequent regression, around 8,800 BP Ladoga became isolated. Ladoga slowly transgressed in its southern part due to uplift of the Baltic Shield in the north. It has been hypothesized, but not proven, that waters of the Litorina Sea, the next brackish-water stage of the Baltic, occasionally invaded Ladoga between 7,000 and 5,000 BP. Around 5,000 BP the waters of the Saimaa Lake penetrated Salpausselkä and formed a new outlet, River Vuoksi, entering Lake Ladoga in the northwestern corner and raising its level by 1–2 m. The River Neva originated when the Ladoga waters at last broke through the threshold at Porogi into the lower portions of Izhora River, then a tributary of the Gulf of Finland, between 4,000 and 2,000 BP. Dating of some sediments in the northwestern part of Lake Ladoga suggests it happened at 3,100 radiocarbon years BP (3,410–3,250 calendar years BP). Wildlife The Ladoga is rich with fish. 48 forms (species and infra specific taxa) of fish have been encountered in the lake, including roach, carp bream, zander, European perch, ruffe, endemic variety of smelt, two varieties of Coregonus albula (vendace), eight varieties of Coregonus lavaretus, a number of other Salmonidae as well as, albeit rarely, endangered Atlantic sturgeon (formerly confused with European sea sturgeon). Commercial fishing was once a major industry but has been hurt by overfishing. After the war, between 1945–1954, the total annual catch increased and reached a maximum of 4,900 tonnes. However, unbalanced fishery led to the drastic decrease of catch in 1955–1963, sometimes to 1,600 tonnes per year. Trawling has been forbidden in Lake Ladoga since 1956 and some other restrictions were imposed. The situation gradually recovered, and in 1971–1990 the catch ranged between 4,900 and 6,900 tonnes per year, about the same level as the total catch in 1938. Fish farms and recreational fishing are developing. It has its own endemic ringed seal subspecies known as the Ladoga seal. Since the beginning of the 1960s Ladoga has become considerably eutrophicated. Nizhnesvirsky Natural Reserve is situated along the shore of Lake Ladoga immediately to the north of the mouth of the River Svir. The Ladoga has a population of Arctic char that is genetically close to the chars of Lake Sommen and Lake Vättern in southern Sweden. History In the Middle Ages, the lake formed a vital part of the trade route from the Varangians to the Eastern Roman Empire, with the Norse emporium at Staraya Ladoga defending the mouth of the Volkhov since the 8th century. In the course of the Swedish–Novgorodian Wars, the area was disputed between the Novgorod Republic and Sweden. In the early 14th century, the fortresses of Korela (Kexholm) and Oreshek (Nöteborg) were established along the banks of the lake. The ancient Valaam Monastery was founded on the island of Valaam, the largest in Lake Ladoga, abandoned between 1611–1715, restored in the 18th century, and evacuated to Finland during the Winter War in 1940. In 1989 the monastic activities in the Valaam were resumed. Other historic cloisters in the vicinity are the Konevets Monastery, which sits on the Konevets island, and the Alexander-Svirsky Monastery, which preserves samples of medieval Muscovite architecture. During the Ingrian War, a fraction of the Ladoga coast was occupied by Sweden. In 1617, by the Treaty of Stolbovo, the northern and western coast was ceded by Russia to Sweden. In 1721, after the Great Northern War, it was restitutioned to Russia by the Treaty of Nystad. In the 18th century, the Ladoga Canal was built to bypass the lake which was prone to winds and storms that destroyed hundreds of cargo ships. Later, from around 1812–1940 the lake was shared between Finland and Russia. According to the conditions of the 1920 Tartu Peace Treaty militarization of the lake was severely restricted. However, both Soviet Russia and Finland had flotillas in Ladoga (see also Finnish Ladoga Naval Detachment). After the Winter War (1939–40) according to the Moscow Peace Treaty, Ladoga, previously shared with Finland, became an internal basin of the Soviet Union. During World War II not only Finnish and Soviet, but also German and Italian vessels operated there (see also Naval Detachment K and Regia Marina). Under these circumstances, during much of the Siege of Leningrad (1941–44), Lake Ladoga provided the only access to the besieged city as a section of the eastern shore remained in Soviet hands. Supplies were transported into Leningrad with trucks on winter roads
|
into an ice stream that fed glacier lobes further east. Deglaciation following the Weichselian glaciation took place in the Lake Ladoga basin between 12,500 and 11,500 radiocarbon years BP. Lake Ladoga was initially part of the Baltic Ice Lake (70–80 m. above present sea level), a historical freshwater stage of Baltic Sea. It is possible, though not certain, that Ladoga was isolated from it during regression of the subsequent Yoldia Sea brackish stage (10,200–9,500 BP). The isolation threshold should be at Heinjoki to the east of Vyborg, where the Baltic Sea and Ladoga were connected by a strait or a river outlet at least until the formation of the River Neva, and possibly even much later, until the 12th century AD or so. At 9,500 BP, Lake Onega, previously draining into the White Sea, started emptying into Ladoga via the River Svir. Between 9,500 and 9,100 BP, during the transgression of Ancylus Lake, the next freshwater stage of the Baltic, Ladoga certainly became part of it, even if they hadn't been connected immediately before. During the Ancylus Lake subsequent regression, around 8,800 BP Ladoga became isolated. Ladoga slowly transgressed in its southern part due to uplift of the Baltic Shield in the north. It has been hypothesized, but not proven, that waters of the Litorina Sea, the next brackish-water stage of the Baltic, occasionally invaded Ladoga between 7,000 and 5,000 BP. Around 5,000 BP the waters of the Saimaa Lake penetrated Salpausselkä and formed a new outlet, River Vuoksi, entering Lake Ladoga in the northwestern corner and raising its level by 1–2 m. The River Neva originated when the Ladoga waters at last broke through the threshold at Porogi into the lower portions of Izhora River, then a tributary of the Gulf of Finland, between 4,000 and 2,000 BP. Dating of some sediments in the northwestern part of Lake Ladoga suggests it happened at 3,100 radiocarbon years BP (3,410–3,250 calendar years BP). Wildlife The Ladoga is rich with fish. 48 forms (species and infra specific taxa) of fish have been encountered in the lake, including roach, carp bream, zander, European perch, ruffe, endemic variety of smelt, two varieties of Coregonus albula (vendace), eight varieties of Coregonus lavaretus, a number of other Salmonidae as well as, albeit rarely, endangered Atlantic sturgeon (formerly confused with European sea sturgeon). Commercial fishing was once a major industry but has been hurt by overfishing. After the war, between 1945–1954, the total annual catch increased and reached a maximum of 4,900 tonnes. However, unbalanced fishery led to the drastic decrease of catch in 1955–1963, sometimes to 1,600 tonnes per year. Trawling has been forbidden in Lake Ladoga since 1956 and some other restrictions were imposed. The situation gradually recovered, and in 1971–1990 the catch ranged between 4,900 and 6,900 tonnes per year, about the same level as the total catch in 1938. Fish farms and recreational fishing are developing. It has its own endemic ringed seal subspecies known as the Ladoga seal. Since the beginning of the 1960s Ladoga has become considerably eutrophicated. Nizhnesvirsky Natural Reserve is situated along the shore of Lake Ladoga immediately to the north of the mouth of the River Svir. The Ladoga has a population of Arctic char that is genetically close to the chars of Lake Sommen and Lake Vättern in southern Sweden. History In the Middle Ages, the lake formed a vital part of the trade route from the Varangians to the Eastern Roman Empire, with the Norse emporium at Staraya Ladoga defending the mouth of the Volkhov since the 8th century. In the course of the Swedish–Novgorodian Wars, the area was disputed between the Novgorod Republic and Sweden. In the early 14th century, the fortresses of Korela (Kexholm) and Oreshek (Nöteborg) were established along the banks of the lake. The ancient Valaam Monastery was founded on the island of Valaam, the largest in Lake Ladoga, abandoned between 1611–1715, restored in the 18th century, and evacuated to Finland during the Winter War in 1940. In 1989 the monastic activities in the Valaam were resumed. Other historic cloisters in the vicinity are the Konevets Monastery, which sits on the Konevets island, and the Alexander-Svirsky Monastery, which preserves samples of medieval Muscovite architecture. During the Ingrian War, a fraction of the Ladoga coast was occupied by Sweden. In 1617, by the Treaty of Stolbovo, the northern and western coast was ceded by Russia to Sweden. In 1721, after the Great Northern War, it was restitutioned to Russia by the Treaty of Nystad. In the 18th century, the Ladoga Canal was built to bypass
|
that enough is known about the isolate to compare it genetically to other languages but no common ancestry or relationship is found with any other known language. A language isolated in its own branch within a family, such as Albanian and Armenian within Indo-European, is often also called an isolate, but the meaning of the word "isolate" in such cases is usually clarified with a modifier. For instance, Albanian and Armenian may be referred to as an "Indo-European isolate". By contrast, so far as is known, the Basque language is an absolute isolate: it has not been shown to be related to any other modern language despite numerous attempts. Another well-known isolate is Mapudungun, the Mapuche language from the Araucanían language family in Chile. A language may be said to be an isolate currently but not historically if related but now extinct relatives are attested. The Aquitanian language, spoken in Roman times, may have been an ancestor of Basque, but it could also have been a sister language to the ancestor of Basque. In the latter case, Basque and Aquitanian would form a small family together. (Ancestors are not considered to be distinct members of a family.) Proto-languages A proto-language can be thought of as a mother language (not to be confused with a mother tongue, which is one that a specific person has been exposed to from birth), being the root which all languages in the family stem from. The common ancestor of a language family is seldom known directly since most languages have a relatively short recorded history. However, it is possible to recover many features of a proto-language by applying the comparative method, a reconstructive procedure worked out by 19th century linguist August Schleicher. This can demonstrate the validity of many of the proposed families in the list of language families. For example, the reconstructible common ancestor of the Indo-European language family is called Proto-Indo-European. Proto-Indo-European is not attested by written records and so is conjectured to have been spoken before the invention of writing. Other classifications of languages Sprachbund A sprachbund is a geographic area having several languages that feature common linguistic structures. The similarities between those languages are caused by language contact, not by chance or common origin, and are not recognized as criteria that define a language family. An example of a sprachbund would be the Indian subcontinent. Shared innovations, acquired by borrowing or other means, are not considered genetic and have no bearing with the language family concept. It has been asserted, for example, that many of the more striking features shared by Italic languages (Latin, Oscan, Umbrian, etc.) might well be "areal features". However, very similar-looking alterations in the systems of long vowels in the West Germanic languages greatly postdate any possible notion of a proto-language innovation (and cannot readily be regarded as "areal", either, since English and continental West Germanic were not a linguistic area). In a similar vein, there are many similar unique innovations in Germanic, Baltic and Slavic that are far more likely to be areal features than traceable to a common proto-language. But legitimate uncertainty about whether shared innovations are areal features, coincidence, or inheritance from a common ancestor, leads to disagreement over the proper subdivisions of any large language family. Contact languages The concept of language families is based on the historical observation that languages develop dialects, which over time may diverge into distinct languages. However, linguistic ancestry is less clear-cut than familiar biological ancestry, in which species do not crossbreed. It is more like
|
isolate with dialects) to nearly twenty—until the classification of Ryukyuan as separate languages within a Japonic language family rather than dialects of Japanese, the Japanese language itself was considered a language isolate and therefore the only language in its family. Isolates Most of the world's languages are known to be related to others. Those that have no known relatives (or for which family relationships are only tentatively proposed) are called language isolates, essentially language families consisting of a single language. There are an estimated 129 language isolates known today. An example is Basque. In general, it is assumed that language isolates have relatives or had relatives at some point in their history but at a time depth too great for linguistic comparison to recover them. It is commonly misunderstood that language isolates are classified as such because there is not sufficient data on or documentation of the language. This is false because a language isolate is classified based on the fact that enough is known about the isolate to compare it genetically to other languages but no common ancestry or relationship is found with any other known language. A language isolated in its own branch within a family, such as Albanian and Armenian within Indo-European, is often also called an isolate, but the meaning of the word "isolate" in such cases is usually clarified with a modifier. For instance, Albanian and Armenian may be referred to as an "Indo-European isolate". By contrast, so far as is known, the Basque language is an absolute isolate: it has not been shown to be related to any other modern language despite numerous attempts. Another well-known isolate is Mapudungun, the Mapuche language from the Araucanían language family in Chile. A language may be said to be an isolate currently but not historically if related but now extinct relatives are attested. The Aquitanian language, spoken in Roman times, may have been an ancestor of Basque, but it could also have been a sister language to the ancestor of Basque. In the latter case, Basque and Aquitanian would form a small family together. (Ancestors are not considered to be distinct members of a family.) Proto-languages A proto-language can be thought of as a mother language (not to be confused with a mother tongue, which is one that a specific person has been exposed to from birth), being the root which all languages in the family stem from. The common ancestor of a language family is seldom known directly since most languages have a relatively short recorded history. However, it is possible to recover many features of a proto-language by applying the comparative method, a reconstructive procedure worked out by 19th century linguist August Schleicher. This can demonstrate the validity of many of the proposed families in the list of language families. For example, the reconstructible common ancestor of the Indo-European language family is called Proto-Indo-European. Proto-Indo-European is not attested by written records and so is conjectured to have been spoken before the invention of writing. Other classifications of languages Sprachbund A sprachbund is a geographic area having several languages that feature common linguistic structures. The similarities between those languages are caused by language contact, not by chance or common origin, and are not recognized as criteria that define a language family. An
|
is as well-known to inhabitants and visitors to Looe as the palms of their hands, no one has determined to what particular class of battleship she belongs, indeed all are familiar with the shapely hulk lying seaward of Hannafore as Looe Island (or, cartographically St. Georges Island)". In the 20th century, Looe island was owned (and inhabited) by two sisters, Babs and Evelyn Atkins, who wrote two books: We Bought An Island and its sequel Tales From Our Cornish Island. They chronicle the purchase of the island and what it was like to live there. Evelyn died in 1997 at the age of 87; Babs continued to live on the island until her death in 2004, at the age of 86. On her death, the island was bequeathed to the Cornwall Wildlife Trust; it will be preserved as a nature reserve in perpetuity. Today the wardens for Cornwall Wildlife Trust live on the island and manage it for the benefit of wildlife. The adjoining islet, formerly known as Little Island, now renamed Trelawny Island and connected by a small bridge, was bequeathed by Miss Atkins back to the Trelawny family, who previously owned Looe Island from 1743 to 1921. Geography Situated in the English Channel, about one mile from East Looe in the direction of Polperro, it is about in area and a mile (1.6 km) in circumference. Its highest point is above sea level. Looe Island, like much of south west England, has a mild climate with frost and snow being rare. The island is owned and managed by the Cornwall Wildlife Trust. This is a non-profit-making venture, the landing fees and other income being devoted to conserving the island's natural environment and providing facilities. The island is open during the summer to day visitors arriving by the Trust's boat. After a short welcome talk visitors are directed to the small visitor centre from where they can pick up a copy of the self-guided trail. Visitors have some two hours on the island and all trips are subject to tides and weather/sea state. While it is normally accessible only by the Cornwall Wildlife Trust's boat, at extremely low spring tides it is possible for the journey to be made by foot across the slippery, seaweed-covered rocky sea floor. However you have to remain on the beach and promptly head back to the mainland. Media appearances In 2008, Channel 4's archaeology series Time Team visited the island to carry out an investigation into its early Christian history. They excavated the sites of Christian chapels built on both the island and on the mainland opposite. During their dig they found the remains of a Benedictine chapel that was built in c.1139 by monks from Glastonbury Abbey, a reliquary, graves and the remains of much earlier Anglo-Romano places of worship built of wood with dating evidence suggesting use by Christians before the reign of Constantine the Great. In 1994/95 Andrew Hugill composed Island Symphony, an electro-acoustic piece utilising sampled sounds sourced over the net plus
|
was like to live there. Evelyn died in 1997 at the age of 87; Babs continued to live on the island until her death in 2004, at the age of 86. On her death, the island was bequeathed to the Cornwall Wildlife Trust; it will be preserved as a nature reserve in perpetuity. Today the wardens for Cornwall Wildlife Trust live on the island and manage it for the benefit of wildlife. The adjoining islet, formerly known as Little Island, now renamed Trelawny Island and connected by a small bridge, was bequeathed by Miss Atkins back to the Trelawny family, who previously owned Looe Island from 1743 to 1921. Geography Situated in the English Channel, about one mile from East Looe in the direction of Polperro, it is about in area and a mile (1.6 km) in circumference. Its highest point is above sea level. Looe Island, like much of south west England, has a mild climate with frost and snow being rare. The island is owned and managed by the Cornwall Wildlife Trust. This is a non-profit-making venture, the landing fees and other income being devoted to conserving the island's natural environment and providing facilities. The island is open during the summer to day visitors arriving by the Trust's boat. After a short welcome talk visitors are directed to the small visitor centre from where they can pick up a copy of the self-guided trail. Visitors have some two hours on the island and all trips are subject to tides and weather/sea state. While it is normally accessible only by the Cornwall Wildlife Trust's boat, at extremely low spring tides it is possible for the journey to be made by foot across the slippery, seaweed-covered rocky sea floor. However you have to remain on the beach and promptly head back to the mainland. Media appearances In 2008, Channel 4's archaeology series Time Team visited the island to carry out an investigation into its early Christian history. They excavated the sites of Christian chapels built on both the island and on the mainland opposite. During their dig they found the remains of a Benedictine chapel that was built in c.1139 by monks from Glastonbury Abbey, a reliquary, graves and the remains of much earlier Anglo-Romano places of worship built of wood with dating evidence suggesting use by Christians before the reign of Constantine the Great. In 1994/95 Andrew Hugill composed Island Symphony, an electro-acoustic piece utilising sampled sounds sourced over the net plus recorded natural sounds from the island itself. In the TV comedy series Yes Prime Minister, there was mention of another St. George's Island, but this one was a fictitious place in the Arabian Sea. See also St Michael's Mount Mont Saint-Michel List of monastic houses in Cornwall References Further reading Looe Island Then and Now: Carolyn Clarke 2014 United P. C Publisher The Looe Island Story: an Illustrated History of St George's Island, Mike Dunn, 2006, Polperro
|
footnotes, cross-references and bibliographies. LaTeX was originally written in the early 1980s by Leslie Lamport at SRI International. The current version is LaTeX2e (stylised as ), released in 1994, but updated in 2020. LaTeX3 () has been under long-term development since the early 1990s. LaTeX is free software and is distributed under the LaTeX Project Public License (LPPL). Typesetting system LaTeX attempts to follow the design philosophy of separating presentation from content, so that authors can focus on the content of what they are writing without attending simultaneously to its visual appearance. In preparing a LaTeX document, the author specifies the logical structure using simple, familiar concepts such as chapter, section, table, figure, etc., and lets the LaTeX system handle the formatting and layout of these structures. As a result, it encourages the separation of the layout from the content — while still allowing manual typesetting adjustments whenever needed. This concept is similar to the mechanism by which many word processors allow styles to be defined globally for an entire document, or the use of Cascading Style Sheets in styling HTML documents. The LaTeX system is a markup language that handles typesetting and rendering, and can be arbitrarily extended by using the underlying macro language to develop custom macros such as new environments and commands. Such macros are often collected into packages, which could then be made available to address some specific typesetting needs such as the formatting of complex mathematical expressions or graphics (e.g., the use of the align environment provided by the amsmath package to produce aligned equations). In order to create a document in LaTeX, you first write a file, say document.tex, using your preferred text editor. Then you give your document.tex file as input to the TeX program (with the LaTeX macros loaded), which prompts TeX to write out a file suitable for onscreen viewing or printing. This write-format-preview cycle is one of the chief ways in which working with LaTeX differs from the What-You-See-Is-What-You-Get (WYSIWYG) style of document editing. It is similar to the code-compile-execute cycle known to computer programmers. Today, many LaTeX-aware editing programs make this cycle a simple matter through the pressing of a single key, while showing the output preview on the screen beside the input window. Some online LaTeX editors even automatically refresh the preview, while other online tools provide incremental editing in-place, mixed in with the preview in a streamlined single window. How it works The example below shows the input to LaTeX and the corresponding output from the system: Note how the equation for (highlighted in the example code) was typeset by the markup: E &= \frac{mc^2}{\sqrt{1-\frac{v^2}{c^2}}} where the square root is denoted by "\sqrt{argument}", and the fractions by "\frac{numerator}{denominator}". Pronouncing and writing "LaTeX" The characters 'T', 'E', and 'X' in the name come from the Greek capital letters tau, epsilon, and chi, as the name of TeX derives from the ('skill', 'art', 'technique'); for this reason, TeX's creator Donald Knuth promotes its pronunciation as () (that is, with a voiceless
|
opened with any text editor. They consist of plain text and do not contain hidden formatting codes or binary instructions. Additionally, TeX documents can be shared by rendering the LaTeX file to Rich Text Format (*.rtf), XML, or the container format. This can be done using the free software programs LaTeX2RTF or TeX4ht. LaTeX can also be rendered to PDF files using the LaTeX extension pdfLaTeX. LaTeX files containing Unicode text can be processed into PDFs with the inputenc package, or by the TeX extensions XeLaTeX and LuaLaTeX. HeVeA is a converter written in Ocaml that converts LaTeX documents to HTML5. It is licensed under the Q Public License. LaTeX2HTML is a converter written in Perl that converts LaTeX documents to HTML. This way, e.g., scientific papers—primarily typeset for printing—can be placed on the Web for online viewing. It is licensed under GNU GPL v2. The latest updates are available from CTAN. LaTeXML is a free, public domain software, written in Perl, which converts LaTeX documents to a variety of structured formats, including HTML5 (with MathML), epub (encapsulation of HTML), jats, tei. Pandoc is a 'universal document converter' able to transform LaTeX into many different file formats, including HTML5, epub, rtf and docx. It is licensed under GNU GPL v2. LaTeX has become the de facto standard to typeset mathematical expression in scientific documents. Hence, there are several conversion tools focusing on mathematical LaTeX expressions, such as converters to MathML or Computer Algebra System. MathJax is a JavaScript library for converting LaTeX to MathML, picture formats, or HTML. The Wikimedia foundation uses it to build Mathoid, a web-service converter using Node.js that converts math inputs, such as LaTeX, to MathML and picture formats, including SVG and PNG. Mathoid is used in Wikipedia to render math. KaTeX is a JavaScript library for converting LaTeX to HTML and MathML. It is developed by the Khan Academy, and is among the fastest LaTeX to HTML converters. Licensing LaTeX is typically distributed along with plain TeX under a free software license: the LaTeX Project Public License (LPPL). The LPPL is not compatible with the GNU General Public License, as it requires that modified files must be clearly differentiable from their originals (usually by changing the filename); this was done to ensure that files that depend on other files will produce the expected behavior and avoid dependency hell. The LPPL is DFSG compliant as of version 1.3. As free software, LaTeX is available on most operating systems, which include UNIX (Solaris, HP-UX, AIX), BSD (FreeBSD, macOS, NetBSD, OpenBSD), Linux (Red Hat, Debian, Arch, Gentoo), Windows, DOS, RISC OS, AmigaOS and Plan9. Versions LaTeX2e is the current version of LaTeX, since it replaced LaTeX 2.09 in 1994. , LaTeX3, which started in the early 1990s, is under a long-term development project. Planned features include improved syntax (separation of content from styling), hyperlink support, a new user interface, access to arbitrary fonts and a new documentation. Some LaTeX3 features are available in LaTeX2e using packages, and by 2020 many features have been enabled in LaTeX2e by default for a gradual transition. There are numerous commercial implementations of the entire TeX system. System vendors may add extra features like additional typefaces and telephone support. LyX is a free, WYSIWYM visual document processor that uses LaTeX for a back-end. TeXmacs is a free, WYSIWYG editor with similar functionalities as LaTeX, but
|
process of "canonization" and each individual jurisdiction within the two Orthodox communions independently maintains parallel lists of saints that have only partial overlap. The Anglican Communion recognizes pre-Reformation saints, as does the United Methodist Church. Persons who have led lives of celebrated sanctity or missionary zeal are included in the Calendar of the Prayer Book "...without thereby enrolling or commending such persons as saints of the Church..." Similarly, any individuals commemorated in the Lutheran calendar of saints will be listed. Other denominations have their own Calendars of Saints they maintain. Christian saints since AD 300 Notes on saints list 4 Common Worship has "Commemoration". 6 Eastern Rite Catholic Churches only. 7 Russian Orthodox Church only. 8 9 Ukrainian Orthodox Church. Catholic known canonizations See also Calendar of saints Calendar of saints (Church of England) Calendar of saints (Episcopal Church) Calendar of saints (Anglican Church of Southern Africa) Calendar of saints (Lutheran) Coptic Orthodox calendar of saints Chronological list of saints and blesseds Doctor of the church Martyrology On the Resting-Places of the Saints (list from 11th century England) Patron saint Roman Martyrology Saint symbology Saints in Anglicanism Saints in Methodism Additional Lists: List of blesseds List of Catholic saints
|
attributes included as part of the historical name). Listed Canonized Roman Catholic saints have been through a formal institutional process resulting in their canonization. There have been thousands of canonizations. (Pope John Paul II alone canonized 110 individuals, as well as many group canonizations such as 110 martyr saints of China, 103 Korean martyrs, 117 Vietnamese martyrs, the Mexican Martyrs, Spanish martyrs and French revolutionary martyrs. Note that 78 popes are considered saints.) Among the Eastern Orthodox and Oriental Orthodox Communions, the numbers may be even higher, since there is no fixed process of "canonization" and each individual jurisdiction within the two Orthodox communions independently maintains parallel lists of saints that have only partial overlap. The Anglican Communion recognizes pre-Reformation saints, as does the United Methodist Church. Persons who have led lives of celebrated sanctity or missionary zeal are included in the Calendar of the Prayer Book "...without thereby enrolling or commending such persons as saints of the Church..." Similarly, any individuals commemorated in the Lutheran calendar of saints will be listed. Other denominations have their own Calendars of Saints they maintain. Christian saints since AD 300 Notes on saints list 4 Common Worship has "Commemoration". 6 Eastern Rite Catholic Churches only. 7
|
obtained by small variation of the Peano curve construction). The dragon curve is another unusual example. Any line in , for , has a zero Lebesgue measure. In general, every proper hyperplane has a zero Lebesgue measure in its ambient space. Properties The Lebesgue measure on Rn has the following properties: If A is a cartesian product of intervals I1 × I2 × ⋯ × In, then A is Lebesgue-measurable and If A is a disjoint union of countably many disjoint Lebesgue-measurable sets, then A is itself Lebesgue-measurable and λ(A) is equal to the sum (or infinite series) of the measures of the involved measurable sets. If A is Lebesgue-measurable, then so is its complement. λ(A) ≥ 0 for every Lebesgue-measurable set A. If A and B are Lebesgue-measurable and A is a subset of B, then λ(A) ≤ λ(B). (A consequence of 2.) Countable unions and intersections of Lebesgue-measurable sets are Lebesgue-measurable. (Not a consequence of 2 and 3, because a family of sets that is closed under complements and disjoint countable unions does not need to be closed under countable unions: .) If A is an open or closed subset of Rn (or even Borel set, see metric space), then A is Lebesgue-measurable. If A is a Lebesgue-measurable set, then it is "approximately open" and "approximately closed" in the sense of Lebesgue measure (see the regularity theorem for Lebesgue measure). A Lebesgue-measurable set can be "squeezed" between a containing open set and a contained closed set. This property has been used as an alternative definition of Lebesgue measurability. More precisely, is Lebesgue-measurable if and only if for every there exist an open set and a closed set such that and . A Lebesgue-measurable set can be "squeezed" between a containing Gδ set and a contained Fσ. I.e, if A is Lebesgue-measurable then there exist a Gδ set G and an Fσ F such that G ⊇ A ⊇ F and λ(G \ A) = λ(A \ F) = 0. Lebesgue measure is both locally finite and inner regular, and so it is a Radon measure. Lebesgue measure is strictly positive on non-empty open sets, and so its support is the whole of Rn. If A is a Lebesgue-measurable set with λ(A) = 0 (a null set), then every subset of A is also a null set. A fortiori, every subset of A is measurable. If A is Lebesgue-measurable and x is an element of Rn, then the translation of A by x, defined by A + x = {a + x : a ∈ A}, is also Lebesgue-measurable and has the same measure as A. If A is Lebesgue-measurable and , then the dilation of by defined by is also Lebesgue-measurable and has measure More generally, if T is a linear transformation and A is a measurable subset of Rn, then T(A) is also Lebesgue-measurable and has the measure . All
|
the Lebesgue outer measure. Whether this outer measure translates to the Lebesgue measure proper depends on an additional condition. This condition is tested by taking subsets of the real numbers using as an instrument to split into two partitions: the part of which intersects with and the remaining part of which is not in : the set difference of and . These partitions of are subject to the outer measure. If for all possible such subsets of the real numbers, the partitions of cut apart by have outer measures whose sum is the outer measure of , then the outer Lebesgue measure of gives its Lebesgue measure. Intuitively, this condition means that the set must not have some curious properties which causes a discrepancy in the measure of another set when is used as a "mask" to "clip" that set, hinting at the existence of sets for which the Lebesgue outer measure does not give the Lebesgue measure. (Such sets are, in fact, not Lebesgue-measurable.) Examples Any closed interval of real numbers is Lebesgue-measurable, and its Lebesgue measure is the length . The open interval has the same measure, since the difference between the two sets consists only of the end points a and b and has measure zero. Any Cartesian product of intervals and is Lebesgue-measurable, and its Lebesgue measure is , the area of the corresponding rectangle. Moreover, every Borel set is Lebesgue-measurable. However, there are Lebesgue-measurable sets which are not Borel sets. Any countable set of real numbers has Lebesgue measure 0. In particular, the Lebesgue measure of the set of algebraic numbers is 0, even though the set is dense in R. The Cantor set and the set of Liouville numbers are examples of uncountable sets that have Lebesgue measure 0. If the axiom of determinacy holds then all sets of reals are Lebesgue-measurable. Determinacy is however not compatible with the axiom of choice. Vitali sets are examples of sets that are not measurable with respect to the Lebesgue measure. Their existence relies on the axiom of choice. Osgood curves are simple plane curves with positive Lebesgue measure (it can be obtained by small variation of the Peano curve construction). The dragon curve is another unusual example. Any line in , for , has a zero Lebesgue measure. In general, every proper hyperplane has a zero Lebesgue measure in its ambient space. Properties The Lebesgue measure on Rn has the following properties: If A is a cartesian product of intervals I1 × I2 × ⋯ × In, then A is Lebesgue-measurable and If A is a disjoint union of countably many disjoint Lebesgue-measurable sets, then A is itself Lebesgue-measurable and λ(A) is equal to the sum (or infinite series) of the measures of the involved measurable sets. If A is Lebesgue-measurable, then so is its complement. λ(A) ≥ 0 for every Lebesgue-measurable set A. If A and B are Lebesgue-measurable and A is a subset of B, then λ(A) ≤ λ(B). (A consequence of 2.) Countable unions and intersections of Lebesgue-measurable sets are Lebesgue-measurable. (Not a consequence of 2 and 3, because a family of sets that is closed under complements and disjoint countable unions does not need to be closed under countable unions: .) If A is an open or closed subset of Rn (or even Borel set, see metric space), then A is Lebesgue-measurable. If A is a Lebesgue-measurable set, then it is "approximately open" and "approximately closed" in the sense of Lebesgue measure (see the regularity theorem for Lebesgue measure). A Lebesgue-measurable set can
|
of a British convoy carrying 10,000 British and Hessian troops to Canada, the Continental forces retreated back down the Champlain Valley to reevaluate their strategy. "I know of no better method than to secure the important posts of Ticonderoga and Crown Point, and by building a number of armed vessels to command the lakes, otherwise the forces now in Canada will be brought down upon us as quick as possible, having nothing to oppose them...They will doubtless try to construct some armed vessels and then endeavor to penetrate the country toward New York." (Brigadier General John Sullivan to George Washington, June 24, 1776). Both British and American forces spent the summer of 1776 building their naval fleets, at opposite ends of Lake Champlain. By the October 1776, the Continental Army had 16 operating naval vessels on Lake Champlain: a great increase to the four small ships they had at the beginning of the summer. General Benedict Arnold commanded the American naval fleet on Lake Champlain, which was composed of volunteers and soldiers drafted from the Northern Army. With great contrast to the Continental navy, experienced Royal Navy officers, British seamen and Hessian artillerymen manned the British fleet on Lake Champlain. By the end of the summer of 1776, the opposing armies were prepared to battle over the strategic advantage of controlling Lake Champlain. Battle of Valcour Island On October 11, 1776, the British and American naval fleets met on the western side of Valcour Island, on Lake Champlain. American General Benedict Arnold established the location, as it provided the Continental fleet with a natural defensive position. The British and American vessels engaged in combat for much of the day, only stopping due to impending nightfall. After a long day of combat, the American fleet was in worse shape than the experienced British Navy. Upon ceasefire, Arnold called a council of war with his fellow officers, proposing to escape the British fleet via rowboats under the cover of night. As the British burned Arnold's flagship, the Royal Savage, to the east, the Americans rowed past the British lines. The following morning, the British learned of the Americans' escape and set out after the fleeing Continental vessels. On October 13, the British fleet caught up to the struggling American ships near Split Rock Mountain. With no hope of fighting off the powerful British navy, Arnold ordered his men to run their five vessels aground in Ferris Bay, Panton, Vermont. The depleted Continental army escaped on land back to Fort Ticonderoga and Mount Independence; however, they no longer controlled the Lake Champlain waterway. The approaching winter of 1776–1777 restricted British movement along the recently-controlled Lake Champlain. As the British abandoned Crown Point and returned to Canada for the winter, the Americans reduced their garrisons in the Champlain Valley from 13,000 to 2,500 soldiers. General Burgoyne’s Campaign In early 1777, British General John Burgoyne led 8,000 troops from Canada, down Lake Champlain and into the Champlain Valley. The goal of this invasion was to divide the New England colonies, thus forcing the Continental Army into a separated fight on multiple fronts. Lake Champlain provided Burgoyne with protected passage deep into the American colonies. Burgoyne's army reached Fort Ticonderoga and Mount Independence in late June, 1777. During the night of July 5, the American forces fled Ticonderoga as the British took control of the fort. However, Burgoyne's southern campaign did not go uncontested. On October 7, 1777, American General Horatio Gates, who occupied Bemis Heights, met Burgoyne's army at the Second Battle of Freeman's Farm. At Freeman's Farm, Burgoyne's army suffered its final defeat and ended its invasion south into the colonies. Ten days later, on October 17, 1777, British General Burgoyne surrendered his army at Saratoga. This defeat was instrumental to the momentum of the Revolutionary War, as the defeat of the British army along the Champlain-Hudson waterway convinced France to ally with the American army. Aftermath of 1777 Following the failed British campaign led by General Burgoyne, the British still maintained control over the Champlain waterway for the duration of the Revolutionary War. The British used the Champlain waterway to supply raids across the Champlain Valley from 1778 to 1780, and Lake Champlain permitted direct transportation of supplies from the British posts at the northern end of the lake. With the end of the Revolutionary War in 1783, the British naval fleet on Lake Champlain retreated up to St. John's. However, British troops garrisoned at Fort Dutchman's Point (North Hero, Vermont) and Fort au Fer (Champlain, New York), on Lake Champlain, did not leave until the 1796 Jay Treaty. Post-Revolutionary War period Eager to take back control of Lake Champlain following the end of the Revolutionary War, Americans flocked to settle the Champlain Valley. Many individuals emigrated from Massachusetts and other New England colonies, such as Salmon Dutton, a settler of Cavendish, Vermont. Dutton emigrated in 1782 and worked as a surveyor, town official and toll-road owner. His home had a dooryard garden, typical of mid-19th century New England village homes, and his experience settling in the Champlain Valley depicts the industries and lifestyles surrounding Lake Champlain following the Revolutionary War. Similar to the experience of Salmon Dutton, former colonial militia Captain Hezekiah Barnes settled in Charlotte, Vermont in 1787. Following the war, Barnes also worked as a road surveyor; he also established an inn and trading post in Charlotte, along the main trade route from Montreal down Lake Champlain. Barnes' stagecoach inn was built in traditional Georgian style, with 10 fireplaces, a ballroom on the interior and a wraparound porch on the outside. In 1800, Continental Army Captain Benjamin Harrington established a distillery business in Shelburne, Vermont, which supplied his nearby inn. Furthermore, Captain Stevens and Jeremiah Trescott built a water-powered sawmill in South Royalton, Vermont in the late 1700s. These individual accounts shed light on the significance of Lake Champlain during the post-Revolutionary War period. War of 1812 During the War of 1812, British and American forces faced each other in the Battle of Lake Champlain, also known as the Battle of Plattsburgh, fought on September 11, 1814. This ended the final British invasion of the northern states during the War of 1812. It was fought just prior to the signing of the Treaty of Ghent, and the American victory denied the British any leverage to demand exclusive control over the Great Lakes or territorial gains against the New England states. Three US Naval ships have been named after this battle: , and a cargo ship used during World War I. Following the War of 1812, the U.S. Army began construction on "Fort Blunder": an unnamed fortification built at the northernmost end of Lake Champlain to protect against attacks from British Canada. Its nickname came from a surveying error: the initial phase of construction on the fort turned out to be taking place on a point north of the Canada–U.S. border. Once this error was spotted, construction was abandoned. Locals scavenged materials used in the abandoned fort for use in their homes and public buildings. By the Webster-Ashburton Treaty of 1842, the Canada–U.S. border was adjusted northward to include the strategically-important site of "Fort Blunder" on the US side. In 1844, work was begun to replace the remains of the 1812-era fort with a massive new Third System masonry fortification, known as Fort Montgomery. Portions of this fort are still standing. Modern history In the early 19th century, the construction of the Champlain Canal connected Lake Champlain to the Hudson River system, allowing north–south commerce by water from New York City to Montreal and Atlantic Canada. In 1909, 65,000 people celebrated the 300th anniversary of the French discovery of the lake. Attending dignitaries included President William Howard Taft, along with representatives from France, Canada and the United Kingdom. In 1929, then-New York Governor Franklin Roosevelt and Vermont Governor John Weeks dedicated the first bridge to span the lake, built from Crown Point to Chimney Point. This bridge lasted until December, 2009. Severe deterioration was found, and the bridge was demolished and replaced with the Lake Champlain Bridge, which opened in November, 2011. On February 19, 1932, boats were able to sail on Lake Champlain. It was the first time that the lake was known to be free of ice during the winter at that time. Lake Champlain briefly became the nation's sixth Great Lake on March 6, 1998, when President Clinton signed Senate Bill 927. This bill, which was led by U.S. Senator Patrick Leahy of Vermont and reauthorized the National Sea Grant Program, contained a line declaring Lake Champlain to be a Great Lake. This status enabled its neighboring states to apply for additional federal research and education funds allocated to these national resources. However, following a small uproar, the Great Lake status was rescinded on March 24 (although New York and Vermont universities continue to receive funds to monitor and study the lake). "Champ", Lake Champlain monster In 1609, Samuel de Champlain wrote that he saw a lake monster long, as thick as a man's thigh, with silver-gray scales a dagger could not penetrate. The alleged monster had jaws with sharp and dangerous teeth. Native Americans claimed to have seen similar monsters long. This mysterious creature is likely the original Lake Champlain monster. The monster has been memorialized in sports teams' names and mascots, i.e., the Vermont Lake Monsters and Champ, the mascot of the state's minor league baseball team. A Vermont Historical Society publication recounts the story and offers possible explanations for accounts of the so-called monster: "floating logs, schools of large sturgeon diving in a row, or flocks of blackbirds flying close to the water". Ecology A pollution prevention, control and restoration plan for Lake Champlain was first endorsed in October, 1996 by the governors of New York and Vermont and the regional administrators of the United States Environmental Protection Agency (EPA). In April, 2003, the plan was updated, and Quebec signed-on to it. The plan is being implemented by the Lake Champlain Basin Program and its partners at the state, provincial, federal and local levels. Renowned as a model for interstate and international cooperation, its primary goals are to reduce phosphorus inputs to Lake Champlain, reduce toxic contamination, minimize the risks to humans from water-related health hazards and control the introduction, spread, and impact of non-native nuisance species to preserve the integrity of the Lake Champlain ecosystem. Senior staff who helped organize the Environmental Protection Agency in 1970 recall that International Paper was one of the first companies to call upon the brand-new agency, because it was being pressured by both New York and Vermont with regard to a discharge of pollution into Lake Champlain. Agricultural and urban runoff from the watershed or drainage basin is the primary source of excess phosphorus, which exacerbates algae blooms in Lake Champlain. The most problematic blooms have been cyanobacteria, commonly called blue-green algae, in the northeastern part of the Lake: primarily Missisquoi Bay. To reduce phosphorus runoff to this part of the lake, Vermont and Quebec agreed to reduce their inputs by 60% and 40%, respectively, by an agreement signed in 2002. While agricultural sources (manure and fertilizers) are the primary sources of phosphorus (about 70%) in the Missisquoi basin, runoff from developed land and suburbs is estimated to contribute about 46% of the phosphorus runoff basin-wide to Lake Champlain, and agricultural lands contributed about 38%. In 2002, the cleanup plan noted that the lake had the capacity to absorb of phosphorus each year. In 2009, a judge noted that were still flowing in annually: more than twice what the lake could handle. Sixty municipal and industrial sewage plants discharge processed waste from the Vermont side. In 2008, the EPA expressed concerns to the State of Vermont that the Lake's cleanup was not progressing fast enough to meet the original cleanup goal of 2016. The state, however, cites its Clean and Clear Action Plan as a model that
|
Arnold called a council of war with his fellow officers, proposing to escape the British fleet via rowboats under the cover of night. As the British burned Arnold's flagship, the Royal Savage, to the east, the Americans rowed past the British lines. The following morning, the British learned of the Americans' escape and set out after the fleeing Continental vessels. On October 13, the British fleet caught up to the struggling American ships near Split Rock Mountain. With no hope of fighting off the powerful British navy, Arnold ordered his men to run their five vessels aground in Ferris Bay, Panton, Vermont. The depleted Continental army escaped on land back to Fort Ticonderoga and Mount Independence; however, they no longer controlled the Lake Champlain waterway. The approaching winter of 1776–1777 restricted British movement along the recently-controlled Lake Champlain. As the British abandoned Crown Point and returned to Canada for the winter, the Americans reduced their garrisons in the Champlain Valley from 13,000 to 2,500 soldiers. General Burgoyne’s Campaign In early 1777, British General John Burgoyne led 8,000 troops from Canada, down Lake Champlain and into the Champlain Valley. The goal of this invasion was to divide the New England colonies, thus forcing the Continental Army into a separated fight on multiple fronts. Lake Champlain provided Burgoyne with protected passage deep into the American colonies. Burgoyne's army reached Fort Ticonderoga and Mount Independence in late June, 1777. During the night of July 5, the American forces fled Ticonderoga as the British took control of the fort. However, Burgoyne's southern campaign did not go uncontested. On October 7, 1777, American General Horatio Gates, who occupied Bemis Heights, met Burgoyne's army at the Second Battle of Freeman's Farm. At Freeman's Farm, Burgoyne's army suffered its final defeat and ended its invasion south into the colonies. Ten days later, on October 17, 1777, British General Burgoyne surrendered his army at Saratoga. This defeat was instrumental to the momentum of the Revolutionary War, as the defeat of the British army along the Champlain-Hudson waterway convinced France to ally with the American army. Aftermath of 1777 Following the failed British campaign led by General Burgoyne, the British still maintained control over the Champlain waterway for the duration of the Revolutionary War. The British used the Champlain waterway to supply raids across the Champlain Valley from 1778 to 1780, and Lake Champlain permitted direct transportation of supplies from the British posts at the northern end of the lake. With the end of the Revolutionary War in 1783, the British naval fleet on Lake Champlain retreated up to St. John's. However, British troops garrisoned at Fort Dutchman's Point (North Hero, Vermont) and Fort au Fer (Champlain, New York), on Lake Champlain, did not leave until the 1796 Jay Treaty. Post-Revolutionary War period Eager to take back control of Lake Champlain following the end of the Revolutionary War, Americans flocked to settle the Champlain Valley. Many individuals emigrated from Massachusetts and other New England colonies, such as Salmon Dutton, a settler of Cavendish, Vermont. Dutton emigrated in 1782 and worked as a surveyor, town official and toll-road owner. His home had a dooryard garden, typical of mid-19th century New England village homes, and his experience settling in the Champlain Valley depicts the industries and lifestyles surrounding Lake Champlain following the Revolutionary War. Similar to the experience of Salmon Dutton, former colonial militia Captain Hezekiah Barnes settled in Charlotte, Vermont in 1787. Following the war, Barnes also worked as a road surveyor; he also established an inn and trading post in Charlotte, along the main trade route from Montreal down Lake Champlain. Barnes' stagecoach inn was built in traditional Georgian style, with 10 fireplaces, a ballroom on the interior and a wraparound porch on the outside. In 1800, Continental Army Captain Benjamin Harrington established a distillery business in Shelburne, Vermont, which supplied his nearby inn. Furthermore, Captain Stevens and Jeremiah Trescott built a water-powered sawmill in South Royalton, Vermont in the late 1700s. These individual accounts shed light on the significance of Lake Champlain during the post-Revolutionary War period. War of 1812 During the War of 1812, British and American forces faced each other in the Battle of Lake Champlain, also known as the Battle of Plattsburgh, fought on September 11, 1814. This ended the final British invasion of the northern states during the War of 1812. It was fought just prior to the signing of the Treaty of Ghent, and the American victory denied the British any leverage to demand exclusive control over the Great Lakes or territorial gains against the New England states. Three US Naval ships have been named after this battle: , and a cargo ship used during World War I. Following the War of 1812, the U.S. Army began construction on "Fort Blunder": an unnamed fortification built at the northernmost end of Lake Champlain to protect against attacks from British Canada. Its nickname came from a surveying error: the initial phase of construction on the fort turned out to be taking place on a point north of the Canada–U.S. border. Once this error was spotted, construction was abandoned. Locals scavenged materials used in the abandoned fort for use in their homes and public buildings. By the Webster-Ashburton Treaty of 1842, the Canada–U.S. border was adjusted northward to include the strategically-important site of "Fort Blunder" on the US side. In 1844, work was begun to replace the remains of the 1812-era fort with a massive new Third System masonry fortification, known as Fort Montgomery. Portions of this fort are still standing. Modern history In the early 19th century, the construction of the Champlain Canal connected Lake Champlain to the Hudson River system, allowing north–south commerce by water from New York City to Montreal and Atlantic Canada. In 1909, 65,000 people celebrated the 300th anniversary of the French discovery of the lake. Attending dignitaries included President William Howard Taft, along with representatives from France, Canada and the United Kingdom. In 1929, then-New York Governor Franklin Roosevelt and Vermont Governor John Weeks dedicated the first bridge to span the lake, built from Crown Point to Chimney Point. This bridge lasted until December, 2009. Severe deterioration was found, and the bridge was demolished and replaced with the Lake Champlain Bridge, which opened in November, 2011. On February 19, 1932, boats were able to sail on Lake Champlain. It was the first time that the lake was known to be free of ice during the winter at that time. Lake Champlain briefly became the nation's sixth Great Lake on March 6, 1998, when President Clinton signed Senate Bill 927. This bill, which was led by U.S. Senator Patrick Leahy of Vermont and reauthorized the National Sea Grant Program, contained a line declaring Lake Champlain to be a Great Lake. This status enabled its neighboring states to apply for additional federal research and education funds allocated to these national resources. However, following a small uproar, the Great Lake status was rescinded on March 24 (although New York and Vermont universities continue to receive funds to monitor and study the lake). "Champ", Lake Champlain monster In 1609, Samuel de Champlain wrote that he saw a lake monster long, as thick as a man's thigh, with silver-gray scales a dagger could not penetrate. The alleged monster had jaws with sharp and dangerous teeth. Native Americans claimed to have seen similar monsters long. This mysterious creature is likely the original Lake Champlain monster. The monster has been memorialized in sports teams' names and mascots, i.e., the Vermont Lake Monsters and Champ, the mascot of the state's minor league baseball team. A Vermont Historical Society publication recounts the story and offers possible explanations for accounts of the so-called monster: "floating logs, schools of large sturgeon diving in a row, or flocks of blackbirds flying close to the water". Ecology A pollution prevention, control and restoration plan for Lake Champlain was first endorsed in October, 1996 by the governors of New York and Vermont and the regional administrators of the United States Environmental Protection Agency (EPA). In April, 2003, the plan was updated, and Quebec signed-on to it. The plan is being implemented by the Lake Champlain Basin Program and its partners at the state, provincial, federal and local levels. Renowned as a model for interstate and international cooperation, its primary goals are to reduce phosphorus inputs to Lake Champlain, reduce toxic contamination, minimize the risks to humans from water-related health hazards and control the introduction, spread, and impact of non-native nuisance species to preserve the integrity of the Lake Champlain ecosystem. Senior staff who helped organize the Environmental Protection Agency in 1970 recall that International Paper was one of the first companies to call upon the brand-new agency, because it was being pressured by both New York and Vermont with regard to a discharge of pollution into Lake Champlain. Agricultural and urban runoff
|
equivalences: two expressions are α-equivalent, if they can be α-converted into the same expression. β-equivalence and η-equivalence are defined similarly. The term redex, short for reducible expression, refers to subterms that can be reduced by one of the reduction rules. For example, (λx.M) N is a β-redex in expressing the substitution of N for x in M. The expression to which a redex reduces is called its reduct; the reduct of (λx.M) N is M[x := N]. If x is not free in M, λx.M x is also an η-redex, with a reduct of M. α-conversion α-conversion, sometimes known as α-renaming, allows bound variable names to be changed. For example, α-conversion of λx.x might yield λy.y. Terms that differ only by α-conversion are called α-equivalent. Frequently, in uses of lambda calculus, α-equivalent terms are considered to be equivalent. The precise rules for α-conversion are not completely trivial. First, when α-converting an abstraction, the only variable occurrences that are renamed are those that are bound to the same abstraction. For example, an α-conversion of λx.λx.x could result in λy.λx.x, but it could not result in λy.λx.y. The latter has a different meaning from the original. This is analogous to the programming notion of variable shadowing. Second, α-conversion is not possible if it would result in a variable getting captured by a different abstraction. For example, if we replace x with y in λx.λy.x, we get λy.λy.y, which is not at all the same. In programming languages with static scope, α-conversion can be used to make name resolution simpler by ensuring that no variable name masks a name in a containing scope (see α-renaming to make name resolution trivial). In the De Bruijn index notation, any two α-equivalent terms are syntactically identical. Substitution Substitution, written M[V := N], is the process of replacing all free occurrences of the variable V in the expression M with expression N. Substitution on terms of the lambda calculus is defined by recursion on the structure of terms, as follows (note: x and y are only variables while M and N are any lambda expression): x[x := N] = N y[x := N] = y, if x ≠ y (M1 M2)[x := N] = M1[x := N] M2[x := N] (λx.M)[x := N] = λx.M (λy.M)[x := N] = λy.(M[x := N]), if x ≠ y and y ∉ FV(N) To substitute into an abstraction, it is sometimes necessary to α-convert the expression. For example, it is not correct for (λx.y)[y := x] to result in λx.x, because the substituted x was supposed to be free but ended up being bound. The correct substitution in this case is λz.x, up to α-equivalence. Substitution is defined uniquely up to α-equivalence. β-reduction β-reduction captures the idea of function application. β-reduction is defined in terms of substitution: the β-reduction of (λV.M) N is M[V := N]. For example, assuming some encoding of 2, 7, ×, we have the following β-reduction: (λn.n × 2) 7 → 7 × 2. β-reduction can be seen to be the same as the concept of local reducibility in natural deduction, via the Curry–Howard isomorphism. η-reduction η-reduction expresses the idea of extensionality, which in this context is that two functions are the same if and only if they give the same result for all arguments. η-reduction converts between λx.f x and f whenever x does not appear free in f. η-reduction can be seen to be the same as the concept of local completeness in natural deduction, via the Curry–Howard isomorphism. Normal forms and confluence For the untyped lambda calculus, β-reduction as a rewriting rule is neither strongly normalising nor weakly normalising. However, it can be shown that β-reduction is confluent when working up to α-conversion (i.e. we consider two normal forms to be equal if it is possible to α-convert one into the other). Therefore, both strongly normalising terms and weakly normalising terms have a unique normal form. For strongly normalising terms, any reduction strategy is guaranteed to yield the normal form, whereas for weakly normalising terms, some reduction strategies may fail to find it. Encoding datatypes The basic lambda calculus may be used to model booleans, arithmetic, data structures and recursion, as illustrated in the following sub-sections. Arithmetic in lambda calculus There are several possible ways to define the natural numbers in lambda calculus, but by far the most common are the Church numerals, which can be defined as follows: and so on. Or using the alternative syntax presented above in Notation: A Church numeral is a higher-order function—it takes a single-argument function , and returns another single-argument function. The Church numeral is a function that takes a function as argument and returns the -th composition of , i.e. the function composed with itself times. This is denoted and is in fact the -th power of (considered as an operator); is defined to be the identity function. Such repeated compositions (of a single function ) obey the laws of exponents, which is why these numerals can be used for arithmetic. (In Church's original lambda calculus, the formal parameter of a lambda expression was required to occur at least once in the function body, which made the above definition of impossible.) One way of thinking about the Church numeral , which is often useful when analysing programs, is as an instruction 'repeat n times'. For example, using the and functions defined below, one can define a function that constructs a (linked) list of n elements all equal to x by repeating 'prepend another x element' n times, starting from an empty list. The lambda term is By varying what is being repeated, and varying what argument that function being repeated is applied to, a great many different effects can be achieved. We can define a successor function, which takes a Church numeral and returns by adding another application of , where '(mf)x' means the function 'f' is applied 'm' times on 'x': Because the -th composition of composed with the -th composition of gives the -th composition of , addition can be defined as follows: can be thought of as a function taking two natural numbers as arguments and returning a natural number; it can be verified that and are β-equivalent lambda expressions. Since adding to a number can be accomplished by adding 1 times, an alternative definition is: Similarly, multiplication can be defined as Alternatively since multiplying and is the same as repeating the add function times and then applying it to zero. Exponentiation has a rather simple rendering in Church numerals, namely The predecessor function defined by for a positive integer and is considerably more difficult. The formula can be validated by showing inductively that if T denotes , then for . Two other definitions of are given below, one using conditionals and the other using pairs. With the predecessor function, subtraction is straightforward. Defining , yields when and otherwise. Logic and predicates By convention, the following two definitions (known as Church booleans) are used for the boolean values and : (Note that is equivalent to the Church numeral zero defined above) Then, with these two lambda terms, we can define some logic operators (these are just possible formulations; other expressions are equally correct): We are now able to compute some logic functions, for example: and we see that is equivalent to . A predicate is a function that returns a boolean value. The most fundamental predicate is , which returns if its argument is the Church numeral , and if its argument is any other Church numeral: The following predicate tests whether the first argument is less-than-or-equal-to the second: , and since , if and , it is straightforward to build a predicate for numerical equality. The availability of predicates and the above definition of and make it convenient to write "if-then-else" expressions in lambda calculus. For example, the predecessor function can be defined as: which can be verified by showing inductively that is the add − 1 function for > 0. Pairs A pair (2-tuple) can be defined in terms of and , by using the Church encoding for pairs. For example, encapsulates the pair (,), returns the first element of the pair, and returns the second. A linked list can be defined as either NIL for the empty list, or the of an element and a smaller list. The predicate tests for the value . (Alternatively, with , the construct obviates the need for an explicit NULL test). As an example of the use of pairs, the shift-and-increment function that maps to can be defined as which allows us to give perhaps the most transparent version of the predecessor function: Additional programming techniques There is a considerable body of programming idioms for lambda calculus. Many of these were originally developed in the context of using lambda calculus as a foundation for programming language semantics, effectively using lambda calculus as a low-level programming language. Because several programming languages include the lambda calculus (or something very similar) as a fragment, these techniques also see use in practical programming, but may then be perceived as obscure or foreign. Named constants In lambda calculus, a library would take the form of a collection of previously defined functions, which as lambda-terms are merely particular constants. The pure lambda calculus does not have a concept of named constants since all atomic lambda-terms are variables, but one can emulate having named constants by setting aside a variable as the name of the constant, using abstraction to bind that variable in the main body, and apply that abstraction to the intended definition. Thus to use to mean M (some explicit lambda-term) in N (another lambda-term, the "main program"), one can say N M Authors often introduce syntactic sugar, such as , to permit writing the above in the more intuitive order MN By chaining such definitions, one can write a lambda calculus "program" as zero or more function definitions, followed by one lambda-term using those functions that constitutes the main body of the program. A notable restriction of this is that the name is not defined in M, since M is outside the scope of the abstraction binding ; this means a recursive function definition cannot be used as the M with . The more advanced syntactic sugar construction that allows writing recursive function definitions in that naive style instead additionally employs fixed-point combinators. Recursion and fixed points Recursion is the definition of a function using the function itself. Lambda calculus cannot express this as directly as some other notations: all functions are anonymous in lambda calculus, so we can't refer to a value which is yet to be defined, inside the lambda term defining that same value. However, recursion can still be achieved by arranging for a lambda expression to receive itself as its argument value, for example in . Consider the factorial function recursively defined by . In the lambda expression which is to represent this function, a parameter (typically the first one) will be assumed to receive the lambda expression itself as its value, so that calling it – applying it to an argument – will amount to recursion. Thus to achieve recursion, the intended-as-self-referencing argument (called here) must always be passed to itself within the function body, at a
|
need for an explicit NULL test). As an example of the use of pairs, the shift-and-increment function that maps to can be defined as which allows us to give perhaps the most transparent version of the predecessor function: Additional programming techniques There is a considerable body of programming idioms for lambda calculus. Many of these were originally developed in the context of using lambda calculus as a foundation for programming language semantics, effectively using lambda calculus as a low-level programming language. Because several programming languages include the lambda calculus (or something very similar) as a fragment, these techniques also see use in practical programming, but may then be perceived as obscure or foreign. Named constants In lambda calculus, a library would take the form of a collection of previously defined functions, which as lambda-terms are merely particular constants. The pure lambda calculus does not have a concept of named constants since all atomic lambda-terms are variables, but one can emulate having named constants by setting aside a variable as the name of the constant, using abstraction to bind that variable in the main body, and apply that abstraction to the intended definition. Thus to use to mean M (some explicit lambda-term) in N (another lambda-term, the "main program"), one can say N M Authors often introduce syntactic sugar, such as , to permit writing the above in the more intuitive order MN By chaining such definitions, one can write a lambda calculus "program" as zero or more function definitions, followed by one lambda-term using those functions that constitutes the main body of the program. A notable restriction of this is that the name is not defined in M, since M is outside the scope of the abstraction binding ; this means a recursive function definition cannot be used as the M with . The more advanced syntactic sugar construction that allows writing recursive function definitions in that naive style instead additionally employs fixed-point combinators. Recursion and fixed points Recursion is the definition of a function using the function itself. Lambda calculus cannot express this as directly as some other notations: all functions are anonymous in lambda calculus, so we can't refer to a value which is yet to be defined, inside the lambda term defining that same value. However, recursion can still be achieved by arranging for a lambda expression to receive itself as its argument value, for example in . Consider the factorial function recursively defined by . In the lambda expression which is to represent this function, a parameter (typically the first one) will be assumed to receive the lambda expression itself as its value, so that calling it – applying it to an argument – will amount to recursion. Thus to achieve recursion, the intended-as-self-referencing argument (called here) must always be passed to itself within the function body, at a call point: with to hold, so and The self-application achieves replication here, passing the function's lambda expression on to the next invocation as an argument value, making it available to be referenced and called there. This solves it but requires re-writing each recursive call as self-application. We would like to have a generic solution, without a need for any re-writes: with to hold, so and where so that Given a lambda term with first argument representing recursive call (e.g. here), the fixed-point combinator will return a self-replicating lambda expression representing the recursive function (here, ). The function does not need to be explicitly passed to itself at any point, for the self-replication is arranged in advance, when it is created, to be done each time it is called. Thus the original lambda expression is re-created inside itself, at call-point, achieving self-reference. In fact, there are many possible definitions for this operator, the simplest of them being: In the lambda calculus, is a fixed-point of , as it expands to: Now, to perform our recursive call to the factorial function, we would simply call , where n is the number we are calculating the factorial of. Given n = 4, for example, this gives: Every recursively defined function can be seen as a fixed point of some suitably defined function closing over the recursive call with an extra argument, and therefore, using , every recursively defined function can be expressed as a lambda expression. In particular, we can now cleanly define the subtraction, multiplication and comparison predicate of natural numbers recursively. Standard terms Certain terms have commonly accepted names: is the identity function. and form complete combinator calculus systems that can express any lambda term - see the next section. is , the smallest term that has no normal form. is standard and defined above. and defined above are commonly abbreviated as and . Abstraction elimination If N is a lambda-term without abstraction, but possibly containing named constants (combinators), then there exists a lambda-term T(,N) which is equivalent to N but lacks abstraction (except as part of the named constants, if these are considered non-atomic). This can also be viewed as anonymising variables, as T(,N) removes all occurrences of from N, while still allowing argument values to be substituted into the positions where N contains an . The conversion function T can be defined by: T(, ) := I T(, N) := K N if is not free in N. T(, M N) := S T(, M) T(, N) In either case, a term of the form T(,N) P can reduce by having the initial combinator I, K, or S grab the argument P, just like β-reduction of N P would do. I returns that argument. K throws the argument away, just like N would do if has no free occurrence in N. S passes the argument on to both subterms of the application, and then applies the result of the first to the result of the second. The combinators B and C are similar to S, but pass the argument on to only one subterm of an application (B to the "argument" subterm and C to the "function" subterm), thus saving a subsequent K if there is no occurrence of in one subterm. In comparison to B and C, the S combinator actually conflates two functionalities: rearranging arguments, and duplicating an argument so that it may be used in two places. The W combinator does only the latter, yielding the B, C, K, W system as an alternative to SKI combinator calculus. Typed lambda calculus A typed lambda calculus is a typed formalism that uses the lambda-symbol () to denote anonymous function abstraction. In this context, types are usually objects of a syntactic nature that are assigned to lambda terms; the exact nature of a type depends on the calculus considered (see Kinds of typed lambda calculi). From a certain point of view, typed lambda calculi can be seen as refinements of the untyped lambda calculus but from another point of view, they can also be considered the more fundamental theory and untyped lambda calculus a special case with only one type. Typed lambda calculi are foundational programming languages and are the base of typed functional programming languages such as ML and Haskell and, more indirectly, typed imperative programming languages. Typed lambda calculi play an important role in the design of type systems for programming languages; here typability usually captures desirable properties of the program, e.g. the program will not cause a memory access violation. Typed lambda calculi are closely related to mathematical logic and proof theory via the Curry–Howard isomorphism and they can be considered as the internal language of classes of categories, e.g. the simply typed lambda calculus is the language of Cartesian closed categories (CCCs). Reduction strategies Whether a term is normalising or not, and how much work needs to be done in normalising it if it is, depends to a large extent on the reduction strategy used. Common lambda calculus reduction strategies include: Normal order The leftmost, outermost redex is always reduced first. That is, whenever possible the arguments are substituted into the body of an abstraction before the arguments are reduced. Applicative order The leftmost, innermost redex is always reduced first. Intuitively this means a function's arguments are always reduced before the function itself. Applicative order always attempts to apply functions to normal forms, even when this is not possible. Full β-reductions Any redex can be reduced at any time. This means essentially the lack of any particular reduction strategy—with regard to reducibility, "all bets are off". Weak reduction strategies do not reduce under lambda abstractions: Call by value A redex is reduced only when its right hand side has reduced to a value (variable or abstraction). Only the outermost redexes are reduced. Call by name As normal order, but no reductions are performed inside abstractions. For example, is in normal form according to this strategy, although it contains the redex . Strategies with sharing reduce computations that are "the same" in parallel: Optimal reduction As normal order, but computations that have the same label are reduced simultaneously. Call by need As call by name (hence weak), but function applications that would duplicate terms instead name the argument, which is then reduced only "when it is needed". Computability There is no algorithm that takes as input any two lambda expressions and outputs or depending on whether one expression reduces to the other. More precisely, no computable function can decide the question. This was historically the first problem for which undecidability could be proven. As usual for such a proof, computable means computable by any model of computation that is Turing complete. In fact computability can itself be defined via the lambda calculus: a function F: N → N of natural numbers is a computable function if and only if there exists a lambda expression f such that for every pair of x, y in N, F(x)=y if and only if f =β , where and are the Church numerals corresponding to x and y, respectively and =β meaning equivalence with β-reduction. See the Church–Turing thesis for other approaches to defining computability and their equivalence. Church's proof of uncomputability first reduces the problem to determining whether a given lambda expression has a normal form. Then he assumes that this predicate is computable, and can hence be expressed in lambda calculus. Building on earlier work by Kleene and constructing a Gödel numbering for lambda expressions, he constructs a lambda expression that closely follows the proof of Gödel's first incompleteness theorem. If is applied to its own Gödel number, a contradiction results. Complexity The notion of computational complexity for the lambda calculus is a bit tricky, because the cost of a β-reduction may vary depending on how it is implemented. To be precise, one must somehow find the location of all of the occurrences of the bound variable in the expression , implying a time cost, or one must keep track of the locations of free variables in some way, implying a space cost. A naïve search for the locations of in is O(n) in the length n of . Director strings were an early approach that traded this time cost for a quadratic space usage. More generally this has led to the study of systems that use explicit substitution. In 2014 it was shown that the number of β-reduction steps taken by normal order reduction to reduce a term is a reasonable time cost model, that is, the reduction can be simulated on a Turing machine in time polynomially proportional to the number of steps. This was a long-standing open problem, due to size explosion, the existence of lambda terms which grow exponentially in size for each β-reduction. The result gets around this by working with a compact shared representation. The result makes clear that the amount of space needed to evaluate a lambda term is not proportional to the size of the term during reduction. It is not currently known what a good measure of space complexity would be. An unreasonable model does not necessarily mean inefficient. Optimal reduction reduces all computations with the same label in one step, avoiding duplicated work, but the number of parallel β-reduction steps to reduce a given term to normal form is approximately linear in the size of the term. This is far too small to be a reasonable cost measure, as any Turing machine may be encoded in the lambda calculus in size linearly proportional to the size of the Turing machine. The true cost of reducing lambda terms is not due to β-reduction per se but rather the handling of the duplication of redexes during β-reduction. It is not known if optimal reduction implementations are reasonable when measured with respect to a reasonable cost model such as the number of leftmost-outermost steps to normal form, but it has been shown for fragments of the lambda calculus that the optimal reduction algorithm is efficient and has at most a quadratic overhead compared to leftmost-outermost. In addition the BOHM prototype implementation of optimal reduction outperformed both Caml Light and Haskell on pure lambda terms. Lambda calculus and programming languages As pointed out by Peter Landin's 1965 paper "A Correspondence between ALGOL 60 and Church's Lambda-notation", sequential procedural programming languages can be understood in terms of the lambda calculus, which provides the basic mechanisms for procedural abstraction and procedure (subprogram) application. Anonymous functions For example, in Lisp the "square" function can be expressed as a lambda expression as follows: (lambda (x) (* x x)) The above example is an expression that evaluates to a first-class function. The symbol
|
video, and images), especially in applications such as streaming media and internet telephony. By contrast, lossless compression is typically required for text and data files, such as bank records and text articles. It can be advantageous to make a master lossless file which can then be used to produce additional copies from. This allows one to avoid basing new compressed copies off of a lossy source file, which would yield additional artifacts and further unnecessary information loss. Types It is possible to compress many types of digital data in a way that reduces the size of a computer file needed to store it, or the bandwidth needed to transmit it, with no loss of the full information contained in the original file. A picture, for example, is converted to a digital file by considering it to be an array of dots and specifying the color and brightness of each dot. If the picture contains an area of the same color, it can be compressed without loss by saying "200 red dots" instead of "red dot, red dot, ...(197 more times)..., red dot." The original data contains a certain amount of information, and there is a lower limit to the size of file that can carry all the information. Basic information theory says that there is an absolute limit in reducing the size of this data. When data is compressed, its entropy increases, and it cannot increase indefinitely. For example, a compressed ZIP file is smaller than its original, but repeatedly compressing the same file will not reduce the size to nothing. Most compression algorithms can recognize when further compression would be pointless and would in fact increase the size of the data. In many cases, files or data streams contain more information than is needed. For example, a picture may have more detail than the eye can distinguish when reproduced at the largest size intended; likewise, an audio file does not need a lot of fine detail during a very loud passage. Developing lossy compression techniques as closely matched to human perception as possible is a complex task. Sometimes the ideal is a file that provides exactly the same perception as the original, with as much digital information as possible removed; other times, perceptible loss of quality is considered a valid tradeoff. The terms "irreversible" and "reversible" are preferred over "lossy" and "lossless" respectively for some applications, such as medical image compression, to circumvent the negative implications of "loss". The type and amount of loss can affect the utility of the images. Artifacts or undesirable effects of compression may be clearly discernible yet the result still useful for the intended purpose. Or lossy compressed images may be 'visually lossless', or in the case of medical images, so-called Diagnostically Acceptable Irreversible Compression (DAIC) may have been applied. Transform coding Some forms of lossy compression can be thought of as an application of transform coding, which is a type of data compression used for digital images, digital audio signals, and digital video. The transformation is typically used to enable better (more targeted) quantization. Knowledge of the application is used to choose information to discard, thereby lowering its bandwidth. The remaining information can then be compressed via a variety of methods. When the output is decoded, the result may not be identical to the original input, but is expected to be close enough for the purpose of the application. The most common form of lossy compression is a transform coding method, the discrete cosine transform (DCT), which was first published by Nasir Ahmed, T. Natarajan and K. R. Rao in 1974. DCT is the most widely used form of lossy compression, for popular image compression formats (such as JPEG), video coding standards (such as MPEG and H.264/AVC) and audio compression formats (such as MP3 and AAC). In the case of audio data, a popular form of transform coding is perceptual coding, which transforms the raw data to a domain that more accurately reflects the information content. For example, rather than expressing a sound file as the amplitude levels over time, one may express it as the frequency spectrum over time, which corresponds more accurately to human audio perception. While data reduction (compression, be it lossy or lossless) is a main goal of transform coding, it also allows other goals: one may represent data more accurately for the original amount of space – for example, in principle, if one starts with an analog or high-resolution digital master, an MP3 file of a given size should provide a better representation than a raw uncompressed audio in WAV or AIFF file of the same size. This is because uncompressed audio can only reduce file size by lowering bit rate or depth, whereas compressing audio can reduce size while maintaining bit rate and depth. This compression becomes a selective loss of the least significant data, rather than losing data across the board. Further, a transform coding may provide a better domain for manipulating or otherwise editing the data – for example, equalization of audio is most naturally expressed in the frequency domain (boost the bass, for instance) rather than in the raw time domain. From this point of view, perceptual encoding is not essentially about discarding data, but rather about a better representation of data. Another use is for backward compatibility and graceful degradation: in color television, encoding color via a luminance-chrominance transform domain (such as YUV) means that black-and-white sets display the luminance, while ignoring the color information. Another example is chroma subsampling: the use of color spaces such as YIQ, used in NTSC, allow one to reduce the resolution on the components to accord with human perception – humans have highest resolution for black-and-white (luma), lower resolution for mid-spectrum colors like yellow and green, and lowest for red and blues – thus NTSC displays approximately 350 pixels of luma per scanline, 150 pixels of yellow vs. green, and 50 pixels of blue vs. red, which are proportional to human sensitivity to each component. Information loss Lossy compression formats suffer from generation loss: repeatedly compressing and decompressing the file will cause it to progressively lose quality. This is in contrast with lossless data compression, where data will not be lost via the use of such a procedure. Information-theoretical foundations for lossy data compression are provided by rate-distortion theory. Much like the use of probability in optimal coding theory, rate-distortion theory heavily draws on Bayesian estimation and decision theory in order to model perceptual distortion and even aesthetic
|
lossy compression algorithm is the discrete cosine transform (DCT), first published by Nasir Ahmed, T. Natarajan and K. R. Rao in 1974. In 2019 a new family of sinusoidal-hyperbolic transform functions, which have comparable properties and performance with DCT, were proposed for lossy compression. Lossy compression is most commonly used to compress multimedia data (audio, video, and images), especially in applications such as streaming media and internet telephony. By contrast, lossless compression is typically required for text and data files, such as bank records and text articles. It can be advantageous to make a master lossless file which can then be used to produce additional copies from. This allows one to avoid basing new compressed copies off of a lossy source file, which would yield additional artifacts and further unnecessary information loss. Types It is possible to compress many types of digital data in a way that reduces the size of a computer file needed to store it, or the bandwidth needed to transmit it, with no loss of the full information contained in the original file. A picture, for example, is converted to a digital file by considering it to be an array of dots and specifying the color and brightness of each dot. If the picture contains an area of the same color, it can be compressed without loss by saying "200 red dots" instead of "red dot, red dot, ...(197 more times)..., red dot." The original data contains a certain amount of information, and there is a lower limit to the size of file that can carry all the information. Basic information theory says that there is an absolute limit in reducing the size of this data. When data is compressed, its entropy increases, and it cannot increase indefinitely. For example, a compressed ZIP file is smaller than its original, but repeatedly compressing the same file will not reduce the size to nothing. Most compression algorithms can recognize when further compression would be pointless and would in fact increase the size of the data. In many cases, files or data streams contain more information than is needed. For example, a picture may have more detail than the eye can distinguish when reproduced at the largest size intended; likewise, an audio file does not need a lot of fine detail during a very loud passage. Developing lossy compression techniques as closely matched to human perception as possible is a complex task. Sometimes the ideal is a file that provides exactly the same perception as the original, with as much digital information as possible removed; other times, perceptible loss of quality is considered a valid tradeoff. The terms "irreversible" and "reversible" are preferred over "lossy" and "lossless" respectively for some applications, such as medical image compression, to circumvent the negative implications of "loss". The type and amount of loss can affect the utility of the images. Artifacts or undesirable effects of compression may be clearly discernible yet the result still useful for the intended purpose. Or lossy compressed images may be 'visually lossless', or in the case of medical images, so-called Diagnostically Acceptable Irreversible Compression (DAIC) may have been applied. Transform coding Some forms of lossy compression can be thought of as an application of transform coding, which is a type of data compression used for digital images, digital audio signals, and digital video. The transformation is typically used to enable better (more targeted) quantization. Knowledge of the application is used to choose information to discard, thereby lowering its bandwidth. The remaining information can then be compressed via a variety of methods. When the output is decoded, the result may not be identical to the original input, but is expected to be close enough for the purpose of the application. The most common form of lossy compression is a transform coding method, the discrete cosine transform (DCT), which was first published by Nasir Ahmed, T. Natarajan and K. R. Rao in 1974. DCT is the most widely used form of lossy compression, for popular image compression formats (such as JPEG), video coding standards (such as MPEG and H.264/AVC) and audio compression formats (such as MP3 and AAC). In the case of audio data, a popular form of transform coding is perceptual coding, which transforms the raw data to a domain that more accurately reflects the information content. For example, rather than expressing a sound file as the amplitude levels over time, one may express it as the frequency spectrum over time, which corresponds more accurately to human audio perception. While data reduction (compression, be it lossy or lossless) is a main goal of transform coding, it also allows other goals: one may represent data more accurately for the original amount of space – for example, in principle, if one starts with an analog or high-resolution digital master, an MP3 file of a given size should provide a better representation than a raw uncompressed audio in WAV or AIFF file of the same size. This is because uncompressed audio can only reduce file size by lowering bit rate or depth, whereas compressing audio can reduce size while maintaining bit rate and depth. This compression becomes a selective loss of the least significant data, rather than losing data across the board. Further, a transform coding may provide a better domain for manipulating or otherwise editing the data – for example, equalization of audio is most naturally expressed in the frequency domain (boost the bass, for instance) rather than in the raw time domain. From this point of view, perceptual encoding is not essentially about discarding data, but rather about a better representation of data. Another use is for backward compatibility and graceful degradation: in color television, encoding color via a luminance-chrominance transform domain (such as YUV) means that black-and-white sets display the luminance, while ignoring the color information. Another example is chroma subsampling: the use of color spaces such as YIQ, used in NTSC, allow one to reduce the resolution on the components to accord with human perception – humans have highest resolution for black-and-white (luma), lower resolution for mid-spectrum colors like yellow and green, and lowest for red and blues – thus NTSC displays approximately 350 pixels of luma per scanline, 150 pixels of yellow vs. green, and 50 pixels of blue vs. red, which are proportional to human sensitivity to each component. Information loss Lossy compression formats suffer from generation loss: repeatedly compressing and decompressing the file will cause it to progressively lose quality. This is in contrast with lossless data compression, where data will not be lost via the use of such a procedure. Information-theoretical foundations for lossy data compression are provided by rate-distortion theory. Much like the use of probability in optimal coding theory, rate-distortion theory heavily draws on Bayesian estimation and decision theory in order to model perceptual distortion and even aesthetic judgment. There are two basic lossy compression schemes: In lossy transform codecs, samples of picture or sound are taken, chopped into small segments, transformed into a new basis space, and quantized. The resulting quantized values are then entropy coded. In lossy predictive codecs, previous and/or subsequent decoded data is used to predict the current sound sample or image frame. The error between the predicted data and the real data, together with any extra information needed to reproduce the prediction, is then quantized and coded. In some systems the two techniques are combined, with transform codecs being used to compress the error signals generated by the predictive stage. Comparison The advantage of lossy methods over lossless methods is that in some cases a lossy method can produce a much smaller compressed file than any lossless method, while still meeting the requirements of the application. Lossy methods are most often used for compressing sound, images or videos. This is because these types of data are intended for human interpretation where the mind can easily "fill in the blanks" or see past very minor errors or inconsistencies – ideally lossy compression is transparent (imperceptible), which can be verified via an ABX test. Data files using lossy compression are smaller in size and thus cost less to store and to transmit over the Internet, a crucial consideration for streaming video services such as Netflix and streaming audio services such as Spotify. Emotional effects A study conducted by the Audio
|
Lossless (Windows Media Lossless) Raster graphics AVIF – AOMedia Video 1 Image File Format FLIF – Free Lossless Image Format HEIF – High Efficiency Image File Format (lossless or lossy compression, using HEVC) ILBM – (lossless RLE compression of Amiga IFF images) JBIG2 – (lossless or lossy compression of B&W images) JPEG 2000 – (includes lossless compression method via LeGall-Tabatabai 5/3 reversible integer wavelet transform) JPEG-LS – (lossless/near-lossless compression standard) JPEG XL – (lossless or lossy compression) JPEG XR – formerly WMPhoto and HD Photo, includes a lossless compression method LDCT – Lossless Discrete Cosine Transform PCX – PiCture eXchange PDF – Portable Document Format (lossless or lossy compression) PNG – Portable Network Graphics TGA – Truevision TGA TIFF – Tagged Image File Format (lossless or lossy compression) WebP – (lossless or lossy compression of RGB and RGBA images) 3D Graphics OpenCTM – Lossless compression of 3D triangle meshes Video See list of lossless video codecs Cryptography Cryptosystems often compress data (the "plaintext") before encryption for added security. When properly implemented, compression greatly increases the unicity distance by removing patterns that might facilitate cryptanalysis. However, many ordinary lossless compression algorithms produce headers, wrappers, tables, or other predictable output that might instead make cryptanalysis easier. Thus, cryptosystems must utilize compression algorithms whose output does not contain these predictable patterns. Genetics and Genomics Genetics compression algorithms (not to be confused with genetic algorithms) are the latest generation of lossless algorithms that compress data (typically sequences of nucleotides) using both conventional compression algorithms and specific algorithms adapted to genetic data. In 2012, a team of scientists from Johns Hopkins University published the first genetic compression algorithm that does not rely on external genetic databases for compression. HAPZIPPER was tailored for HapMap data and achieves over 20-fold compression (95% reduction in file size), providing 2- to 4-fold better compression much faster than leading general-purpose compression utilities. Genomic sequence compression algorithms, also known as DNA sequence compressors, explore the fact that DNA sequences have characteristic properties, such as inverted repeats. The most successful compressors are XM and GeCo. For eukaryotes XM is slightly better in compression ratio, though for sequences larger than 100 MB its computational requirements are impractical. Executables Self-extracting executables contain a compressed application and a decompressor. When executed, the decompressor transparently decompresses and runs the original application. This is especially often used in demo coding, where competitions are held for demos with strict size limits, as small as 1k. This type of compression is not strictly limited to binary executables, but can also be applied to scripts, such as JavaScript. Lossless compression benchmarks Lossless compression algorithms and their implementations are routinely tested in head-to-head benchmarks. There are a number of better-known compression benchmarks. Some benchmarks cover only the data compression ratio, so winners in these benchmarks may be unsuitable for everyday use due to the slow speed of the top performers. Another drawback of some benchmarks is that their data files are known, so some program writers may optimize their programs for best performance on a particular data set. The winners on these benchmarks often come from the class of context-mixing compression software. Matt Mahoney, in his February 2010 edition of the free booklet Data Compression Explained, additionally lists the following: The Calgary Corpus dating back to 1987 is no longer widely used due to its small size. Matt Mahoney maintained the Calgary Compression Challenge, created and maintained from May 21, 1996, through May 21, 2016, by Leonid A. Broukhis. The Large Text Compression Benchmark and the similar Hutter Prize both use a trimmed Wikipedia XML UTF-8 data set. The Generic Compression Benchmark, maintained by Matt Mahoney, tests compression of data generated by random Turing machines. Sami Runsas (the author of NanoZip) maintained Compression Ratings, a benchmark similar to Maximum Compression multiple file test, but with minimum speed requirements. It offered the calculator that allowed the user to weight the importance of speed and compression ratio. The top programs were fairly different due to the speed requirement. In January 2010, the top program was NanoZip followed by FreeArc, CCM, flashzip, and 7-Zip. The Monster of Compression benchmark by Nania Francesco Antonio tested compression on 1Gb of public data with a 40-minute time limit. In December 2009, the top ranked archiver was NanoZip 0.07a and the top ranked single file compressor was ccmx 1.30c. The Compression Ratings website published a chart summary of the "frontier" in compression ratio and time. The Compression Analysis Tool is a Windows application that enables end users to benchmark the performance characteristics of streaming implementations of LZF4, Deflate, ZLIB, GZIP, BZIP2 and LZMA using their own data. It produces measurements and charts with which users can compare the compression speed, decompression speed and compression ratio of the different compression methods and to examine how the compression level, buffer size and flushing operations affect the results. Limitations Lossless data compression algorithms (that do not attach compression id labels to their output data sets) cannot guarantee compression for all input data sets. In other words, for any lossless data compression algorithm, there will be an input data set that does not get smaller when processed by the algorithm, and for any lossless data compression algorithm that makes at least one file smaller, there will be at least one file that it makes larger. This is easily proven with elementary mathematics using a counting argument called the pigeonhole principle, as follows: Assume that each file is represented as a string of bits of some arbitrary length. Suppose that there is a compression algorithm that transforms every file into an output file that is no longer than the original file, and that at least one file will be compressed into an output file that is shorter than the original file. Let M be the least number such that there is a file F with length M bits that compresses to something shorter. Let N be the length (in bits) of the compressed version of F. Because N<M, every file of length N keeps its size during compression. There are 2N such files possible. Together with F, this makes 2N+1 files that all compress into one of the 2N files of length N. But 2N is smaller than 2N+1, so by the pigeonhole principle there must be some file of length N that is simultaneously the output of the compression function on two different inputs. That file cannot be decompressed reliably (which of the two originals should that yield?), which contradicts the assumption that the algorithm was lossless. We must therefore conclude that our original hypothesis (that the compression function makes no file longer) is necessarily untrue. Most practical compression algorithms provide an "escape" facility that can turn off the normal coding for files that would become longer by being encoded. In theory, only a single additional bit is required to tell the decoder that the normal coding has been turned off for the entire input; however, most encoding algorithms use at least one full byte (and typically more than one) for this purpose. For example, deflate compressed files never need to grow by more than 5 bytes per 65,535 bytes of input. In fact, if we consider files of length N, if all files were equally probable, then for any lossless compression that reduces the size of some file, the expected length of a compressed file (averaged over all possible files of length N) must necessarily be greater than N. So if we know nothing about the properties of the data we are compressing, we might as well not compress it at all. A lossless compression algorithm is useful only when we are more likely to compress certain types of files than others; then the algorithm could be designed to compress those types of data better. Thus, the main lesson from the argument is not that one risks big losses, but merely that one cannot always win. To choose an algorithm always means implicitly to select a subset of all files that will become usefully shorter. This is the theoretical reason why we need to have different compression algorithms for different kinds of files: there cannot be any algorithm that is good for all kinds of data. The "trick" that allows lossless compression algorithms, used on the type of data they were designed for, to consistently compress such files to a shorter form is that the files the algorithms are designed to act on all have some form of easily modeled redundancy that the algorithm is designed to remove, and thus belong to the subset of files that that algorithm can make shorter, whereas other files would not get compressed or even get bigger. Algorithms are generally quite specifically tuned to a particular type of file: for example, lossless audio compression programs do not work well on text files, and vice versa. In particular, files of random data cannot be consistently compressed by any conceivable lossless data compression algorithm; indeed, this result is used to define the concept of randomness in Kolmogorov complexity. It is provably impossible
|
then this model is stored with the compressed data. This approach is simple and modular, but has the disadvantage that the model itself can be expensive to store, and also that it forces using a single model for all data being compressed, and so performs poorly on files that contain heterogeneous data. Adaptive models dynamically update the model as the data is compressed. Both the encoder and decoder begin with a trivial model, yielding poor compression of initial data, but as they learn more about the data, performance improves. Most popular types of compression used in practice now use adaptive coders. Lossless compression methods may be categorized according to the type of data they are designed to compress. While, in principle, any general-purpose lossless compression algorithm (general-purpose meaning that they can accept any bitstring) can be used on any type of data, many are unable to achieve significant compression on data that are not of the form for which they were designed to compress. Many of the lossless compression techniques used for text also work reasonably well for indexed images. Multimedia These techniques take advantage of the specific characteristics of images such as the common phenomenon of contiguous 2-D areas of similar tones. Every pixel but the first is replaced by the difference to its left neighbor. This leads to small values having a much higher probability than large values. This is often also applied to sound files, and can compress files that contain mostly low frequencies and low volumes. For images, this step can be repeated by taking the difference to the top pixel, and then in videos, the difference to the pixel in the next frame can be taken. A hierarchical version of this technique takes neighboring pairs of data points, stores their difference and sum, and on a higher level with lower resolution continues with the sums. This is called discrete wavelet transform. JPEG2000 additionally uses data points from other pairs and multiplication factors to mix them into the difference. These factors must be integers, so that the result is an integer under all circumstances. So the values are increased, increasing file size, but hopefully the distribution of values is more peaked. The adaptive encoding uses the probabilities from the previous sample in sound encoding, from the left and upper pixel in image encoding, and additionally from the previous frame in video encoding. In the wavelet transformation, the probabilities are also passed through the hierarchy. Historical legal issues Many of these methods are implemented in open-source and proprietary tools, particularly LZW and its variants. Some algorithms are patented in the United States and other countries and their legal usage requires licensing by the patent holder. Because of patents on certain kinds of LZW compression, and in particular licensing practices by patent holder Unisys that many developers considered abusive, some open source proponents encouraged people to avoid using the Graphics Interchange Format (GIF) for compressing still image files in favor of Portable Network Graphics (PNG), which combines the LZ77-based deflate algorithm with a selection of domain-specific prediction filters. However, the patents on LZW expired on June 20, 2003. Many of the lossless compression techniques used for text also work reasonably well for indexed images, but there are other techniques that do not work for typical text that are useful for some images (particularly simple bitmaps), and other techniques that take advantage of the specific characteristics of images (such as the common phenomenon of contiguous 2-D areas of similar tones, and the fact that color images usually have a preponderance of a limited range of colors out of those representable in the color space). As mentioned previously, lossless sound compression is a somewhat specialized area. Lossless sound compression algorithms can take advantage of the repeating patterns shown by the wave-like nature of the data – essentially using autoregressive models to predict the "next" value and encoding the (hopefully small) difference between the expected value and the actual data. If the difference between the predicted and the actual data (called the error) tends to be small, then certain difference values (like 0, +1, −1 etc. on sample values) become very frequent, which can be exploited by encoding them in few output bits. It is sometimes beneficial to compress only the differences between two versions of a file (or, in video compression, of successive images within a sequence). This is called delta encoding (from the Greek letter Δ, which in mathematics, denotes a difference), but the term is typically only used if both versions are meaningful outside compression and decompression. For example, while the process of compressing the error in the above-mentioned lossless audio compression scheme could be described as delta encoding from the approximated sound wave to the original sound wave, the approximated version of the sound wave is not meaningful in any other context. Lossless compression methods No lossless compression algorithm can efficiently compress all possible data (see the section Limitations below for details). For this reason, many different algorithms exist that are designed either with a specific type of input data in mind or with specific assumptions about what kinds of redundancy the uncompressed data are likely to contain. Some of the most common lossless compression algorithms are listed below. General purpose Run-length encoding (RLE) – Simple scheme that provides good compression of data containing many runs of the same value Huffman coding – Entropy encoding, pairs well with other algorithms Arithmetic coding – Entropy encoding ANS – Entropy encoding, used by LZFSE and Zstandard Lempel-Ziv compression (LZ77 and LZ78) – Dictionary-based algorithm that forms the basis for many other algorithms Lempel–Ziv–Storer–Szymanski (LZSS) – Used by WinRAR in tandem with Huffman coding Deflate – Combines LZSS compression with Huffman coding, used by ZIP, gzip, and PNG images Lempel–Ziv–Welch (LZW) – Used by GIF images and Unix's compress utility Lempel–Ziv–Markov chain algorithm (LZMA) – Very high compression ratio, used by 7zip and xz Burrows–Wheeler transform reversible transform for making textual data more compressible, used by bzip2 Prediction by partial matching (PPM) – Optimized for compressing plain text Audio Apple Lossless (ALAC – Apple Lossless Audio Codec) Adaptive Transform Acoustic Coding (ATRAC) Audio Lossless Coding (also known as MPEG-4 ALS) Direct Stream Transfer (DST) Dolby TrueHD DTS-HD Master Audio Free Lossless Audio Codec (FLAC) Meridian Lossless Packing (MLP) Monkey's Audio (Monkey's Audio APE) MPEG-4 SLS (also known as HD-AAC) OptimFROG Original Sound Quality (OSQ) RealPlayer (RealAudio Lossless) Shorten (SHN) TTA (True Audio Lossless) WavPack (WavPack lossless) WMA Lossless (Windows Media Lossless) Raster graphics AVIF – AOMedia Video 1 Image File Format FLIF – Free Lossless Image Format HEIF – High Efficiency Image File Format (lossless or lossy compression, using HEVC) ILBM
|
efficient version of a Dyson sphere, which could produce the effect of surface gravity through rotation. Given that spinning a Dyson sphere would result in the atmosphere pooling around the equator, the Ringworld removes all the extraneous parts of the structure, leaving a spinning band landscaped on the sun-facing side, with the atmosphere and inhabitants kept in place through centrifugal force and high perimeter walls (rim walls). After publication of Ringworld two friends, Dan Alderson and Ctein, told Niven that the Ringworld was dynamically unstable: if the center of rotation drifts away from the central sun, gravitational forces will not "re-center" it, thus allowing the ring to eventually contact the sun and be destroyed. Niven used this as a core plot element in the sequel novel, The Ringworld Engineers. This idea proved influential, serving as an alternative to a full Dyson sphere that required fewer assumptions (such as artificial gravity) and allowed a day/night cycle to be introduced (through the use of a smaller ring of "shadow squares", rotating between the ring and its sun). This was further developed by Iain M. Banks in his Culture series, which features about ringworld–size megastructures called Orbitals that orbit a star rather than encircling it entirely (actual "Rings" and Dyson "Spheres" are also mentioned but are much rarer). Alastair Reynolds also uses ringworlds in his 2008 novel House of Suns. The Ringworld-like namesake of the Halo video game series is the eponymous Halo megastructure/superweapon. In the Magic: The Gathering trading card game, the card Nevinyrral's Disk uses his name, spelled backwards. This tribute was paid because the game's system where mana from lands is used to power spells was inspired by his book The Magic Goes Away. The card Nevinyrral, Urborg Tyrant was added in Commander Legends, adding the Niven's namesake character fully to the game. Politics According to author Michael Moorcock, in 1967, Niven was among those Science Fiction Writers of America members who voiced opposition to the Vietnam War. However, in 1968 Niven's name appeared in a prowar advertisement in Galaxy Science Fiction. Niven was an adviser to Ronald Reagan on the creation of the Strategic Defense Initiative antimissile policy, as part of the Citizens' Advisory Council on National Space Policy—as covered in the BBC documentary Pandora's Box by Adam Curtis. In 2007, Niven, in conjunction with a think tank of science fiction writers known as SIGMA, founded and led by Dr. Arlan Andrews, Sr., began advising the U.S. Department of Homeland Security as to future trends affecting terror policy and other topics. Among those topics was reducing costs for hospitals to which Niven offered the solution to spread rumors in Latino communities that organs were being harvested illegally in hospitals. Niven's laws Larry Niven is also known in science fiction fandom for "Niven's Law": "There is no cause so right that one cannot find a fool following it." Over the course of his career Niven has added to this first law a list of Niven's Laws which he describes as "how the Universe works" as far as he can tell. Bibliography References External links Bibliography and works with bibliography Larry Niven at Fantastic Fiction Interviews Audio interview with Larry Niven 1938 births 20th-century American novelists 21st-century American novelists Activists from California American agnostics American anti–Vietnam War activists American comics writers American male novelists American science fiction writers Filkers Hugo Award-winning writers Inkpot Award winners Living people People from Los Angeles Nebula Award winners SFWA Grand Masters Writers from Los Angeles 20th-century American male
|
stories, The Flight of the Horse, and a novel, Rainbow Mars, which involve a nominal time machine sent back to retrieve long-extinct animals, but which travels, in fact, into alternative realities and brings back mythical creatures such as a roc and a unicorn. Much of his writing since the 1970s has been in collaboration, particularly with Jerry Pournelle and Steven Barnes, but also Brenda Cooper and Edward M. Lerner. Other works One of Niven's best known humorous works is "Man of Steel, Woman of Kleenex", in which he uses real-world physics to underline the difficulties of Superman and a human woman (Lois Lane or Lana Lang) mating. Influence In Niven's novel Ringworld, he envisions a Ringworld: a band of material, roughly a million miles wide, of approximately the same diameter as Earth's orbit, rotating around a star. The idea originated in Niven's attempts to imagine a more efficient version of a Dyson sphere, which could produce the effect of surface gravity through rotation. Given that spinning a Dyson sphere would result in the atmosphere pooling around the equator, the Ringworld removes all the extraneous parts of the structure, leaving a spinning band landscaped on the sun-facing side, with the atmosphere and inhabitants kept in place through centrifugal force and high perimeter walls (rim walls). After publication of Ringworld two friends, Dan Alderson and Ctein, told Niven that the Ringworld was dynamically unstable: if the center of rotation drifts away from the central sun, gravitational forces will not "re-center" it, thus allowing the ring to eventually contact the sun and be destroyed. Niven used this as a core plot element in the sequel novel, The Ringworld Engineers. This idea proved influential, serving as an alternative to a full Dyson sphere that required fewer assumptions (such as artificial gravity) and allowed a day/night cycle to be introduced (through the use of a smaller ring of "shadow squares", rotating between the ring and its sun). This was further developed by Iain M. Banks in his Culture series, which features about ringworld–size megastructures called Orbitals that orbit a star rather than encircling it entirely (actual "Rings" and Dyson "Spheres" are also mentioned but are much rarer). Alastair Reynolds also uses ringworlds in his 2008 novel House of Suns. The Ringworld-like namesake of the Halo video game series is the eponymous Halo megastructure/superweapon. In the Magic: The Gathering trading card game, the card Nevinyrral's Disk uses his name, spelled backwards. This tribute was paid because the game's system where mana from lands is used to power spells was inspired by his book The Magic Goes Away. The card Nevinyrral, Urborg Tyrant was added in Commander Legends, adding the Niven's namesake character fully to the game. Politics According to author Michael Moorcock, in 1967, Niven was among those Science Fiction Writers of America members who voiced opposition to the Vietnam War. However, in 1968 Niven's name appeared in a prowar advertisement in Galaxy Science Fiction. Niven was an adviser to Ronald Reagan on the creation of the Strategic Defense Initiative antimissile policy, as part of the Citizens' Advisory Council on National Space Policy—as covered in the BBC documentary Pandora's Box by Adam Curtis. In 2007, Niven, in conjunction with a think tank of science fiction writers known as SIGMA, founded and led by Dr. Arlan Andrews, Sr., began advising the
|
the first binaries until the system is self-hosting. This can be done via compilation on another system capable of building binaries for the intended target (possibly by cross-compilation). For example, see Linux From Scratch. Types and trends In broad terms, Linux distributions may be: Commercial or non-commercial Designed for enterprise users, power users, or for home users Supported on multiple types of hardware, or platform-specific, even to the extent of certification by the platform vendor Designed for servers, desktops, or embedded devices General purpose or highly specialized toward specific machine functionalities (e.g. firewalls, network routers, and computer clusters) Targeted at specific user groups, for example through language internationalization and localization, or through inclusion of many music production or scientific computing packages Built primarily for security, usability, portability, or comprehensiveness Standard release or rolling release, see below. The diversity of Linux distributions is due to technical, organizational, and philosophical variation among vendors and users. The permissive licensing of free software means that users with sufficient knowledge and interest can customize any existing distribution, or design one to suit their own needs. Rolling distributions Rolling Linux distributions are kept updated using small and frequent updates. The terms partially rolling and partly rolling (along with synonyms semi-rolling and half-rolling), fully rolling, truly rolling and optionally rolling are sometimes used by software developers and users. Repositories of rolling distributions usually contain very recent software releases – often the latest stable software releases available. They have pseudo-releases and installation media that are simply a snapshot of the software distribution at the time of the release of the installation image. Typically, a rolling release operating system installed from an older installation medium can be fully updated post-installation to a current state. Depending on the use case, there can be pros and cons to both standard release and rolling release software development methodologies. In terms of the software development process, standard releases require significant development effort being spent on keeping old versions up to date due to propagating bug fixes back to the newest branch, versus focusing more on the newest development branch. Also, unlike rolling releases, standard releases require more than one code branch to be developed and maintained, which increases the software development and software maintenance workload of the software developers and software maintainers. On the other hand, software features and technology planning are easier in standard releases due to a better understanding of upcoming features in the next version(s). Software release cycles can also be synchronized with those of major upstream software projects, such as desktop environments. As far as the user experience, standard releases are often viewed as more stable and bug-free since software conflicts can be more easily addressed and the software stack more thoroughly tested and evaluated, during the software development cycle. For this reason, they tend to be the preferred choice in enterprise environments and mission-critical tasks. However, rolling releases offer more current software which can also provide increased stability and fewer software bugs along with the additional benefits of new features, greater functionality, faster running speeds, and improved system and application security. Regarding software security, the rolling release model can have advantages in timely security updates, fixing system or application security bugs and vulnerabilities, that standard releases may have to wait till the next release for or patch in various versions. In a rolling release distribution, where the user has chosen to run it as a highly dynamic system, the constant flux of software packages can introduce new unintended vulnerabilities. Installation-free distributions (live CD/USB) A "live" distribution is a Linux distribution that can be booted from removable storage media such as optical discs or USB flash drives, instead of being installed on and booted from a hard disk drive. The portability of installation-free distributions makes them advantageous for applications such as demonstrations, borrowing someone else's computer, rescue operations, or as installation media for a standard distribution. When the operating system is booted from a read-only medium such as a CD or DVD, any user data that needs to be retained between sessions cannot be stored on the boot device but must be written to another storage device, such as a USB flash drive or a hard disk drive. Many Linux distributions provide a "live" form in addition to their conventional form, which is a network-based or removable-media image intended to be used only for installation; such distributions include SUSE, Ubuntu, Linux Mint, MEPIS and Fedora Linux. Some distributions, including Knoppix, Puppy Linux, Devil-Linux, SuperGamer, SliTaz GNU/Linux and dyne:bolic, are designed primarily for live use. Additionally, some minimal distributions can be run directly from as little space as one floppy disk without the need to change the contents of the system's hard disk drive. Examples The website DistroWatch lists many Linux distributions, and displays some of the ones that have the most web traffic on the site. The Wikimedia Foundation released an analysis of the browser User Agents of visitors to WMF websites until 2015, which includes details of the most popular Operating System identifiers, including some Linux distributions. Many of the popular distributions are listed below. Widely used GNU-based or GNU-compatible distributions Debian, a non-commercial distribution and one of the earliest, maintained by a volunteer developer community with a strong commitment to free software principles and democratic project management. Knoppix, the first Live CD distribution to run completely from removable media without installation to a hard disk, derived from Debian. Linux Mint Debian Edition (LMDE) uses Debian packages directly (rather than Ubuntu's) Ubuntu, a desktop and server distribution derived from Debian, maintained by British company Canonical Ltd. There are several distributions based on Ubuntu that mainly replace the GNOME stock desktop environment, like: Kubuntu based on KDE, Lubuntu based on LXQT, Xubuntu based on XFCE, Ubuntu MATE based on MATE, Ubuntu Budgie based on Budgie. Other official forks have specific uses like: Ubuntu Kylin for Chinese-speaking users, or Ubuntu Studio for media content creators. Linux Mint, a distribution based on and compatible with Ubuntu. Supports multiple desktop environments, among others GNOME Shell fork Cinnamon and GNOME 2 fork MATE. Fedora Linux, a community distribution sponsored by American company Red Hat and the successor to the company's previous offering, Red Hat Linux. It aims to be a technology testbed for Red Hat's commercial Linux offering, where new open-source software is prototyped, developed, and tested in a communal setting before maturing into Red Hat Enterprise Linux. Red Hat Enterprise Linux (RHEL), a derivative of Fedora Linux, maintained and commercially supported by Red Hat. It seeks to provide tested, secure, and stable Linux server and workstation support to businesses. CentOS, a distribution derived from the same sources used by Red Hat, maintained by a dedicated volunteer community of developers with both 100% Red Hat-compatible versions and an upgraded version that is not always 100% upstream compatible. Oracle Linux, which is a derivative of Red Hat Enterprise Linux, maintained and commercially supported by Oracle Mandriva Linux was a Red Hat Linux derivative popular in several European countries and Brazil, backed by the French company of the same name. After the company went bankrupt, it was superseded by OpenMandriva Lx, although a number of derivatives now have a larger user base. Mageia, a community fork of Mandriva Linux created in 2010 PCLinuxOS, a derivative of Mandriva, which grew from a group of packages into a community-spawned desktop distribution openSUSE, a community distribution mainly sponsored by German company SUSE. SUSE Linux Enterprise, derived from openSUSE, maintained and commercially supported by SUSE Arch Linux, a rolling release distribution targeted at experienced Linux users and maintained by a volunteer community, offers official binary packages and a wide range of unofficial user-submitted source packages. Packages are usually defined by a single PKGBUILD text file. Manjaro Linux, a derivative of Arch Linux that includes a graphical installer and other ease-of-use features for less experienced Linux users. Gentoo, a distribution targeted at power users, known for its FreeBSD Ports-like automated system for compiling applications from source code Slackware, created in 1993, one of the first Linux distributions and among the earliest still maintained, committed to remain highly Unix-like and easily modifiable by end users Linux kernel based operating
|
sessions cannot be stored on the boot device but must be written to another storage device, such as a USB flash drive or a hard disk drive. Many Linux distributions provide a "live" form in addition to their conventional form, which is a network-based or removable-media image intended to be used only for installation; such distributions include SUSE, Ubuntu, Linux Mint, MEPIS and Fedora Linux. Some distributions, including Knoppix, Puppy Linux, Devil-Linux, SuperGamer, SliTaz GNU/Linux and dyne:bolic, are designed primarily for live use. Additionally, some minimal distributions can be run directly from as little space as one floppy disk without the need to change the contents of the system's hard disk drive. Examples The website DistroWatch lists many Linux distributions, and displays some of the ones that have the most web traffic on the site. The Wikimedia Foundation released an analysis of the browser User Agents of visitors to WMF websites until 2015, which includes details of the most popular Operating System identifiers, including some Linux distributions. Many of the popular distributions are listed below. Widely used GNU-based or GNU-compatible distributions Debian, a non-commercial distribution and one of the earliest, maintained by a volunteer developer community with a strong commitment to free software principles and democratic project management. Knoppix, the first Live CD distribution to run completely from removable media without installation to a hard disk, derived from Debian. Linux Mint Debian Edition (LMDE) uses Debian packages directly (rather than Ubuntu's) Ubuntu, a desktop and server distribution derived from Debian, maintained by British company Canonical Ltd. There are several distributions based on Ubuntu that mainly replace the GNOME stock desktop environment, like: Kubuntu based on KDE, Lubuntu based on LXQT, Xubuntu based on XFCE, Ubuntu MATE based on MATE, Ubuntu Budgie based on Budgie. Other official forks have specific uses like: Ubuntu Kylin for Chinese-speaking users, or Ubuntu Studio for media content creators. Linux Mint, a distribution based on and compatible with Ubuntu. Supports multiple desktop environments, among others GNOME Shell fork Cinnamon and GNOME 2 fork MATE. Fedora Linux, a community distribution sponsored by American company Red Hat and the successor to the company's previous offering, Red Hat Linux. It aims to be a technology testbed for Red Hat's commercial Linux offering, where new open-source software is prototyped, developed, and tested in a communal setting before maturing into Red Hat Enterprise Linux. Red Hat Enterprise Linux (RHEL), a derivative of Fedora Linux, maintained and commercially supported by Red Hat. It seeks to provide tested, secure, and stable Linux server and workstation support to businesses. CentOS, a distribution derived from the same sources used by Red Hat, maintained by a dedicated volunteer community of developers with both 100% Red Hat-compatible versions and an upgraded version that is not always 100% upstream compatible. Oracle Linux, which is a derivative of Red Hat Enterprise Linux, maintained and commercially supported by Oracle Mandriva Linux was a Red Hat Linux derivative popular in several European countries and Brazil, backed by the French company of the same name. After the company went bankrupt, it was superseded by OpenMandriva Lx, although a number of derivatives now have a larger user base. Mageia, a community fork of Mandriva Linux created in 2010 PCLinuxOS, a derivative of Mandriva, which grew from a group of packages into a community-spawned desktop distribution openSUSE, a community distribution mainly sponsored by German company SUSE. SUSE Linux Enterprise, derived from openSUSE, maintained and commercially supported by SUSE Arch Linux, a rolling release distribution targeted at experienced Linux users and maintained by a volunteer community, offers official binary packages and a wide range of unofficial user-submitted source packages. Packages are usually defined by a single PKGBUILD text file. Manjaro Linux, a derivative of Arch Linux that includes a graphical installer and other ease-of-use features for less experienced Linux users. Gentoo, a distribution targeted at power users, known for its FreeBSD Ports-like automated system for compiling applications from source code Slackware, created in 1993, one of the first Linux distributions and among the earliest still maintained, committed to remain highly Unix-like and easily modifiable by end users Linux kernel based operating systems Android, Google's commercial operating system based on Android OSP that runs on many devices such as smart phones, smart TVs, set-top boxes. Chrome OS, Google's commercial operating system based on Chromium OS that only runs on Chromebooks, Chromeboxes and tablet computers. Like Android, it has the Google Play Store and other Google apps. Support for applications that require GNU compatibility is available through a virtual machine called Crostini and referred to by Google as Linux support, see Chromebook#Integration with Linux. Whether the above operating systems count as a "Linux distribution" is a controversial topic. They use the Linux kernel, so the Linux Foundation and Chris DiBona, Google's open-source chief, agree that Android is a Linux distribution; others, such as Google engineer Patrick Brady, disagree by noting the lack of support for many GNU tools in Android, including glibc. Other Linux kernel based operating systems include Cyanogenmod, its fork LineageOS, Android-x86 and recently Tizen, Mer/Sailfish OS and KaiOS. Lightweight distributions Lightweight Linux distributions are those that have been designed with support for older hardware in mind, allowing older hardware to still be used productively, or, for maximum possible speed in newer hardware by leaving more resources available for use by applications. Examples include Tiny Core Linux, Puppy Linux and Slitaz. Niche distributions Other distributions target specific niches, such as: Routers for example, targeted by the tiny embedded router distribution OpenWrt Internet of things for example, targeted by Ubuntu Core Home theater PCs for example, targeted by KnoppMyth, Kodi (former XBMC) and Mythbuntu Specific platforms for example, Raspberry Pi OS targets the Raspberry Pi platform Education examples are Edubuntu and Karoshi, server systems based on PCLinuxOS Scientific computer servers and workstations for example, targeted by Scientific Linux Digital audio workstations for music production for example, targeted by Ubuntu Studio Computer Security, digital forensics and penetration testing examples are Kali Linux and Parrot Security OS Privacy and anonymity for example, targeted by Tails, Whonix, Qubes, or FreedomBox Offline use for example, Endless OS Microsoft's Azure Sphere Interdistribution issues The Free Standards Group is an organization formed by major software and hardware vendors that aims to improve interoperability between different distributions. Among their proposed standards are the Linux Standard Base, which defines a common ABI and packaging system for Linux, and the Filesystem Hierarchy Standard which recommends a standard filenaming chart, notably the basic directory names found on the root of the tree of any Linux filesystem. Those standards, however, see limited use, even among the distributions developed by members of the organization. The diversity of Linux distributions means that not all software runs on all distributions, depending on what libraries and other system attributes are required. Packaged software and software repositories are usually specific to a particular distribution, though cross-installation is sometimes possible on closely related distributions. Tools for choosing a distribution The process of constantly switching between distributions is often referred to as "distro hopping". Virtual machines such as VirtualBox and VMware Workstation virtualize hardware allowing users to test live media on a virtual machine. Some websites like DistroWatch offer lists of distributions, and link to screenshots of operating systems as a way to get a first impression of various distributions. There are tools available to help people select an appropriate distribution, such as several versions of the Linux Distribution Chooser, and the universal package search tool whohas. There are easy ways to try out several Linux distributions before deciding on one: Multi Distro is a Live CD that contains nine space-saving distributions. Installation There are several ways to install a Linux distribution. The most common method of installing Linux is by booting from a live USB memory stick, which can be created by using a USB image writer application and the ISO image, which can be downloaded from the various Linux distribution websites. DVD disks, CD disks, network installations and even other hard drives can also be used as "installation media". In the 1990s Linux distributions were installed using sets of floppies but this has been abandoned by all major distributions. By the 2000s many distributions offered CD and DVD sets with the vital packages on the first disc and less important packages on later ones. Some distributions, such as Debian also enabled installation over a network after booting from either a set of floppies or a CD with only a small amount of data on it. New users tend to begin by partitioning a hard drive in order to keep their previously installed operating system. The Linux distribution can then be installed on its own separate partition without affecting previously saved data. In a Live CD setup, the computer boots the entire operating system from CD without first installing it on the computer's hard disk. Many distributions have a Live CD installer, where the computer boots the operating system from the disk, and it can then be installed on the computer's hard disk, providing a seamless transition from the OS running from the CD to the OS running from the hard disk. Both servers and personal computers that come with Linux already installed are available from vendors including Hewlett-Packard, Dell and System76. On embedded devices, Linux is typically held in the device's firmware and may or may not be consumer-accessible. Anaconda, one of the more popular installers, is used by Red Hat Enterprise Linux, Fedora (which uses the Fedora Media Writer) and other distributions to simplify the installation process. Debian, Ubuntu and many others use Debian-Installer. Installation via an existing operating system Some distributions let the user install Linux on top of their current system, such as WinLinux or coLinux. Linux is installed to the Windows hard disk partition, and can be started from inside Windows itself. Virtual machines (such as VirtualBox or VMware) also make it possible for Linux to be run inside another OS. The VM software simulates a separate computer onto which the Linux system is installed. After installation, the virtual machine can be booted as if it were an independent computer. Various tools are also available to perform full dual-boot installations from existing platforms without a CD, most notably: The (now deprecated) Wubi installer, which allows Windows users to download and install Ubuntu or its derivatives into a FAT32 or an NTFS partition without an installation CD, allowing users to easily dual boot between either operating system on the same hard drive without losing data. Replaced by Ubiquity. Win32-loader, which is in the process of being integrated in official Debian CDs/DVDs, and allows Windows users to install Debian without a CD, though it performs a network installation and thereby requires repartitioning UNetbootin, which allows Windows and Linux users to perform similar no-CD network installations for a wide variety of Linux distributions and additionally provides live USB creation support Proprietary software Some specific proprietary software products are not available in any form for Linux. As of September 2015, the Steam gaming service has 1,500 games available on Linux, compared to 2,323 games for Mac and 6,500 Windows games. Emulation and API-translation projects like Wine and CrossOver make it possible to run non-Linux-based software on Linux systems, either by emulating a proprietary operating system or by translating proprietary API calls (e.g., calls to Microsoft's Win32 or DirectX APIs) into native Linux API calls. A virtual machine can also be used to run a proprietary OS (like Microsoft Windows) on top of Linux. OEM contracts Computer hardware is usually sold with an operating system other than Linux already installed by the original equipment manufacturer (OEM). In the case of IBM PC compatibles the OS is usually Microsoft Windows; in the case of Apple Macintosh computers it has always been a version of Apple's OS, currently macOS; Sun Microsystems sold SPARC hardware with the Solaris installed; video game consoles such as the Xbox, PlayStation, and Wii each have their own proprietary OS. This limits Linux's market share: consumers are unaware that an alternative exists, they must make a conscious effort to use a different operating system, and they must either perform the actual installation themselves, or depend on support from a friend, relative, or computer professional. However, it is possible to buy hardware with Linux already installed. Lenovo, Hewlett-Packard, Dell, Affordy, Purism, Pine64 and System76 all sell general-purpose Linux laptops. Custom-order PC
|
attendance, attracting over 3.8 million fans. On March 28, 2008, the Dodgers set the world record for the largest attendance for a single baseball game during an exhibition game against the Boston Red Sox at the Los Angeles Memorial Coliseum in honor of the Dodgers' 50th anniversary, with 115,300 fans in attendance. In 2009, the Dodgers led the MLB in total attendance. The Dodger baseball cap is consistently in the top three in sales. Given the team's proximity to Hollywood, numerous celebrities can often be seen attending home games at Dodger Stadium. Celebrities such as co-owner Magic Johnson, Mary Hart, DaBaby, Larry King, Tiger Woods, Alyssa Milano, Shia LaBeouf, Lana Del Rey, Mila Kunis and Ashton Kutcher are known to frequently attend Dodger games, with some sitting at field box seats behind home plate where they sign autographs for fellow Dodger fans. Actor Bryan Cranston is a lifelong Dodger fan. Primarily, Dodgers fans are from their own location in southern California and also parts of southern Nevada. However, there are also numerous strong pockets of supporters in Mexico due to the impact of players such as Fernando Valenzuela or more recently; Julio Urias and the fanbase is ever present throughout Asian countries such as South Korea and Japan, and their away games throughout the US will usually attract substantial numbers of expats and traveling fans. Radio and television Vin Scully called Dodgers games from 1950 to 2016. His longtime partners were Jerry Doggett (1956–1987) and Ross Porter (1977–2004). In 1976, he was selected by Dodgers fans as the Most Memorable Personality (on the field or off) in the team's history. He is also a recipient of the Baseball Hall of Fame's Ford C. Frick Award for broadcasters (inducted in 1982). Unlike the modern style in which multiple sportscasters have an on-air conversation (usually with one functioning as play-by-play announcer and the other[s] as color commentator), Scully, Doggett and Porter generally called games solo, trading with each other inning-by-inning. In the 1980s and 1990s, Scully would call the entire radio broadcast except for the third and seventh inning, allowing the other Dodger commentators to broadcast an inning. When Doggett retired after the 1987 season, he was replaced by Hall-of-Fame Dodgers pitcher Don Drysdale, who previously broadcast games for the California Angels and Chicago White Sox. Drysdale died in his hotel room following a heart attack before a game in Montreal in 1993. This was a difficult broadcast for Scully and Porter who could not mention it on-air until Drysdale's family had been notified and the official announcement made. He was replaced by former Dodgers outfielder Rick Monday. Porter's tenure ended after the 2004 season, after which the format of play-by-play announcers and color commentators was installed, led by Monday and newcomer Charley Steiner. Scully, however, continued to announce solo. Scully called roughly 100 games per season (all home games and road games in California and Arizona) for both flagship radio station KLAC and on television for Spectrum SportsNet LA. Scully was simulcast for the first three innings of each of his appearances, then announced only for the TV audience. If Scully was calling the game, Steiner took over play-by-play on radio beginning with the fourth inning, with Monday as color commentator. If Scully was not calling the game, Steiner and Orel Hershiser called the entire game on television while Monday and Kevin Kennedy did the same on radio. In the event the Dodgers were in post-season play, Scully called the first three and last three innings of the radio broadcast alone and Steiner and Monday handled the middle innings. Vin Scully retired from calling games in 2016. His tenure with the Dodgers was the longest with any single sports team at 67 years. Youthful announcer Joe Davis was selected in 2017 by Dodgers management to handle play by play on television with Orel Hershiser as his colorman; when Davis is on assignment for Fox Sports' MLB and NFL broadcasts, Tim Neverett would fill in. The Dodgers also broadcast on radio in two other languages, Spanish and Korean. In Spanish, the play-by-play is voiced by another Frick Award winner, Jaime Jarrín, who has been with the Dodgers since 1959. The color analyst for some games is former Dodger pitcher Fernando Valenzuela, for whom Jarrin once translated post-game interviews. The Spanish-language radio flagship station is KTNQ. Meanwhile, the Dodgers' Korean broadcast began in 2013 through KMPC. Management Owner: Guggenheim Baseball Management Chairman/Controlling Partner: Mark Walter Partner: Earvin "Magic" Johnson Partner: Peter Guber Partner: Todd Boehly Partner: Billie Jean King Partner: Ilana Kloss Partner: Robert "Bobby" Patton, Jr. Partner: Alan Smolinisky Partner: Robert L. Plummer President/chief executive officer: Stan Kasten President of Baseball Operations: Andrew Friedman General Manager: Brandon Gomes Achievements Baseball Hall of Famers Ford C. Frick Award recipients Team captains Leo Durocher 1938–1941 Pee Wee Reese 1950–1958 Duke Snider 1962 Maury Wills 1963–1966 Davey Lopes 1978–1979 Retired numbers Koufax, Campanella, and Robinson were the first Dodgers to have their numbers retired, in a ceremony at Dodger Stadium on June 4, 1972. This was the year in which Koufax was inducted into the Baseball Hall of Fame; Robinson and Campanella were already Hall-of-Famers. Alston's number was retired in the year following his retirement as the Dodgers manager, six years before he was inducted into the Hall of Fame. Gilliam died suddenly in 1978 after a 28-year career with the Dodgers organization. The Dodgers retired his number two days after his death, prior to Game 1 of the 1978 World Series. As of 2018, he is the only non-Hall-of-Famer to have his number retired by the Dodgers (Alston's number was retired before he was elected to the Hall of Fame). Beginning in 1980, the Dodgers have retired the numbers of longtime Dodgers (Snider, Reese, Drysdale, Lasorda, and Sutton) during the seasons in which each was inducted into the Hall of Fame. In 1997, 50 years after he broke the color barrier and 25 years after the Dodgers retired his number, Robinson's No. 42 was retired throughout Major League Baseball. Robinson is the only major league baseball player to have this honor bestowed upon him. Starting in the 2007 season, Jackie Robinson Day (April 15, commemorating Opening Day of Robinson's rookie season of 1947) has featured many or all players and coaches wearing the number 42 as a tribute to Robinson. The Dodgers have not issued the number 34 since the departure of Fernando Valenzuela in 1991, although it has not been officially retired. In 2017, the Dodgers honored broadcaster Vin Scully with a microphone displayed alongside the team's retired numbers. In 2018 Spanish language broadcaster Jaime Jarrín was honored with a microphone displayed alongside the team's retired numbers. Awards Most Valuable Player (NL) Brooklyn – Jake Daubert 1924 – Dazzy Vance 1941 – Dolph Camilli 1949 – Jackie Robinson 1951 – Roy Campanella 1953 – Roy Campanella 1955 – Roy Campanella 1956 – Don Newcombe Los Angeles 1962 – Maury Wills 1963 – Sandy Koufax 1974 – Steve Garvey 1988 – Kirk Gibson 2014 – Clayton Kershaw 2019 – Cody Bellinger World Series MVP 1955 – Johnny Podres 1959 – Larry Sherry 1963 – Sandy Koufax 1965 – Sandy Koufax 1981 – Ron Cey, Pedro Guerrero and Steve Yeager 1988 – Orel Hershiser 2020 – Corey Seager Cy Young Award (NL) Brooklyn 1956 – Don Newcombe (MLB) Los Angeles 1962 – Don Drysdale (MLB) 1963 – Sandy Koufax (MLB) 1965 – Sandy Koufax (MLB) 1966 – Sandy Koufax (MLB) 1974 – Mike Marshall 1981 – Fernando Valenzuela 1988 – Orel Hershiser 2003 – Éric Gagné 2011 – Clayton Kershaw 2013 – Clayton Kershaw 2014 – Clayton Kershaw Triple Crown Brooklyn 1924 – Dazzy Vance Los Angeles 1963 – Sandy Koufax 1965 – Sandy Koufax 1966 – Sandy Koufax 2011 – Clayton Kershaw Rookie of the Year Award (NL) Brooklyn 1947 – Jackie Robinson (MLB) 1949 – Don Newcombe 1952 – Joe Black 1953 – Jim Gilliam Los Angeles 1960 – Frank Howard 1965 – Jim Lefebvre 1969 – Ted Sizemore 1979 – Rick Sutcliffe 1980 – Steve Howe 1981 – Fernando Valenzuela 1982 – Steve Sax 1992 – Eric Karros 1993 – Mike Piazza 1994 – Raúl Mondesi 1995 – Hideo Nomo 1996 – Todd Hollandsworth 2016 – Corey Seager 2017 – Cody Bellinger Team records Personnel Current roster Presidents Charlie Byrne (1883–1897) Charles Ebbets (1898–1925) Edward McKeever (1925, interim) Wilbert Robinson (1925–1929) Frank B. York (1930–1932) Stephen McKeever (1933–1938) Larry MacPhail (1939–1942) Branch Rickey (1943–1950) Walter O'Malley (1950–1970) Peter O'Malley (1970–1997) Bob Graziano (1998–2004) Jamie McCourt (2004–2009) Dennis Mannion (2009–2010) Stan Kasten (2012–present) Managers Since 1884, the Dodgers have used a total of 31 Managers, the most current being Dave Roberts, who was appointed following the 2015 postseason, after the departure of Don Mattingly. Over the nearly 43 years from 1954 to mid-1996, the Dodgers employed only two managers, Walter Alston and Tommy Lasorda, both of whom are in the Hall of Fame. During this entire time period of extraordinary stability, the Dodgers were family-owned by Walter O'Malley and then his son Peter O'Malley. It was during this era that the Dodgers won 11 of their 24 pennants, and their first six World Series championships. The managers of the Los Angeles Dodgers (1958–present) are as follows: Walter Alston (1958–1976) (in Brooklyn since 1954) Tommy Lasorda (1976–1996) Bill Russell (1996–1998) Glenn Hoffman (1998) Davey Johnson (1999–2000) Jim Tracy (2001–2005) Grady Little (2006–2007) Joe Torre (2008–2010) Don Mattingly (2011–2015) Dave Roberts (2016–present) General Managers Larry MacPhail (1938–1942) Branch Rickey (1943–1950) Buzzie Bavasi (1950–1968) Fresco Thompson (1968) Al Campanis (1968–1987) Fred Claire (1987–1998) Tommy Lasorda (1998) Kevin Malone (1999–2001) Dave Wallace (2001) Dan Evans (2001–2004) Paul DePodesta (2004–2005) Ned Colletti (2005–2014) Farhan Zaidi (2014–2018) Vacant (2019–present) Public address announcers/organists From the Dodgers' move to Los Angeles from Brooklyn in 1958, the Dodgers employed a handful of well-known public address announcers; the most famous of which was John Ramsey, who served as the PA voice of the Dodgers from 1958 until his retirement in 1982; he was also well known for announcing at other venerable Los Angeles venues, including the Los Angeles Memorial Coliseum and Sports Arena, and the Forum. Ramsey died in 1990. From 1958 to 1982, Doug Moore, Philip Petty, and Dennis Packer served as back-up voices for John Ramsey for the Dodgers, California Angels, Los Angeles Chargers, USC football and Los Angeles Rams. Packer was Ramsey's primary backup for the Los Angeles Lakers and Los Angeles Kings until Ramsey's retirement from the Forum in 1978. Thereafter, Packer became the public address announcer for the Lakers, Kings, indoor soccer and indoor tennis events at the Forum. Nick Nickson, a radio broadcaster for the Los Angeles Kings, replaced John Ramsey as the Dodger Stadium public address announcer in 1983 and served in that capacity through the 1989 season to work with the Kings full-time. Dennis Packer and Pete Arbogast were emulators of John Ramsey, using the same stentorian style of announcing Ramsey was famous for. Packer and Arbogast shared the stadium announcing chores for the 1994 FIFA World Cup matches at the Rose Bowl. Arbogast won the Dodgers job on the day that Ramsey died on January 25, 1990, by doing a verbatim imitation of Ramsey's opening and closing remarks that were standard at each game. His replacement, in 1994 was Mike Carlucci, who remained as the Dodgers' PA voice announcer until he resigned in 2002 to concentrate on his voiceover and acting career along with his Olympics announcing duties. From 2003 to 2014, the Dodgers public address announcer was Eric Smith, who also announces for the Los Angeles Clippers and USC Trojans. On April 3, 2015, the Dodgers announced that former radio broadcaster Todd Leitz was hired to become their new public address announcer. Leitz was an anchor and news reporter in Los Angeles at KNX 1070 AM for 10 years, and a news reporter at KABC 790 for two years. From 1988 to 2015, Nancy Bea enjoyed popularity behind the Dodger Stadium keyboard similar to Gladys Goodding. Since retirement in 2015, Bea's replacement and current organist is Dieter Ruehle, who also plays at Staples Center for Los Angeles Kings games. Other Vin Scully is permanently honored in the Baseball Hall of Fame's "Scribes & Mikemen" exhibit as a result of winning the Ford C. Frick Award in 1982. Frick Award recipients are not official members of the Hall. Sue Falsone, was the first female physical therapist in Major League baseball, and from 2012 to 2013, was the first female head athletic trainer. Minor league affiliations The Los Angeles Dodgers farm system consists of seven minor league affiliates. See also 1994 in baseball Dodger Dog List of Los Angeles Dodgers broadcasters List of Los Angeles Dodgers managers List of Los Angeles Dodgers seasons Los Angeles Dodgers all-time roster Los Angeles Dodgers minor league players Roy Campanella Award Notelist References Further reading Red Barber, Rhubarb in the Catbird Seat Stanley Cohen, Dodgers! The First
|
longer well-served by its aging infrastructure and the Dodgers could no longer sell out the park even in the heat of a pennant race, despite largely dominating the National League from 1946 to 1957. O'Malley wanted to build a new, state-of-the-art stadium in Brooklyn. But City Planner Robert Moses and New York politicians refused to grant him the eminent domain authority required to build pursuant to O'Malley's plans. To put pressure on the city, during the 1955 season, O'Malley announced that the team would play seven regular-season games and one exhibition game at Jersey City's Roosevelt Stadium in 1956. Moses and the City considered this an empty threat, and did not believe O'Malley would go through with moving the team from New York City. After teams began to travel to and from games by air instead of train, it became possible to include locations in the far west. Los Angeles officials attended the 1956 World Series looking to the Washington Senators to move to the West Coast. When O'Malley heard that LA was looking for a club, he sent word to the Los Angeles officials that he was interested in talking. LA offered him what New York would not: a chance to buy land suitable for building a ballpark, and own that ballpark, giving him complete control over all revenue streams. When the news came out, NYC Mayor Robert F. Wagner, Jr. and Moses made an offer to build a ballpark on the World's Fair Grounds in Queens that would be shared by the Giants and Dodgers. However, O'Malley was interested in his park under only his conditions, and the plans for a new stadium in Brooklyn seemed like a pipe dream. O'Malley decided to move the Dodgers to California, convincing Giants owner Horace Stoneham to move to San Francisco instead of Minneapolis to keep the Giants-Dodgers rivalry alive on the West Coast. The Dodgers played their final game at Ebbets Field on September 24, 1957, which the Dodgers won 2–0 over the Pittsburgh Pirates. New York remained a one-team town with the New York Yankees until 1962, when Joan Payson founded the New York Mets and brought National League baseball back to the city. The blue background used by the Dodgers was adopted by the Mets, honoring their New York NL forebears with a blend of Dodgers blue and Giants orange. Los Angeles Dodgers The Dodgers were the first Major League Baseball team to ever play in Los Angeles. On April 18, 1958, the Dodgers played their first LA game, defeating the former New York and now new San Francisco Giants, 6–5, before 78,672 fans at the Los Angeles Memorial Coliseum. Catcher Roy Campanella, left partially paralyzed in an off-season accident, was never able to play in Los Angeles. Construction on Dodger Stadium was completed in time for Opening Day 1962. With its clean, simple lines and its picturesque setting amid hills and palm trees, the ballpark quickly became an icon of the Dodgers and their new California lifestyle. O'Malley was determined that there would not be a bad seat in the house, achieving this by cantilevered grandstands that have since been widely imitated. More importantly for the team, the stadium's spacious dimensions, along with other factors, gave defense an advantage over offense and the Dodgers moved to take advantage of this by assembling a team that would excel with its pitching. Since moving to Los Angeles, the Dodgers have won 12 more National League Championships and six more World Series rings. Other historical notes Historical records and firsts First baseball team to win championships in different leagues in consecutive years (1889–1890) First television broadcast (1939) First use of batting helmets (1941) First MLB team to employ and start an African-American player in the 20th century (Jackie Robinson, 1947) First MLB team to have numbers on the front of their uniforms (1952) First West Coast team (1958) – along with the San Francisco Giants First Western team to win a World Series (1959) First MLB team to allow a female sports journalist into a locker room (Anita Martini, 1974) First MLB team to establish a baseball academy in the Dominican Republic when they opened the doors to Campo Las Palmas (1987) Largest home-opener attendance: 78,672 (1958) (since broken by the Colorado Rockies in 1993) Largest single game attendance: 93,103 (1959) and 115,300 (2008) *World Record First MLB team to open an office in Asia (1998) Longest MLB record for home start going 13–0 (2009) North American record for the buying of a sports team ($2 billion, 2012) Most no-hitters (26) Most Cy Young award winners (12) First MLB team to employ a female lead trainer (Sue Falsone, 2012) 11,000 franchise wins 8-30-2020 (vs Texas) Most runs scored in a single inning of a postseason game (11 runs in 2020 NLCS Game 3, 2020) Most Rookie of the Year awards (18) First team to draw 3 million fans First team to have a pair of two-slam games in a season (2021) Origin of the nickname The Dodgers' official history reports that the term "Trolley Dodgers" was attached to the Brooklyn ballclub due to the complex maze of trolley cars that weaved its way through the borough of Brooklyn. In 1892, the city of Brooklyn (Brooklyn was an independent city until annexed by New York City in 1898) began replacing its slow-moving, horse-drawn trolley lines with the faster, more powerful electric trolley lines. Within less than three years, by the end of 1895, electric trolley accidents in Brooklyn had resulted in more than 130 deaths and maimed well over 500 people. Brooklyn's high profile, the significant number of widely reported accidents, and a trolley strike in early 1895, combined to create a strong association in the public's mind between Brooklyn and trolley dodging. Sportswriters started using the name "Trolley Dodgers" to refer to the Brooklyn team early in the 1895 season. The name was shortened to, on occasion, the "Brooklyn Dodgers" as early as 1898. Sportswriters in the early 20th century began referring to the Dodgers as the "Bums", in reference to the team's fans and possibly because of the "street character" nature of Jack Dawkins, the "Artful Dodger" in Charles Dickens' Oliver Twist. Newspaper cartoonist Willard Mullin used a drawing of famous clown Emmett Kelly to depict "Dem Bums": the team would later use "Weary Willie" in promotional images, and Kelly himself was a club mascot during the 1950s. Other team names used by the franchise were the Atlantics, Grays, Grooms, Bridegrooms, Superbas and Robins. All of these nicknames were used by fans and sportswriters to describe the team, but not in any official capacity. The team's legal name was the Brooklyn Base Ball Club. However, the Trolley Dodger nickname was used throughout this period, simultaneously with these other nicknames, by fans and sportswriters of the day. The team did not use the name in any formal sense until 1932, when the word "Dodgers" appeared on team jerseys. The "conclusive shift" came in 1933, when both home and road jerseys for the team bore the name "Dodgers". Examples of how the many popularized names of the team were used are available from newspaper articles before 1932. A New York Times article describing a game in 1916 starts out: "Jimmy Callahan, pilot of the Pirates, did his best to wreck the hopes the Dodgers have of gaining the National League pennant", but then goes on to comment: "the only thing that saved the Superbas from being toppled from first place was that the Phillies lost one of the two games played". What is interesting about the use of these two nicknames is that most baseball statistics sites and baseball historians generally now refer to the pennant-winning 1916 Brooklyn team as the Robins. A 1918 New York Times article uses the nickname in its title: "Buccaneers Take Last From Robins", but the subtitle of the article reads: "Subdue The Superbas By 11 To 4, Making Series An Even Break". Another example of the use of the many nicknames is found on the program issued at Ebbets Field for the 1920 World Series, which identifies the matchup in the series as "Dodgers vs. Indians" despite the fact that the Robins nickname had been in consistent use for around six years. The "Robins" nickname was derived from the name of their Hall of Fame manager, Wilbert Robinson, who led the team from 1914 to 1931. Uniforms The Dodgers' uniform has remained relatively unchanged since the 1930s. The home jersey is white with "Dodgers" written in script across the chest in royal. The road jersey is gray with "Los Angeles" written in script across the chest in royal. The word "Dodgers" was first used on the front of the team's home jersey in 1933; the uniform was then white with red pinstripes and a stylized "B" on the left shoulder. The Dodgers also wore green outlined uniforms and green caps throughout the 1937 season but reverted to blue the following year. The current design was created in 1939, and has remained the same ever since with only cosmetic changes. Originally intended for the 1951 World Series for which the ballclub failed to qualify, red numbers under the "Dodgers" script were added to the home uniform in 1952. The road jersey also has a red uniform number under the script. When the franchise moved from Brooklyn to Los Angeles, the city name on the road jersey changed, and the stylized "B" was replaced with the interlocking "LA" on the caps in 1958. In 1970, the Dodgers removed the city name from the road jerseys and had "Dodgers" on both the home and away uniforms. The city script returned to the road jerseys in 1999, and the tradition-rich Dodgers flirted with an alternate uniform for the first time since 1944 (when all-blue satin uniforms were introduced). These 1999 alternate jerseys had a royal top with the "Dodgers" script in white across the chest, and the red number on the front. These were worn with white pants and a new cap with silver brim, top button and Dodger logo. These alternates proved unpopular and the team abandoned them after only one season. In 2014, the Dodgers introduced an alternate road jersey: a gray version with the "Dodgers" script instead of the city name. Since its introduction, however, the road jersey with the "Dodgers" script was used more often than the road jersey with the "Los Angeles" script, so much that the team now considers it as a primary road uniform. In 2018, the Dodgers wore their 60th anniversary patch to honor the 60 years of being in Los Angeles. Asian players The Dodgers have been groundbreaking in their signing of players from Asia; mainly Japan, South Korea, and Taiwan. Former owner Peter O'Malley began reaching out in 1980 by starting clinics in China and South Korea, building baseball fields in two Chinese cities, and in 1998 becoming the first major league team to open an office in Asia. The Dodgers were the second team to start a Japanese player in recent history, pitcher Hideo Nomo, the first team to start a South Korean player, pitcher Chan Ho Park, and the first Taiwanese player, Chin-Feng Chen. In addition, they were the first team to send out three Asian pitchers, from different Asian countries, in one game: Park, Hong-Chih Kuo of Taiwan, and Takashi Saito of Japan. In the 2008 season, the Dodgers had the most Asian players on its roster of any major league team with five. They included Japanese pitchers Takashi Saito and Hiroki Kuroda; South Korean pitcher Chan Ho Park; and Taiwanese pitcher Hong-Chih Kuo and infielder Chin-Lung Hu. In 2005, the Dodgers' Hee Seop Choi became the first Asian player to compete in the Home Run Derby. For the 2013 season, the Dodgers signed starting pitcher Hyun-Jin Ryu with a six-year, $36 million contract, after posting a bid of nearly $27 million to acquire him from the KBO's Hanhwa Eagles. For the 2016 season, the Dodgers signed starting pitcher Kenta Maeda with an eight-year, $25 million contract, after posting a bid of $20 million to acquire him from the NPB's Hiroshima Toyo Carp. Rivalries The Dodgers' rivalry with the San Francisco Giants dates back to the 19th century, when the two teams were based in New York; the rivalry with the New York Yankees took place when the Dodgers were based in New York, but was revived with their East Coast/West Coast World Series battles in 1963, 1977, 1978, and 1981. The Dodgers rivalry with the Philadelphia Phillies also dates back to their days in New York, but was most fierce during the 1970s, 1980s, and 2000s. The Dodgers also had a heated rivalry with the Cincinnati Reds during the 1970s, 1980s and early 1990s. The intra-city rivalry with the Los Angeles Angels dates back to the Angels' inaugural season in 1961. San Francisco Giants The Dodgers–Giants rivalry is one of the longest-standing rivalries in U.S. baseball. The feud between the Dodgers and the San Francisco Giants began in the late 19th century when both clubs were based in New York City, with the Dodgers playing in Brooklyn and the Giants playing at the Polo Grounds in Manhattan. After the 1957 season, Dodgers owner Walter O'Malley moved the team to Los Angeles for financial and other reasons. Along the way, he managed to convince Giants owner Horace Stoneham—who was considering moving his team to Minnesota—to preserve the rivalry by bringing his team to California as well. New York baseball fans were stunned and heartbroken by the move. Given that the cities of Los Angeles and San Francisco have been bitter rivals in economic, cultural, and political arenas for over a century and a half, the new venue in California became fertile ground for its transplantation. Each team's ability to endure for over a century while moving across an entire continent, as well as the rivalry's leap from a cross-city to a cross-state engagement, have led to the rivalry being considered one of the greatest in American sports history. Unlike many other historic baseball match-ups in which one team remains dominant for most of their history, the Dodgers–Giants rivalry has exhibited a persistent balance in the respective successes of the two teams. While the Giants have more wins in franchise history, the Dodgers have the most National League pennants at 24, with the Giants following close behind at 23. The Giants have won eight World Series titles, while the Dodgers have won seven. The 2010 World Series was the Giants' first championship since moving to California, while the Dodgers had won six World Series titles since their move, their last title coming in the 2020 World Series. Los Angeles Angels This rivalry refers to a series of games played with the Los Angeles Angels. The Freeway Series takes its name from the massive freeway system in the greater Los Angeles metropolitan area, the home of both teams; one could travel from one team's stadium to the other simply by traveling along Interstate 5. The term is akin to Subway Series which refers to meetings between New York City baseball teams. The term "Freeway Series" also inspired the official name of the region's NHL rivalry: the Freeway Face-Off. Animosity between the team's fanbases grew stronger in 2005, when the Angels' new team owner Arte Moreno changed the name of his ball club from the 'Anaheim Angels', to the 'Los Angeles Angels of Anaheim'. Since the city of Anaheim is located roughly 30 miles from Downtown Los Angeles, the Angels franchise was ridiculed throughout the league for the contradictory nature surrounding the name, especially by Dodgers owner Frank McCourt, who filed a formal complaint to commissioner Bud Selig. Once the complaint was denied, McCourt devised a t-shirt mocking the crosstown rivals reading 'The Los Angeles Dodgers of Los Angeles', which remains popular amongst the fanbase to this day. Historical rivalry New York Yankees The Dodgers–Yankees rivalry is one of the most well-known rivalries in Major League Baseball. The two teams have met eleven times in the World Series, more times than any other pair from the American and National Leagues. The initial significance was embodied in the two teams' proximity in New York City, when the Dodgers initially played in Brooklyn. After the Dodgers moved to Los Angeles in 1958, the rivalry retained its significance as the two teams represented the dominant cities on each coast of the United States, and since the 1980s, the two largest cities in the United States. Although the rivalry's significance arose from the two teams' numerous World Series meetings, the Yankees and Dodgers have not met in the World Series since . They would not play each other in a non-exhibition game until 2004, when they played a three-game interleague series. Their last meeting was in August 2019, when the Yankees won two out of three games in Los Angeles. Fan support The Dodgers have a loyal fanbase, evidenced by the fact that the Dodgers were the first MLB team to attract more than 3 million fans in a season (in 1978), and accomplished that feat six more times before any other franchise did it once. The Dodgers drew at least 3 million fans for 15 consecutive seasons from 1996 to 2010, the longest such streak among all MLB teams. The team's largest fan club, Pantone 294 (a reference to the Pantone code of Dodger blue), regularly travel to away games to cheer for the Dodgers. On July 3, 2007, Dodgers management announced that total franchise attendance, dating back to 1901, had reached 175 million, a record for all professional sports. In 2007, the Dodgers set a franchise record for single-season attendance, attracting over 3.8 million fans. On March 28, 2008, the Dodgers set the world record for the largest attendance for a single baseball game during an exhibition game against the Boston Red Sox at the Los Angeles Memorial Coliseum in honor of the Dodgers' 50th anniversary, with 115,300 fans in attendance. In 2009, the Dodgers led the MLB in total attendance. The Dodger baseball cap is consistently in the top three in sales. Given the team's proximity to Hollywood, numerous celebrities can often be seen attending home games at Dodger Stadium. Celebrities such as co-owner Magic Johnson, Mary Hart, DaBaby, Larry King, Tiger Woods, Alyssa Milano, Shia LaBeouf, Lana Del Rey, Mila Kunis and Ashton Kutcher are known to frequently attend Dodger games, with some sitting at field box seats behind home plate where they sign autographs for fellow Dodger fans. Actor Bryan Cranston is a lifelong Dodger fan. Primarily, Dodgers fans are from their own location in southern California and also parts of southern Nevada. However, there are also numerous strong pockets of supporters in Mexico due to the impact of players such as Fernando Valenzuela or more recently; Julio Urias and the fanbase is ever present throughout Asian countries such as South Korea and Japan, and their away games throughout the US will usually attract substantial numbers of expats and traveling fans. Radio and television Vin Scully called Dodgers games from 1950 to 2016. His longtime partners were Jerry Doggett (1956–1987) and Ross Porter (1977–2004). In 1976, he was selected by Dodgers fans as the Most Memorable Personality (on the field or off) in the team's history. He is also a recipient of the Baseball Hall of Fame's Ford C. Frick Award for broadcasters (inducted in 1982). Unlike the modern style in which multiple sportscasters have an on-air conversation (usually with one functioning as play-by-play announcer and the other[s] as color commentator), Scully, Doggett and Porter generally called games solo, trading with each other inning-by-inning. In the 1980s and 1990s, Scully would call the entire radio broadcast except for the third and seventh inning, allowing the other Dodger commentators to broadcast an inning. When Doggett retired after the 1987 season, he was replaced by Hall-of-Fame Dodgers pitcher Don Drysdale, who previously broadcast games for the California Angels and Chicago White Sox. Drysdale died in his hotel room following a heart attack before a game in Montreal in 1993. This was a difficult broadcast for Scully and Porter who could not mention it on-air until Drysdale's family had been notified and the official announcement made. He was replaced by former Dodgers outfielder Rick Monday. Porter's tenure ended after the 2004 season, after which the format of play-by-play announcers and color commentators was installed, led by Monday and newcomer Charley Steiner. Scully, however, continued to announce solo. Scully called roughly 100 games per season (all home games and road games in California and Arizona) for both flagship radio station KLAC and on television for Spectrum SportsNet LA. Scully was simulcast for the first three innings
|
Berio. Andriessen taught at the Royal Conservatory of The Hague from 1974 to 2012, influencing notable composers. His opera La Commedia, based on Dante's Divine Comedy, won the 2011 Grawemeyer Award for Music Composition and was selected in 2019 by critics at The Guardian as one of the most outstanding compositions of the 21st century. Life and career Andriessen was born in Utrecht on 6 June 1939 to a musical family, the son of the composer Hendrik Andriessen and Johanna Justina Anschütz (1898–1975). His father was professor of composition at the Royal Conservatory of The Hague, and later its director. His siblings are composers Jurriaan Andriessen and Caecilia Andriessen (1931–2019), and he is the nephew of Willem Andriessen (1887–1964). Andriessen originally studied with his father and Kees van Baaren at the Royal Conservatory of The Hague, graduating in 1961 with a first prize, before embarking upon two years of study with Italian composer Luciano Berio in Milan and Berlin. His father introduced him to the works of Francis Poulenc and Eric Satie which he came to love. From 1961-65, Andriessen wrote for the daily De Volkskrant, and for De Gids magazine from 1966-69. Andriessen lived in Amsterdam since 1965. In 1969, he was part of a group of protesters at a concert of the Concertgebouw Orchestra. They disrupted the concert with nutcrackers and bicycle horns, handing out leaflets on the dismal representation of Dutch new music in the orchestra's programming. The next year, he and the other "Nutcrackers" were given one-week prison sentences, and yet their protest sparked something of a social reform in the Dutch music scene. Andriessen was internationally recognised as a composer with his 1976 De Staat which included texts from Plato's Republic. He was one of the founders of the Hague School, an avant-garde and minimalist movement from the second half of the 20th century. In later decades, he accepted commissions from major orchestras, including the San Francisco Symphony, the Los Angeles Philharmonic, the BBC Symphony Orchestra and the New York Philharmonic. Andriessen was the focus of festivals in Tanglewood (1994), London (1994; 2002), Tokyo (2000), Brisbane (2001) and New York (2004). In 2008, he was elected an honorary member of the International Society for Contemporary Music ISCM. He held the Richard and Barbara Debs Composer's Chair at Carnegie Hall during the 2009–10 season. Ensembles In 1969, Andriessen co-founded Studio voor Elektro-Instrumentale Muziek STEIM in Amsterdam. In opposition to the classical orchestra, a structure seen as "hierarchical", he also helped founding the instrumental groups Orkest de Volharding and Hoketus, both of which performed compositions of the same names, formed by classical, jazz and pop musicians. He later became closely involved with the Schonberg and Asko ensembles and inspired the formation of the British ensemble Icebreaker. Teaching Andriessen joined the faculty of the Royal Conservatory in 1974. He taught instrumentation from 1974 to 1978 and taught composition there from 1978 to 2012, where he influenced notable students including Michel van der Aa, Richard Ayres and Steve Martland. Yale University invited him in 1987 to lecture on theory and composition, he was also guest lecturer at New York State University, Buffalo (1989) and Princeton (1996). The arts faculty of the University of Leiden appointed him professor in 2004. Personal life Andriessen was married to guitarist Jeanette Yanikian (1935–2008). They were a couple for over 40 years, and were married in 1996. La Commedia is dedicated to Yanikian. He was married in 2012 a second time to violinist Monica Germino, for whom he wrote several works. In December 2020, she announced that the composer was suffering from dementia. He died on 1 July 2021 in Weesp at age 82. Style and notable works Andriessen began in the style of an intentionally dry neoclassicism, but then turned into a strict serialist. His early works show experimentation with various contemporary trends: post-war serialism (Series, 1958), pastiche (Anachronie I, 1966–67), and tape (Il Duce, 1973). His reaction to what he perceived as the conservatism of much of the Dutch contemporary music scene quickly moved him to form a radically alternative musical aesthetic of his own. From the early 1970s on he refused to write for conventional symphony orchestras and instead opted to write for his own idiosyncratic instrumental combinations, which often retain some traditional orchestral instruments alongside electric guitars, electric basses, and congas. Andriessen repeatedly used his music for political confessions and messages, but he also referred to painting and philosophy. His range of inspiration was wide, from the music of Charles Ives in Anachronie I, the art of Mondriaan in De Stijl, and medieval poetic visions in Hadewijch, to writings on shipbuilding and atomic theory in De Materie Part I. Andriessen's later style is a unique blend of American sounds and European forms. His mature music combines the influences of jazz, American minimalism, Igor Stravinsky, and Claude Vivier. The music consists of minimalist polyrhythms, lyrical melodic fragments, predominantly consonant harmonies disrupted by explosive blocks of concentrated dissonance. Andriessen's music thus departs from post-war European serialism and its offshoots. By the 21st century he was widely regarded as Europe's most important minimalist composer. His notable works include Workers Union (1975), a melodically indeterminate piece "for any loud sounding group of instruments" whose score specifies rhythm and contour but not exact pitch; Mausoleum (1979) for two baritones and large ensemble; De Tijd (Time, 1979–81) for female singers and ensemble; De Snelheid (Velocity, 1982–83), for three amplified ensembles; De Materie (Matter, 1984–88), a large four-part work for voices and ensemble; collaborations with filmmaker and librettist Peter Greenaway on the film M is for Man, Music, Mozart and the operas Rosa: A Horse Drama (1994) and Writing to Vermeer (1998); and La Passione (2000–02) for female voice, violin and ensemble. His opera La Commedia, based on Dante's Divine Comedy, is particularly renowned; it won the 2011 Grawemeyer Award for Music Composition and was selected in 2019 by critics at The Guardian as No 7 of the then most outstanding compositions of the 21st century. Awards and honours 1959 Gaudeamus International Composers Award 1977 Matthijs Vermeulen Award for De Staat 1977 UNESCO International Rostrum of Composers in Paris 1992 Matthijs Vermeulen Award for M. is for Man, Music and Mozart; Facing Death, Dances, Hout en Lacrimosa 1993 Edison Award 2010 Honorary doctorate from the Birmingham City University 2011 Grawemeyer Award for Music Composition for the multimedia opera La Commedia (2004–2008). 2016 Marie-Josée Kravis Prize for New Music 2019 Honorary doctorate from the University of Amsterdam Works Andriessen's primary publishers are Boosey & Hawkes and Donemus. Complete list of works: Rondo Barbaro (1954) for piano Sonata (1956) for flute and piano (dedicated to Lucas van Regteren Altena) Elegy (1957) for cello and piano Elegy (1957) for double bass and piano (arrangement by Quirijn van Regteren
|
by Mikhail Bakunin, Arthur Arnould) for 2 high baritones, orchestra (12 brass, 2 harps, cimbalom, 2 pianos, 2 percussion, minimum 10 strings, bass guitar) Music for the film The Alien (1980) (Rudolf van den Berg) George Sand (1980) (text by Mia Meyer) Music theatre work for 8 mixed voices, 4 pianos Un beau baiser (1980) for mixed chorus Messe des pauvres by Erik Satie, arrangement by Louis Andriessen for choir, 15 solo strings, accordion, contrabass clarinet and harp (1980) Ende (1981) for 2 alto recorders (1 player) (dedicated to Frans Brüggen) Anfang (1981) for sopranino recorder and piano De Tijd (1979–81) (text by St. Augustine of Hippo) for female chorus, percussion ensemble, orchestra (6 flutes, 2 alto flutes, 3 clarinets, contrabass clarinet, 6 trumpets, 2 harps, 2 pianos, Hammond organ, strings, 2 bass guitars) Commentaar (1981) (text by Wilhelm Schön) for voice and piano La voce (1981) (to a text by Cesare Pavese) for cello and voice Disco (1982) for violin and piano Overture to Orpheus (1982) for harpsichord De Snelheid (1982–83 rev. 1984) for 3 amplified ensembles Y después (1983) (text by Federico García Lorca) for voice and piano Menuet voor Marianne (1983) for piano Trepidus (1983) for piano Doctor Nero (1984) Music theatre work Berceuse voor Annie van Os (1985) for piano De Lijn (1986) for 3 flutes Dubbelspoor (1986 rev. 1994) Ballet music for piano, harpsichord, celesta, glockenspiel De Materie (1984–88) (texts from the Plakkaat van Verlatinge, Nicolaes Witsen, David Gorlaeus, Hadewijch, M.H.J. Schoenmaekers, Madame van Domselaer-Middelkoop, Willem Kloos, Marie Curie, Françoise Giroud). Music theatre work for soprano, tenor, 2 female speakers, 8 amplified mixed voices, amplified orchestra (15 winds, 13 brass, harp, 2 electric guitars, 2 pianos [one + electric piano], off-stage upright piano, celesta, 2 synthesizers, 6 percussion, minimum 9 strings, bass guitar. Two of its four sections may be performed separately as concert works: [2] Hadewijch, [3] De Stijl De Toren (1988, rev. 2000) for carillon Nietzsche redet (1989) (text by Friedrich Nietzsche) for speaker, alto flute, English horn, clarinet, bass clarinet, bassoon, 2 violins, viola, 2 celli, double bass, 2 pianos Flora Tristan (1990) for mixed choir a cappella (text by Fleur Bourgonje) Facing Death (1990) for amplified string quartet Facing Death (1990) for saxophone quartet (arrangement by Aurelia Saxophone Quartet) Dances (1991) (text by Joan Grant, choreography by Bianca van Dillen) For soprano, small orchestra (amplified harp, amplified piano, percussion, strings). May be performed as a concert work. M is for Man, Music, Mozart (1991) (texts by the composer, Jeroen van der Linden, Peter Greenaway) for female jazz voice, flute (+ piccolo), soprano saxophone, alto saxophone, tenor saxophone, horn, 3 trumpets, 2 trombones, bass trombone, double bass, piano (TV score; may be performed as a concert work with one additional song) Lacrimosa (1991) for 2 bassoons Lacrimosa (1991) for 2 flutes (arrangement by Manuel Zurria) Hout (1991) for tenor saxophone, electric guitar, piano and marimba (+ woodblocks) Romance voor Caecilia (1991) for piano Nadir en Zenit (1992) improvisations on poems by Sybren Polet for voice and piano (+ synthesizer) ...not being sundered (1992) (text by Rainer Maria Rilke) for soprano, flute, cello Song Lines (1992) for 3–6 saxophones Deuxième chorale (1992) for music box The Memory of Roses (1992) for piano (+ toy piano) Chorale (1992) for piano M is Muziek, Monoloog en Moord (1993) (text by Lodewijk de Boer) Music theatre work Lied (1993) for piano Rosa – A Horse Drama: The Death of a Composer (1993–94) (libretto by Peter Greenaway) Opera for 2 sopranos, tenor, 2 baritones, female speaker, 8 mixed voices, orchestra. Een lied van de zee (1994) (text by Hélène Swarth) for female voice Zilver (1994) for flute, clarinet, violin, cello, piano, vibraphone and marimba Base (1994) for piano left hand Odysseus' Women (1995) (text by Homer, choreography by Beppie Blankert) for 2 sopranos, 2 altos, sampler De komst van Willibrord (1995) for carillon To Pauline O (1995) for oboe Machmes Wos (1996) for voice, piano Trilogie van de Laatste Dag (1996–97) (each of its three sections may be performed separately: (i) The Last Day (texts by Lucebert, folksong A Woman and Her Lass) for boy soprano, 4 male voices, orchestra; (ii) TAO (texts by Laozi, Kotaro Takamura) for 4 female voices, piano [+ voice, koto], small orchestra [5 winds, 2 horns, harp, piano (+ celesta), 2 percussion, minimum 14 strings]; (iii) Dancing on the Bones (text by the composer) for children's chorus, orchestra, 1997) De herauten (1997) for 3 horns, 3 trumpets, 3 trombones, tuba, timpani Not an Anfang (1997) for piano De eerste minnaar (1998) (text by Toon Tellegen) for boy soprano, organ, 1998 (section of music theatre work Oldenbarneveldt; may be performed as a concert work) Tuin van Zink (1998) for viola and live electronics Writing to Vermeer (1997–99) (libretto by Peter Greenaway) Opera for 2 children's voices, 2 sopranos, mezzo-soprano, female chorus, orchestra (7 winds, 2 horns, 2 trumpets [2nd + bass trumpet], 2 harps, 2 electric guitars, cimbalom, 2 pianos, on-stage harpsichord, 2 percussion, minimum 22 strings), CD (music by Michel van der Aa) Woodpecker (1999) for percussion Image de Moreau (1999) for piano Dirck Sweelinck Missed the Prince (1999) for harpsichord Passeggiata in tram in America e ritorno (1999) (text by Dino Campana) for female Italian voice, violin and piano What Shall I Buy You, Son? (2000) for voice, piano Boodschappenlijstje van een gifmengster (2000) (text by the composer) for vocalist (also writes), voice (may be performed as Shopping List of a Poisoner [translated by Nicoline Gatehouse] Inanna's Descent (2000) for mezzo-soprano, piccolo, oboe, violin, piano, 2 percussion ensembles (4–12 total players) The New Math(s) (2000) (text by Hal Hartley) for soprano, transverse flute, violin, marimba, CD (music by Michel van der Aa), 2000 (film score; may be performed as a concert work) Feli-citazione (2000) for piano Passeggiata in tram in America e ritorno (2001) (text by Dino Campana) for female Italian voice, 3 trumpets, 3 trombones, electric guitar, electric violin, double bass, piano, percussion, 1998 (also version for voice, flute, horn, 3 trumpets, 3 trombones, amplified violin, double bass, piano De vleugels van de herinnering (2001) (text by Larissa Tiginachvili [Dutch translation]) for voice, piano Fanfare om te beginnen (2001) for 6 groups of horns La Passione (2000–02) (text by Dino Campana) for female jazz voice, violin, small orchestra (7 winds, 7 brass, electric guitar, cimbalom, 2 pianos, synthesizer, 2 percussion, 3 violins, bass guitar) Very Sharp Trumpet Sonata (2002) for trumpet Tuin van Eros (Garden of Eros) (2002) for string quartet Klokken voor Haarlem (Bells for Haarlem) (2002) for piano, celesta, synthesizer, vibraphone (+ glockenspiel) Pupazzetti by Alfredo Casella, arranged by Louis Andriessen for ensemble in 2002–2003 Inanna (2003) texts by Hal Hartley, Theo J.H. Krispijn) for 4 voices, 3 actors, mixed chorus, contrabass clarinet, 4 saxophones, violin, film (by Hal Hartley) Letter from Cathy (2003) (text from a letter by Cathy Berberian to the composer) for female jazz voice, harp, violin, double bass, piano, percussion Tuin van Eros (2003) for violin and piano RUTTMANN Opus II, III, IV (2003) for flute, 3 saxophones, horn, 3 trumpets, 3 trombones, double bass, piano (film music for a film of Walter Ruttman, written for the Filmmuseum Biennale 2003) Haags Hakkûh (The Hague Hacking) (2003) for 2 pianos. Renamed to Haags Hakkûh Stukje (The Hague Hacking Scrap) in 2008. Racconto dall'inferno (2004) (text by Dante Alighieri) for female jazz voice, small orchestra (8 winds, 6 brass, guitar, cimbalom, 2 pianos, 2 percussion, minimum 8 strings, bass guitar). Part II of La Commedia (2004–08). De Opening (2005) for ensemble (combined Orkest de Volharding, ASKO Ensemble, Schoenberg Ensemble) Vermeer Pictures (2005) concert suite for orchestra from Writing to Vermeer (arrangement by Clark Rundell) XENIA (2005) for violin Hymn to the memory of Darius Milhaud for ensemble (1974/2006) Hellende Fanfare (Inclined fanfare; Fanfara inclinata) (2006) for voice and ensemble (Text by Dino Campana) Raadsels (Riddle) (2006) for solo violin Johann Sebastian Bach's Prelude in b minor from the Well-Tempered Clavier BWV 866, arranged for string quartet with the first six bars augmented with a viola part by Igor Stravinsky, completed by Louis Andriessen (2006) ..miserere... (2006–07) for string quartet The City of Dis or: The Ship of Fools (2007) for voices and ensemble. Part I of La Commedia (2004–08). La Commedia (2004–08). Film opera in five parts (texts by Dante and Vondel and from the Old Testament) Haags Hakkûh (The Hague Hacking) (2008) for two pianos and large ensemble Christiaan Andriessens uitzicht op de Amstel (Christiaan Andriessen's view on the river Amstel) (2009) for ensemble Life (2009) for ensemble, with film by Marijke van Warmerdam Anaïs Nin (2009/10) for singer, ensemble and film La Girò (2011), for violin solo and ensemble Mysteriën (2013), for orchestra Tapdance (2013), concerto for percussion and large ensemble Two way ticket (2014), for piano Theatre of the World (2013–15), a 'grotesque stagework' in nine scenes (Libretto by Helmut Krausser) Mach's mit mir, Gott (Do unto me, God) (2016), for organ Signs and Symbols (2016), for wind ensemble and percussion Ahania Weeping (2016), for mixed chorus De goddelijke routine (The divine routine) (2017), for organ Rimsky or La Monte Young (2017), for piano Agamemnon (2017), for speaker and large orchestra Searching for unison (étude) (2018), for piano The Only One (2018), song cycle for female jazz singer and large ensemble, dedicated to Nora Fischer, who premiered the work at The Proms 2019 May (2019), for choir and orchestra References Sources Further reading Adlington, Robert: De Staat. Hants. (UK): Ashgate (2004). Andriessen, Louis and Elmer Schonberger (trans. Jeff Hamburg): The Apollonian Clockwork: On Stravinsky Amsterdam: Amsterdam UP (reprint, 2006). Everett, Yayoi Uno. The Music of Louis Andriessen. Cambridge: Cambridge University Press (2006). . Zegers, Mirjam (ed.): Trans. Clare Yates. The Art of Stealing Time. Arc Publications. . External links Louis Andriessen / 1939 – 2021 ( biography, works list, recordings and performance search) Boosey and Hawkes 2021 Andriessen on Andriessen (documentary) Louis Andriessen Nonesuch Records Robert Davidson: Louis Andriessen interview topologymusic.com 2001 1939 births 2021 deaths 20th-century classical composers 20th-century Dutch composers 20th-century Dutch male musicians
|
Butler, all AIM members who were present on the Jumping Bull compound at the time of the shootings. Leonard Peltier provided numerous alibis to several people about his activities on the morning of the attacks. In an interview with the author Peter Matthiessen (In the Spirit of Crazy Horse 1983), Peltier described working on a car in Oglala, claiming to have driven back to the Jumping Bull Compound about an hour before the shooting started. In an interview with Lee Hill, he described being awakened in the tent city at the ranch by the sound of gunshots. To Harvey Arden, for Prison Writings, he described enjoying a beautiful morning before he heard the firing. On September 5, 1975, Agent Coler's .308 rifle and handgun and Agent Williams's handgun were recovered from an automobile in the vicinity of Butler's arrest location. The FBI forwarded a description of a recreational vehicle (RV) and the Plymouth station wagon recently purchased by Peltier to law enforcement during the hunt for the suspects. The RV was stopped by an Oregon State Trooper, but the driver, later discovered to be Peltier, fled on foot following a small shootout. Both Peltier's thumbprint and Agent Coler's handgun were discovered under the RV's front seat. On September 10, 1975, AIM members Robert Robideau, Norman Charles, and Michael Anderson were injured in the explosion of a station wagon on the Kansas Turnpike close to Wichita. Agent Coler's .308 rifle and an AR-15 rifle were found in the burned vehicle. Trial On December 22, 1975, Peltier was named to the FBI Ten Most Wanted Fugitives list. On February 6, 1976, Peltier was arrested at Robert Smallboy's camp along the Brazeau River south of Hinton, Alberta. In December 1976, he was extradited from Canada based on documents submitted by the FBI. Warren Allmand, Canada's Solicitor General at the time, later stated that these documents contained false information. One of those documents was an affidavit signed by Myrtle Poor Bear, a Native American woman local to the area near Pine Ridge Reservation. While Poor Bear stated that she was Peltier's girlfriend during that time and watched the killings, Peltier and others at the scene said that Poor Bear did not know Peltier and was not present during the murders. Poor Bear later admitted to lying to the FBI, but said that the agents interviewing her had coerced her into making these claims above. When Poor Bear tried to testify against the FBI, the judge barred her testimony because of mental incompetence. Peltier fought extradition to the United States. Robideau and Butler were acquitted on the grounds of self-defense by a federal jury in Cedar Rapids, Iowa. Peltier returned too late to be tried with Robideau and Butler, and he was subsequently tried separately. Peltier's trial was held in Fargo, North Dakota, where a jury convicted Peltier of the murders of Coler and Williams. Unlike the testimony in the trial for Butler and Robideau, the jury was informed that the two FBI agents were killed by close-range shots to their heads, when they were already defenseless due to previous gunshot wounds. Consequently, Peltier could not submit a self-defense testimony that may have resulted in an acquittal. The jury was also shown autopsy and crime scene photographs of the two agents, which had not been shown to the jury at Cedar Rapids. In April 1977, Peltier was convicted and sentenced to two consecutive life sentences. Inconsistencies in the prosecution's case Numerous doubts have been raised over Peltier's guilt and the fairness of his trial, based on allegations and inconsistencies regarding the FBI and prosecution's handling of this case. Several key witnesses in the initial trial have recanted their statements and admitted they were made under duress at the hands of the FBI. At least one witness was given immunity from prosecution in exchange for testimony against Peltier. Recanted witness statements Peltier was convicted in 1977 largely on the evidence presented by three witness affidavits, all signed by Myrtle Poor Bear, that placed him at the scene of the shootout and contended that Peltier planned his crimes. Poor Bear claimed to be Peltier's girlfriend at the time, but later admitted that she never knew him personally. Moreover, Poor Bear was known to be mentally unstable. This was confirmed when the FBI deemed her unfit to testify at court. But her testimony, as put forth in her previous affidavits, remained a key part of the prosecution's case against Peltier. Two other witnesses whose testimony was used to place Peltier at the scene of the crime also later recanted. They alleged that the FBI had coerced and threatened them by tying them to chairs, denying them their right to talk to their attorney, and otherwise intimidated them. Discrepancies in material evidence FBI radio intercepts indicated that the two FBI agents Williams and Coler had entered the Pine Ridge Reservation in pursuit of a suspected thief in a red pickup truck. The FBI confirmed this claim the day after the shootout, but red pickup trucks near the reservation had been stopped for weeks, and Leonard Peltier did not drive a red pickup truck. Evidence was given that Peltier was driving a Chevrolet Suburban; a large station wagon-style sedan built on a pickup truck chassis, with an enclosed rear section. Peltier's vehicle was orange with a white roof—not a red, open-tray pickup truck with no white paint. At Peltier's trial, the FBI changed their previous statements that they had been in search of a red pickup truck and instead said that they were looking for an orange and white van, similar to the one Peltier drove. This contradictory statement by the FBI was a highly contentious matter of evidence in the trials. Though the FBI's investigation indicated that an AR-15 was used to kill the agents, several different AR-15s were in the area at the time of the shootout. Also, no other cartridge cases or evidence about them were offered by the prosecutor's office, although other bullets were fired at the crime scene. During the trial, all the bullets and bullet fragments found at the scene were provided as evidence and detailed by Cortland Cunningham, FBI Firearms expert, in testimony (Ref US v. Leonard Peltier, Vol 9). Years later, a request under the Freedom of Information Act prompted another examination of the FBI ballistics report used to convict Peltier. An impartial expert evaluated the firing pin linked to the gun that shot Williams and Coler and concluded that the cartridge case from the scene of the crime did not come from the rifle tied to Peltier. This evidence negated a key facet of the prosecution's case against Peltier. The court did not allow the defense to present the Fargo jury with information about other cases in which the FBI had been rebuked for tampering with evidence and witnesses. In some similar prosecutions against AIM leaders at the time, defense attorneys did present such evidence to the juries. 1979 prison escape Peltier began serving his sentences in 1977. On July 20, 1979, he and two other inmates escaped from Federal Correctional Institution, Lompoc. One inmate was shot dead by a guard outside the prison and the other was captured 90 minutes later, approximately away. Peltier remained at large until he was captured by a search party three days later near Santa Maria, California, after a farmer alerted authorities that Peltier had consumed some of his crops for food. Peltier was later apprehended without incident. As he was in possession of a Ruger Mini-14 rifle at the time of his capture, Peltier was convicted and sentenced to serve a five-year sentence for escape and a two-year sentence for being a felon in possession of a firearm, in addition to his preexisting two life sentences. Clemency appeals Support for clemency Peltier's conviction sparked great controversy and has drawn criticism from a number of prominent figures across a wide range of disciplines. In 1999, Peltier asserted on CNN that he did not commit the murders and that he has no knowledge who shot the FBI agents nor knowledge implicating others in the crime. Peltier has described himself as a political prisoner. Numerous public and legal appeals have been filed on his behalf; however, due to the consistent objection of the FBI, none of the resulting rulings has been made in his favor. His appeals for clemency received support from world famous civil rights advocates including Nelson Mandela, Archbishop Desmond Tutu, and Rev. Jesse Jackson, Tenzin Gyatso (the 14th Dalai Lama), Nobel Peace Prize Laureate and activist Rigoberta Menchú, and Mother Teresa. International government entities such as the Office of the United Nations High Commissioner on Human Rights, the United Nations Working Group on Indigenous Populations, the European Parliament, the Belgian Parliament, and the Italian Parliament have all passed resolutions in favor of Peltier's clemency. Moreover, several human rights groups including The International Federation of Human Rights and Amnesty International have launched campaigns advocating for Peltier's clemency. In the United States, the Kennedy Memorial Center for Human Rights, the Committee of Concerned Scientists, Inc., the National Lawyers Guild, and the American Association of Jurists are all active supporters of clemency for Peltier. The police officer that arrested Peltier is convinced that he "was extradited illegally and that he didn't get a fair trial in the United States." Denial of clemency In 1999, Peltier filed a habeas corpus petition, but it was rejected by the 10th Circuit Court on November 4, 2003. Near the end of the Clinton administration in 2001, rumors began circulating that Bill Clinton was considering granting Peltier clemency. Opponents of Peltier campaigned against his possible clemency; about 500 FBI agents and families protested outside the White House, and FBI director Louis Freeh sent a letter opposing Peltier's clemency to the White House. Clinton did not grant Peltier clemency. In 2002, Peltier filed a civil rights lawsuit in the U.S. District Court for the District of Columbia against the FBI, Louis Freeh and FBI agents who had participated in the campaign against his clemency petition, alleging that they "engaged in a systematic and officially sanctioned campaign of misinformation and disinformation." On March 22, 2004, the suit was dismissed. In January 2009, President George W. Bush denied Peltier's clemency petition before leaving office. In 2016, Peltier's attorney's filed a clemency application with the White House's Office of the Pardon Attorney, and his supporters organized a campaign to convince President Barack Obama to commute Peltier's sentence, a campaign which included an appeal by Pope Francis, as well as James Reynolds, a senior attorney and former US Attorney who supervised the prosecution against Peltier in the appeal period following his initial trial. In a letter to the United States Department of Justice, Reynolds wrote that clemency was "in the best interest of justice in considering the totality of all matters involved". In a subsequent letter to the Chicago Tribune, Reynolds added that the case against Peltier "was a very thin case that likely would not be upheld by courts today. It is a gross overstatement to label Peltier a 'cold-blooded murderer' on the basis of the minimal proof that survived the appeals in his case." On January 18, 2017, two days before President Obama left office, the Office of the Pardon Attorney announced that Obama had denied Peltier's application for clemency. On June 8, 2018, KFGO Radio in Fargo, N.D., reported that Peltier filed a formal clemency request with President Trump. KFGO obtained and published a letter that was sent by Peltier's attorney to the White House. Remaining questions In the documentary film Incident at Oglala (1992), AIM activist Robert Robideau said that the FBI agents had been shot by a 'Mr X'. When Peltier was interviewed about 'Mr X', he said he knew who the man was. Dino Butler, in a 1995 interview with E.K. Caldwell of News From Indian Country, said that 'Mr X' was fictional and had been named as the murderer in an attempt to gain Peltier's release from prison. In a 2001 interview with News From Indian Country, Bernie Lafferty said that she had witnessed Peltier's referring to his murder of one of the agents. Later developments 2002 editorial about deaths of agents and Aquash In January 2002 in the News from Indian Country, publisher Paul DeMain wrote an editorial that an "unnamed delegation" told him that Peltier had murdered the FBI agents. DeMain described the delegation as "grandfathers and grandmothers, AIM activists, Pipe carriers and others who have carried a heavy unhealthy burden within them that has taken its toll." DeMain said he was also told that the motive for the execution-style murder of high-ranking AIM activist Anna Mae Aquash in December 1975 at Pine Ridge "allegedly was her knowledge that Leonard Peltier had shot the two agents, as he was convicted." DeMain did not accuse Peltier of participation in the Aquash murder. In 2003 two Native American men were indicted and later convicted of the murder. On May 1, 2003, Peltier sued DeMain for libel for similar statements about the case published on March 10, 2003, in News from Indian Country. On May 25, 2004, Peltier withdrew the suit after he and DeMain settled the case. DeMain issued a statement saying he did not think Peltier was given a fair trial for the two murder convictions, nor did he think Peltier was connected to Aquash's death. DeMain stated he did not retract his allegations that Peltier was guilty of the murders of the FBI agents and that the motive for Aquash's murder was the fear that she might inform on the activist. Indictments and trials for the murder of Aquash In 2003 there were federal grand jury hearings on charges against Arlo Looking Cloud and John Graham for the murder of Anna Mae Aquash. Bruce Ellison, Leonard Peltier's lawyer since the 1970s, was subpoenaed and invoked his Fifth Amendment rights against self-incrimination, refusing to testify. He also refused to testify, on the same grounds, at Looking Cloud's trial in 2004. During the trial, the federal prosecutor named Ellison as a co-conspirator in the Aquash case. Witnesses said that Ellison participated in interrogating Aquash about being an FBI informant on December 11, 1975, shortly before her murder. In February 2004, Fritz Arlo Looking Cloud, an Oglala Sioux, was tried and convicted of the murder of Aquash. In Looking Cloud's trial, the federal prosecution argued that AIM leaders' suspicion of Aquash stemmed from her having heard Peltier admit to the murders. Darlene "Kamook" Nichols, former wife of AIM leader Dennis Banks, was a witness for the prosecution. She testified that in late 1975, Peltier told her and a small group of AIM fugitive activists about shooting the FBI agents. At the time, all were fleeing law enforcement after the Pine Ridge shootout. The other fugitives included her sister Bernie Nichols, her husband Dennis Banks, and Aquash, among several others. Bernie Nichols-Lafferty testified with a similar account of Peltier's statement. Earlier in 1975, AIM member Douglass Durham had been revealed to be an undercover FBI agent and dismissed from the organization. AIM leaders were fearful of infiltration. Other witnesses have testified that, when Aquash was suspected of being an informant, Peltier interrogated her while holding a gun to her head. Peltier and David Hill were said to have Aquash participate in bomb-making so that her fingerprints would be on the bombs. Prosecutors alleged in court documents that the trio planted these bombs at two power plants on the Pine Ridge Indian Reservation on Columbus Day 1975. During the trial, Nichols acknowledged receiving $42,000 from the FBI in connection with her cooperation on the case. She said it was compensation for travel expenses to collect evidence and moving expenses to be farther from her ex-husband Dennis Banks, whom she feared because she had implicated him as a witness. Peltier has claimed that Kamook Nichols committed perjury with her testimony. On June 26, 2007, the Supreme Court of British Columbia ordered the extradition of John Graham to the United States to stand trial for his alleged role in the murder of Aquash. He was eventually tried by the state of South Dakota in 2010. During Graham's trial, Darlene "Kamook" Ecoffey said Peltier told both
|
taken its toll." DeMain said he was also told that the motive for the execution-style murder of high-ranking AIM activist Anna Mae Aquash in December 1975 at Pine Ridge "allegedly was her knowledge that Leonard Peltier had shot the two agents, as he was convicted." DeMain did not accuse Peltier of participation in the Aquash murder. In 2003 two Native American men were indicted and later convicted of the murder. On May 1, 2003, Peltier sued DeMain for libel for similar statements about the case published on March 10, 2003, in News from Indian Country. On May 25, 2004, Peltier withdrew the suit after he and DeMain settled the case. DeMain issued a statement saying he did not think Peltier was given a fair trial for the two murder convictions, nor did he think Peltier was connected to Aquash's death. DeMain stated he did not retract his allegations that Peltier was guilty of the murders of the FBI agents and that the motive for Aquash's murder was the fear that she might inform on the activist. Indictments and trials for the murder of Aquash In 2003 there were federal grand jury hearings on charges against Arlo Looking Cloud and John Graham for the murder of Anna Mae Aquash. Bruce Ellison, Leonard Peltier's lawyer since the 1970s, was subpoenaed and invoked his Fifth Amendment rights against self-incrimination, refusing to testify. He also refused to testify, on the same grounds, at Looking Cloud's trial in 2004. During the trial, the federal prosecutor named Ellison as a co-conspirator in the Aquash case. Witnesses said that Ellison participated in interrogating Aquash about being an FBI informant on December 11, 1975, shortly before her murder. In February 2004, Fritz Arlo Looking Cloud, an Oglala Sioux, was tried and convicted of the murder of Aquash. In Looking Cloud's trial, the federal prosecution argued that AIM leaders' suspicion of Aquash stemmed from her having heard Peltier admit to the murders. Darlene "Kamook" Nichols, former wife of AIM leader Dennis Banks, was a witness for the prosecution. She testified that in late 1975, Peltier told her and a small group of AIM fugitive activists about shooting the FBI agents. At the time, all were fleeing law enforcement after the Pine Ridge shootout. The other fugitives included her sister Bernie Nichols, her husband Dennis Banks, and Aquash, among several others. Bernie Nichols-Lafferty testified with a similar account of Peltier's statement. Earlier in 1975, AIM member Douglass Durham had been revealed to be an undercover FBI agent and dismissed from the organization. AIM leaders were fearful of infiltration. Other witnesses have testified that, when Aquash was suspected of being an informant, Peltier interrogated her while holding a gun to her head. Peltier and David Hill were said to have Aquash participate in bomb-making so that her fingerprints would be on the bombs. Prosecutors alleged in court documents that the trio planted these bombs at two power plants on the Pine Ridge Indian Reservation on Columbus Day 1975. During the trial, Nichols acknowledged receiving $42,000 from the FBI in connection with her cooperation on the case. She said it was compensation for travel expenses to collect evidence and moving expenses to be farther from her ex-husband Dennis Banks, whom she feared because she had implicated him as a witness. Peltier has claimed that Kamook Nichols committed perjury with her testimony. On June 26, 2007, the Supreme Court of British Columbia ordered the extradition of John Graham to the United States to stand trial for his alleged role in the murder of Aquash. He was eventually tried by the state of South Dakota in 2010. During Graham's trial, Darlene "Kamook" Ecoffey said Peltier told both her and Aquash that he had killed the FBI agents in 1975. Ecoffey testified under oath, "He (Peltier) held his hand like this", she said, pointing her index finger like a gun, "and he said 'that (expletive) was begging for his life but I shot him anyway.'" Graham was convicted of murdering Aquash and sentenced to life in prison. Presidential politics Peltier was the candidate for the Peace and Freedom Party in the 2004 election for President of the United States. While numerous states have laws that prohibit prison inmates convicted of felonies from voting (Maine and Vermont are exceptions), the United States Constitution has no prohibition against felons being elected to federal offices, including President. The Peace and Freedom Party secured ballot status for Peltier only in California. His presidential candidacy received 27,607 votes, approximately 0.2% of the vote in that state. In 2020 he ran as the vice-presidential running mate of Gloria La Riva, on the ticket of the Party for Socialism and Liberation in the presidential campaign. He was forced to resign from the ticket for health reasons in early August 2020, and was replaced with Sunil Freeman. Ruling on FBI documents In a February 27, 2006, decision, U.S. District Judge William Skretny ruled that the FBI did not have to release five of 812 documents relating to Peltier and held at their Buffalo field office. He ruled that the particular documents were exempted on the grounds of "national security and FBI agent/informant protection". In his opinion, Judge Skretny wrote, "Plaintiff has not established the existence of bad faith or provided any evidence contradicting (the FBI's) claim that the release of these documents would endanger national security or would impair this country's relationship with a foreign government." In response, Michael Kuzma, a member of Peltier's defense team, said, "We're appealing. It's incredible that it took him 254 days to render a decision." Kuzma further said, "The pages we were most intrigued about revolved around a teletype from Buffalo ... a three-page document that seems to indicate that a confidential source was being advised by the FBI not to engage in conduct that would compromise attorney-client privilege." Peltier's supporters have tried to obtain more than 100,000 pages of documents from FBI field offices, claiming that the files should have been turned over at the time of his trial or following a Freedom of Information Act (FOIA) request filed soon after. Victim of prison violence On January 13, 2009, Peltier was beaten by inmates at the United States Penitentiary, Canaan, where he had been transferred from USP Lewisburg. He was sent back to Lewisburg, where he remained until the fall of 2011, when he was transferred to a federal penitentiary in Florida. As of 2016, Leonard Peltier is housed at Coleman Federal Correctional Complex in Coleman, Florida. In popular culture Sculpture In 2016, a statue of Peltier, based on a self portrait he made in prison, was created by artist Rigo 23 and installed on the grounds of American University in Washington, D.C.. After the university received complaints from the FBI Agents Association, the statue was removed and relocated to the Main Museum in Los Angeles. Films Incident at Oglala: The Leonard Peltier Story (1992) is a documentary by Michael Apted about Peltier and narrated by Robert Redford. The film argues in favour of the assertion that the government's prosecution of Peltier was unjust and politically motivated. Thunderheart (1992) is a fictional movie by Michael Apted, partly based on Peltier's case but with no pretense to accuracy. Warrior, The Life of Leonard Peltier (1992) is a feature documentary film about Peltier's life, the American Indian Movement, and his trial directed by Suzie Baer. The film argues that the government's prosecution of Peltier was unjust and motivated by the hugely profitable energy interests in the area. Music Free Salamander Exhibit released the song "Undestroyed" on December 13, 2016. The lyrics are drawn nearly verbatim from Peltier's book, Prison Writings: My Life Is My Sun Dance. Little Steven released the song "Leonard Peltier" on his 1989 album Revolution. The song discusses Peltier's case and the struggle of the Native Americans. The Indigo Girls popularized Buffy St. Marie's song, "Bury My Heart at Wounded Knee", with a cover on their 1995 live album 1200 Curfews. The song mentions Peltier, saying, "the bullets don’t match the gun." Sixteen Canadian artists contributed to Pine Ridge: An Open Letter to Allan Rock – Songs for Leonard Peltier, a benefit CD released in 1996 by What Magazine. Toad the Wet Sprocket reference Peltier, as well as the conflict at Pine Ridge and the Wounded Knee massacre, in their song "Crazy Life" on their album Coil: What have you done with Peltier? (1997) Anal Cunt released the song "Laughing While Lennard Peltier Gets Raped In Prison" as apart of their album It Just Gets Worse. U2 recorded the song "Native Son" about Peltier. It was later reworked into their hit song "Vertigo" on their album, How to Dismantle an Atomic Bomb (2004). Five years later, "Native Son" was released on their digital album Unreleased and Rare (2009). Bring Leonard Peltier Home in 2012 was a concert that took place at the Beacon Theatre in New York City. The concert featured Pete Seeger, Harry Belafonte, Jackson Browne, Common, Mos Def, Michael Moore, Danny Glover, Rubin "Hurricane" Carter, Bruce Cockburn, Margo Thunderbird, Silent Bear, Bill Miller, etc. all standing up for the immediate release of Leonard Peltier. In 2015, Sarah Meyer, formerly of the band Velveteen Dream, released a cover of Toad the Wet Sprocket's "Crazy Life" from their 1997 album Coil, which asks, "What have you done with Peltier?" Their SoundCloud single features an image of Sacheen Littlefeather, the Native American civil rights activist who served as a proxy for Marlon Brando when he was awarded a 1973 Academy Award for Academy Award for Best Actor for starring in The Godfather. Brando was involved in AIM with Peltier during the early 1970s and sought Littlefeather's help in 1973 to protest the ongoing Wounded Knee Incident standoff. Rage Against The Machine's 1994 "Freedom" video clip shows footage of the case and ends with a picture of Peltier in prison and the phrase "justice has not been done". "Sacrifice" from Contact from the Underworld of Redboy, the 1998 music recording by Robbie Robertson (formerly of The Band), features voice recordings of Peltier throughout the song, and surrounded with melody and vocals. The song ends with Peltier alone sayin, "I've gone too far now to start backing down. I don't give up. Not 'til my people are free will I give up and if I have to sacrifice some more, then I sacrifice some more." French singer Renaud released a song called "Leonard's Song" in his 2006 album Rouge Sang. It supports Peltier and Native American rights, comparing in its lyrics the foundation of America to conducting an equivalent of The Holocaust against the Native American people. Alternative hip-hop trio The Goats mention Peltier several times on their 1992 debut album Tricks of the Shade: in a track entitled "Leonard Peltier in a Cage", and in the song "Do the Digs Dug" (which also mentions activist Annie Mae Aquash – lyrics referencing them are "Leonard Peltier Leonard Peltier Who da hell is that, why the f*** should ya care? In jail, in jail, in jail like a dealer F*** George Bush says my T-Shirt squeeler Please oh please set Leonard P. free Cause ya wiped out his race like an ant colony Whatcha afraid of, Annie Mae Aquash? Found her lying in the ditch with no place for a watch") Other It was reported by Joseph Corré that the last words of his father, Malcolm McLaren, were "Free Leonard Peltier". Publications Arden, Harvey (& Leonard Peltier). "Have You Thought of Leonard Peltier Lately?" HYT Publishing, 2004. . Peltier, Leonard. Prison Writings: My Life Is My Sun Dance. New York, 1999. . See also List of memoirs of political prisoners List of longest prison sentences served Category:Native American activists Lapu Lapu Omar Mukhtar Chino Roces References Further reading "Writer Sues Peltier", Kansas City Star, July 3, 1992.
|
variety called a MOO. It is the oldest MOO today. LambdaMOO was founded in 1990 by Pavel Curtis at Xerox PARC. Now hosted in the state of Washington, it is operated and administered entirely on a volunteer basis. Guests are allowed, and membership is free to anyone with an e-mail address. LambdaMOO gained some notoriety when Julian Dibbell wrote a book called My Tiny Life describing his experiences there. Over its history, LambdaMOO has been highly influential in the examination of virtual-world social issues. History LambdaMOO has its roots in the 1978–1980 work by Roy Trubshaw and Richard Bartle to create and expand the concept of Multi-User Dungeon (MUD) – virtual communities. Around 1987–1988, the expansion of the global internet allowed more users to experience the MUD. Pavel Curtis at Xerox Parc noted that they were "almost exclusively for recreational purposes." Curtis determined to explore whether the MUD could be non-recreational. He developed LambdaMOO software to run on the LambdaMOO server, which implements the MOO programming language. This software was subsequently made available to the public. Several starter databases, known as cores, are available for MOOs; LambdaMOO itself uses the LambdaCore database. The "Lambda"
|
a second area, "The Linen Closet" (specially programmed as a silent area) was later added as an alternative connection point. The coat closet opens onto the center of the house in The Living Room, a common hangout and place for conversation; its fixtures include a fireplace (where things can be roasted), The Living Room Couch (which periodically causes players' objects to 'fall through' to underneath the couch), and a pet Cockatoo who repeats overheard phrases (which is sometimes found with its beak gagged). Occasionally, the Cockatoo is replaced with a more seasonal creature: a Turkey near Thanksgiving, a Raven near Halloween, et cetera. To the north of the Living Room is the Entrance Hall, the Front Yard, and a limited residential area along LambdaStreet. There is an extensive subterranean complex located down the manhole, including a sewage system. Players walking to the far west along LambdaStreet may be given the option to 'jump off the edge of the world', which disables access to their account for three months. To the south of the Living Room is a pool deck, a hot tub, and some of the extensive grounds of the mansion, featuring gardens, hot air balloon landing pads, open fields, fishing holes, and the like. To the northwest of the living room are the laundry room, garage, dining room, smoking room, drawing room, housekeeper's quarters, and kitchen. To the east of the entry hall, hallways provide access to some individual rooms, the Linen Closet, and to the eastern wing of the house. In the eastern wing can be found the Library of online books, the Museum of generic objects (which account-holders may create instances of), and an extensive area for the LambdaMOO RPG. Since the creation of the original LambdaMOO map, many users have expanded the MOO by making additional rooms with the command "@dig." Politics While most MOOs are run by administrative fiat, in summer of 1993 LambdaMOO implemented a petition/ballot mechanism, allowing the community to propose and vote on new policies and other administrative actions. A petition may be created by anyone eligible to participate in politics (those who have maintained accounts at the MOO for at least 30 days), can be signed by other players, and may then be submitted
|
BC. The armor was first used in the early 1st century. Although, the exact time in which the Romans adopted the armor remains unknown. Some say it was after Crassus' defeat at Carrhae in 53 BC. Others say the armor was adopted in 21 AD after the Revolt of Julius Sacrovir and Julius Florus. One form of the armor was used as early as 9 AD. Because the soldiers at the Battle of Teutoberg Forest wore the lorica segmentata, we can conclude the armor must have been in use before 21 AD. Around the middle of the third century the lorica segmentata fell out of favor with the Roman army. Although, it did remain in use during the Late Roman Empire. The armor was still around in the 4th century. Soldiers wearing the lorica segmentata were depicted on the Arch of Constantine, a monument erected in 315. However, it has been argued that these depictions are from an earlier monument by Marcus Aurelius, from which Constantine incorporated portions into his Arch. The latest known use of the armor was in the 4th century. Over time the type of lorica segmentata would change. From 9 BC to 43 AD the Roman soldier wore the Dngestetten-Kalkriese-Vindonissa type, from 69 to 100 the Corbridge-Carnuntum was used and from 164 to 180 Newstead type was used. The time the armors were worn would overlap. It is possible that there was a fourth type, covering the body with segmented armour joined to scale shoulder defences. However, this is only known from one badly-damaged statue originating at Alba Iulia in Romania. The currently accepted range for the use of the armour is from about 14 B.C. to the late 3rd century A.D. The lorica segmentata's use in the Roman army was geographically widespread, but the mail armor lorica hamata may have been more common at all times. Usage in the Roman Army The question as to precisely who used the armour is debated. On the monument, Auxilia are generally shown wearing mail, cuirasses, and carrying oval shields. Legionaries are uniformly depicted wearing the lorica segmentata and carrying the curved rectangular shield. On this basis, it has been supposed that lorica segmentata was exclusively used by legionaries and praetorians. However, some historians consider Trajan's Column to be inaccurate as a historical source due to its inaccurate and stylised portrayal of Roman armour. These historians also say that "it is probably safest to interpret the Column reliefs as 'impressions', rather than accurate representations." The discovery of parts of the lorica segmentata at areas where auxiliary soldiers would have been stationed implies that auxiliary troops used the lorica segmentata. However, it is entirely possible that the reason behind the presence of the lorica segmentata in these areas could because these areas had a small number of legionaries stationed there. On the Adamclisi Tropaeum, the lorica segmentata does not appear at all, and legionaries and auxilia alike are depicted wearing the lorica squamata. Some experts are of the opinion that the Adamclisi monument is a more accurate portrayal of the situation, the segmentata used rarely, maybe only for set-piece battles and parades.
|
century BC. The armor was first used in the early 1st century. Although, the exact time in which the Romans adopted the armor remains unknown. Some say it was after Crassus' defeat at Carrhae in 53 BC. Others say the armor was adopted in 21 AD after the Revolt of Julius Sacrovir and Julius Florus. One form of the armor was used as early as 9 AD. Because the soldiers at the Battle of Teutoberg Forest wore the lorica segmentata, we can conclude the armor must have been in use before 21 AD. Around the middle of the third century the lorica segmentata fell out of favor with the Roman army. Although, it did remain in use during the Late Roman Empire. The armor was still around in the 4th century. Soldiers wearing the lorica segmentata were depicted on the Arch of Constantine, a monument erected in 315. However, it has been argued that these depictions are from an earlier monument by Marcus Aurelius, from which Constantine incorporated portions into his Arch. The latest known use of the armor was in the 4th century. Over time the type of lorica segmentata would change. From 9 BC to 43 AD the Roman soldier wore the Dngestetten-Kalkriese-Vindonissa type, from 69 to 100 the Corbridge-Carnuntum was used and from 164 to 180 Newstead type was used. The time the armors were worn would overlap. It is possible that there was a fourth type, covering the body with segmented armour joined to scale shoulder defences. However, this is only known from one badly-damaged statue originating at Alba Iulia in Romania. The currently accepted range for the use of the armour is from about 14 B.C. to the late 3rd century A.D. The lorica segmentata's use in the Roman army was geographically widespread, but the mail armor lorica hamata may have been more common at all times. Usage in the Roman Army The question as to precisely who used the armour is debated. On the monument, Auxilia are generally shown wearing mail, cuirasses, and carrying oval shields. Legionaries are uniformly depicted wearing the lorica segmentata and carrying the curved rectangular shield. On this basis, it has been supposed that lorica segmentata was exclusively used by legionaries and praetorians. However, some historians consider Trajan's Column to be inaccurate as a historical source due to its inaccurate and stylised portrayal of Roman armour. These historians also say that "it is probably safest to interpret the Column reliefs as 'impressions', rather than accurate representations." The discovery of parts of the lorica segmentata at areas where auxiliary soldiers would have been stationed implies that auxiliary troops used the lorica segmentata. However, it is entirely possible that the reason behind the presence of the lorica segmentata in these areas could because these areas had a small number of legionaries stationed there. On the Adamclisi Tropaeum, the lorica segmentata does not appear at all, and legionaries and auxilia alike are depicted wearing the lorica squamata. Some experts are of the opinion that the Adamclisi monument is a more accurate portrayal of the situation, the segmentata used rarely, maybe only for set-piece battles and parades. This viewpoint considers the figures in Trajan's Column to be highly stereotyped, in order to distinguish clearly between different types of troops. It's also debated if the lorica segmentata was only used in the west. Every
|
dense and too hot to breathe, and is inhabited only by the Bandersnatchi. The zones between the vacuum areas and the high-density belt area have atmosphere breathable by humans. Jinx's "East" and "West" ends become a major in vacuo manufacturing area. Jinxian humans are short and squat, the strongest bipeds in Known Space. But they tend to die early, from heart and circulatory problems. There is a tourist industry which provides substantial useful interplanetary trade credits for the Bandersnatchi, who allow themselves to be hunted by humans under strict protocols. Wunderland is a planet circling Alpha Centauri, and was the earliest extra-solar colony in Known Space's human history. It has a surface gravity of 60% that of Earth's and is hospitable to human life. Wunderland was invaded and its population enslaved by the Kzinti during the first Man-Kzin War. It was freed near the end of the First War by the human Hyperdrive Armada from We Made It. The system has an asteroid belt in the shape of a crescent, which gives it its name—the Serpent Swarm. The capital asteroid, Tiamat, houses one of the largest Kzin populations in Known Space. We Made It, orbiting Procyon A, got its name because the first colony ship crash-landed. Gravity is about three-fifths Earth's. The planet's axis is pointed along the plane of its ecliptic (like Uranus), creating ferocious winds on the order of 500 mph (800 km/h) during half of the planet's year, forcing the people to live underground. Natives are known as "Crashlanders", tend to be very tall, and many are albinos. Their capital, which was the site of their colony ship's landing, is called Crashlanding City. We Made It also has viscous, algae-choked "oceans" and a big icy moon, ironically named Desert Isle. Plateau in the Tau Ceti system is Venus-like, with a plateau (called Mount Lookitthat), half the size of California, rising high enough out of the dense atmosphere to be habitable. Inhabitants ("Mountaineers") are divided into two rigid hereditary castes, the "crew" and the "colonists", depending on whether their ancestors piloted the colonizing vessel. The crew are the upper caste, and hold power through their monopoly on organ transplantation and control of the police. The original colonists signed the "Covenant of Planetfall", agreeing that this outcome was just recompense for the labors of the crew during the voyage; that they signed at gunpoint as they were awakened from hibernation is kept secret from later generations, and also that those who refused, died. This repressive system is overthrown in A Gift From Earth, and the former inequality and caste system appears to have disappeared by the time The Ethics of Madness takes place. Home orbits the star Epsilon Indi, about 12 light years from Earth. The planet received its name because of its remarkable similarity to Earth; its day is nearly 24 hours long and its surface gravity is a comfortable 1.08 g. Oceans, mean global temperature, seasons, and moon (Home's moon is called Metaluna, but is often referred to as "the Moon" by Homers) are also similar. According to Protector, the original colonists had planned to call their world "Flatland" as a sort of joke, but once settled on Home they had changed their minds—"a belated attack of patriotism", Elroy Truesdale of Protector muses. The entire population of Home is secretly destroyed as a consequence of Brennan's and Truesdale's war with the Pak—Brennan turns the entire population into human Protectors to create an army to fight the Pak invaders. Home is resettled quickly though, since another ramjet with colonists is already on its way when the colony "fails". In Procrustes and other later stories, Home is once again presented as a vibrant colony. Canyon was once an uninhabitable Mars-like world known as Warhead. It is the second of seven planets around p Eridani A, 22 light-years from Earth. It was used as a military outpost by the Kzinti, until the planet was hit by a weapon called the "Wunderland Treatymaker" during the Third War. The attack tore a long, narrow, kilometers-deep crater into the crust approximately the size of the Baja Peninsula. The air and moisture in the thin atmosphere gathered at the bottom of this artificial canyon, creating a breathable environment, complete with a sea at the bottom. The planet was then renamed for the crater, and settled by humans in a huge city running up the crater wall. Archaic (hyper-aggressive and intractable) Kzinti were entombed in stasis field shells during the attack and are still beneath the lava, and someday, somebody will have to deal with them. The attack by the Wunderland Treatymaker is detailed as a part of Destiny's Forge by Paul Chafe, a part of the Man-Kzin Wars shared universe. Gummidgy is a jungle world popular with hunters. It is home to the Gummidgy Orchid-Thing, a sessile carnivore which hangs from trees and is a popular trophy for the wealthy. It orbits CY Aquarii, a blue giant SX Phoenicis variable star; due to the resulting high levels of ultraviolet light, most humans (except Jinxians) require melanin-boosting medication to venture outdoors. Fafnir is a former Kzin colony covered almost entirely in water. When under Kzinti control it was called Shasht, a Kzin word meaning "burrowing murder." It was captured by humans during the Man-Kzin Wars. Humans and Kzinti now cohabitate. The humans prefer to live on the coral islands while the Kzinti prefer the single large continent which they continue to call Shasht. Margrave is a late addition to the family of Human colonies. In the Ringworld era it is still a frontier world, and is home to enormous birds the inhabitants have dubbed "rocs". It orbits Lambda Serpentis (27 Serpentis), a G0 star 34.7 light-years from Earth. It is named after its discoverer, J. Margrave Julland. Silvereyes is, at the time of Ringworld, the furthest Human world from Earth (21.3 light-years, 60 days at Quantum-I hyperdrive speeds), orbiting Beta Hydri. In Niven's obscure story The Color of Sunfire it has entire continents covered with Slaver sunflowers (bred as defense for Thrint manors, they focus sunlight using silver leaves as parabolic reflectors), giving it an appearance from orbit of having "silver eyes". The Man-Kzin Wars books, conversely, have it entirely covered by a world ocean, with groves of sunflowers growing up from the bottom of the ocean. The Ringworld Roleplaying Game describes it as an ocean planet dotted with island shield volcanoes. The Fleet of Worlds is the five (at one point six, as detailed in Fleet of Worlds) planets that are home to the Puppeteers (see above), presently being moved in formation at sub-light speeds out of the galaxy to avoid destruction as the wave of radiation from an explosion of the galactic core sweeps towards the outer reaches of the galaxy. They orbit about each other in a Klemperer rosette. Hearth is the homeworld of the Pierson's Puppeteers, with a population of around one trillion and is covered by arcologies, most over one mile tall. Its industries and population generate so much waste heat it no longer requires a star for warmth (the four other "farmworlds", simply named "Nature Preserves" or NP1, NP2, etc., use artificial orbital lights to grow food). Together they are often referred as "the fleet of Worlds" and do not orbit any star, but use Outsider manufactured drives to move in order to flee the galactic core explosion discovered by Beowulf Schaffer. Kobold was a tiny artificial world created in the outer Sol System by Jack Brennan, a human Protector, composed of a small sphere of neutronium in the center ringed by a larger torus. Gravity generators facilitated movement between the two sections and were used in games and art. Brennan destroyed Kobold just prior to leaving for his war with the Pak Protectors. The Ringworld is an artificial world structure with three million times the surface area of Earth, built in the shape of a giant ring circling its sun, a million miles wide and with a diameter of 186 million miles. It was built by the Pak, who either abandoned it, or more likely died out much as the Earth Pak did, due to a lack of a key yamlike root which produces the conversion to Protector-stage Pak (which required a very specifically targeted soil chemistry to grow). It is inhabited by a number of different evolved hominid species, and includes representative samples of Bandersnatchi, Martians and Kzinti, and possibly other alien races that existed at the time of its construction. Sheathclaws is a planet colonized by humans aboard Angel's Pencil and descendants of a rogue Kzin telepath. It orbits an as-yet-unspecified star 98 light-years from Earth, and kept its existence secret for several centuries. The Patriarchy would dearly love to capture the entire population of potential Telepaths and press them into service. "Kzin" translates as "Home-of-the-Kzinti" or "Kzinhome" in the Hero's Tongue. It orbits 61 Ursae Majoris and has higher gravity than Earth and more oxygen in the atmosphere. It has two moons, known as the Hunter's Moon and the Traveler's Moon. Cue Ball is an uninhabitable ice world orbiting Beta Lyrae. Jm'ho A moon similar to Europa, homeword to the Gw'oth. It orbits a gas giant called Tl'ho. The star is simply called G567-X2 in the Puppeteers' catalogue Kl'mo A Gw'oth colony founded by Ol't'ro. Not much is explained about this world, except that it seems very primitive and has a very strong gravity. Oceanus A primitive world briefly surveyed by the crew of "Explorer" in the first "Fleet of worlds" book. Technology The series features a number of "superscience" inventions which figure as plot devices. Stories earlier in the timeline feature technology such as Bussard ramjets, Drouds (wires capable of directly stimulating the pleasure centers of the brain) and explore how organ transplantation technology enables the new crime of organlegging (as well as the general sociological effects of widespread transplant technology), while later stories feature hyperdrive, invulnerable starship hulls, stasis fields, molecular monofilaments, transfer booths (teleporters used only on planetary surfaces), the lifespan-extending drug boosterspice, and the tasp which is an extension of the wirehead development which works without direct contact. Boosterspice Boosterspice is a compound that increases the longevity and reverses aging of human beings. With the use of boosterspice, humans can easily live hundreds of years and, theoretically, indefinitely. Developed by the Institute of Knowledge on Jinx, it is said to be made from genetically engineered ragweed (although early stories have it ingested in the form of edible seeds). In Ringworld's Children, it is suggested boosterspice may actually be adapted from Tree-of-Life, without the symbiotic virus that enabled hominids to metamorphose from Pak Breeder stage to Pak Protector stage (mutated Pak breeders were the ancestors of both Homo sapiens and the hominids of the Ringworld). On the Ringworld, there is an analogous (and apparently more potent) compound developed from Tree-of-Life, but they are mutually incompatible; in The Ringworld Engineers, Louis Wu learns that the character Halrloprillalar died when in ARM custody after leaving the Ringworld, as a result of having taken boosterspice after having used the Ringworld equivalent. Boosterspice only works on Homo sapiens, whereas the Tree-of-Life compound will work on any hominid descended from the Pak. Hyperdrive Faster-than-light (FTL) propulsion, or hyperdrive, was obtained from the Outsiders at the end of the First Man-Kzin War. In addition to winning the war for humanity, it allowed the re-integration of all the human colonies, which were previously separated by distance. Standard hyperdrive covers a distance of one light-year every three days (121.75 x c). A more advanced Quantum II Hyperdrive introduced later is able to cover the same distance in one and a quarter minutes (420,768 x c). In Niven's first novel, World of Ptavvs, the hyperdrive used by the Thrintun required a ship to be going faster than 93% of the speed of light. However, this is the only time that Hyperdrive is described this way. In the vast majority of Known Space material, hyperdrive requires that a ship be outside a star's gravity well to use. Ships which activate hyperdrive close to a star are likely to disappear without a trace. This effect is regarded as a limitation based on the laws of physics. In Niven's novel Ringworld's Children the Ringworld itself is converted into a gigantic Quantum II hyperdrive and launched into hyperspace while within its star's gravity well. Ringworld's Children reveals that there is life in hyperspace around gravity wells and that hyperspace predators eat spaceships which appear in hyperspace close to large masses, thus explaining why a structure as large as the Ringworld can safely engage the hyperdrive in a star's gravity well. One phenomenon travellers in hyperspace can experience is the so-called 'blind spot' should they look through a porthole or camera screen, giving the impression that the walls around the porthole or sides of the camera view screen are expanding to 'cover up the outside'. The phenomenon is the result of hyperspace being so fundamentally different from 'normal/Einstein' space that a traveller's senses can not truly comprehend it, and instead the observer 'sees' a form of nothingness that can be hypnotic and dangerous. Staring too long into the 'blind' spot can be insanity inducing, so as a precaution all view ports on ships are blinded when a ship enters hyperspace. Invulnerable hulls The Puppeteer firm, General Products, produces an invulnerable starship hull, known simply as a General Products Hull. The hulls are impervious to any type of matter or energy, with the exception of antimatter (which destroys the hull), gravitation, and visible light (which passes through the hull). While invulnerable themselves, this is no guarantee that the contents are likewise protected. For example, though a high speed impact with the surface of a planet or star may cause no harm to the hull, the occupants will be crushed if they are not protected by additional measures such as a stasis field or a gravity compensating field. In Fleet of Worlds, the characters tour a General Products factory and receive clues that allow them to destroy a General Products hull from the inside using only a high-powered interstellar communications laser. In Juggler of Worlds, the Puppeteers, attempting to surmise how this was done without antimatter, identify another technique which can be used to destroy the otherwise invulnerable hulls, one which does suggest some potential defense options. Organ transplantation On Earth in the mid-21st century, it became possible to transplant any organ from any person to another, with the exception of brain and central nervous system tissue. Individuals were categorized according to their so-called "rejection spectrum" which allowed doctors to counter any immune system responses to the new organs, allowing transplants to "take" for life. It also enabled the crime of "organlegging" which lasted well into the 24th century. Stasis fields A Slaver stasis field creates a bubble of space/time disconnected from the entropy gradient of the rest of the universe. Time slows effectively to a stop for an object in stasis, at a ratio of some billions of years outside to a second inside. An object in stasis is invulnerable to anything occurring outside the field, as well as being preserved indefinitely. A stasis field may be recognized by its perfectly reflecting surface, so perfect that it reflects 100% of all radiation and particles, including neutrinos. However one stasis field cannot exist inside another. This is used in World of Ptavvs where humans develop a stasis field technology and realize that a mirrored artifact known as the Sea Statue must be actually an alien in a stasis field. They place it with a human envoy, who is a telepath, and envelop both in field. By doing this, they unleash the last living member of the Slaver species on the world. Stepping disks Stepping disks are a fictional teleportation technology. They were invented by the Pierson's Puppeteers, and their existence is not generally known to other races until the events of The Ringworld Engineers. The stepping disks are an outgrowth and improvement of the transfer booth technology used by humans and other Known Space races. Unlike the booths, the disks do not require an enclosed chamber, and somehow can differentiate between solid masses and air, for example. They also have a far greater range than transfer booths, extending several astronomical units. Several limitations to stepping disks are mentioned in the Ringworld novels. If there is a difference in velocity between two disks, any matter transferred between them must be accelerated by the disk accordingly. If there is not enough energy to do so, the transfer cannot take place. This becomes a problem with disks that are a significant distance apart on the Ringworld surface, as they will have different velocities: same speed, different direction. Transfer booths Transfer booths or displacement booths are an inexpensive form of teleportation. Short-range booths are similar in appearance to an old style telephone booth: one enters, "dials" one's desired destination, and is immediately deposited in a corresponding booth at the destination. Longer-range booths operate similarly, but are housed in former airports due to requiring "equipment to compensate for the difference in rotational velocity between different points on the Earth". They
|
perfection of organ transplant technology, all state executions were done in hospitals to provide organ transplants, and to maximize their availability nearly all crimes carried the death penalty, including such offenses as multiple traffic tickets or tax evasion. This period ended when Jack Brennan, who had consumed the Tree-of-Life root and become a human version of the Pak Protector, used his superior intelligence to engineer social change in medical technology and social attitudes that eventually reduced the use of organ banks to reasonable levels. Part of Brennan's manipulation was the development of a science known as "psychistry". Psychistry was used to "correct" all forms of "mental aberration" - the populace is extremely docile. To combat overpopulation (one estimate is 18 billion people), a license is required to procreate, only available after exhaustive testing has determined that a prospect is free of "abnormalities"; unlicensed procreation is a capital crime. This policy, in addition to the existence of the transfer booth and a one-world language and economy, has led to the populace eventually becoming fairly genetically homogeneous. To prevent the development of new WMDs, all scientific research is regulated by the government and potentially dangerous technology is suppressed. Due to such suppression, Earth has had fewer real breakthroughs in science than would be expected. A common title for people born on Earth is "Flatlander"; having been born and raised in the only environment in Known Space to which humans are well-adapted, they are considered naïve and a bit helpless by humans from colony worlds. The Moon is a separate entity, with its own distinct culture but is under the control of the same government as Earth. Humans native to the Moon are called "Lunies", and tend toward tall, lean body types regularly reaching eight feet in height. They are frequently referred to as looking much like Tolkien's Elves due to their physiques and alien allure. Mars, fourth planet in the Solar System and the first planetary colony in Known Space. Native "Martians" were exterminated by the Brennan genocide. No one goes there, as resources are easier to mine in the Belt and Jovian moons. Earth ultimately colonized Mars specifically to study the descent landing pod used by Phssthpok the Pak in 2124 AD and the research colony was still in existence in 2183 when the Martians were exterminated by Brennan. The colony expanded greatly during the first Man-Kzin war 2367-2433. The Sol Belt possesses an abundance of valuable ores, which are easily accessible due to the low to negligible gravity of the rocks containing them. Originally a harsh frontier under U.N. control, the Belt declared independence after creating Confinement Asteroid, a habitat with spin gravity that permitted safe gestation of children, and Farmer's Asteroid, the Belt's primary food source. Almost immediately a lively competition began between the fiercely independent "Belters" and the technology police of the U.N. Several years of tension and economic conflicts followed, but soon settled into a relatively peaceful trade relationship as the Belt has so many resources that the UN and the Earth need. Mercury is also a colony world with a small number of inhabitants, used mainly for mining and as a gravitational anchor for orbiting solar power stations which beam power to the more remote colonies using gigantic lasers. At the time of the First Man-Kzin War, human society is so pacifistic that no weapons exist; those who are able to even contemplate killing another sentient being or constructing a weapon for that purpose are regarded as mental aberrations and must take drugs to control their thoughts. However, an enormous laser, whether constructed as a weapon or not, makes a highly effective one, and it's strongly implied that the existence of the Mercury power satellites is a large part of what enabled Sol System to hold off the Kzinti in the early part of the war. Down is the home world of the Grogs and a former Kzinti colony. It orbits "L5-1668", a faint, cool M-type star, significantly redder and cooler than Sol and 12.3 light-years from it. Down is made habitable in part because of its large moon, Sheila. Grogs, though friendly, are feared by humanity, due to their telepathic ability to control the minds of animals (and possibly sentient species as well). Because of this fear, humans have placed a Bussard ramjet field generator in close orbit around Down's sun, thus enabling them to destroy the Grog population should they ever take hostile action against any sentient species. Jinx, orbiting Sirius A, is a massive moon of a gas giant (called Primary), stretched by tidal forces into an egg shape and tidally locked. In the habitable areas it has high surface gravity near the limits of human extended tolerance. The points nearest to and farthest from Primary (called the "East" and "West" ends) lie elevated out of the atmosphere in vacuum. The atmosphere of the belt-region halfway between them is too dense and too hot to breathe, and is inhabited only by the Bandersnatchi. The zones between the vacuum areas and the high-density belt area have atmosphere breathable by humans. Jinx's "East" and "West" ends become a major in vacuo manufacturing area. Jinxian humans are short and squat, the strongest bipeds in Known Space. But they tend to die early, from heart and circulatory problems. There is a tourist industry which provides substantial useful interplanetary trade credits for the Bandersnatchi, who allow themselves to be hunted by humans under strict protocols. Wunderland is a planet circling Alpha Centauri, and was the earliest extra-solar colony in Known Space's human history. It has a surface gravity of 60% that of Earth's and is hospitable to human life. Wunderland was invaded and its population enslaved by the Kzinti during the first Man-Kzin War. It was freed near the end of the First War by the human Hyperdrive Armada from We Made It. The system has an asteroid belt in the shape of a crescent, which gives it its name—the Serpent Swarm. The capital asteroid, Tiamat, houses one of the largest Kzin populations in Known Space. We Made It, orbiting Procyon A, got its name because the first colony ship crash-landed. Gravity is about three-fifths Earth's. The planet's axis is pointed along the plane of its ecliptic (like Uranus), creating ferocious winds on the order of 500 mph (800 km/h) during half of the planet's year, forcing the people to live underground. Natives are known as "Crashlanders", tend to be very tall, and many are albinos. Their capital, which was the site of their colony ship's landing, is called Crashlanding City. We Made It also has viscous, algae-choked "oceans" and a big icy moon, ironically named Desert Isle. Plateau in the Tau Ceti system is Venus-like, with a plateau (called Mount Lookitthat), half the size of California, rising high enough out of the dense atmosphere to be habitable. Inhabitants ("Mountaineers") are divided into two rigid hereditary castes, the "crew" and the "colonists", depending on whether their ancestors piloted the colonizing vessel. The crew are the upper caste, and hold power through their monopoly on organ transplantation and control of the police. The original colonists signed the "Covenant of Planetfall", agreeing that this outcome was just recompense for the labors of the crew during the voyage; that they signed at gunpoint as they were awakened from hibernation is kept secret from later generations, and also that those who refused, died. This repressive system is overthrown in A Gift From Earth, and the former inequality and caste system appears to have disappeared by the time The Ethics of Madness takes place. Home orbits the star Epsilon Indi, about 12 light years from Earth. The planet received its name because of its remarkable similarity to Earth; its day is nearly 24 hours long and its surface gravity is a comfortable 1.08 g. Oceans, mean global temperature, seasons, and moon (Home's moon is called Metaluna, but is often referred to as "the Moon" by Homers) are also similar. According to Protector, the original colonists had planned to call their world "Flatland" as a sort of joke, but once settled on Home they had changed their minds—"a belated attack of patriotism", Elroy Truesdale of Protector muses. The entire population of Home is secretly destroyed as a consequence of Brennan's and Truesdale's war with the Pak—Brennan turns the entire population into human Protectors to create an army to fight the Pak invaders. Home is resettled quickly though, since another ramjet with colonists is already on its way when the colony "fails". In Procrustes and other later stories, Home is once again presented as a vibrant colony. Canyon was once an uninhabitable Mars-like world known as Warhead. It is the second of seven planets around p Eridani A, 22 light-years from Earth. It was used as a military outpost by the Kzinti, until the planet was hit by a weapon called the "Wunderland Treatymaker" during the Third War. The attack tore a long, narrow, kilometers-deep crater into the crust approximately the size of the Baja Peninsula. The air and moisture in the thin atmosphere gathered at the bottom of this artificial canyon, creating a breathable environment, complete with a sea at the bottom. The planet was then renamed for the crater, and settled by humans in a huge city running up the crater wall. Archaic (hyper-aggressive and intractable) Kzinti were entombed in stasis field shells during the attack and are still beneath the lava, and someday, somebody will have to deal with them. The attack by the Wunderland Treatymaker is detailed as a part of Destiny's Forge by Paul Chafe, a part of the Man-Kzin Wars shared universe. Gummidgy is a jungle world popular with hunters. It is home to the Gummidgy Orchid-Thing, a sessile carnivore which hangs from trees and is a popular trophy for the wealthy. It orbits CY Aquarii, a blue giant SX Phoenicis variable star; due to the resulting high levels of ultraviolet light, most humans (except Jinxians) require melanin-boosting medication to venture outdoors. Fafnir is a former Kzin colony covered almost entirely in water. When under Kzinti control it was called Shasht, a Kzin word meaning "burrowing murder." It was captured by humans during the Man-Kzin Wars. Humans and Kzinti now cohabitate. The humans prefer to live on the coral islands while the Kzinti prefer the single large continent which they continue to call Shasht. Margrave is a late addition to the family of Human colonies. In the Ringworld era it is still a frontier world, and is home to enormous birds the inhabitants have dubbed "rocs". It orbits Lambda Serpentis (27 Serpentis), a G0 star 34.7 light-years from Earth. It is named after its discoverer, J. Margrave Julland. Silvereyes is, at the time of Ringworld, the furthest Human world from Earth (21.3 light-years, 60 days at Quantum-I hyperdrive speeds), orbiting Beta Hydri. In Niven's obscure story The Color of Sunfire it has entire continents covered with Slaver sunflowers (bred as defense for Thrint manors, they focus sunlight using silver leaves as parabolic reflectors), giving it an appearance from orbit of having "silver eyes". The Man-Kzin Wars books, conversely, have it entirely covered by a world ocean, with groves of sunflowers growing up from the bottom of the ocean. The Ringworld Roleplaying Game describes it as an ocean planet dotted with island shield volcanoes. The Fleet of Worlds is the five (at one point six, as detailed in Fleet of Worlds) planets that are home to the Puppeteers (see above), presently being moved in formation at sub-light speeds out of the galaxy to avoid
|
German woman and an American soldier who was stationed in West Germany, grew up on Long Island in New York, where he always dreamed of flying. As a child, he assembled model airplanes, collected aviation memorabilia and read books on aviation. He was 15 years old when he started flight instruction in a Cessna 152. Working part-time jobs after school to pay for flying lessons, he completed his first solo trip at the age of 16 and obtained his private pilot's certificate in 1983. Homer was graduated from Ss. Cyril and Methodius School in 1979 and St. John the Baptist Diocesan High School in 1983. He entered the United States Air Force Academy as a member of the class of 1987. As an upperclassman, he was a member of Cadet Squadron 31. He graduated on May 27, 1987, and was commissioned as a second lieutenant in the U.S. Air Force. After completing his USAF pilot training in 1988, he was assigned to McGuire Air Force Base in New Jersey, flying a Lockheed C-141 Starlifter. While on active duty, he served in the Gulf War and later supported operations in Somalia. He received many commendations, awards and medals during his military career. In 1993, he was named the Twenty-First Air Force "Aircrew Instructor of the Year". Homer achieved the rank of captain before his honorable discharge from active duty in 1995 and his acceptance of a reserve commission in order to continue his career as an Air Force officer. Homer continued his military career as a member of the U.S. Air Force Reserve, initially as a C-141 instructor pilot with the 356th Airlift Squadron at Wright-Patterson Air Force Base in Ohio, then subsequently as an Academy Liaison Officer, recruiting potential candidates for both the Air Force Academy and the Air Force Reserve Officer Training Corps. During his time in the Air Force Reserve, he achieved the rank of major. He continued his flying career by joining United Airlines in May 1995. His first assignment was Second Officer on the Boeing 727. He then upgraded to First Officer on the Boeing 757/Boeing 767 in 1996, where he remained until September 11, 2001. He married his wife, Melodie, on May 24, 1998, and his first child, Laurel, was born in late November 2000. They resided together in Marlton, New
|
Methodius School in 1979 and St. John the Baptist Diocesan High School in 1983. He entered the United States Air Force Academy as a member of the class of 1987. As an upperclassman, he was a member of Cadet Squadron 31. He graduated on May 27, 1987, and was commissioned as a second lieutenant in the U.S. Air Force. After completing his USAF pilot training in 1988, he was assigned to McGuire Air Force Base in New Jersey, flying a Lockheed C-141 Starlifter. While on active duty, he served in the Gulf War and later supported operations in Somalia. He received many commendations, awards and medals during his military career. In 1993, he was named the Twenty-First Air Force "Aircrew Instructor of the Year". Homer achieved the rank of captain before his honorable discharge from active duty in 1995 and his acceptance of a reserve commission in order to continue his career as an Air Force officer. Homer continued his military career as a member of the U.S. Air Force Reserve, initially as a C-141 instructor pilot with the 356th Airlift Squadron at Wright-Patterson Air Force Base in Ohio, then subsequently as an Academy Liaison Officer, recruiting potential candidates for both the Air Force Academy and the Air Force Reserve Officer Training Corps. During his time in the Air Force Reserve, he achieved the rank of major. He continued his flying career by joining United Airlines in May 1995. His first assignment was Second Officer on the Boeing 727. He then upgraded to First Officer on the Boeing 757/Boeing 767 in 1996, where he remained until September 11, 2001. He married his wife, Melodie, on May 24, 1998, and his first child, Laurel, was born in late November 2000. They resided together in Marlton, New Jersey. September 11 attacks On September 11, 2001, Homer was flying with Captain Jason M. Dahl on United Airlines Flight 93 from Newark, New Jersey, to San Francisco. The plane was hijacked by four al-Qaeda terrorists as part of the September 11 attacks.
|
Long Beach Airport (IATA code), California, US Other uses The Larger Grain Borer (LGB), Prostephanus truncatus Laser-guided bomb Lectures on Government and
|
campus of the International School of Geneva Long Beach Airport (IATA code), California, US Other uses The Larger Grain Borer
|
and services ranging from variety of accounts, attractive rates for fixed deposits, international debit and credit cards, international money transfer services, treasury and forex services, mobile wallet and trade finance facilities. References "Capitalism Comes to Afghanistan". Time. (December 4, 2006). "Life's a lottery in the new Afghanistan". Sydney Morning Herald. (September 18,
|
on June 13, 2006, and is headquartered in Zanbaq Square, Kabul, Afghanistan. The banks caters to a wide gamut of products and services ranging from variety of accounts, attractive rates for fixed deposits, international debit and
|
the future, who offer to help him escape to their time permanently; but he asks instead to be returned to the pre-war time of his childhood, hoping to find the woman again. He is returned to the past, placed on the jetty at the airport, and it occurs to him that the child version of himself is probably also there at the same time. He is more concerned with locating the woman, and quickly spots her. However, as he rushes to her, he notices an agent of his jailers who has followed him and realizes the agent is about to kill him. In his final moments, he comes to understand that the incident he witnessed as a child, which has haunted him ever since, was his own death. Cast Jean Négroni as Narrator Hélène Châtelain as The Woman Davos Hanich as The Man Jacques Ledoux as The Experimenter Ligia Branice as Woman From The Future Janine Kleina as Woman From The Future William Klein as Man From The Future Production La Jetée is constructed almost entirely from optically printed photographs playing out as a photomontage of varying rhythm. It contains only one brief shot (of the woman mentioned above sleeping and suddenly waking up) originating on a motion-picture camera, this due to the fact that Marker could only afford to hire one for an afternoon. The stills were taken with a Pentax Spotmatic and the motion-picture segment was shot with a 35 mm Arriflex. The film has no dialogue aside from small sections of muttering in German and people talking in an airport terminal. The story is told by a voice-over narrator. The scene in which the hero and the woman look at a cut-away trunk of a tree is a reference to Alfred Hitchcock's 1958 film Vertigo which Marker also references in his 1983 film Sans soleil. The editing of La Jetée adds to the intensity of the film. With the use of cut-ins and fade-outs, it produces the eerie and unsettling nature adding to the theme of the apocalyptic destruction of World War III. Terry Gilliam, director of 12 Monkeys, describes the editing as "simply poetic" in the combination of editing and soundtrack that is used in the short film. As the film plays out as a photomontage, the only continuous variable is the sound. The sound used in this production is minimal, showing up in the form of narration, Orchestral score and sound effect. The rhythmic patterns of the soundtrack act as a framework to add to the intensity of the film. "The dissolve is synchronized with the sound. As the story moves from the past to the present, La Jetee creates mental continuity." The soundtrack adds to the illusion of movement within the film and the change of time. Interpretation In Black and Blue, her study of postwar French fiction, Carol Mavor describes La Jetée as "taking place in a no-place (u-topia) in no-time (u-chronia)" which she connects to the time and place of the fairy tale. She further elaborates: "even the sound of the title resonates with the fairy-tale surprise of finding oneself in another world: La Jetée evokes 'là j'étais' (there I was)". By "u-topia", Mavor does not refer to "utopia" as the word is commonly used; she also describes an ambiguity of dystopia/utopia in the film: "It is dystopia
|
and they develop a romantic relationship. After his successful passages to the past, the experimenters attempt to send him into the far future. In a brief meeting with the technologically advanced people of the future, he is given a power unit sufficient to regenerate his own destroyed society. Upon his return, with his mission accomplished, he discerns that he is to be executed by his jailers. He is contacted by the people of the future, who offer to help him escape to their time permanently; but he asks instead to be returned to the pre-war time of his childhood, hoping to find the woman again. He is returned to the past, placed on the jetty at the airport, and it occurs to him that the child version of himself is probably also there at the same time. He is more concerned with locating the woman, and quickly spots her. However, as he rushes to her, he notices an agent of his jailers who has followed him and realizes the agent is about to kill him. In his final moments, he comes to understand that the incident he witnessed as a child, which has haunted him ever since, was his own death. Cast Jean Négroni as Narrator Hélène Châtelain as The Woman Davos Hanich as The Man Jacques Ledoux as The Experimenter Ligia Branice as Woman From The Future Janine Kleina as Woman From The Future William Klein as Man From The Future Production La Jetée is constructed almost entirely from optically printed photographs playing out as a photomontage of varying rhythm. It contains only one brief shot (of the woman mentioned above sleeping and suddenly waking up) originating on a motion-picture camera, this due to the fact that Marker could only afford to hire one for an afternoon. The stills were taken with a Pentax Spotmatic and the motion-picture segment was shot with a 35 mm Arriflex. The film has no dialogue aside from small sections of muttering in German and people talking in an airport terminal. The story is told by a voice-over narrator. The scene in which the hero and the woman look at a cut-away trunk of a tree is a reference to Alfred Hitchcock's 1958 film Vertigo which Marker also references in his 1983 film Sans soleil. The editing of La Jetée adds to the intensity of the film. With the use of cut-ins and fade-outs, it produces the eerie and unsettling nature adding to the theme of the apocalyptic destruction of World War III. Terry Gilliam, director of 12 Monkeys, describes the editing as "simply poetic" in the combination of editing and soundtrack that is used in the short film. As the film plays out as a photomontage, the only continuous variable is the sound. The sound used in this production is minimal, showing up in the form of narration, Orchestral score and sound effect. The rhythmic patterns of the soundtrack act as a framework to add to the intensity of the film. "The dissolve is synchronized with the sound. As the story moves from the past to the present, La Jetee creates mental continuity." The soundtrack adds to the illusion of movement within the film and the change of time. Interpretation In Black and Blue, her study of postwar French fiction, Carol Mavor describes La Jetée as "taking place in a no-place (u-topia) in no-time (u-chronia)" which she connects to the time and place of the fairy tale. She further elaborates: "even the sound of the title resonates with the fairy-tale surprise of finding oneself in another world: La Jetée evokes 'là j'étais' (there I was)". By "u-topia", Mavor does not refer to "utopia" as the word is commonly used; she also describes an ambiguity of dystopia/utopia in the film: "It is dystopia with the hope of utopia, or is it utopia cut by the threat of dystopia." Tor Books blogger Jake Hinkson summed up his interpretation in the title of an essay about the film, "There's No Escape Out of Time". He elaborated: Hinkson also addresses the symbolic use of imagery: "The Man is blindfolded with some kind of padded device and he sees images. The Man is
|
seahorses. In New Zealand, important little penguin prey items include arrow squid, slender sprat, Graham's gudgeon, red cod and ahuru. Since the year 2000, the little penguins of Port Phillip Bay's diet has consisted mainly of barracouta, anchovy, and arrow squid. Pilchards previously featured more prominently in southern Australian little penguin diets prior to mass sardine mortality events of the 1990s. These mass mortality events affected sardine stocks over 5,000 kilometres of coastline. Jellyfish including species in the genera Chrysaora and Cyanea were found to be actively sought-out food items, while they previously had been thought to be only accidentally ingested. Similar preferences were found in the Adélie penguin, yellow-eyed penguin and Magellanic penguin. An important crustacean present in the little penguin diet is the krill, Nyctiphanes australis, which surface-swarms during the day. Little penguins are generally inshore feeders. The use of data loggers has shown that in the diving behaviour of little penguins, 50% of dives go no deeper than 2 m, and the mean diving time is 21 seconds. In the 1980s, average little penguin dive time was estimated to be 23–24 seconds. The maximum recorded depth and time submerged are 66.7 metres and 90 seconds respectively. Tracking technology is allowing researchers from IMAS and the University of Tasmania to garner new insights into the foraging behavior of little penguins. Parasites Little penguins play an important role in the ecosystem as not only a predator to parasites but also a host. Recent studies have shown a new species of feather mite that feeds on the preening oil on the feathers of the penguin. Little penguins preen their mates to strengthen social bonds and remove parasites, especially from their partner's head where self-preening is difficult. Reproduction Little penguins reach sexual maturity at different ages. The female matures at two years old and the male at three years old. Between June and August, males return to shore to renovate or dig new burrows and display to attract a mate for the season. Males compete for partners with their displays. Breeding occurs annually, but the timing and duration of the breeding season varies from location to location and from year to year. Breeding occurs during spring and summer when oceans are most productive and food is plentiful. Little penguins remain faithful to their partner during a breeding season and whilst hatching eggs. At other times of the year they tend to swap burrows. They exhibit site fidelity to their nesting colonies and nesting sites over successive years. Little penguins can breed as isolated pairs, in colonies, or semi-colonially. Nesting Penguins' nests vary depending on the available habitat. They are established close to the sea in sandy burrows excavated by the birds' feet or dug previously by other animals. Nests may also be made in caves, rock crevices, under logs or in or under a variety of man-made structures including nest boxes, pipes, stacks of wood or timber, and buildings. Nests have been occasionally observed to be shared with prions, while some burrows are occupied by short-tailed shearwaters and little penguins in alternating seasons. In the 1980s, little was known on the subject of competition for burrows between bird species. Timing The timing of breeding seasons varies across the species' range. In the 1980s, the first egg laid at a penguin colony on Australia's eastern coast could be expected to come as early as May or as late as October. Eastern Australian populations (including at Phillip Island, Victoria) lay their eggs from July to December. In South Australia's Gulf St. Vincent, eggs are laid between April and October and south of Perth in Western Australia, peak egg-laying occurred in June and continued until mid-October (based on observations from the 1980s). Male and female birds share incubating and chick-rearing duties. They are the only species of penguin capable of producing more than one clutch of eggs per breeding season, but few populations do so. In ideal conditions, a penguin pair is capable of raising two or even three clutches of eggs over an extended season, which can last between eight and twenty-eight weeks. The one or two (on rare occasions, three) white or lightly mottled brown eggs are laid between one and four days apart. Each egg typically weighs around 55 grams at time of laying. Incubation takes up to 36 days. Chicks are brooded for 18–38 days and fledge after 7–8 weeks. On Australia's east coast, chicks are raised from August to March. In Gulf St. Vincent, chicks are raised from June through November. Little penguins typically return to their colonies to feed their chicks at dusk. The birds tend to come ashore in small groups to provide some defence against predators, which might otherwise pick off individuals. In Australia, the strongest colonies are usually on cat-free and fox-free islands. However, the population on Granite Island (which is a fox, cat and dog-free island) has been severely depleted, from around 2000 penguins in 2001 down to 22 in 2015. Granite Island is connected to the mainland via a timber causeway. Native predators Predation by native animals is not considered a threat to little penguin populations, as these predators' diets are diverse. In Australia, large native reptiles including the tiger snake and Rosenberg's goanna are known to take little penguin chicks and blue-tongued lizards are known to take eggs. At sea, little penguins are eaten by long-nosed fur seals. A study conducted by researchers from the South Australian Research and Development Institute found that roughly 40 percent of seal droppings in South Australia's Granite Island area contained little penguin remains. Other marine predators include Australian sea lions, sharks and barracouta. The introduction of Tasmanian Devils to the Australian island of Maria Island in 2012 has led to the complete destruction of a population of little penguins that numbered 3,000 breeding pairs before the introduction. Little penguins are also preyed upon by white-bellied sea eagles. These large birds-of-prey are endangered in South Australia and not considered a threat to colony viability there. Other avian predators include: kelp gulls, pacific gulls, brown skuas and currawongs. In Victoria, at least one penguin death has been attributed to a water rat. Mass mortalities A mass mortality event occurred in Port Phillip Bay in March 1935. The event coincided with moulting and deaths were attributed to fatigue. Another event occurred at Phillip Island in Victoria in 1940. The population there was believed to have fallen from 2000 birds to 200. Dead birds were allegedly in healthy-looking condition so speculation pointed to a disease or pathogen. Oil spills resulting from shipping activity have occasionally resulted in mass mortalities of Little penguins. The worst of these was the Iron Baron oil spill at Low Head, Tasmania in 1995, followed by the Rena oil spill in New Zealand in 2011. Citizens have raised concerns about mass mortality of penguins alleging a lack of official interest in the subject. Discoveries of dead penguins in Australia should be reported to the corresponding state's environment department. In South Australia, a mortality register was established in 2011. Relationship with humans Little penguins have long been a curiosity to humans Captive animals are often exhibited in zoos. Over time attitudes towards penguins have evolved from direct exploitation (for meat, skins and eggs) to the development of tourism ventures, conservation management and the protection of both birds and their habitat. Direct exploitation During the 19th and 20th centuries, little penguins were shot for sport, killed for their skins, captured for amusement and eaten by ship-wrecked sailors and castaways to avoid starvation. Their eggs were also collected for human consumption by indigenous and non-indigenous people. In 1831, N. W. J. Robinson noted that penguins were typically soaked in water for many days to tenderise the meat before eating. One of the colonies raided for penguin skins was Lady Julia Percy Island in Victoria. The following directions for preparing penguin skin were published in The Chronicle in 1904:'F.W.M.,' Port Lincoln. — To clean penguin skins, scrape off as much fat as you can with a blunt knife. Then peg the skin out carefully, stretching it well. Let it remain in the sun till most of the fat is dried out of it, then rub with a compound of powdered alum, salt, and pepper in about equal proportions. Continue to rub this on at intervals until the skin becomes soft and pliable.An Australian taxidermist was once commissioned to make a woman's hat for a cocktail party from the remains of a dead little penguin. The newspaper described it as "a smart little toque of white and black feathers, with black flippers set at a jaunty angle on the crown." In the 20th century, little penguins were maliciously attacked by humans, used as bait to catch Southern rock lobster, used to free snagged fishing tackle, killed as incidental bycatch by fishermen using nets, and killed by vehicle strikes on roads and on the water. However, towards the end of the 20th century and the beginning of the 21st, more mutually beneficial relationships between penguins and humans developed. The sites of some breeding colonies have become carefully managed tourist destinations which provide an economic boost for coastal and island communities in Australia and New Zealand. These locations also often provide facilities and volunteer staff to support population surveys, habitat improvement works and little penguin research programs. Tourism At Phillip Island, Victoria, a viewing area has been established at the Phillip Island Nature Park to allow visitors to view the nightly "penguin parade". Lights and concrete stands have been erected to allow visitors to see but not photograph or film the birds (this is because it can blind or scare them) interacting in their colony. In 1987, more international visitors viewed the penguins coming ashore at Phillip Island than visited Uluru. In the financial year 1985–86, 350,000 people saw the event, and at that time audience numbers were growing 12% annually. In Bicheno, Tasmania, evening penguin viewing tours are offered by a local tour operator at a rookery on private land. A similar sunset tour is offered at Low Head, near the mouth of the Tamar River on Tasmania's north coast. Observation platforms exist near some of Tasmania's other little penguin colonies, including Bruny Island and Lillico Beach near Devonport. South of Perth, Western Australia, visitors to Penguin Island are able to view penguin feeding within a penguin rehabilitation centre and may also encounter wild penguins ashore in their natural habitat. The island is accessible via a short passenger ferry ride, and visitors depart the island before dusk to protect the colony from disturbance. Visitors to Kangaroo Island, South Australia, have nightly opportunities to observe penguins at the Kangaroo Island Marine Centre in Kingscote and at the Penneshaw Penguin Centre. Granite Island at Victor Harbor, South Australia continues to offer guided tours at dusk, despite its colony dropping from thousands in the 1990s to dozens in 2014. There is also a Penguin Centre located on the island where the penguins can be viewed in captivity. In the Otago, New Zealand town of Oamaru, visitors view the birds returning to their colony at dusk. In Oamaru it is common for penguins to nest within the cellars and foundations of local shorefront properties, especially in the old historic precinct of the town. Little penguin viewing facilities have been established at Pilots Beach on the Otago Peninsula in Dunedin. Here visitors are guided by volunteer wardens to watch penguins returning to their burrows at dusk. Threats Prey availability Food availability appears to strongly influence the survival and breeding success of little penguin populations across their range. Variation in prey abundance and distribution from year to year causes young birds to be washed up dead from starvation or in weak condition. This problem is not constrained to young birds, and has been observed throughout the 20th century. The breeding season of 1984–1985 in Australia was particularly bad, with minimal breeding success. Eggs were deserted prior to hatching and many chicks starved to death. Malnourished penguin carcasses were found washed up on beaches and the trend continued the following year. In April 1986, approximately 850 dead penguins were found washed ashore in south-western Victoria. The phenomenon was ascribed to lack of available food. There are two seasonal peaks in the discovery of dead little penguins in Victoria. The first follows moult and the second occurs in mid-winter. Moulting penguins are under stress, and some return to the water in a weak condition afterwards. Mid-winter marks the season of lowest prey availability, thus increasing the probability of malnutrition and starvation. In 1990, 24
|
spend the largest part of their day swimming and foraging at sea. During the breeding and chick-rearing seasons, little penguins leave their nest at sunrise, forage for food throughout the day and return to their nests just after dusk. Thus, sunlight, moonlight and artificial lights can affect the behaviour of attendance to the colony. Also, increased wind speeds negatively affect the little penguins' efficiency in foraging for chicks, but for reasons not yet understood. Little penguins preen their feathers to keep them waterproof. They do this by rubbing a tiny drop of oil onto every feather from a special gland above the tail. Range Tagged or banded birds later recaptured or found deceased have shown that individual birds can travel great distances during their lifetimes. In 1984, a penguin that had been tagged at Gabo Island in eastern Victoria was found dead at Victor Harbor in South Australia. Another little penguin was found near Adelaide in 1970 after being tagged at Phillip Island in Victoria the previous year. In 1996, a banded penguin was found dead at Middleton. It had been banded in 1991 at Troubridge Island in Gulf St Vincent, South Australia. The little penguin's foraging range is quite limited in terms of distance from shore when compared to seabirds that can fly. Feeding Little penguins feed by hunting small clupeoid fish, cephalopods and crustaceans, for which they travel and dive quite extensively including to the sea floor. Researcher Tom Montague studied a Victorian population for two years in order to understand its feeding patterns. Montague's analysis revealed a penguin diet consisting of 76% fish and 24% squid. Nineteen fish species were recorded, with pilchard and anchovy dominating. The fish were usually less than 10 cm long and often post-larval or juvenile. Less common little penguin prey include: crab larvae, eels, jellyfish and seahorses. In New Zealand, important little penguin prey items include arrow squid, slender sprat, Graham's gudgeon, red cod and ahuru. Since the year 2000, the little penguins of Port Phillip Bay's diet has consisted mainly of barracouta, anchovy, and arrow squid. Pilchards previously featured more prominently in southern Australian little penguin diets prior to mass sardine mortality events of the 1990s. These mass mortality events affected sardine stocks over 5,000 kilometres of coastline. Jellyfish including species in the genera Chrysaora and Cyanea were found to be actively sought-out food items, while they previously had been thought to be only accidentally ingested. Similar preferences were found in the Adélie penguin, yellow-eyed penguin and Magellanic penguin. An important crustacean present in the little penguin diet is the krill, Nyctiphanes australis, which surface-swarms during the day. Little penguins are generally inshore feeders. The use of data loggers has shown that in the diving behaviour of little penguins, 50% of dives go no deeper than 2 m, and the mean diving time is 21 seconds. In the 1980s, average little penguin dive time was estimated to be 23–24 seconds. The maximum recorded depth and time submerged are 66.7 metres and 90 seconds respectively. Tracking technology is allowing researchers from IMAS and the University of Tasmania to garner new insights into the foraging behavior of little penguins. Parasites Little penguins play an important role in the ecosystem as not only a predator to parasites but also a host. Recent studies have shown a new species of feather mite that feeds on the preening oil on the feathers of the penguin. Little penguins preen their mates to strengthen social bonds and remove parasites, especially from their partner's head where self-preening is difficult. Reproduction Little penguins reach sexual maturity at different ages. The female matures at two years old and the male at three years old. Between June and August, males return to shore to renovate or dig new burrows and display to attract a mate for the season. Males compete for partners with their displays. Breeding occurs annually, but the timing and duration of the breeding season varies from location to location and from year to year. Breeding occurs during spring and summer when oceans are most productive and food is plentiful. Little penguins remain faithful to their partner during a breeding season and whilst hatching eggs. At other times of the year they tend to swap burrows. They exhibit site fidelity to their nesting colonies and nesting sites over successive years. Little penguins can breed as isolated pairs, in colonies, or semi-colonially. Nesting Penguins' nests vary depending on the available habitat. They are established close to the sea in sandy burrows excavated by the birds' feet or dug previously by other animals. Nests may also be made in caves, rock crevices, under logs or in or under a variety of man-made structures including nest boxes, pipes, stacks of wood or timber, and buildings. Nests have been occasionally observed to be shared with prions, while some burrows are occupied by short-tailed shearwaters and little penguins in alternating seasons. In the 1980s, little was known on the subject of competition for burrows between bird species. Timing The timing of breeding seasons varies across the species' range. In the 1980s, the first egg laid at a penguin colony on Australia's eastern coast could be expected to come as early as May or as late as October. Eastern Australian populations (including at Phillip Island, Victoria) lay their eggs from July to December. In South Australia's Gulf St. Vincent, eggs are laid between April and October and south of Perth in Western Australia, peak egg-laying occurred in June and continued until mid-October (based on observations from the 1980s). Male and female birds share incubating and chick-rearing duties. They are the only species of penguin capable of producing more than one clutch of eggs per breeding season, but few populations do so. In ideal conditions, a penguin pair is capable of raising two or even three clutches of eggs over an extended season, which can last between eight and twenty-eight weeks. The one or two (on rare occasions, three) white or lightly mottled brown eggs are laid between one and four days apart. Each egg typically weighs around 55 grams at time of laying. Incubation takes up to 36 days. Chicks are brooded for 18–38 days and fledge after 7–8 weeks. On Australia's east coast, chicks are raised from August to March. In Gulf St. Vincent, chicks are raised from June through November. Little penguins typically return to their colonies to feed their chicks at dusk. The birds tend to come ashore in small groups to provide some defence against predators, which might otherwise pick off individuals. In Australia, the strongest colonies are usually on cat-free and fox-free islands. However, the population on Granite Island (which is a fox, cat and dog-free island) has been severely depleted, from around 2000 penguins in 2001 down to 22 in 2015. Granite Island is connected to the mainland via a timber causeway. Native predators Predation by native animals is not considered a threat to little penguin populations, as these predators' diets are diverse. In Australia, large native reptiles including the tiger snake and Rosenberg's goanna are known to take little penguin chicks and blue-tongued lizards are known to take eggs. At sea, little penguins are eaten by long-nosed fur seals. A study conducted by researchers from the South Australian Research and Development Institute found that roughly 40 percent of seal droppings in South Australia's Granite Island area contained little penguin remains. Other marine predators include Australian sea lions, sharks and barracouta. The introduction of Tasmanian Devils to the Australian island of Maria Island in 2012 has led to the complete destruction of a population of little penguins that numbered 3,000 breeding pairs before the introduction. Little penguins are also preyed upon by white-bellied sea eagles. These large birds-of-prey are endangered in South Australia and not considered a threat to colony viability there. Other avian predators include: kelp gulls, pacific gulls, brown skuas and currawongs. In Victoria, at least one penguin death has been attributed to a water rat. Mass mortalities A mass mortality event occurred in Port Phillip Bay in March 1935. The event coincided with moulting and deaths were attributed to fatigue. Another event occurred at Phillip Island in Victoria in 1940. The population there was believed to have fallen from 2000 birds to 200. Dead birds were allegedly in healthy-looking condition so speculation pointed to a disease or pathogen. Oil spills resulting from shipping activity have occasionally resulted in mass mortalities of Little penguins. The worst of these was the Iron Baron oil spill at Low Head, Tasmania in 1995, followed by the Rena oil spill in New Zealand in 2011. Citizens have raised concerns about mass mortality of penguins alleging a lack of official interest in the subject. Discoveries of dead penguins in Australia should be reported to the corresponding state's environment department. In South Australia, a mortality register was established in 2011. Relationship with humans Little penguins have long been a curiosity to humans Captive animals are often exhibited in zoos. Over time attitudes towards penguins have evolved from direct exploitation (for meat, skins and eggs) to the development of tourism ventures, conservation management and the protection of both birds and their habitat. Direct exploitation During the 19th and 20th centuries, little penguins were shot for sport, killed for their skins, captured for amusement and eaten by ship-wrecked sailors and castaways to avoid starvation. Their eggs were also collected for human consumption by indigenous and non-indigenous people. In 1831, N. W. J. Robinson noted that penguins were typically soaked in water for many days to tenderise the meat before eating. One of the colonies raided for penguin skins was Lady Julia Percy Island in Victoria. The following directions for preparing penguin skin were published in The Chronicle in 1904:'F.W.M.,' Port Lincoln. — To clean penguin skins, scrape off as much fat as you can with a blunt knife. Then peg the skin out carefully, stretching it well. Let it remain in the sun till most of the fat is dried out of it, then rub with a compound of powdered alum, salt, and pepper in about equal proportions. Continue to rub this on at intervals until the skin becomes soft and pliable.An Australian taxidermist was once commissioned to make a woman's hat for a cocktail party from the remains of a dead little penguin. The newspaper described it as "a smart little toque of white and black feathers, with black flippers set at a jaunty angle on the crown." In the 20th century, little penguins were maliciously attacked by humans, used as bait to catch Southern rock lobster, used to free snagged fishing tackle, killed as incidental bycatch by fishermen using nets, and killed by vehicle strikes on roads and on the water. However, towards the end of the 20th century and the beginning of the 21st, more mutually beneficial relationships between penguins and humans developed. The sites of some breeding colonies have become carefully managed tourist destinations which provide an economic boost for coastal and island communities in Australia and New Zealand. These locations also often provide facilities and volunteer staff to support population surveys, habitat improvement works and little penguin research programs. Tourism At Phillip Island, Victoria, a viewing area has been established at the Phillip Island Nature Park to allow visitors to view the nightly "penguin parade". Lights and concrete stands have been erected to allow visitors to see but not photograph or film the birds (this is because it can blind or scare them) interacting in their colony. In 1987, more international visitors viewed the penguins coming ashore at Phillip Island than visited Uluru. In the financial year 1985–86, 350,000 people saw the event, and at that time audience numbers were growing 12% annually. In Bicheno, Tasmania, evening penguin viewing tours are offered by a local tour operator at a rookery on private land. A similar sunset tour is offered at Low Head, near the mouth of the Tamar River on Tasmania's north coast. Observation platforms exist near some of Tasmania's other little penguin colonies, including Bruny Island and Lillico Beach near Devonport. South of Perth, Western Australia, visitors to Penguin Island are able to view penguin feeding within a penguin rehabilitation centre and may also encounter wild penguins ashore in their natural habitat. The island is accessible via a short passenger ferry ride, and visitors depart the island before dusk to protect the colony from disturbance. Visitors to Kangaroo Island, South Australia, have nightly opportunities to observe penguins at the Kangaroo Island Marine Centre in Kingscote and at the Penneshaw Penguin Centre. Granite Island at Victor Harbor, South Australia continues to offer guided tours at dusk, despite its colony dropping from thousands in the 1990s to dozens in 2014. There is also a Penguin Centre located on the island where the penguins can be viewed in captivity. In the Otago, New Zealand town of Oamaru, visitors view the birds returning to their colony at dusk. In Oamaru it is common for penguins to nest within the cellars and foundations of local shorefront properties, especially in the old historic precinct of the town. Little penguin viewing facilities have been established at Pilots Beach on the Otago Peninsula in Dunedin. Here visitors are guided by volunteer wardens to watch penguins returning to their burrows at dusk. Threats Prey availability Food availability appears to strongly influence the survival and breeding success of little penguin populations across their range. Variation in prey abundance and distribution from year to year causes young birds to be washed up dead from starvation or in weak condition. This problem is not constrained to young birds, and has been observed throughout the 20th century. The breeding season of 1984–1985 in Australia was particularly bad, with minimal breeding success. Eggs were deserted prior to hatching and many chicks starved to death. Malnourished penguin carcasses were found washed up on beaches and the trend continued the following year. In April 1986, approximately 850 dead penguins were found washed ashore in south-western Victoria. The phenomenon was ascribed to lack of available food. There are two seasonal peaks in the discovery of dead little penguins in Victoria. The first follows moult and the second occurs in mid-winter. Moulting penguins are under stress, and some return to the water in a weak condition afterwards. Mid-winter marks the season of lowest prey availability, thus increasing the probability of malnutrition and starvation. In 1990, 24 dead penguins were found in the Encounter Bay area in South Australia during a week spanning late April to early May. A State government park ranger explained that many of the birds were juvenile and had starved after moulting. In 1995 pilchard mass mortality events occurred, which reduced the penguins' available prey and resulted in starvation and breeding failure. Another similar event occurred in 1999. Both mortality events were attributed to an exotic pathogen which spread across the entire Australian population of the fish, reducing the breeding biomass by 70%. Crested tern and gannet populations also suffered following these events. In 1995, 30 dead penguins were found ashore between Waitpinga and Chiton Rocks in the Encounter Bay area. The birds has suffered severe bacterial infections and the mortalities may have been linked to the mass mortality of pilchards that resulted from the spread of an exotic pathogen that year. In the late 1980s, it was believed that penguins did not compete with the fishing industry, despite anchovy being commercially caught. That assertion was made prior to the establishment and development of South Australia's commercial pilchard fishery in the 1990s. In South Africa, the overfishing of species of preferred penguin prey has caused Jackass penguin populations to decline. Overfishing is a potential (but not proven) threat to the little penguin. Introduced predators Introduced mammalian predators present the greatest terrestrial risk to little penguins and include cats, dogs, rats,
|
been resort centres for the Hungarian aristocracy, it was only in the late 19th century that the Hungarian middle class began to visit the lake. The construction of railways in 1861 and 1909 increased tourism substantially, but the post-war boom of the 1950s was much larger. By the turn of the 20th century, Balaton had become a center of research by Hungarian biologists, geologists, hydrologists, and other scientists, leading to the country's first biological research institute being built on its shore in 1927. The last major German offensive of World War II, Operation Frühlingserwachen, was conducted in the region of Lake Balaton in March 1945, being referred to as "the Lake Balaton Offensive" in many British histories of the war. The battle was a German attack by Sepp Dietrich's Sixth Panzer Army and the Hungarian Third Army between 6 March and 16 March 1945, and in the end, resulted in a Red Army victory. Several Ilyushin Il-2 wrecks have been pulled out of the lake after having been shot down during the later months of the war. During the 1960s and 1970s, Balaton became a major tourist destination due to focused government efforts, causing the number of overnight guests in local hotels and campsites to increase from 700,000 in July 1965 to two million in July 1975. Weekend visitors to the region, including tens of thousands from Budapest, reached more than 600,000 by 1975. It was visited by ordinary working Hungarians and especially for subsidised holiday excursions for labor union members. It also attracted many East Germans and other residents of the Eastern Bloc. West Germans could also visit, making Balaton a common meeting place for families and friends separated by the Berlin Wall until 1989. Tourism The major resorts around the lake are Siófok, Keszthely, and Balatonfüred. Zamárdi, another resort town on the
|
forests and swamps along the river Zala. His well-fortified castle and capital of Lower Pannonian Principality that became known as Blatnohrad or Moosburg ("Swamp Fortress") served as a bulwark both against the Bulgarians and the Moravians. The German name for the lake is . It is unlikely it was given that name for being shallow since the adjective is a Greek loanword that was borrowed via French and entered the general German vocabulary in the 17th century. It is also noteworthy that the average depth of Balaton () is not extraordinary for the area (cf. the average depth of the neighbouring Neusiedler See, which is roughly ). Climate Lake Balaton affects the local area precipitation. The area receives approximately more precipitation than most of Hungary, resulting in more cloudy days and less extreme temperatures. The lake's surface freezes during winters. The microclimate around Lake Balaton has also made the region ideal for viticulture. The Mediterranean-like climate, combined with the soil (containing volcanic rock), has made the region notable for its production of wines since the Roman period two thousand years ago. History While a few settlements on Lake Balaton, including Balatonfüred and Hévíz, have long been resort centres for the Hungarian aristocracy, it was only in the late 19th century that the Hungarian middle class began to visit the lake. The construction of railways in 1861 and 1909 increased tourism substantially, but the post-war boom of the 1950s was much larger. By the turn of the 20th century, Balaton had become a center of research by Hungarian biologists, geologists, hydrologists, and other scientists, leading to the country's first biological research institute being built on its shore in 1927. The last major German offensive of World War II, Operation Frühlingserwachen, was conducted in the region of Lake Balaton in March 1945, being referred to as "the Lake Balaton Offensive" in many British histories of the war. The battle was a German attack by Sepp Dietrich's Sixth Panzer Army and the Hungarian Third Army between 6 March and 16 March 1945, and in the end, resulted in a Red Army victory. Several Ilyushin Il-2 wrecks have been pulled out of the lake after having been shot down during the later months of the war. During the 1960s and 1970s, Balaton became a major tourist destination due to focused government efforts, causing the number of overnight guests in local hotels and campsites to increase from 700,000 in July 1965 to two million in July 1975. Weekend visitors to the region, including tens of thousands from Budapest, reached more than 600,000 by 1975. It was visited by ordinary working Hungarians and especially for subsidised holiday excursions for labor union members. It also attracted many East Germans and other residents of the Eastern Bloc. West Germans could also visit, making Balaton a common meeting place for families and friends separated by the Berlin Wall until 1989. Tourism The major resorts around the lake are Siófok, Keszthely, and Balatonfüred. Zamárdi, another resort town on the southern shore, has been the site of Balaton Sound, a notable electronic music festival since 2007. Balatonkenese has hosted
|
across the brow, and a red, full-lipped mouth that hints at the Gothic affectations in figural representation coming out of France during the late twelfth and early thirteenth centuries. The style in the miniature in Folio 76v is markedly different from the style in Folio 53v. In this case, the framed miniature contains two men, perhaps Spanish, with uncovered wavy light brown hair that falls to the jaw line. The men seem young, as the player on the left has no facial hair and his face is unlined. In both folios, both pairs of players are playing backgammon and seem to be well-dressed, although there is no addition of gold detailing to their robes as seen in the wardrobes of aristocratic players in other miniatures. These players are seated on the ground, leaning on pillows that are placed next to a backgammon board. In this miniature, the figure on the left side of the board faces the reader, while the figure on the right leans in to the board with his back to the reader. In other words, each player is leaning on his left elbow, using his right hand to reach across his body to play. In the miniatures of this style, the emphasis seems to be more on the posture of the player than the detail of their faces; this crossed, lounging style is only found in the folios of the Libro de tablas, the third section of the Libro de juegos which explains the game of backgammon, again perhaps indicative of the work of a particular artist. Other visual details contemporaneous of Alfonso's court and social and cultural milieu infuse the Libro de juegos. Although some of the miniatures are framed by simple rectangles with corners embellished by the golden castles and lions of Castile and León, other are framed by medieval Spanish architectural motifs, including Gothic and Mudéjar arcades of columns and arches. At times, the figural depictions are hierarchical, especially in scenes with representations of Alfonso, where the king is seated on a raised throne while dictating to scribes or meting out punishments to gamblers. Yet a contemporary atmosphere of Spanish convivencia is evoked by the inclusion nobility, rogues, vagrants, young and old, men, women, Christian, Muslim, and Jewish characters. Alfonso himself is depicted throughout the text, both as participant and spectator and as an older man and as a younger. The pages are filled with many social classes and ethnicities in various stages of solving the challenges presented by games. Iconography The Libro de juegos can be divided into three parts: the games and problems it explores textually, the actual illuminations themselves, and the metaphysical allegories, where an analysis of the texts and illuminations reveals the movements of the macrocosmos of the universe and the microcosmos of man. The symbolism within the medieval illuminations, as explained by the accompanying texts, reveal allusions to medieval literature, art, science, law and philosophy. Intended as a didactic text, the manuscript functions as a manual that documents and explains how and why one plays games ranging from pure, intellectual strategy (chess), to games of pure chance (dice), to games that incorporate both elements (backgammon). Conceivably, Alfonso hoped to elucidate for himself how to better play the game of life, while also providing a teaching tool for others. The game of ajedrex, or chess, is not the only game explained in the Libro de Juegos, but it does occupy the primary position in the text and is given the most attention to detail. In the thirteenth century, chess had been played in Europe for almost two hundred years, having been introduced into Europe by Arabs around the year 1000. The Arabs had become familiar with the game as early as the eighth century when the Islamic empire conquered Persia, where the game of chess was alleged to have been originated. It is said that a royal advisor had invented the game in order to teach his king prudence without having to overtly correct him. As Arab contact with the West expanded, so too did the game and its various permutations, and by the twelfth century, chess was becoming an entertaining diversion among a growing population of Europeans, including some scholars, clergy, the aristocracy, and the merchant classes; thus, by the thirteenth century, the iconography and symbolism associated with chess would have been accessible and familiar to Alfonso and his literate court culture, who may have had access to the private library, and manuscripts, of Alfonso, including the Libro de juegos. The Libro de juegos manuscript was a Castilian translation of Arabic texts, which were themselves translations of Persian manuscripts. The visual trope portrayed in the Libro de juegos miniatures is seen in other European transcriptions of the Arabic translations, most notably the German Carmina Burana Manuscript: two figures, one on either side of the board, with the board tilted up to reveal to the readers the moves made by the players. The juxtaposition of chess and dice in Arabic tradition, indicating the opposing values of skill (chess) and ignorance (dice), was given a different spin in Alfonso's manuscript, however. As Alfonso elucidates in the opening section of the Libro de Juegos, the Libro de ajedrex (Book of chess) demonstrates the value of the intellect, the Libro de los dados (Book of dice) illustrates that chance has supremacy over pure intellect, and the Libro de las tablas (Book of tables) celebrates a conjoined use of both intellect and chance. Further, the iconographic linkage between chess and kingship in the Western tradition continued to evolve and became symbolic of kingly virtues, including skill, prudence, and intelligence. Significance Most of the work accomplished in Alfonso's scriptorium consisted of translations into the Spanish vernacular from Arabic translations of Greek texts or classical Jewish medicinal texts. As a result, very few original works were produced by this scholar-king, relative to the huge amount of work that was translated under his auspices. This enormous focus on translation was perhaps an attempt by Alfonso to continue the legacy of academic openness in Castile, initiated by Islamic rulers in Córdoba, where the emirates had also employed armies of translators in order to fill their libraries with Arabic translations of classic Greek texts. Alfonso was successful in promoting Castilian society and culture through his emphasis on the use of Galaico-Portuguese and Castilian, in academic, juridical, diplomatic, literary, and historical works. This emphasis also had the effect of reducing the universality of his translated works and original academic writings, as Latin was the lingua franca in both Iberia and Europe; yet Alfonso never desisted in his promotion of the Castilian vernacular. Legacy In 1217, Alfonso had captured the Kingdom of Murcia, on the Mediterranean coast south of Valencia, for his father, King Alfonso IX, thereby unifying the kingdoms of Castile and León, bringing together the northern half
|
be seated on rugs on the ground, as suggested by the ceramic containers that are placed on or front of the rug near the man on the right side of the board, the figures' seated positions, which are full frontal with knees bent at right angles, suggests that they are seated on stools or perhaps upholstered benches. The figures' robes display a Byzantine conservatism, with their modeled three-dimensionality and allusion to a Classical style, yet the iconic hand gestures are reminiscent of a Romanesque energy and theatricality. Although the figures are seated with their knees and torsos facing front, their shoulders and heads rotate in three-quarter profile toward the center of the page, the chess board, and each other. The proximal, inner arm of each player (the arm that is closest to the board) is raised in a speaking gesture; the distal, outside arms of the players are also raised and are bent at the elbows, creating a partial crossing of each player's torso as the hands lift in speaking gestures. The faces reveal a striking specificity of subtle detail, particular to a limited number of miniatures throughout the Libro de juegos, perhaps indicative of a particular artist's hand. These details include full cheeks, realistic wrinkles around the eyes and across the brow, and a red, full-lipped mouth that hints at the Gothic affectations in figural representation coming out of France during the late twelfth and early thirteenth centuries. The style in the miniature in Folio 76v is markedly different from the style in Folio 53v. In this case, the framed miniature contains two men, perhaps Spanish, with uncovered wavy light brown hair that falls to the jaw line. The men seem young, as the player on the left has no facial hair and his face is unlined. In both folios, both pairs of players are playing backgammon and seem to be well-dressed, although there is no addition of gold detailing to their robes as seen in the wardrobes of aristocratic players in other miniatures. These players are seated on the ground, leaning on pillows that are placed next to a backgammon board. In this miniature, the figure on the left side of the board faces the reader, while the figure on the right leans in to the board with his back to the reader. In other words, each player is leaning on his left elbow, using his right hand to reach across his body to play. In the miniatures of this style, the emphasis seems to be more on the posture of the player than the detail of their faces; this crossed, lounging style is only found in the folios of the Libro de tablas, the third section of the Libro de juegos which explains the game of backgammon, again perhaps indicative of the work of a particular artist. Other visual details contemporaneous of Alfonso's court and social and cultural milieu infuse the Libro de juegos. Although some of the miniatures are framed by simple rectangles with corners embellished by the golden castles and lions of Castile and León, other are framed by medieval Spanish architectural motifs, including Gothic and Mudéjar arcades of columns and arches. At times, the figural depictions are hierarchical, especially in scenes with representations of Alfonso, where the king is seated on a raised throne while dictating to scribes or meting out punishments to gamblers. Yet a contemporary atmosphere of Spanish convivencia is evoked by the inclusion nobility, rogues, vagrants, young and old, men, women, Christian, Muslim, and Jewish characters. Alfonso himself is depicted throughout the text, both as participant and spectator and as an older man and as a younger. The pages are filled with many social classes and ethnicities in various stages of solving the challenges presented by games. Iconography The Libro de juegos can be divided into three parts: the games and problems it explores textually, the actual illuminations themselves, and the metaphysical allegories, where an analysis of the texts and illuminations reveals the movements of the macrocosmos of the universe and the microcosmos of man. The symbolism within the medieval illuminations, as explained by the accompanying texts, reveal allusions to medieval literature, art, science, law and philosophy. Intended as a didactic text, the manuscript functions as a manual that documents and explains how and why one plays games ranging from pure, intellectual strategy (chess), to games of pure chance (dice), to games that incorporate both elements (backgammon). Conceivably, Alfonso hoped to elucidate for himself how to better play the game of life, while also providing a teaching tool for others. The game of ajedrex, or chess, is not the only game explained in the Libro de Juegos, but it does occupy the primary position in the text and is given the most attention to detail. In the thirteenth century, chess had been played in Europe for almost two hundred years, having been introduced into Europe by Arabs around the year 1000. The Arabs had become familiar with the game as early as the eighth century when the Islamic empire conquered Persia, where the game of chess was alleged to have been originated. It is said that a royal advisor had invented the game in order to teach his king prudence without having to overtly correct him. As Arab contact with the West expanded, so too did the game and its various permutations, and by the twelfth century, chess was becoming an entertaining diversion among a growing population of Europeans, including some scholars, clergy, the aristocracy, and the merchant classes; thus, by the thirteenth century, the iconography and symbolism associated with chess would have been accessible
|
treatment of manic states and bipolar disorder. There is extensive pharmacology of lithium, the active component of this salt. Lithia water contains various lithium salts, including the citrate. An early version of Coca-Cola available in pharmacies' soda fountains called Lithia Coke was a mixture of Coca-Cola syrup and lithia water. The
|
formulated in 1929 because it contained lithium citrate. The beverage was a patent medicine marketed as a cure for hangover. Lithium citrate was removed from 7Up in 1948. References Citrates Lithium compounds Mood
|
used to impart a red color to fireworks. Properties and reactions Unlike sodium carbonate, which forms at least three hydrates, lithium carbonate exists only in the anhydrous form. Its solubility in water is low relative to other lithium salts. The isolation of lithium from aqueous extracts of lithium ores capitalizes on this poor solubility. Its apparent solubility increases 10-fold under a mild pressure of carbon dioxide; this effect is due to the formation of the metastable bicarbonate, which is more soluble: + + 2 The extraction of lithium carbonate at high pressures of and its precipitation upon depressurizing is the basis of the Quebec process. Lithium carbonate can also be purified by exploiting its diminished solubility in hot water. Thus, heating a saturated aqueous solution causes crystallization of . Lithium carbonate, and other carbonates of group 1, do not decarboxylate readily. decomposes at temperatures around 1300 °C. Production Lithium is extracted from primarily two sources: spodumene in pegmatite deposits, and lithium salts in underground brine pools. About 82,000 tons were produced in 2020, showing significant and consistent growth. From underground brine reservoirs As an example, in the Salar de Atacama in the Atacama desert of Northern Chile, SQM produces lithium carbonate and hydroxide from brine. The process involves pumping up lithium rich brine from below the ground into shallow pans for evaporation. The brine contains many different dissolved ions, and as the concentration increases, salts precipitate out of solution and sink. The remaining liquid (the supernatant) is used for the next step. The exact sequence of pans may vary depending on the concentration of ions in a particular source of brine. In the first pan, halite (sodium chloride or common salt) crystallises. This has insufficient economic value and is discarded. The supernatant, with ever increasing concentration of dissolved solids, is transferred successively to the sylvinite (sodium potassium chloride) pan, the carnalite (potassium magnesium chloride) pan and finally a pan designed to maximise the concentration of lithium chloride. The process takes about 15 months. The concentrate (30-35% lithium chloride solution) is trucked to Salar del Carmen. There, boron and magnesium are removed (typically residual boron is removed by solvent extraction and/or ion exchange and magnesium by raising the pH above 10 with sodium hydroxide) then in the final step, by addition of sodium carbonate, the desired lithium carbonate is precipitated out, separated, and processed. Some of the by-products from the evaporation process may also have economic value. There is considerable focus on the use of water in
|
central nervous system and renal system and can be lethal. Red pyrotechnic colorant Lithium carbonate is used to impart a red color to fireworks. Properties and reactions Unlike sodium carbonate, which forms at least three hydrates, lithium carbonate exists only in the anhydrous form. Its solubility in water is low relative to other lithium salts. The isolation of lithium from aqueous extracts of lithium ores capitalizes on this poor solubility. Its apparent solubility increases 10-fold under a mild pressure of carbon dioxide; this effect is due to the formation of the metastable bicarbonate, which is more soluble: + + 2 The extraction of lithium carbonate at high pressures of and its precipitation upon depressurizing is the basis of the Quebec process. Lithium carbonate can also be purified by exploiting its diminished solubility in hot water. Thus, heating a saturated aqueous solution causes crystallization of . Lithium carbonate, and other carbonates of group 1, do not decarboxylate readily. decomposes at temperatures around 1300 °C. Production Lithium is extracted from primarily two sources: spodumene in pegmatite deposits, and lithium salts in underground brine pools. About 82,000 tons were produced in 2020, showing significant and consistent growth. From underground brine reservoirs As an example, in the Salar de Atacama in the Atacama desert of Northern Chile, SQM produces lithium carbonate and hydroxide from brine. The process involves pumping up lithium rich brine from below the ground into shallow pans for evaporation. The brine contains many different dissolved ions, and as the concentration increases, salts precipitate out of solution and sink. The remaining liquid (the supernatant) is used for the next step. The exact sequence of pans may vary depending on the concentration of ions in a particular source of brine. In the first pan, halite (sodium chloride or common salt) crystallises. This has insufficient economic value and is discarded. The supernatant, with ever increasing concentration of dissolved solids, is transferred successively to the sylvinite (sodium potassium chloride) pan, the carnalite (potassium magnesium chloride) pan and finally a pan designed to maximise the concentration of lithium chloride. The process takes about 15 months. The concentrate (30-35% lithium chloride solution) is trucked to Salar del
|
International to make a preliminary study of the shelter and its related vehicle. Because of the potential need for an enclosed vehicle for enlarged future lunar explorations, those design efforts continued for some time, and resulted in several full-scale test vehicles. With pressure from Congress to hold down Apollo costs, Saturn V production was reduced, allowing only a single launch per mission. Any roving vehicle would have to fit on the same lunar module as the astronauts. In November 1964, two-rocket models were put on indefinite hold, but Bendix and Boeing were given study contracts for small rovers. The name of the lunar excursion module was changed to simply the lunar module, indicating that the capability for powered "excursions" away from a lunar-lander base did not yet exist. There could be no mobile lab — the astronauts would work out of the LM. Marshall continued to also examine uncrewed robotic rovers that could be controlled from the Earth. From the beginnings at Marshall, the Brown Engineering Company of Huntsville, Alabama, had participated in all of the lunar mobility efforts. In 1965, Brown became the prime support contractor for Marshall's P&VE Laboratory. With an urgent need to determine the feasibility of a two-man self-contained lander, von Braun bypassed the usual procurement process and had P&VE's Advanced Studies Office directly task Brown to design, build, and test a prototype vehicle. While Bendix and Boeing would continue to refine concepts and designs for a lander, test model rovers were vital for Marshall human factors studies involving spacesuit-clad astronauts interfacing with power, telemetry, navigation, and life-support rover equipment. Brown's team made full use of the earlier small-rover studies, and commercially available components were incorporated wherever possible. The selection of wheels was of great importance, and almost nothing was known at that time about the lunar surface. The Marshall Space Sciences Laboratory (SSL) was responsible for predicting surface properties, and Brown was also prime support contractor for this lab; Brown set up a test area to examine a wide variety of wheel-surface conditions. To simulate Pavlics' "resilient wheel," a four-foot-diameter inner tube wrapped with nylon ski rope was used. On the small test rover, each wheel had a small electric motor, with overall power provided by standard truck batteries. A roll bar gave protection from overturn accidents. In early 1966, Brown's vehicle became available for examining human factors and other testing. Marshall built a small test track with craters and rock debris where the several different mock-ups were compared; it became obvious that a small rover would be best for the proposed missions. The test vehicle was also operated in remote mode to determine characteristics that might be dangerous to the driver, such as acceleration, bounce-height, and turn-over tendency as it traveled at higher speeds and over simulated obstacles. The test rover's performance under one-sixth gravity was obtained through flights on a KC-135A aircraft in a Reduced Gravity parabolic maneuver; among other things, the need for a very soft wheel and suspension combination was shown. Although Pavlics' wire-mesh wheels were not initially available for the reduced gravity tests, the mesh wheels were tested on various soils at the Waterways Experiment Station of the U.S. Army Corps of Engineers at Vicksburg, Mississippi. Later, when wire-mesh wheels were tested on low-g flights, the need for wheel fenders to reduce dust contamination was found. The model was also extensively tested at the U.S. Army's Yuma Proving Ground in Arizona, as well as the Army's Aberdeen Proving Ground in Maryland. Lunar Roving Vehicle Project During 1965 and 1967, the Summer Conference on Lunar Exploration and Science brought together leading scientists to assess NASA's planning for exploring the Moon and to make recommendations. One of their findings was that the LSSM was critical to a successful program and should be given major attention. At Marshall, von Braun established a Lunar Roving Task Team, and in May 1969, NASA approved the Manned Lunar Rover Vehicle Program as a Marshall hardware development. Saverio "Sonny" Morea was named Lunar Roving Vehicle Project Manager. On 11 July 1969, just before the successful Moon landing of Apollo 11, a request for proposal for the final development and building the Apollo LRV was released by Marshall. Boeing, Bendix, Grumman, and Chrysler submitted proposals. Following three months of proposal evaluation and negotiations, Boeing was selected as the Apollo LRV prime contractor on 28 October 1969. Boeing would manage the LRV project under Henry Kudish in Huntsville, Alabama. As a major subcontractor, the General Motors' Defense Research Laboratories in Santa Barbara, California, would furnish the mobility system (wheels, motors, and suspension); this effort would be led by GM Program Manager Samuel Romano andFerenc Pavlics. Boeing in Seattle, Washington, would furnish the electronics and navigation system. Vehicle testing would take place at the Boeing facility in Kent, Washington, and the chassis manufacturing and overall assembly would be at the Boeing facility in Huntsville. The first cost-plus-incentive-fee contract to Boeing was for $19,000,000 and called for delivery of the first LRV by 1 April 1971. Cost overruns, however, led to a final cost of $38,000,000, which was about the same as NASA's original estimate. Four lunar rovers were built, one each for Apollo missions 15, 16, and 17; and one used for spare parts after the cancellation of further Apollo missions. Other LRV models were built: a static model to assist with human factors design; an engineering model to design and integrate the subsystems; two one-sixth gravity models for testing the deployment mechanism; a one-gravity trainer to give the astronauts instruction in the operation of the rover and allow them to practice driving it; a mass model to test the effect of the rover on the LM structure, balance, and handling; a vibration test unit to study the LRV's durability and handling of launch stresses; and a qualification test unit to study integration of all LRV subsystems. A paper by Saverio Morea gives details of the LRV system
|
assumption, allowing a large, heavy, roving vehicle. Grumman and Northrop, in the fall of 1962, began to design pressurized-cabin vehicles, with electric motors for each wheel. At about this same time Bendix and Boeing started their own internal studies on lunar transportation systems. Mieczysław Bekker, now with General Motors Defense Research Laboratories at Santa Barbara, California, was completing a study for NASA's Jet Propulsion Laboratory on a small, uncrewed lunar roving vehicle for the Surveyor program. Ferenc Pavlics, originally from Hungary, used a wire-mesh design for "resilient wheels," a design that would be followed in future small rovers. In early 1963, NASA selected Marshall for studies in an Apollo Logistics Support System (ALSS). Following reviews of all earlier efforts, this resulted in a 10-volume report. Included was the need for a pressurized vehicle in the weight range, accommodating two men with their expendables and instruments for traverses up to two weeks in duration. In June 1964, Marshall awarded contracts to Bendix and to Boeing, with GM's lab designated as the vehicle technology subcontractor. Bell Aerospace was already under contract for studies of Lunar Flying Vehicles. Even as the Bendix and Boeing studies were underway, Marshall was examining a less ambitious surface exploration activity, the LSSM. This would be composed of a fixed, habitable shelter–laboratory with a small lunar-traversing vehicle that could either carry one man or be remotely controlled. This mission would still require a dual launch with the moon vehicle carried on the "lunar truck". Marshall's Propulsion and Vehicle Engineering (P&VE) lab contracted with Hayes International to make a preliminary study of the shelter and its related vehicle. Because of the potential need for an enclosed vehicle for enlarged future lunar explorations, those design efforts continued for some time, and resulted in several full-scale test vehicles. With pressure from Congress to hold down Apollo costs, Saturn V production was reduced, allowing only a single launch per mission. Any roving vehicle would have to fit on the same lunar module as the astronauts. In November 1964, two-rocket models were put on indefinite hold, but Bendix and Boeing were given study contracts for small rovers. The name of the lunar excursion module was changed to simply the lunar module, indicating that the capability for powered "excursions" away from a lunar-lander base did not yet exist. There could be no mobile lab — the astronauts would work out of the LM. Marshall continued to also examine uncrewed robotic rovers that could be controlled from the Earth. From the beginnings at Marshall, the Brown Engineering Company of Huntsville, Alabama, had participated in all of the lunar mobility efforts. In 1965, Brown became the prime support contractor for Marshall's P&VE Laboratory. With an urgent need to determine the feasibility of a two-man self-contained lander, von Braun bypassed the usual procurement process and had P&VE's Advanced Studies Office directly task Brown to design, build, and test a prototype vehicle. While Bendix and Boeing would continue to refine concepts and designs for a lander, test model rovers were vital for Marshall human factors studies involving spacesuit-clad astronauts interfacing with power, telemetry, navigation, and life-support rover equipment. Brown's team made full use of the earlier small-rover studies, and commercially available components were incorporated wherever possible. The selection of wheels was of great importance, and almost nothing was known at that time about the lunar surface. The Marshall Space Sciences Laboratory (SSL) was responsible for predicting surface properties, and Brown was also prime support contractor for this lab; Brown set up a test area to examine a wide variety of wheel-surface conditions. To simulate Pavlics' "resilient wheel," a four-foot-diameter inner tube wrapped with nylon ski rope was used. On the small test rover, each wheel had a small electric motor, with overall power provided by standard truck batteries. A roll bar gave protection from overturn accidents. In early 1966, Brown's vehicle became available for examining human factors and other testing. Marshall built a small test track with craters and rock debris where the several different mock-ups were compared; it became obvious that a small rover would be best for the proposed missions. The test vehicle was also operated in remote mode to determine characteristics that might be dangerous to the driver, such as acceleration, bounce-height, and turn-over tendency as it traveled at higher speeds and over simulated obstacles. The test rover's performance under one-sixth gravity was obtained through flights on a KC-135A aircraft in a Reduced Gravity parabolic maneuver; among other things, the need for a very soft wheel and suspension combination was shown. Although Pavlics' wire-mesh wheels were not initially available for the reduced gravity tests, the mesh wheels were tested on various soils at the Waterways Experiment Station of the U.S. Army Corps of Engineers at Vicksburg, Mississippi. Later, when wire-mesh wheels were tested on low-g flights, the need for wheel fenders to reduce dust contamination was found. The model was also extensively tested at the U.S. Army's Yuma Proving Ground in Arizona, as well as the Army's Aberdeen Proving Ground in Maryland. Lunar Roving Vehicle Project During 1965 and 1967, the Summer Conference on Lunar Exploration and Science brought together leading scientists to assess NASA's planning for exploring the Moon and to make recommendations. One of their findings was that the LSSM was critical to a successful program and should be given major attention. At Marshall, von Braun established a Lunar Roving Task Team, and in May 1969, NASA approved the Manned Lunar Rover Vehicle Program as a Marshall hardware development. Saverio "Sonny" Morea was named Lunar Roving Vehicle Project Manager. On 11 July 1969, just before the successful Moon landing of Apollo 11, a request for proposal for the final development and building the Apollo LRV was released by Marshall. Boeing, Bendix, Grumman, and Chrysler submitted proposals. Following three months of proposal evaluation and negotiations, Boeing was selected as the Apollo LRV prime contractor on 28 October 1969. Boeing would manage the LRV project under Henry Kudish in Huntsville, Alabama. As a major subcontractor, the General Motors' Defense Research Laboratories in Santa Barbara, California, would furnish the mobility system (wheels, motors, and suspension); this effort would be led by GM Program Manager Samuel Romano andFerenc Pavlics. Boeing in Seattle, Washington, would furnish the electronics and navigation system. Vehicle testing would take place at the Boeing facility in Kent, Washington, and the chassis manufacturing and overall assembly would be at the Boeing facility in Huntsville. The first cost-plus-incentive-fee contract to Boeing was for $19,000,000 and called for delivery of the first LRV by 1 April 1971. Cost overruns, however, led to a final cost of $38,000,000, which was about the same as NASA's original estimate. Four lunar rovers were built, one each for Apollo missions 15, 16, and 17; and one used for spare parts after the cancellation of further Apollo missions. Other LRV models were built: a static model to assist with human factors design; an engineering model to design and integrate the subsystems; two one-sixth gravity models for testing the deployment mechanism; a one-gravity trainer to give the astronauts instruction in the operation of the rover and allow them to practice driving it; a mass model to test the effect of the rover on the LM structure, balance, and handling; a vibration test unit to study the LRV's durability and handling of launch stresses; and a qualification test unit to study integration of all LRV subsystems. A paper by Saverio Morea gives details of the LRV system and its development. LRVs were used for greater surface mobility during the Apollo J-class missions, Apollo 15, Apollo 16, and Apollo 17. The rover was first used on 31 July 1971, during the Apollo 15 mission. This greatly expanded the range of the lunar explorers. Previous teams of
|
of the nine Air Force Space Surveillance System (formerly NAVSPASUR) sites is located at Lake Kickapoo (). It is the master transmitter and the most powerful continuous wave (CW) station in the
|
(). It is the master transmitter and the most powerful continuous wave (CW) station in the world, at 768 kW radiated power. External links Protected areas of Archer County, Texas Kickapoo 1947 establishments in Texas Protected areas established in 1947 Bodies of water of Archer
|
the solid surface of the Earth that is not covered by water. Land, lands, The Land or the Lands may also refer to: Entertainment and media Film Land (1987 film), a British television film by Barry Collins Land (2018 film), an international drama by Babak Jalali Land (2021 film), a drama directed by and starring Robin Wright Music Dah (band), a former Yugoslav/Belgian rock band, known as Land during 1975-1976 period Land (1975–2002), an album by Patti Smith Land (band), an American rock band Land (Land album), 1995 Land (worship band), a Scottish Christian band Land (The Comsat Angels album), 1983 Land (Týr album), 2008 Lands (band), a Japanese rock band Other media Land (book), a 2021
|
a Japanese rock band Other media Land (book), a 2021 non-fiction book by Simon Winchester Land (magazine), a Swedish weekly magazine The Land (weekly newspaper) Places Land Glacier, Antarctica Land, Norway The Lands, common name for Anangu Pitjantjatjara Yankunytjatjara, or APY Lands, in South Australia Division of a country Länder of Austria (singular: Land), the states of Austria Länder of Germany , the states of Germany (singular: Land) Lands of Denmark Lands of Finland Lands of Norway Lands of Sweden Other uses -land, a suffix used in the names of several countries and
|
in 1821. The site was also used by German soldiers to store ammunition during the Second World War. Howarth's investigation was shown on a documentary produced for the National Geographic Channel. The Egyptian labyrinth More generally, labyrinth might be applied to any extremely complicated maze-like structure. In Book II of his Histories, Herodotus applies the term "labyrinth" to a building complex in Egypt "near the place called the City of Crocodiles", that he considered to surpass the pyramids: During the nineteenth century, the remains of this ancient Egyptian structure were discovered at Hawara in the Faiyum Oasis by Flinders Petrie at the foot of the pyramid of the twelfth-dynasty pharaoh Amenemhat III (reigned c. 1860 BC to c. 1814 BC). The Classical accounts of various authors (Herodotus, Strabo, Pliny the Elder, among others) are not entirely consistent, perhaps due to degradation of the structure during Classical times. The structure may have been a collection of funerary temples such as are commonly found near Egyptian pyramids. Records indicate that Amenemhat's daughter Sobekneferu made additions to the complex during her reign as king of Egypt. In 1898, the Harpers Dictionary of Classical Antiquities described the structure as "the largest of all the temples of Egypt, the so-called Labyrinth, of which, however, only the foundation stones have been preserved." Herodotus' description of the Egyptian Labyrinth inspired some central scenes in Bolesław Prus' 1895 historical novel, Pharaoh. Pliny's Lemnian labyrinth Pliny the Elder's Natural History (36.90) lists the legendary Smilis, reputed to be a contemporary of Daedalus, together with the historical mid-sixth-century BC architects and sculptors Rhoikos and Theodoros as two of the makers of the Lemnian labyrinth, which Andrew Stewart regards as "evidently a misunderstanding of the Samian temple's location en limnais ['in the marsh']." Pliny's Italian labyrinth According to Pliny, the tomb of the great Etruscan general Lars Porsena contained an underground maze. Pliny's description of the exposed portion of the tomb is intractable; Pliny, it seems clear, had not observed this structure himself, but is quoting the historian and Roman antiquarian Varro. Ancient labyrinths outside Europe A design essentially identical to the 7-course "classical" pattern appeared in Native American culture, the Tohono O'odham people labyrinth which features I'itoi, the "Man in the Maze." The Tonoho O'odham pattern has two distinct differences from the classical: it is radial in design, and the entrance is at the top, where traditional labyrinths have the entrance at the bottom (see below). The earliest appearances cannot be dated securely; the oldest is commonly dated to the 17th century. Unsubstantiated claims have been made for the early appearance of labyrinth figures in India, such as a prehistoric petroglyph on a riverbank in Goa purportedly dating to circa 2500 BC. Other examples have been found among cave art in northern India and on a dolmen shrine in the Nilgiri Mountains, but are difficult to date accurately. Securely datable examples begin to appear only around 250 BC. Early labyrinths in India typically follow the Classical pattern or a local variant of it; some have been described as plans of forts or cities. Labyrinths appear in Indian manuscripts and Tantric texts from the 17th century onward. They are often called "Chakravyuha" in reference to an impregnable battle formation described in the ancient Mahabharata epic. Lanka, the capital city of mythic Rāvana, is described as a labyrinth in the 1910 translation of Al-Beruni's India (c. 1030 AD) p. 306 (with a diagram on the following page). By the White Sea, notably on the Solovetsky Islands, there have been preserved more than 30 stone labyrinths. The most remarkable monument is the Stone labyrinths of Bolshoi Zayatsky Island – a group of some 13 stone labyrinths on 0.4 km2 area of one small island. Local archaeologists have speculated that these labyrinths may be 2,000–3,000 years old, though most researchers remain dubious. Labyrinth as pattern The 7-course "Classical" or "Cretan" pattern known from Cretan coins (ca 400–200 BC) appears in several examples from antiquity, some perhaps as early as the late Stone Age or early Bronze Age. Roman floor mosaics typically unite four copies of the classical labyrinth (or a similar pattern) interlinked around the center, squared off as the medium requires, but still recognisable. An image of the Minotaur or an allusion to the legend of the Minotaur appears at the center of many of these mosaic labyrinths. The four-axis medieval patterns may have developed from the Roman model, but are more varied in how the four quadrants of the design are traced out. The Minotaur or other danger is retained in the center of several medieval examples. The Chartres pattern (named for its appearance in Chartres Cathedral) is the most common medieval design; it appears in manuscripts as early as the 9th century. Medieval labyrinths and turf mazes When the early humanist Benzo d'Alessandria visited Verona before 1310, he noted the "Laberinthum which is now called the Arena"; perhaps he was seeing the cubiculi beneath the arena's missing floor. The full flowering of the medieval labyrinth came about from the twelfth through fourteenth centuries with the grand pavement labyrinths of the gothic cathedrals, notably Chartres, Reims and Amiens in northern France. The symbolism or purpose behind these is unclear, and may have varied from one installation to the next. Descriptions survive of French clerics performing a ritual Easter dance along the path on Easter Sunday. Some labyrinths may have originated as allusions to the Holy City; and some modern writers have theorized that prayers and devotions may have accompanied the perambulation of their intricate paths. Although some books (in particular guidebooks) suggest that the mazes on cathedral floors served as substitutes for pilgrimage paths, the earliest attested use of the phrase "chemin de Jerusalem" (path to Jerusalem) dates to the late 18th century when it was used to describe mazes at Reims and Saint-Omer. The accompanying ritual, depicted in Romantic illustrations as involving pilgrims following the maze on their knees while praying, may have been practiced at Chartres during the 17th century. The cathedral labyrinths are thought to be the inspiration for the many turf mazes in the UK, such as survive at Wing, Hilton, Alkborough, and Saffron Walden. Over the same general period, some 500 or more non-ecclesiastical labyrinths were constructed in Scandinavia. These labyrinths, generally in coastal areas, are marked out with stones, most often in the simple 7- or 11-course classical forms. They often have
|
accessed by a narrow crack but expanding into interlinking caverns. Unlike the Skotino cave, these caverns have smooth walls and columns, and appear to have been at least partially man-made. This site corresponds to a labyrinth symbol on a 16th-century map of Crete in a book of maps in the library of Christ Church, Oxford. A map of the caves themselves was produced by the French in 1821. The site was also used by German soldiers to store ammunition during the Second World War. Howarth's investigation was shown on a documentary produced for the National Geographic Channel. The Egyptian labyrinth More generally, labyrinth might be applied to any extremely complicated maze-like structure. In Book II of his Histories, Herodotus applies the term "labyrinth" to a building complex in Egypt "near the place called the City of Crocodiles", that he considered to surpass the pyramids: During the nineteenth century, the remains of this ancient Egyptian structure were discovered at Hawara in the Faiyum Oasis by Flinders Petrie at the foot of the pyramid of the twelfth-dynasty pharaoh Amenemhat III (reigned c. 1860 BC to c. 1814 BC). The Classical accounts of various authors (Herodotus, Strabo, Pliny the Elder, among others) are not entirely consistent, perhaps due to degradation of the structure during Classical times. The structure may have been a collection of funerary temples such as are commonly found near Egyptian pyramids. Records indicate that Amenemhat's daughter Sobekneferu made additions to the complex during her reign as king of Egypt. In 1898, the Harpers Dictionary of Classical Antiquities described the structure as "the largest of all the temples of Egypt, the so-called Labyrinth, of which, however, only the foundation stones have been preserved." Herodotus' description of the Egyptian Labyrinth inspired some central scenes in Bolesław Prus' 1895 historical novel, Pharaoh. Pliny's Lemnian labyrinth Pliny the Elder's Natural History (36.90) lists the legendary Smilis, reputed to be a contemporary of Daedalus, together with the historical mid-sixth-century BC architects and sculptors Rhoikos and Theodoros as two of the makers of the Lemnian labyrinth, which Andrew Stewart regards as "evidently a misunderstanding of the Samian temple's location en limnais ['in the marsh']." Pliny's Italian labyrinth According to Pliny, the tomb of the great Etruscan general Lars Porsena contained an underground maze. Pliny's description of the exposed portion of the tomb is intractable; Pliny, it seems clear, had not observed this structure himself, but is quoting the historian and Roman antiquarian Varro. Ancient labyrinths outside Europe A design essentially identical to the 7-course "classical" pattern appeared in Native American culture, the Tohono O'odham people labyrinth which features I'itoi, the "Man in the Maze." The Tonoho O'odham pattern has two distinct differences from the classical: it is radial in design, and the entrance is at the top, where traditional labyrinths have the entrance at the bottom (see below). The earliest appearances cannot be dated securely; the oldest is commonly dated to the 17th century. Unsubstantiated claims have been made for the early appearance of labyrinth figures in India, such as a prehistoric petroglyph on a riverbank in Goa purportedly dating to circa 2500 BC. Other examples have been found among cave art in northern India and on a dolmen shrine in the Nilgiri Mountains, but are difficult to date accurately. Securely datable examples begin to appear only around 250 BC. Early labyrinths in India typically follow the Classical pattern or a local variant of it; some have been described as plans of forts or cities. Labyrinths appear in Indian manuscripts and Tantric texts from the 17th century onward. They are often called "Chakravyuha" in reference to an impregnable battle formation described in the ancient Mahabharata epic. Lanka, the capital city of mythic Rāvana, is described as a labyrinth in the 1910 translation of Al-Beruni's India (c. 1030 AD) p. 306 (with a diagram on the following page). By the White Sea, notably on the Solovetsky Islands, there have been preserved more than 30 stone labyrinths. The most remarkable monument is the Stone labyrinths of Bolshoi Zayatsky Island – a group of some 13 stone labyrinths on 0.4 km2 area of one small island. Local archaeologists have speculated that these labyrinths may be 2,000–3,000 years old, though most researchers remain dubious. Labyrinth as pattern The 7-course "Classical" or "Cretan" pattern known from Cretan coins (ca 400–200 BC) appears in several examples from antiquity, some perhaps as early as the late Stone Age or early Bronze Age. Roman floor mosaics typically unite four copies of the classical labyrinth (or a similar pattern) interlinked around the center, squared off as the medium requires, but still recognisable. An image of the Minotaur or an allusion to the legend of the Minotaur appears at the center of many of these mosaic labyrinths. The four-axis medieval patterns may have developed from the Roman model, but are more varied in how the four quadrants of the design are traced out. The Minotaur or other danger is retained in the center of several medieval examples. The Chartres pattern (named for its appearance in Chartres Cathedral) is the most common medieval design; it appears in manuscripts as early as the 9th century. Medieval labyrinths and turf mazes When the early humanist Benzo d'Alessandria visited Verona before 1310, he noted the "Laberinthum which is now called the Arena"; perhaps he was seeing the cubiculi beneath the arena's missing floor. The full flowering of the medieval labyrinth came about from the twelfth through fourteenth centuries with the grand pavement labyrinths of the gothic cathedrals, notably Chartres, Reims and Amiens in northern France. The symbolism or purpose behind these is unclear, and may have varied from one installation to the next. Descriptions survive of French clerics performing a ritual Easter dance along the path on Easter Sunday. Some labyrinths may have originated as allusions to the Holy City; and some modern writers have theorized that prayers and devotions may have accompanied the perambulation of their intricate paths. Although some books (in particular guidebooks) suggest that the mazes on cathedral floors served as substitutes for pilgrimage paths, the earliest attested use of the phrase "chemin de Jerusalem" (path to Jerusalem) dates to the late 18th century when it was used to describe mazes at Reims and Saint-Omer. The accompanying ritual, depicted in Romantic illustrations as involving pilgrims following the maze on their knees while praying, may have been practiced at Chartres during the 17th century. The cathedral labyrinths are thought to be the inspiration for the many turf mazes in the UK, such as survive at Wing, Hilton, Alkborough, and Saffron Walden. Over the same general period, some 500 or more non-ecclesiastical labyrinths were constructed in Scandinavia. These labyrinths, generally in coastal areas, are marked out with stones, most often in the simple 7- or 11-course classical forms. They often have names which translate as "Troy Town." They are thought to have been constructed by fishing communities: trapping malevolent trolls or winds in the labyrinth's coils might ensure a safe fishing expedition. There are also stone labyrinths on the Isles of Scilly, although none is known to date from before the nineteenth century. There are examples of labyrinths in many disparate cultures. The symbol has appeared in various forms and media (petroglyphs, classic-form, medieval-form, pavement, turf, and basketry) at some time throughout most parts of the world, from Native North and South America to Australia, Java, India, and Nepal. Modern labyrinths In recent years, there has been a resurgence of interest in labyrinths and a revival in labyrinth building, of both unicursal and multicursal patterns. Approximately 6,000 labyrinths have been registered with the Worldwide Labyrinth Locator; these are located around the world in private properties, libraries, schools, gardens, recreational
|
of the column, base, and feet, and a fleur de lis pattern at the bottom of the column. It is available in a gold version. It is tall, and weighs about . Lyon & Healy produces one of the most ornate and elaborate harps in the world, the Louis XV, which includes carvings of leaves, flowers, scrolls, and shells along its neck and kneeblock, as well the soundboard edges. Lyon would later form a new company with E.A. Potter called Lyon & Potter, and remained there until his death on January 12, 1894. Healy died of pneumonia on April 3, 1905. In the 1890s the company—which used the slogan,"Everything in music"—began building pipe organs. In 1894 Robert J. Bennett came to Lyon & Healy from the Hutchings company of Boston to head their organ department. The largest surviving Lyon & Healy pipe organ is at the Our Lady of Sorrows Basilica in Chicago. It is a large organ of four manuals and 57 ranks of pipes. They also made small pipe organs. An example survives at St. Mary's Catholic Church in Aspen Colorado. It is a two manual tracker with a 30 note straight pedalboard and 7 ranks. It is believed to have been built around 1900, and can still be pumped by hand. By the 1900s, Lyon & Healy was one of the largest music publishers in the world, and was a major producer of musical instruments. However, In late 1920s, Lyon & Healy sold its brass musical instrument manufacturing branch (see "New Langwill Index"). In the 1970s, the firm concentrated solely upon making and selling harps. In 1928, Lyon & Healy introduced one of the most unusual harps ever mass-produced, the Salzedo Model. The company designed it in collaboration with the harpist Carlos Salzedo. It an Art Deco style instrument that incorporates bold red and white lines on the soundboard to create a stylized and distinct appearance. In the 1960s, Lyon & Healy introduced a smaller lever harp, the Troubadour, a 36-string harp for young beginners with smaller hands, and for casual players. This harp stands , and weighs . In the late 1970s, Steinway & Sons (then owned by CBS) purchased Lyon & Healy and soon after closed all retail stores, which sold sheet music and musical instruments, to focus on harp production. By 1985, Lyon & Healy also made folk harps, also known as Irish harps, which are even smaller than the Troubadour. The "Shamrock model folk harp" has 34 strings. It stands tall with its legs. The legs can be removed so the player can hold the instrument lap—style on the knees. It weighs about . It features Celtic designs on the soundboard. An Irish or folk harp player is sometimes called a harper rather than harpist. DePaul University now owns the Wabash building. Lyon & Healy harps are still in Chicago, Illinois, at 168 North Ogden Avenue. The building was once home to the recording studios of Orlando R. Marsh. Craftsmanship Wood in harp construction varies by instrument, but Sitka Spruce (Picea sitchensis) is the most common soundboard wood. Various Lyon & Healy guitars, mandolins, and many other instrument types reside in major musical instrument museums in the U.S. and Europe. Lyon and Healy now primarily manufactures four types of harps—the lever harp, petite pedal harp, semi-grande pedal harp, and concert grand harp. They also make limited numbers of special harps called concert grands. Lyon & Healy makes electric lever harps in nontraditional colors such as pink, green, blue, and red. Lyon & Healy Corporation Lyon & Healy Corporation is a musical product distribution company in North America representing brands such as Delta, Relish Guitars, SIM1, Paoletti Guitars and Acus Sound Engineering. Lyon & Healy Corporation aims to become the leading provider of premium quality musical instruments and accessories. See also Washburn Guitars List of Stradivarius instruments Notes External links Official website for Lyon & Healy Musical instrument manufacturing companies based in Chicago Harp makers Former CBS Corporation
|
In 1928, Lyon & Healy introduced one of the most unusual harps ever mass-produced, the Salzedo Model. The company designed it in collaboration with the harpist Carlos Salzedo. It an Art Deco style instrument that incorporates bold red and white lines on the soundboard to create a stylized and distinct appearance. In the 1960s, Lyon & Healy introduced a smaller lever harp, the Troubadour, a 36-string harp for young beginners with smaller hands, and for casual players. This harp stands , and weighs . In the late 1970s, Steinway & Sons (then owned by CBS) purchased Lyon & Healy and soon after closed all retail stores, which sold sheet music and musical instruments, to focus on harp production. By 1985, Lyon & Healy also made folk harps, also known as Irish harps, which are even smaller than the Troubadour. The "Shamrock model folk harp" has 34 strings. It stands tall with its legs. The legs can be removed so the player can hold the instrument lap—style on the knees. It weighs about . It features Celtic designs on the soundboard. An Irish or folk harp player is sometimes called a harper rather than harpist. DePaul University now owns the Wabash building. Lyon & Healy harps are still in Chicago, Illinois, at 168 North Ogden Avenue. The building was once home to the recording studios of Orlando R. Marsh. Craftsmanship Wood in harp construction varies by instrument, but Sitka Spruce (Picea sitchensis) is the most common soundboard wood. Various Lyon & Healy guitars, mandolins, and many other instrument types reside in major musical instrument museums in the U.S. and Europe. Lyon and Healy now primarily manufactures four types of harps—the lever harp, petite pedal harp, semi-grande pedal harp, and concert grand harp. They also make limited numbers of special harps called concert grands. Lyon & Healy makes electric lever harps in nontraditional colors such as pink, green, blue, and red. Lyon & Healy Corporation Lyon & Healy Corporation is a musical product distribution company in North America representing brands such as Delta, Relish Guitars, SIM1, Paoletti Guitars and Acus Sound Engineering. Lyon & Healy Corporation aims to become the
|
al-Abharī Atisha Atlantis Atlas Shrugged Atman (Buddhism) Ātman (Buddhism) Atman (Hinduism) Atomic fact Atomic sentence Atomism Atonement in Christianity Atonement in Judaism Atopy (philosophy) Atrocity story Attacking Faulty Reasoning Attalus (Stoic) Attempt at a Critique of All Revelation Attentional bias Atticus (philosopher) Attitude (psychology) Attitude polarization Attorney–client privilege Attorney misconduct Attorney/client privilege Attribute grammar Attribution theory Attributional bias Auberon Herbert Auctoritas Auctoritates Aristotelis Aufheben Augmented Backus–Naur form Augoeides August Cieszkowski August Wilhelm Schlegel Auguste Comte Auguste Vaillant Augustin Bonnetty Augustin Souchy Augustine Eriugena Augustine of Hippo Augustinian Studies Augustinian values Augusto César Sandino Augusto Vera Augustus De Morgan Aulus Egnatius Priscillianus Aulus Gellius Aurel Kolnai Austin Farrer Austin Marsden Farrer Austin Woodbury Australasian Association of Philosophy Australasian Journal of Philosophy Australian materialism Australian realism Austrofascism Autarchism Authenticity (philosophy) Authoritarianism Authority Auto-destructive art Autocracy Autoepistemic logic Autological Automata theory Automated reasoning Automatic sequence Automaton Autonomedia Autonomism Autonomous Action Autonomy Autopoiesis Avadhuta Gita Availability heuristic Avant-garde Avant-Garde and Kitsch Avatar Avecebrol Avempace Average and total utilitarianism Averaging argument Averroes Averroës Averroism Aversion therapy Avicebrol Avicebron Avicenna Avicenna Prize Avicennism Avidya (Hinduism) Avidyā (Buddhism) Avishai Margalit Avital Ronell Avodah Avraham son of Rambam Avrum Stroll Awareness Awareness League Axel Hägerström Axel Honneth Axial Age Axiochus (dialogue) Axiology Axiom Axiom of abstraction Axiom of choice Axiom of comprehension Axiom of Equity Axiom of extensionality Axiom of infinity Axiom of projective determinacy Axiom of reducibility Axiom of replacement Axiom of separation Axiom S5 Axiom schema Axiomatic method Axiomatic set theory Axiomatic system Axiomatization Axiothea of Phlius Ayatana Ayn al-Quzat Hamadani Ayn Rand Ayn Rand: A Sense of Life Ayn Rand: The Russian Radical Ayurveda Ayyavazhi Ayyavazhi phenomenology Azizah Y. al-Hibri Aztec philosophy B B-series B-Theory of time B. F. Skinner B. R. Ambedkar B. Traven Babette Babich Baby K Backgammon Backus–Naur form Backward causation Backward chaining Bad faith Bad faith (existentialism) Baden School Bahmanyār Bahshamiyya Bahya ibn Paquda Baker Brownell Balance (metaphysics) Balance of nature Balangoda Ananda Maitreya Baltasar Gracián Balthasar Bekker Banality of evil Banausos Bandwagon effect Bantu Philosophy Baptista Mantuanus Baptists in the history of separation of church and state Barba non facit philosophum Barbara Barbara Forrest Barbara Herrnstein Smith Barber paradox Barbershop paradox Barbizon school Barcan formula Barcelona May Days Bardo Bare particular Bargaining theory Barhaspatya sutras Barlaam of Seminara Baron d'Holbach Baron de Montesquieu Baron Herbert of Cherbury Baroque Baroque Revival architecture Barracks communism Barrie Karp Barrows Dunham Barry Loewer Barry Smith (ontologist) Barry Stroud Bartholomäus Keckermann Bartholomew Des Bosses Bartholomew Keckermann Bartholomew of Bologna (philosopher) Bartolomé de Medina Bartolommeo Spina Bartolus de Saxoferrato Baruch Spinoza Barwise prize Barzillai Quaife Bas C. van Fraassen Bas Haring Bas van Fraassen Base and superstructure Base and superstructure (Marxism) Base rate fallacy Basic belief Basic Limiting Principle Basic norm Basic Points Unifying the Theravāda and the Mahāyāna Basil Mitchell (academic) Basilides Basilides (Stoic) Basilides the Epicurean Basilios Bessarion Batis of Lampsacus Batman: Anarky Battle of Peregonovka (1919) Bauhaus Bay Area Figurative Movement Bayes' theorem Bayes's rule Bayes's theorem Bayesian probability Bayesianism Beatific vision Béatrice Longuenesse Beatriz Sarlo Beauty Becoming Becoming (philosophy) Bedeutung Beelzebub's Tales to His Grandson Beerwolf Begging the question Begriffsschrift Behavior therapy Behavioral script Behavioralism Behaviorism Behaviourism Behind the Mirror: A Search for a Natural History of Human Knowledge Behold a Pale Horse (film) Being Being and becoming Being and Nothingness Being and Time Being beautiful in spirit Being for itself Being in itself Béla Balázs Béla Hamvas Belief Belief-Desire-Intention model Belief-in Belief bias Belief in Belief revision Bell's inequality Bell's theorem Bellum omnium contra omnes Belmont Report Ben Salem Himmich Benedetto Croce Benedict de Spinoza Benedict Pereira Benedictus Spinoza Benedito Nunes Beneficence Benjamin Apthorp Gould Fuller Benjamin Constant Benjamin Franklin Benjamin Lee (academic) Benjamin Paul Blood Benjamin Peirce Benjamin Tucker Benjamin Whichcote Benny Lévy Benoît Broutchoux Benoît de Maillet Benson Mates Berlin Circle Bernard-Henri Lévy Bernard A. O. Williams Bernard Arthur Owen Williams Bernard Bolzano Bernard Bosanquet (philosopher) Bernard d'Espagnat Bernard de Fontenelle Bernard Delfgaauw Bernard Gert Bernard le Bovier de Fontenelle Bernard Le Bovier de Fontenelle Bernard Lonergan Bernard Mandeville Bernard Mayo Bernard Narokobi Bernard Nieuwentyt Bernard of Chartres Bernard of Clairvaux Bernard of Trilia Bernard Philip Kelly Bernard Rollin Bernard Silvestris Bernard Stiegler Bernard Williams Bernard Yack Bernardino Telesio Bernardino Varisco Bernhard Riemann Bernoulli's principle Bernoulli's theorem Berry's paradox Bert Mosselmans Berthold of Moosburg Berthold Wulf Bertil Mårtensson Bertrand paradox (economics) Bertrand paradox (probability) Bertrand's box paradox Bertrand Arthur William Russell Bertrand de Jouvenel Bertrand Russell Bertrand Russell's views on philosophy Bertrand Russell's views on society Best of all possible worlds Bête machine Betrayal Between Facts and Norms Between Heaven and Hell (novel) Between Past and Future Beuron Art School Beyond Belief: Science, Religion, Reason and Survival Beyond Freedom and Dignity Beyond Good and Evil Beyond the Pleasure Principle Bhagavad Gita Bhakti Bhartrhari Bhava Bhavanga Bhāvaviveka Bhedabheda Bhikhu Parekh, Baron Parekh Bhumi (Buddhism) Bias Bias blind spot Bible Biblical literalism Bibliography for Ayn Rand and Objectivism Biconditional Biconditional elimination Biconditional introduction Biennio rosso Big Book (thought experiment) Bigram Bill Martin (philosophy) Bilocation Binary opposition Biocentric universe Biocentrism (ethics) Biodefense Bioethics Bioethics (journal) Biofact (philosophy) Biofacticity Biographia Literaria Biographical fallacy Biological determinism Biological naturalism Biological warfare Biomedical tissue Bion of Borysthenes Biopolitics Biopower Biosafety Biosecurity Biosophy Biotic Baking Brigade Bisexuality Bite the bullet Bivalence Bjarni Jónsson Bl(A)ck Tea Society Black-Body Theory and the Quantum Discontinuity Black anarchism Black Artists Group Black Arts Movement Black bloc Black box Black box theory Black existentialism Black Flag (newspaper) Black Laundry Black Mask (anarchists) Black Panther Party Black Sotnia Black Star (anarchist group) Black swan theory Blackbird Raum Blackwell Companion to Philosophy Blaise Pascal Blame Blanquism Bleen Blindsight Blockhead (thought experiment) Blossius Bluestocking (journal) Bluestockings (bookstore) Blyenbergh Boasting Boatmen of Thessaloníki Bob Black Bob Hale (philosopher) Bodhi Bodhimandala Bodhisattva Precepts Bodhisena Body donation Body of Knowledge Body politic Body without organs Bodymind Boethius Boethus of Sidon Boethus of Sidon (Stoic) Boetius of Dacia Bohm interpretation Bohr–Einstein debates Bohr Einstein debate Bolam v Friern Hospital Management Committee Bolshevik Bolus of Mendes Bonapartism (Marxism) Bonaventure Boncompagno da Signa Bonifaty Kedrov Bonini's paradox Bonnie Honig Bonnie Steinbock Bonnot Gang Book of Causes Book of Changes Book of Life Boolean algebra (logic) Boolean grammar Bootstrapping Borden Parker Bowne Boredom Boris Chicherin Boris Furlan Boris Grushin Boris Hessen Borussian myth Bound variable Bourgeois Bourgeois socialism Bourgeoisie Bowling Green Studies in Applied Philosophy Boyd Henry Bode Boyle Lectures Bracha L. Ettinger Bracketing (phenomenology) Bracketing paradox Brad Hooker Brahma Brahmacharya Brahman Brahmavihara Brahmin Brahmo Samaj Brain Brain-in-a-vat theory Brain dump Brain event Brain in a vat Brainstorm machine Brainstorms Brand Blanshard Brandon Darby Branko Bošnjak Brazilian Workers Confederation Breaking the Spell (film) Breaking the Spell: Religion as a Natural Phenomenon Brethren of Purity Brian Barry Brian Boyd Brian David Ellis Brian Davies (philosopher) Brian Klug Brian Leftow Brian Leiter Brian MacKenzie Infoshop Brian Massumi Brian O'Shaughnessy (philosopher) Brian Orend Brian Skyrms Brian Weatherson Bridge ethics Brie Gertler Brights movement British Empiricists British Humanist Association British idealism British Idealism British Journal of Aesthetics British Philosophical Association British philosophy Broadway Barks Bronisław Trentowski Bronius Kuzmickas Brontinus Brother Wolf Brownie points Bruce Lee Bruce Weinstein Bruce Wilshire Brunetto Latini Bruno Bauch Bruno Bauer Bruno de Finetti Bruno Leoni Brute fact Bryan Caplan Bryan Magee Bryson of Achaea Bryson of Heraclea Buchmanism Budaya Buddha-nature Buddhaghosa Buddhahood Buddhapālita Buddhism Buddhism and evolution Buddhist anarchism Buddhist ethics Buddhist philosophy Buddhist schools Buddhist view of marriage Buenaventura Durruti Bullshit Bulverism Bunched logic Bundle theory Bundle theory of the self Burali-Forte paradox Burali-Forti's paradox Burchard de Volder Burden of proof (logical fallacy) Bureaucracy Bureaucratic collectivism Burghart Schmidt Buridan's ass Burleigh Taylor Wilkins Burrhus Frederic Skinner Burton Dreben Business ethics Buttered cat paradox By any means necessary Byzantine philosophy Byzantine rhetoric Byzantinism C C. Anthony Anderson C. D. Broad C. E. M. Joad C. I. Lewis C. Lloyd Morgan C. S. Lewis C. S. Lewis bibliography C. Stephen Evans C. T. K. Chari C. A. J. Coady Cabbala Café Philosophique Cahal Daly Cai Yuanpei Caigentan Cairo Declaration on Human Rights in Islam Cajetan Calcidius Calculus Calculus of structures Calculus ratiocinator Calippus of Syracuse Callicles Calliphon Calliphon of Croton Callippus Callistratus (sophist) Calvin Normore Calvin Seerveld Calvinism Camas Bookstore and Infoshop Cambridge change Cambridge Philosophical Society Cambridge Platonism Cambridge Platonists Camera del Lavoro Camera obscura Camilo Cienfuegos Camp (style) Canadian Journal of Philosophy Canadian Society for History and Philosophy of Mathematics Candace Vogler Candide Candrakīrti Canonical form (Boolean algebra) Cantor's paradox Cantor's theorem Capacity Capital accumulation Capital punishment Capital, Volume I Capitalism Capitalism: The Unknown Ideal Capitalist mode of production Capitalist realism Cappadocian Fathers Carceral state Cardinal Mercier Prize for International Philosophy Cardinal utility Cardinal virtues Cardinality Care Care Not Killing Carew Arthur Meredith Cargo cult science Carl Cohen Carl Dahlhaus Carl Elliott (philosopher) Carl Friedrich Gauss Carl Friedrich von Weizsäcker Carl G. Hempel Carl Ginet Carl Gustav Carus Carl Gustav Hempel Carl Gustav Jung Carl Hempel Carl Joachim Friedrich Carl Jung Carl Linnaeus Carl Mitcham Carl Schmitt Carl Stumpf Carl von Linnaeus Carlo Cattaneo Carlo Lottieri Carlo Michelstaedter Carlo Penco Carlo Rosselli Carlo Tresca Carlos Bernardo González Pecotche Carlos Brandt Carlos Castrodeza Carlos Castaneda Carlos Cirne Lima Carlos Santiago Nino Carlos Vaz Ferreira Carmen Laforet Ramsey sentence Carneades Carneiscus Carol Gilligan Caroline Joan S. Picart Carolingian renaissance Carolus Sigonius Carolyn Merchant Carsun Chang Cartesian anxiety Cartesian circle Cartesian demon Cartesian doubt Cartesian dualism Cartesian materialism Cartesian Meditations Cartesian Other Cartesian product Cartesian Self Cartesian skepticism Cartesian theater Cartesianism Cārvāka Carveth Read Case-based reasoning Casimir Lewy Caspar Isenkrahe Cassius Longinus (philosopher) Casuistry Cat's Cradle Catch-22 (logic) Catechism of a Revolutionary Categoriae decem Categorical Categorical imperative Categorical logic Categorical proposition Categorical theory Categoricity Categories (Aristotle) Categories (Peirce) Categories of the understanding Categorization Category (Kant) Category (philosophy) Category mistake Category of being Category theory Catharine Macaulay Catharsis Catherine Clément Catherine Elgin Catherine Malabou Catherine of Siena Catherine Perret Catherine Trotter Catherine Trotter Cockburn Catholic guilt Catholic Probabilism Catius Cato Maior de Senectute Cato the Elder Cato the Younger Catonism Causa sui Causal-historical theory of reference Causal adequacy principle Causal chain Causal closure Causal decision theory Causal determinism Causal diagram Causal Markov condition Causal relation Causal theory of proper names Causal theory of reference Causalism Causality Causality loop Causation (law) Causative verb Cause Cavalcante de' Cavalcanti Cebes Celestial spheres Célestin Bouglé Celia Green Celine's laws Cellar door Cellular automaton Celsus Cemal Yildirim Center Leo Apostel for Interdisciplinary Studies Centre de recherche et de documentation sur Hegel Centre for Applied Ethics Centre for Applied Philosophy and Public Ethics (CAPPE) Centre for History and Philosophy of Science, University of Leeds Cercidas Cercops Certainty César Chesneau Dumarsais César Dávila Andrade Cesare Beccaria Cesare Cremonini (philosopher) Ceteris paribus CH Ch'i Ch'ien Ch'ien Mu Ch'ing Ch'uan Chaeremon of Alexandria Chaerephon Chaeron of Pellene Chaïm Perelman Chain of events Chaldean Oracles Chamaeleon (philosopher) Chanakya Chance (Ancient Greek concept) Chandragomin Change Chantal Maillard Chao Cuo Chaos Chaos theory Chaotic system Character Strengths and Virtues (book) Character structure Character traits Characteristica universalis Chariot Allegory Charismatic authority Charity (practice) Charity (virtue) Charity International Charles A. Moore Charles Babbage Charles Batteux Charles Bernard Renouvier Charles Blount (deist) Charles Bonnet Charles Butterworth (philosopher) Charles Carroll Everett Charles Darwin Charles de Secondat, baron de Montesquieu Charles Fourier Charles François d'Abra de Raconis Charles Frankel Charles Fremont Dight Charles Graves (bishop) Charles Hartshorne Charles Kay Ogden Charles L. Stevenson Charles Leonard Hamblin Charles Leslie Stevenson Charles Louis de Secondat, Baron de Montesquieu Charles Lutwidge Dodgson Charles Malato Charles Maurras Charles Morris, Baron Morris of Grasmere Charles Parsons (philosopher) Charles Renouvier Charles Robert Darwin Charles Sanders Peirce Charles Sanders Peirce bibliography Charles Secrétan Charles Stevenson Charles Taylor (philosopher) Charles W. Morris Charles Waddington (philosopher) Charles Winquist Charlotte Perkins Gilman Charlotte Wilson Charmadas Charmides (dialogue) Charter for Compassion Chastity Chatral Rinpoche Chauncey Wright Chaz Bufe Chemism Chen Chung-hwan Chen Daqi Chen Duxiu Chen Hongmou Cheng Hao Cheng Yi (philosopher) Chernoe Znamia Cherry picking (fallacy) Cheung Kam Ching Chia I Chia Yi Chicago school (mathematical analysis) Chicken or the egg Chih Chih-I Chih Tun Child labour China brain Chinese Classics Chinese Legalism Chinese philosophy Chinese room Chinese world Chinoiserie Chinul Chion of Heraclea Chivalry Chöd Choe Chung Chögyam Trungpa Choice Choice-supportive bias Choice sequence Chomsky hierarchy Chomsky normal form Choosing Chora Choricius of Gaza Chovot ha-Levavot Chrematistics Chris Bobonich Chris Crass Chris Huebner Christiaan Cornelissen Christiaan Huygens Christian anarchism Christian August Crusius Christian de Quincey Christian Discourses Christian ethics Christian existentialism Christian Friedrich Hebbel Christian Garve Christian Hermann Weisse Christian humanism Christian Kabbalah Christian materialism Christian philosophy Christian Realism Christian Thomasius Christian von Ehrenfels Christian Wolff (philosopher) Christianity and environmentalism Christine Buci-Glucksmann Christine de Pizan Christine Korsgaard Christine Ladd-Franklin Christofascism Christological argument Christology Christoph Gottfried Bardili Christoph Meiners Christoph Schrempf Christoph von Sigwart Christopher Cherniak Christopher D. Green Christopher Fynsk Christopher Jacob Boström Christopher Janaway Christopher Norris (critic) Christopher Peacocke Christopher Potter (author) Christopher R. Phillips Christos Yannaras Chronocentrism Chronological snobbery Chronology protection conjecture Chrysanthius Chrysippus Chrysorrhoas Chu Anping Chu Hsi Chuck Munson Chumbawamba Chün-tzu Chung-ying Cheng Chung-yung Chung Yung Chunyu Kun Church's theorem Church's thesis Church–Turing thesis Church–Turing–Deutsch principle Church fathers Cicero Cienfuegos press Cincinnati Time Store Cindy Milstein Cinema 1: The Movement Image Cipriano Mera Circle of Tchaikovsky Circular cause and consequence Circular definition Circular reasoning Circumcision controversies Citationality Citizen Cyborg Citizenship City of God (book) Civic humanism Civic virtue Civics Civil discourse Civil disobedience Civil liberties Civil rights Civil society Civil union Civilization and Its Discontents Claim right Clairvoyance Clare W. Graves Clarembald of Arras Clarence Irving Lewis Clarity of scripture Clarity test Class (philosophy) Class collaboration Class consciousness Class struggle Classical conditioning Classical liberalism Classical logic Classical mechanics Classical Realism Classical republicanism Classical theism Classicism Classics Classification of the sciences (Peirce) Classificatory disputes about art Classless society Claude-Arien Helvetius Claude Adrien Helvétius Claude Buffier Claude Henri de Rouvroy, comte de Saint-Simon Claude Lefort Claude Lévi-Strauss Claude Lévi-Strauss Claude Tresmontant Claudio Canaparo Claudio Ulpiano Claudius Maximus Claus Emmeche Clause (logic) Cleanliness Cleanthes Clearchus of Soli Cleinias of Tarentum Clémence Royer Clemens Baeumker Clemens Timpler Clement Greenberg Clement of Alexandria Clément Rosset Cleobulus Cleomedes Cleomenes the Cynic Clerical fascism Clerical philosophers Clericalism Clifford Harper Clifford Williams (academic) Climate ethics Clinamen Clinical death Clinical equipoise Clinomachus Clitomachus (philosopher) Clitophon (dialogue) Clive Bell Clive Staples Lewis CLODO Cloning Close reading Closed circle Closed concept Closed formula Closed loop Closed sentence Closed world assumption Cloudesley Clustering illusion Co-premise Coase theorem Code (law) Coercion Cogency Cogito (magazine) Cogito ergo sum Cognition Cognitive architecture Cognitive bias Cognitive closure (philosophy) Cognitive description Cognitive development Cognitive dissonance Cognitive liberty Cognitive map Cognitive meaning Cognitive module Cognitive neuroscience Cognitive ontology Cognitive psychology Cognitive relativism Cognitive revolution Cognitive science Cognitive science of mathematics Cognitive synonymy Cognitivism (ethics) Coherence (philosophical gambling strategy) Coherence theory of truth Coherentism Coimbra commentaries Coimbra group Cointerpretability Colin Howson Colin McGinn Colin Murray Turbayne Colin Wilson Collapse (journal) Collapse theories (quantum mechanics) Collective belief Collective memory Collective responsibility Collective unconscious Collectivism Collectivist anarchism Collectivity Collège international de philosophie Collegium Conimbricense Colloque Walter Lippmann Colloquial language Color Color Field Color realism (philosophy) Colotes Combinational logic Combinatory logic Comedy Comenius Comité Consultatif National d'Ethique Commensurability (ethics) Commensurability (philosophy of science) Commentaria in Aristotelem Graeca Commentaries on Aristotle Commentaries on Plato Commission of Anarchist Relations Committee for the Scientific Examination of Religion Commodification Commodity (Marxism) Commodity fetishism Commodity form theory Common good Common Ground Collective Common knowledge Common knowledge (logic) Common law Common ownership Common rule Common sense Common sense and the Diallelus Common sense reasoning Commonsense reasoning Communication Communication theory Communicative action Communicative rationality Communism Communitarianism Community
|
Longuenesse Beatriz Sarlo Beauty Becoming Becoming (philosophy) Bedeutung Beelzebub's Tales to His Grandson Beerwolf Begging the question Begriffsschrift Behavior therapy Behavioral script Behavioralism Behaviorism Behaviourism Behind the Mirror: A Search for a Natural History of Human Knowledge Behold a Pale Horse (film) Being Being and becoming Being and Nothingness Being and Time Being beautiful in spirit Being for itself Being in itself Béla Balázs Béla Hamvas Belief Belief-Desire-Intention model Belief-in Belief bias Belief in Belief revision Bell's inequality Bell's theorem Bellum omnium contra omnes Belmont Report Ben Salem Himmich Benedetto Croce Benedict de Spinoza Benedict Pereira Benedictus Spinoza Benedito Nunes Beneficence Benjamin Apthorp Gould Fuller Benjamin Constant Benjamin Franklin Benjamin Lee (academic) Benjamin Paul Blood Benjamin Peirce Benjamin Tucker Benjamin Whichcote Benny Lévy Benoît Broutchoux Benoît de Maillet Benson Mates Berlin Circle Bernard-Henri Lévy Bernard A. O. Williams Bernard Arthur Owen Williams Bernard Bolzano Bernard Bosanquet (philosopher) Bernard d'Espagnat Bernard de Fontenelle Bernard Delfgaauw Bernard Gert Bernard le Bovier de Fontenelle Bernard Le Bovier de Fontenelle Bernard Lonergan Bernard Mandeville Bernard Mayo Bernard Narokobi Bernard Nieuwentyt Bernard of Chartres Bernard of Clairvaux Bernard of Trilia Bernard Philip Kelly Bernard Rollin Bernard Silvestris Bernard Stiegler Bernard Williams Bernard Yack Bernardino Telesio Bernardino Varisco Bernhard Riemann Bernoulli's principle Bernoulli's theorem Berry's paradox Bert Mosselmans Berthold of Moosburg Berthold Wulf Bertil Mårtensson Bertrand paradox (economics) Bertrand paradox (probability) Bertrand's box paradox Bertrand Arthur William Russell Bertrand de Jouvenel Bertrand Russell Bertrand Russell's views on philosophy Bertrand Russell's views on society Best of all possible worlds Bête machine Betrayal Between Facts and Norms Between Heaven and Hell (novel) Between Past and Future Beuron Art School Beyond Belief: Science, Religion, Reason and Survival Beyond Freedom and Dignity Beyond Good and Evil Beyond the Pleasure Principle Bhagavad Gita Bhakti Bhartrhari Bhava Bhavanga Bhāvaviveka Bhedabheda Bhikhu Parekh, Baron Parekh Bhumi (Buddhism) Bias Bias blind spot Bible Biblical literalism Bibliography for Ayn Rand and Objectivism Biconditional Biconditional elimination Biconditional introduction Biennio rosso Big Book (thought experiment) Bigram Bill Martin (philosophy) Bilocation Binary opposition Biocentric universe Biocentrism (ethics) Biodefense Bioethics Bioethics (journal) Biofact (philosophy) Biofacticity Biographia Literaria Biographical fallacy Biological determinism Biological naturalism Biological warfare Biomedical tissue Bion of Borysthenes Biopolitics Biopower Biosafety Biosecurity Biosophy Biotic Baking Brigade Bisexuality Bite the bullet Bivalence Bjarni Jónsson Bl(A)ck Tea Society Black-Body Theory and the Quantum Discontinuity Black anarchism Black Artists Group Black Arts Movement Black bloc Black box Black box theory Black existentialism Black Flag (newspaper) Black Laundry Black Mask (anarchists) Black Panther Party Black Sotnia Black Star (anarchist group) Black swan theory Blackbird Raum Blackwell Companion to Philosophy Blaise Pascal Blame Blanquism Bleen Blindsight Blockhead (thought experiment) Blossius Bluestocking (journal) Bluestockings (bookstore) Blyenbergh Boasting Boatmen of Thessaloníki Bob Black Bob Hale (philosopher) Bodhi Bodhimandala Bodhisattva Precepts Bodhisena Body donation Body of Knowledge Body politic Body without organs Bodymind Boethius Boethus of Sidon Boethus of Sidon (Stoic) Boetius of Dacia Bohm interpretation Bohr–Einstein debates Bohr Einstein debate Bolam v Friern Hospital Management Committee Bolshevik Bolus of Mendes Bonapartism (Marxism) Bonaventure Boncompagno da Signa Bonifaty Kedrov Bonini's paradox Bonnie Honig Bonnie Steinbock Bonnot Gang Book of Causes Book of Changes Book of Life Boolean algebra (logic) Boolean grammar Bootstrapping Borden Parker Bowne Boredom Boris Chicherin Boris Furlan Boris Grushin Boris Hessen Borussian myth Bound variable Bourgeois Bourgeois socialism Bourgeoisie Bowling Green Studies in Applied Philosophy Boyd Henry Bode Boyle Lectures Bracha L. Ettinger Bracketing (phenomenology) Bracketing paradox Brad Hooker Brahma Brahmacharya Brahman Brahmavihara Brahmin Brahmo Samaj Brain Brain-in-a-vat theory Brain dump Brain event Brain in a vat Brainstorm machine Brainstorms Brand Blanshard Brandon Darby Branko Bošnjak Brazilian Workers Confederation Breaking the Spell (film) Breaking the Spell: Religion as a Natural Phenomenon Brethren of Purity Brian Barry Brian Boyd Brian David Ellis Brian Davies (philosopher) Brian Klug Brian Leftow Brian Leiter Brian MacKenzie Infoshop Brian Massumi Brian O'Shaughnessy (philosopher) Brian Orend Brian Skyrms Brian Weatherson Bridge ethics Brie Gertler Brights movement British Empiricists British Humanist Association British idealism British Idealism British Journal of Aesthetics British Philosophical Association British philosophy Broadway Barks Bronisław Trentowski Bronius Kuzmickas Brontinus Brother Wolf Brownie points Bruce Lee Bruce Weinstein Bruce Wilshire Brunetto Latini Bruno Bauch Bruno Bauer Bruno de Finetti Bruno Leoni Brute fact Bryan Caplan Bryan Magee Bryson of Achaea Bryson of Heraclea Buchmanism Budaya Buddha-nature Buddhaghosa Buddhahood Buddhapālita Buddhism Buddhism and evolution Buddhist anarchism Buddhist ethics Buddhist philosophy Buddhist schools Buddhist view of marriage Buenaventura Durruti Bullshit Bulverism Bunched logic Bundle theory Bundle theory of the self Burali-Forte paradox Burali-Forti's paradox Burchard de Volder Burden of proof (logical fallacy) Bureaucracy Bureaucratic collectivism Burghart Schmidt Buridan's ass Burleigh Taylor Wilkins Burrhus Frederic Skinner Burton Dreben Business ethics Buttered cat paradox By any means necessary Byzantine philosophy Byzantine rhetoric Byzantinism C C. Anthony Anderson C. D. Broad C. E. M. Joad C. I. Lewis C. Lloyd Morgan C. S. Lewis C. S. Lewis bibliography C. Stephen Evans C. T. K. Chari C. A. J. Coady Cabbala Café Philosophique Cahal Daly Cai Yuanpei Caigentan Cairo Declaration on Human Rights in Islam Cajetan Calcidius Calculus Calculus of structures Calculus ratiocinator Calippus of Syracuse Callicles Calliphon Calliphon of Croton Callippus Callistratus (sophist) Calvin Normore Calvin Seerveld Calvinism Camas Bookstore and Infoshop Cambridge change Cambridge Philosophical Society Cambridge Platonism Cambridge Platonists Camera del Lavoro Camera obscura Camilo Cienfuegos Camp (style) Canadian Journal of Philosophy Canadian Society for History and Philosophy of Mathematics Candace Vogler Candide Candrakīrti Canonical form (Boolean algebra) Cantor's paradox Cantor's theorem Capacity Capital accumulation Capital punishment Capital, Volume I Capitalism Capitalism: The Unknown Ideal Capitalist mode of production Capitalist realism Cappadocian Fathers Carceral state Cardinal Mercier Prize for International Philosophy Cardinal utility Cardinal virtues Cardinality Care Care Not Killing Carew Arthur Meredith Cargo cult science Carl Cohen Carl Dahlhaus Carl Elliott (philosopher) Carl Friedrich Gauss Carl Friedrich von Weizsäcker Carl G. Hempel Carl Ginet Carl Gustav Carus Carl Gustav Hempel Carl Gustav Jung Carl Hempel Carl Joachim Friedrich Carl Jung Carl Linnaeus Carl Mitcham Carl Schmitt Carl Stumpf Carl von Linnaeus Carlo Cattaneo Carlo Lottieri Carlo Michelstaedter Carlo Penco Carlo Rosselli Carlo Tresca Carlos Bernardo González Pecotche Carlos Brandt Carlos Castrodeza Carlos Castaneda Carlos Cirne Lima Carlos Santiago Nino Carlos Vaz Ferreira Carmen Laforet Ramsey sentence Carneades Carneiscus Carol Gilligan Caroline Joan S. Picart Carolingian renaissance Carolus Sigonius Carolyn Merchant Carsun Chang Cartesian anxiety Cartesian circle Cartesian demon Cartesian doubt Cartesian dualism Cartesian materialism Cartesian Meditations Cartesian Other Cartesian product Cartesian Self Cartesian skepticism Cartesian theater Cartesianism Cārvāka Carveth Read Case-based reasoning Casimir Lewy Caspar Isenkrahe Cassius Longinus (philosopher) Casuistry Cat's Cradle Catch-22 (logic) Catechism of a Revolutionary Categoriae decem Categorical Categorical imperative Categorical logic Categorical proposition Categorical theory Categoricity Categories (Aristotle) Categories (Peirce) Categories of the understanding Categorization Category (Kant) Category (philosophy) Category mistake Category of being Category theory Catharine Macaulay Catharsis Catherine Clément Catherine Elgin Catherine Malabou Catherine of Siena Catherine Perret Catherine Trotter Catherine Trotter Cockburn Catholic guilt Catholic Probabilism Catius Cato Maior de Senectute Cato the Elder Cato the Younger Catonism Causa sui Causal-historical theory of reference Causal adequacy principle Causal chain Causal closure Causal decision theory Causal determinism Causal diagram Causal Markov condition Causal relation Causal theory of proper names Causal theory of reference Causalism Causality Causality loop Causation (law) Causative verb Cause Cavalcante de' Cavalcanti Cebes Celestial spheres Célestin Bouglé Celia Green Celine's laws Cellar door Cellular automaton Celsus Cemal Yildirim Center Leo Apostel for Interdisciplinary Studies Centre de recherche et de documentation sur Hegel Centre for Applied Ethics Centre for Applied Philosophy and Public Ethics (CAPPE) Centre for History and Philosophy of Science, University of Leeds Cercidas Cercops Certainty César Chesneau Dumarsais César Dávila Andrade Cesare Beccaria Cesare Cremonini (philosopher) Ceteris paribus CH Ch'i Ch'ien Ch'ien Mu Ch'ing Ch'uan Chaeremon of Alexandria Chaerephon Chaeron of Pellene Chaïm Perelman Chain of events Chaldean Oracles Chamaeleon (philosopher) Chanakya Chance (Ancient Greek concept) Chandragomin Change Chantal Maillard Chao Cuo Chaos Chaos theory Chaotic system Character Strengths and Virtues (book) Character structure Character traits Characteristica universalis Chariot Allegory Charismatic authority Charity (practice) Charity (virtue) Charity International Charles A. Moore Charles Babbage Charles Batteux Charles Bernard Renouvier Charles Blount (deist) Charles Bonnet Charles Butterworth (philosopher) Charles Carroll Everett Charles Darwin Charles de Secondat, baron de Montesquieu Charles Fourier Charles François d'Abra de Raconis Charles Frankel Charles Fremont Dight Charles Graves (bishop) Charles Hartshorne Charles Kay Ogden Charles L. Stevenson Charles Leonard Hamblin Charles Leslie Stevenson Charles Louis de Secondat, Baron de Montesquieu Charles Lutwidge Dodgson Charles Malato Charles Maurras Charles Morris, Baron Morris of Grasmere Charles Parsons (philosopher) Charles Renouvier Charles Robert Darwin Charles Sanders Peirce Charles Sanders Peirce bibliography Charles Secrétan Charles Stevenson Charles Taylor (philosopher) Charles W. Morris Charles Waddington (philosopher) Charles Winquist Charlotte Perkins Gilman Charlotte Wilson Charmadas Charmides (dialogue) Charter for Compassion Chastity Chatral Rinpoche Chauncey Wright Chaz Bufe Chemism Chen Chung-hwan Chen Daqi Chen Duxiu Chen Hongmou Cheng Hao Cheng Yi (philosopher) Chernoe Znamia Cherry picking (fallacy) Cheung Kam Ching Chia I Chia Yi Chicago school (mathematical analysis) Chicken or the egg Chih Chih-I Chih Tun Child labour China brain Chinese Classics Chinese Legalism Chinese philosophy Chinese room Chinese world Chinoiserie Chinul Chion of Heraclea Chivalry Chöd Choe Chung Chögyam Trungpa Choice Choice-supportive bias Choice sequence Chomsky hierarchy Chomsky normal form Choosing Chora Choricius of Gaza Chovot ha-Levavot Chrematistics Chris Bobonich Chris Crass Chris Huebner Christiaan Cornelissen Christiaan Huygens Christian anarchism Christian August Crusius Christian de Quincey Christian Discourses Christian ethics Christian existentialism Christian Friedrich Hebbel Christian Garve Christian Hermann Weisse Christian humanism Christian Kabbalah Christian materialism Christian philosophy Christian Realism Christian Thomasius Christian von Ehrenfels Christian Wolff (philosopher) Christianity and environmentalism Christine Buci-Glucksmann Christine de Pizan Christine Korsgaard Christine Ladd-Franklin Christofascism Christological argument Christology Christoph Gottfried Bardili Christoph Meiners Christoph Schrempf Christoph von Sigwart Christopher Cherniak Christopher D. Green Christopher Fynsk Christopher Jacob Boström Christopher Janaway Christopher Norris (critic) Christopher Peacocke Christopher Potter (author) Christopher R. Phillips Christos Yannaras Chronocentrism Chronological snobbery Chronology protection conjecture Chrysanthius Chrysippus Chrysorrhoas Chu Anping Chu Hsi Chuck Munson Chumbawamba Chün-tzu Chung-ying Cheng Chung-yung Chung Yung Chunyu Kun Church's theorem Church's thesis Church–Turing thesis Church–Turing–Deutsch principle Church fathers Cicero Cienfuegos press Cincinnati Time Store Cindy Milstein Cinema 1: The Movement Image Cipriano Mera Circle of Tchaikovsky Circular cause and consequence Circular definition Circular reasoning Circumcision controversies Citationality Citizen Cyborg Citizenship City of God (book) Civic humanism Civic virtue Civics Civil discourse Civil disobedience Civil liberties Civil rights Civil society Civil union Civilization and Its Discontents Claim right Clairvoyance Clare W. Graves Clarembald of Arras Clarence Irving Lewis Clarity of scripture Clarity test Class (philosophy) Class collaboration Class consciousness Class struggle Classical conditioning Classical liberalism Classical logic Classical mechanics Classical Realism Classical republicanism Classical theism Classicism Classics Classification of the sciences (Peirce) Classificatory disputes about art Classless society Claude-Arien Helvetius Claude Adrien Helvétius Claude Buffier Claude Henri de Rouvroy, comte de Saint-Simon Claude Lefort Claude Lévi-Strauss Claude Lévi-Strauss Claude Tresmontant Claudio Canaparo Claudio Ulpiano Claudius Maximus Claus Emmeche Clause (logic) Cleanliness Cleanthes Clearchus of Soli Cleinias of Tarentum Clémence Royer Clemens Baeumker Clemens Timpler Clement Greenberg Clement of Alexandria Clément Rosset Cleobulus Cleomedes Cleomenes the Cynic Clerical fascism Clerical philosophers Clericalism Clifford Harper Clifford Williams (academic) Climate ethics Clinamen Clinical death Clinical equipoise Clinomachus Clitomachus (philosopher) Clitophon (dialogue) Clive Bell Clive Staples Lewis CLODO Cloning Close reading Closed circle Closed concept Closed formula Closed loop Closed sentence Closed world assumption Cloudesley Clustering illusion Co-premise Coase theorem Code (law) Coercion Cogency Cogito (magazine) Cogito ergo sum Cognition Cognitive architecture Cognitive bias Cognitive closure (philosophy) Cognitive description Cognitive development Cognitive dissonance Cognitive liberty Cognitive map Cognitive meaning Cognitive module Cognitive neuroscience Cognitive ontology Cognitive psychology Cognitive relativism Cognitive revolution Cognitive science Cognitive science of mathematics Cognitive synonymy Cognitivism (ethics) Coherence (philosophical gambling strategy) Coherence theory of truth Coherentism Coimbra commentaries Coimbra group Cointerpretability Colin Howson Colin McGinn Colin Murray Turbayne Colin Wilson Collapse (journal) Collapse theories (quantum mechanics) Collective belief Collective memory Collective responsibility Collective unconscious Collectivism Collectivist anarchism Collectivity Collège international de philosophie Collegium Conimbricense Colloque Walter Lippmann Colloquial language Color Color Field Color realism (philosophy) Colotes Combinational logic Combinatory logic Comedy Comenius Comité Consultatif National d'Ethique Commensurability (ethics) Commensurability (philosophy of science) Commentaria in Aristotelem Graeca Commentaries on Aristotle Commentaries on Plato Commission of Anarchist Relations Committee for the Scientific Examination of Religion Commodification Commodity (Marxism) Commodity fetishism Commodity form theory Common good Common Ground Collective Common knowledge Common knowledge (logic) Common law Common ownership Common rule Common sense Common sense and the Diallelus Common sense reasoning Commonsense reasoning Communication Communication theory Communicative action Communicative rationality Communism Communitarianism Community Community arts Communization Compactness Compactness theorem Comparatio Compassion Compassionate conservatism Compatibilism Compatibilism and incompatibilism Compensation (essay) Compensationism Completeness (logic) Completeness theorem Complexity Composition (logical fallacy) Composition of Causes Compositionality Compossibility Compossible Compound question Comprehension (logic) Compromise Computability Computability logic Computable Computational complexity Computational epistemology Computational humor Computational theories of mind Computational theory of mind Computer ethics Computer modeling Computer program Computer science Computer theory Computers Comtism Conatus Concept Concept and object Concepts Conceptual analysis Conceptual art Conceptual definition Conceptual framework Conceptual metaphor Conceptual model Conceptual necessity Conceptual role semantics Conceptual scheme Conceptual system Conceptualism Concerned Philosophers for Peace Conciliarism Conciliation Concluding Unscientific Postscript to Philosophical Fragments Conclusive evidence Concord School of Philosophy Concrescence Concretion Concretism Concupiscence Condemnations of 1210–1277 Condensed detachment Conditio sine qua non Condition of possibility Conditional probability Conditional proof Conditioned disjunction Condorcet Condorcet winner Conduct Confederación Nacional del Trabajo Confederalism Confédération nationale du travail Configurations Confirmation Confirmation bias Confirmation holism Confirmational holism Conflict between good and evil Conflict of interest Conflict theory Conformism Confucian Analects Confucian philosophy Confucian view of marriage Confucianism Confucianism in Indonesia Confucius Confusion of the inverse Congruence bias Conimbricenses Conjecture Conjectures and Refutations Conjunction elimination Conjunction fallacy Conjunction introduction Conjunctive grammar Conjunctive normal form Connectionism Connectives Connexive logic Connotation Conscience Conscience clause (medical) Conscious automatism Conscious mind Consciousness Consciousness-only Consciousness and Cognition Consciousness Explained Consensual crime Consensual living Consensus Consensus decision-making Consensus democracy Consensus reality Consensus theory of truth Consent Consent theory Consequence relation Consequent Consequentia mirabilis Consequentialism Consequentialist justifications of the state Consequentialist libertarianism Conservation (ethic) Conservation biology Conservation ethic Conservation movement Conservatism Considerations on Representative Government Consilience Consistent life ethic Consolatio Literary Genre Consolation of Philosophy Constance Naden Constant capital Constant sum game Constantin Brunner Constantin Noica Constantin Rădulescu-Motru Constantin Schifirneţ Constantin Stere Constantine of Kostenets Constantinos Speras Constitution Constitution of the Athenians (Aristotle) Constitution of the Athenians (Pseudo-Xenophon) Constitutional law Constitutional right Constitutionalism Construct (philosophy of science) Constructible universe Constructive dilemma Constructive empiricism Constructive realism Constructivism (art) Constructivism (mathematics) Constructivist epistemology Constructivist Foundations Consubstantiation Consumerism Consumption of fixed capital Container (Type theory) Container space Containment Contemporary anarchism Contemporary Islamic philosophy Contemporary philosophy Contemporary Political Theory Contemporary Pragmatism Contemporary Whitehead Studies Contentment Context-free grammar Context-free language Context-sensitive grammar Context-sensitive language Context principle Contextual empiricism Contextualism Contiguity Continental philosophy Contingency Contingency (philosophy) Contingency, irony, and solidarity Contingent Continuity (fiction) Continuum fallacy Continuum hypothesis Continuum of Humanist Education Contra Celsum Contra principia negantem disputari non potest Contract theory Contractarianism Contractualism Contradiction Contradictions Contraposition Contraposition (traditional logic) Contrapositive Contrast effect Contrast theory of meaning Contrastivism Contributions to Philosophy (From Enowning) Contributory value Control (management) Controversy over Cantor's theory Convention (norm) Convention T Conventionalism Convergence (series) Conversational implicature Converse accident Converse implication Converse nonimplication Converse relation Conversion (logic) Convivio Convolution (computer science) Cool (aesthetic) Cooperation Cooperative federalism Cooperative principle Coordination problem Coordinative definition Copernican principle Copernican revolution Copernican Revolution (metaphor) Copula (linguistics) Cora Diamond Core ontology Corelative Coriscus of Scepsis Corliss Lamont Cornel West Cornelian dilemma Cornelio Fabro Cornelis Willem Opzoomer Cornelius Castoriadis Cornelius de Pauw Cornell realism Corollary Corporate behaviour Corporate crime Corporate nationalism Corporate social responsibility Corporate statism Corporatism Corpus Aristotelicum Correlation does not imply causation Correlative-based fallacies Correspondence theory of truth Corresponding conditional (logic) Corroboration Corruption (philosophical concept) Cosimo Boscaglia Cosmic consciousness Cosmic pluralism Cosmicism Cosmocentrism Cosmogony Cosmographia (Bernard Silvestris) Cosmological argument Cosmology Cosmology (metaphysics) Cosmopolitanism Cosmos Cosmotheology Cost-benefit analysis Costanzo Preve Costas Douzinas Council communism Count Lev Nikolaevich Tolstoi Count noun Richard von Coudenhove-Kalergi Countable Counter-Enlightenment Counterargument Counterexample Counterfactual conditional Counterfactual conditionals Counterfactuals Counterinduction Counterintuitive Counterpart theory Counting Coup d'État: A Practical Handbook Courage Course in General Linguistics Covering-law model Covering law model Cowardice Cowley Club CPNSS Craig's theorem Craig reduct Crantor Crass Crates of Athens Crates of Mallus Crates of Thebes Cratippus of Pergamon Cratylism Cratylus Cratylus (dialogue) Cream City Collectives Creation ex nihilo Creation myth Creationism Creative accounting Creative destruction Creative Evolution (book) Creativity Credibility Credo quia absurdum Credo quia absurdum est Credo ut intelligam Crescens the Cynic Cressida Heyes Cries and Whispers Crime Crime against humanity Crime and punishment Crime and Punishment CrimethInc. CrimethInc. Guerilla Film Series, Volume One CrimethInc. N©! license CrimethInc. publications Criminal justice Crinis Crispin Sartwell Crispin Wright Cristina Bicchieri Cristoforo Landino Criteria of truth Criterion Critias (dialogue) Critic Critica Sociale Critical discourse analysis Critical historiography Critical Language Awareness Critical legal studies Critical Mass Critical pedagogy Critical philosophy Critical race theory Critical rationalism Critical reading Critical realism Critical social thought Critical theory Critical thinking Critical vocabulary Criticism of capitalism Criticism of Christianity Criticism of Hinduism Criticism of Islam Criticism of Jesus Criticism of Judaism Criticism of monotheism Criticism of postmodernism Criticism of religion Criticism of the Bible Criticism of the Catholic Church Criticism of the Latter Day Saint movement Criticism of the Qur'an Criticisms of anarchism Criticisms of electoralism Critique Critique (Journal of Socialist Theory) Critique of Cynical Reason Critique of Dialectical Reason Critique of Hegel's Philosophy of Right Critique of ideology Critique of Judgement Critique of Practical Reason Critique of Pure Reason Critiques of Slavoj Žižek Crito Critolaus Cronaca Sovversiva Cronius the Pythagorean Crooked Timber Crucial experiment Cruelty Crusties Crypto-anarchism Crypto-fascism Crystallized self Ctheory Cuban Libertarian Movement Cubism Cultural bias Cultural evolution Cultural hegemony Cultural history Cultural identity Cultural influence of Plato's Republic Cultural materialism (anthropology) Cultural materialism (cultural studies) Cultural nationalism Cultural relativism Cultural studies Culture Culture of life Culture of the Song Dynasty Cum hoc ergo propter hoc Cura te ipsum Curie Curiosity Curious George Brigade Curry's paradox Curt John
|
the Chrysler Corporation in 1987. After replacing the Countach with the Diablo and discontinuing the Jalpa and the LM002, Chrysler sold Lamborghini to Malaysian investment group Mycom Setdco and Indonesian group V'Power Corporation in 1994. In 1998, Mycom Setdco and V'Power sold Lamborghini to the Volkswagen Group where it was placed under the control of the group's Audi division. New products and model lines were introduced to the brand's portfolio and brought to the market and saw an increased productivity for the brand Lamborghini. In the late 2000s, during the worldwide financial crisis and the subsequent economic crisis, Lamborghini's sales saw a drop of nearly 50 per cent. In 2021, the CEO of Lamborghini said that by 2024 all its models will be hybrid. Products Automobiles As of the 2018 model year, Lamborghini's automobile product range consists of three model lines, two of which are mid-engine two-seat sports cars while the third one is a front engined, all-wheel drive SUV. Models in production Aventador The current V12-powered Aventador production line consists of the LP 740–4 Aventador Ultimate and SVJ coupés and roadsters and it is said that the production of all Aventador models will end in 2022. Huracán The V10-powered Huracán line currently includes the all-wheel-drive LP 610-4 coupé and Spyder, the low cost rear-wheel-drive LP 580-2 coupé and spyder and the most powerful, track oriented LP 640-4 Performanté coupé and spyder. Urus With the intention of doubling its sales volume by 2019, Lamborghini also added an SUV named Urus in its line-up which is powered by a twin-turbo V8 engine and utilises a front engine, all-wheel drive layout. Marine engines Motori Marini Lamborghini produces a large V12 marine engine block for use in World Offshore Series Class 1 powerboats. A Lamborghini branded marine engine displaces approximately and outputs approximately . Lamborghini motorcycle In the mid-1980s, Lamborghini produced a limited-production run of a sports motorcycle. UK weekly newspaper Motor Cycle News reported in 1994 – when featuring an example available through an Essex motorcycle retailer – that 24 examples were produced with a Lamborghini alloy frame having adjustable steering head angle, Kawasaki GPz1000RX engine/transmission unit, Ceriani front forks and Marvic wheels. The bodywork was plastic and fully integrated with front fairing merged into fuel tank and seat cover ending in a rear tail-fairing. The motorcycles were designed by Lamborghini stylists and produced by French business Boxer Bikes. Branded merchandise Lamborghini licenses its brand to manufacturers that produce a variety of Lamborghini-branded consumer goods including scale models, clothing, accessories, bags, electronics and laptop computers. Motorsport Automobiles produced Lamborghini Motorsport Division Squadra Corse produces GT3 cars and cars for their Super Trofeo events based on the Gallardo and Huracán. Apart from them, the Squadra Corse builds cars upon customer request. GT3 and Super Trofeo Cars Gallardo LP 570-4 Super Trofeo Gallardo LP560-4 Super Trofeo Huracán LP 620-2 Super Trofeo EVO Huracán LP 620-2 Super Trofeo EVO2 Huracán Super Trofeo GT2 Huracán GT3 Huracán GT3 Evo Special cars These cars were built by Squadra Corse upon customer request. Essenza SCV12 SC18 Alston SC20 Events held Lamborghini Super Trofeo The Super Trofeo is a series of Motorsport events held by Squadra corse using their Super Trofeo model vehicles (currently the Huracán Super Trofeo EVO) which are racing versions of the road-approved models (Huracán and Gallardo models). The Super Trofeo events are held in three different series, in three continents: America, Asia and Europe. Many private race team participate each of these events. Every series consists of six rounds, each of which feature free practice sessions, qualifying and two races lasting 50 minutes each. There are four categories of drivers: Pro, Pro-Am, Am and Lamborghini Cup. The season ends in the Lamborghini Super Trofeo World Final. Lamborghini GT3 The Lamborghini GT3 is a series of Motorsport events held by The Squadra Corse using Huracán GT3 cars that comply with the FIA GT3 regulations. The racing event is open to any Huracán GT3 customer. Lamborghini currently uses Huracán GT3 Evo cars for these events and more than 60 private race teams participate these events. Lamborghini F1 career In contrast to his rival Enzo Ferrari, Ferruccio Lamborghini had decided early on that there would be no factory-supported racing of Lamborghinis, viewing motorsport as too expensive and too draining on company resources. This was unusual for the time, as many sports car manufacturers sought to demonstrate speed, reliability, and technical superiority through motorsport participation. Enzo Ferrari in particular was known for considering his road car business mostly a source of funding for his participation in motor racing. Ferruccio's policy led to tensions between him and his engineers, many of whom were racing enthusiasts; some had previously worked at Ferrari. When Dallara, Stanzani, and Wallace began dedicating their spare time to the development of the P400 prototype, they designed it to be a road car with racing potential, one that could win on the track and also be driven on the road by enthusiasts. When Ferruccio discovered the project, he allowed them to go ahead, seeing it as a potential marketing device for the company, while insisting that it would not be raced. The P400 went on to become the Miura. The closest the company came to building a true race car under Lamborghini's supervision were a few highly modified prototypes, including those built by factory test driver Bob Wallace, such as the Miura SV-based "Jota" and the Jarama S-based "Bob Wallace Special". In the mid-1970s, while Lamborghini was under the management of Georges-Henri Rossetti, Lamborghini entered into an agreement with BMW to develop, then manufacture 400 cars for BMW in order to meet Group 4 homologation requirements. BMW lacked experience developing a mid-engined vehicle and believed that Lamborghini's experience in that area would make Lamborghini an ideal choice of partner. Due to Lamborghini's shaky finances, Lamborghini fell behind schedule developing the car's structure and running gear. When Lamborghini failed to deliver working prototypes on time, BMW took the program in house, finishing development without Lamborghini. BMW contracted with Baur to produce the car, which BMW named the M1, delivering the first vehicle in October 1978. In 1985, Lamborghini's British importer developed the Countach QVX, in conjunction with Spice Engineering, for the 1986 Group C championship season. One car was built, but lack of sponsorship caused it to miss the season. The QVX competed in only one race, the non-championship 1986 Southern Suns 500 km race at Kyalami in South Africa, driven by Tiff Needell. Despite the car finishing better than it started, sponsorship could once again not be found and the programme was cancelled. Lamborghini was an engine supplier in Formula One for the 1989 through 1993 Formula One seasons. It supplied engines to Larrousse (1989–1990, 1992–1993), Lotus (1990), Ligier (1991), Minardi (1992), and to the Modena team in 1991. While the latter is commonly referred to as a factory team, the company saw itself as a supplier, not a backer. The 1992 Larrousse–Lamborghini was largely uncompetitive but noteworthy in its tendency to spew oil from its exhaust system. Cars following closely behind the Larrousse were commonly coloured yellowish-brown by the end of the race. Lamborghini's best result was achieved with Larrousse at the 1990 Japanese Grand Prix, when Aguri Suzuki finished third on home soil. In late 1991, a Lamborghini Formula One motor was used in the Konrad KM-011 Group C sports car, but the car only lasted a few races before the project was cancelled. The same engine, re-badged a Chrysler, Lamborghini's then-parent company, was tested by McLaren towards the end of the 1993 season, with the intent of using it during the 1994 season. Although driver Ayrton Senna was reportedly impressed with the engine's performance, McLaren pulled out of negotiations, choosing a Peugeot engine instead, and Chrysler ended the project. Two racing versions of the Diablo were built for the Diablo Supertrophy, a single-model racing series held annually from 1996 to 1999. In the first year, the model used in the series was the Diablo SVR, while the Diablo 6.0 GTR was used for the remaining three years. Lamborghini developed the Murciélago R-GT as a production racing car to compete in the FIA GT Championship, the Super GT Championship and the American Le Mans Series in 2004. The car's highest placing in any race that year was the opening round of the FIA GT Championship at Valencia, where the car entered by Reiter Engineering finished third from a fifth-place start. In 2006, during the opening round of the Super GT championship at Suzuka, a car run by the Japan Lamborghini Owners Club garnered the first victory (in class) by an R-GT. A GT3 version of the Gallardo has been developed by Reiter Engineering. A Murciélago R-GT entered by All-Inkl.com racing, driven by Christophe Bouchut and Stefan Mücke, won the opening round of the FIA GT Championship held at Zhuhai International Circuit, achieving the first major international race victory for Lamborghini. Complete Formula One results (key) (results in bold indicate pole position) Marketing Brand identity The world of bullfighting is a key part of Lamborghini's identity. In 1962, Ferruccio Lamborghini visited the Seville ranch of Don Eduardo Miura, a renowned breeder of Spanish fighting bulls. Lamborghini, a Taurus himself, was so impressed by the majestic Miura animals that he decided to adopt a raging bull as the emblem for the automaker he would open shortly. Vehicle nomenclature After producing two cars with alphanumeric designations, Lamborghini once again turned to the bull breeder for inspiration. Don Eduardo was filled with pride when he learned that Ferruccio had named a car for his family and their line of bulls; the fourth Miura to be produced was
|
bodywork was plastic and fully integrated with front fairing merged into fuel tank and seat cover ending in a rear tail-fairing. The motorcycles were designed by Lamborghini stylists and produced by French business Boxer Bikes. Branded merchandise Lamborghini licenses its brand to manufacturers that produce a variety of Lamborghini-branded consumer goods including scale models, clothing, accessories, bags, electronics and laptop computers. Motorsport Automobiles produced Lamborghini Motorsport Division Squadra Corse produces GT3 cars and cars for their Super Trofeo events based on the Gallardo and Huracán. Apart from them, the Squadra Corse builds cars upon customer request. GT3 and Super Trofeo Cars Gallardo LP 570-4 Super Trofeo Gallardo LP560-4 Super Trofeo Huracán LP 620-2 Super Trofeo EVO Huracán LP 620-2 Super Trofeo EVO2 Huracán Super Trofeo GT2 Huracán GT3 Huracán GT3 Evo Special cars These cars were built by Squadra Corse upon customer request. Essenza SCV12 SC18 Alston SC20 Events held Lamborghini Super Trofeo The Super Trofeo is a series of Motorsport events held by Squadra corse using their Super Trofeo model vehicles (currently the Huracán Super Trofeo EVO) which are racing versions of the road-approved models (Huracán and Gallardo models). The Super Trofeo events are held in three different series, in three continents: America, Asia and Europe. Many private race team participate each of these events. Every series consists of six rounds, each of which feature free practice sessions, qualifying and two races lasting 50 minutes each. There are four categories of drivers: Pro, Pro-Am, Am and Lamborghini Cup. The season ends in the Lamborghini Super Trofeo World Final. Lamborghini GT3 The Lamborghini GT3 is a series of Motorsport events held by The Squadra Corse using Huracán GT3 cars that comply with the FIA GT3 regulations. The racing event is open to any Huracán GT3 customer. Lamborghini currently uses Huracán GT3 Evo cars for these events and more than 60 private race teams participate these events. Lamborghini F1 career In contrast to his rival Enzo Ferrari, Ferruccio Lamborghini had decided early on that there would be no factory-supported racing of Lamborghinis, viewing motorsport as too expensive and too draining on company resources. This was unusual for the time, as many sports car manufacturers sought to demonstrate speed, reliability, and technical superiority through motorsport participation. Enzo Ferrari in particular was known for considering his road car business mostly a source of funding for his participation in motor racing. Ferruccio's policy led to tensions between him and his engineers, many of whom were racing enthusiasts; some had previously worked at Ferrari. When Dallara, Stanzani, and Wallace began dedicating their spare time to the development of the P400 prototype, they designed it to be a road car with racing potential, one that could win on the track and also be driven on the road by enthusiasts. When Ferruccio discovered the project, he allowed them to go ahead, seeing it as a potential marketing device for the company, while insisting that it would not be raced. The P400 went on to become the Miura. The closest the company came to building a true race car under Lamborghini's supervision were a few highly modified prototypes, including those built by factory test driver Bob Wallace, such as the Miura SV-based "Jota" and the Jarama S-based "Bob Wallace Special". In the mid-1970s, while Lamborghini was under the management of Georges-Henri Rossetti, Lamborghini entered into an agreement with BMW to develop, then manufacture 400 cars for BMW in order to meet Group 4 homologation requirements. BMW lacked experience developing a mid-engined vehicle and believed that Lamborghini's experience in that area would make Lamborghini an ideal choice of partner. Due to Lamborghini's shaky finances, Lamborghini fell behind schedule developing the car's structure and running gear. When Lamborghini failed to deliver working prototypes on time, BMW took the program in house, finishing development without Lamborghini. BMW contracted with Baur to produce the car, which BMW named the M1, delivering the first vehicle in October 1978. In 1985, Lamborghini's British importer developed the Countach QVX, in conjunction with Spice Engineering, for the 1986 Group C championship season. One car was built, but lack of sponsorship caused it to miss the season. The QVX competed in only one race, the non-championship 1986 Southern Suns 500 km race at Kyalami in South Africa, driven by Tiff Needell. Despite the car finishing better than it started, sponsorship could once again not be found and the programme was cancelled. Lamborghini was an engine supplier in Formula One for the 1989 through 1993 Formula One seasons. It supplied engines to Larrousse (1989–1990, 1992–1993), Lotus (1990), Ligier (1991), Minardi (1992), and to the Modena team in 1991. While the latter is commonly referred to as a factory team, the company saw itself as a supplier, not a backer. The 1992 Larrousse–Lamborghini was largely uncompetitive but noteworthy in its tendency to spew oil from its exhaust system. Cars following closely behind the Larrousse were commonly coloured yellowish-brown by the end of the race. Lamborghini's best result was achieved with Larrousse at the 1990 Japanese Grand Prix, when Aguri Suzuki finished third on home soil. In late 1991, a Lamborghini Formula One motor was used in the Konrad KM-011 Group C sports car, but the car only lasted a few races before the project was cancelled. The same engine, re-badged a Chrysler, Lamborghini's then-parent company, was tested by McLaren towards the end of the 1993 season, with the intent of using it during the 1994 season. Although driver Ayrton Senna was reportedly impressed with the engine's performance, McLaren pulled out of negotiations, choosing a Peugeot engine instead, and Chrysler ended the project. Two racing versions of the Diablo were built for the Diablo Supertrophy, a single-model racing series held annually from 1996 to 1999. In the first year, the model used in the series was the Diablo SVR, while the Diablo 6.0 GTR was used for the remaining three years. Lamborghini developed the Murciélago R-GT as a production racing car to compete in the FIA GT Championship, the Super GT Championship and the American Le Mans Series in 2004. The car's highest placing in any race that year was the opening round of the FIA GT Championship at Valencia, where the car entered by Reiter Engineering finished third from a fifth-place start. In 2006, during the opening round of the Super GT championship at Suzuka, a car run by the Japan Lamborghini Owners Club garnered the first victory (in class) by an R-GT. A GT3 version of the Gallardo has been developed by Reiter Engineering. A Murciélago R-GT entered by All-Inkl.com racing, driven by Christophe Bouchut and Stefan Mücke, won the opening round of the FIA GT Championship held at Zhuhai International Circuit, achieving the first major international race victory for Lamborghini. Complete Formula One results (key) (results in bold indicate pole position) Marketing Brand identity The world of bullfighting is a key part of Lamborghini's identity. In 1962, Ferruccio Lamborghini visited the Seville ranch of Don Eduardo Miura, a renowned breeder of Spanish fighting bulls. Lamborghini, a Taurus himself, was so impressed by the majestic Miura animals that he decided to adopt a raging bull as the emblem for the automaker he would open shortly. Vehicle nomenclature After producing two cars with alphanumeric designations, Lamborghini once again turned to the bull breeder for inspiration. Don Eduardo was filled with pride when he learned that Ferruccio had named a car for his family and their line of bulls; the fourth Miura to be produced was unveiled to him at his ranch in Seville. The automaker would continue to draw upon the bullfighting connection in future years. The Islero was named for the Miura bull that killed the famed bullfighter Manolete in 1947. Espada is the Spanish word for sword, sometimes used to refer to the bullfighter himself. The Jarama's name carried a special double meaning; though it was intended to refer only to the historic bullfighting region in Spain, Ferruccio was concerned about confusion with the also historic Jarama motor racing track. After christening the Urraco after a bull breed, in 1974, Lamborghini broke from tradition, naming the Countach () not for a bull, but for (), a Piedmontese expletive. Legend has it that stylist Nuccio Bertone uttered the word in surprise when he first saw the Countach prototype, "Project 112". The LM002 (LM for Lamborghini Militaire) sport utility vehicle and the Silhouette (named after the popular racing category of the time) were other exceptions to the tradition. The Jalpa of 1982 was named for a bull breed; Diablo, for the Duke of Veragua's ferocious bull famous for fighting an epic battle against El Chicorro in Madrid in 1869; Murciélago, the legendary bull whose life was spared by El Lagartijo for his performance in 1879; Gallardo, named for one of the five ancestral castes of the Spanish fighting bull breed; and Reventón, the bull that defeated young Mexican torero Félix Guzmán in 1943. The Estoque concept of 2008 was named for the estoc, the sword traditionally used by matadors during bullfights. Concept vehicles Throughout its history, Lamborghini has envisioned and
|
3, 1999, by lethal gas, and currently remains the last person executed by that method in the United States. The case Germany initiated legal action in the International Court of Justice against the United States regarding Walter LaGrand. Hours before Walter LaGrand was due to be executed, Germany applied for the Court to grant a provisional court order, requiring the United States to delay the execution of Walter LaGrand, which the court granted. Germany then initiated action in the U.S. Supreme Court for enforcement of the provisional order. In its judgment, the U.S. Supreme Court held that it lacked jurisdiction with respect to Germany's complaint against Arizona due to the Eleventh Amendment of the U.S. constitution, which prohibits federal courts from hearing lawsuits of foreign states against a U.S. state. With respect to Germany's case against the United States, it held that the doctrine of procedural default was not incompatible with the Vienna Convention, and that even if procedural default did conflict with the Vienna Convention it had been overruled by later federal law – the Antiterrorism and Effective Death Penalty Act of 1996, which explicitly legislated the doctrine of procedural default. (Subsequent federal legislation overrides prior self-executing treaty provisions, Whitney v. Robertson, ). The U.S. Solicitor General sent a letter to the Supreme Court, as part of these proceedings, arguing that provisional measures of the International Court of Justice are not legally binding. The United States Department of State also conveyed the ICJ's provisional measure to the Governor of Arizona without comment. The Arizona clemency board recommended a stay to the governor, on the basis of the pending ICJ case; but the Governor of Arizona ignored the recommendation. Germany then modified its complaint in the case before the ICJ, alleging furthermore that the U.S. violated international law by failing to implement the provisional measures. In opposition to the German submissions, the United States argued that the Vienna Convention did not grant rights to individuals, only to states; that the convention was meant to be exercised subject to the laws of each state party,
|
the German submissions, the United States argued that the Vienna Convention did not grant rights to individuals, only to states; that the convention was meant to be exercised subject to the laws of each state party, which in the case of the United States meant subject to the doctrine of procedural default; and that Germany was seeking to turn the ICJ into an international court of criminal appeal. ICJ decision On June 27, 2001, the ICJ, rejecting all of the United States' arguments, ruled in favor of Germany. The ICJ held that the Vienna Convention on Consular Relations of April 24, 1963, granted rights to individuals on the basis of its plain meaning, and that domestic laws could not limit the rights of the accused under the convention, but only specify the means by which those rights were to be exercised. The ICJ also found that its own provisional measures were legally binding. The nature of provisional measures has been a subject of great dispute in international law; the English text of the Statute of the International Court of Justice implies they are not binding, while the French text implies that they are. Faced with a contradiction between two equally authentic texts of the statute, the court considered which interpretation better served the objects and purposes of the statute, and hence found that they are binding. This was the first time in the court's history it had ruled as such. The court also found that the United States violated the Vienna Convention through its application of procedural default. The court was at pains to point out that it was not passing judgment on the doctrine itself, but only its application to cases involving the Vienna Convention. See also Capital punishment in Arizona List of people executed in Arizona Avena case Leal Garcia v. Texas (2011) Linda Carty List of United States Supreme Court cases, volume 526 References External links Judgments of the International Court of Justice Judgment of U.S. Supreme Court, Federal Republic of Germany vs. United States ASIL Insight article on LaGrand case Federal Republic of Germany v. United States, 526 U.S. 111 (1999) The opinion by the Supreme Court in the matter referenced in the article. Stewart v. LaGrand, 526 U.S. 115 (1999) The Companion Case
|
compatible with 1-2-3. An Apple II software company promised that its spreadsheet had "the power of 1-2-3". Because spreadsheets use large amounts of memory, 1‐2‐3 helped popularize greater RAM capacities in PCs, and especially the advent of expanded memory, which allowed greater than 640k to be accessed. Rivals Lotus 1-2-3 inspired imitators, the first of which was Mosaic Software's "The Twin", written in the fall of 1985 largely in the C language, followed by VP-Planner, which was backed by Adam Osborne. These were able to not only read 1-2-3 files, but also execute many or most macro programs by incorporating the same command structure. Copyright law had first been understood to only cover the source code of a program. After the success of lawsuits which claimed that the very "look and feel" of a program were covered, Lotus sought to ban any program which had a compatible command and menu structure. Program commands had not been considered to be covered before, but the commands of 1-2-3 were embedded in the words of the menu displayed on the screen. 1-2-3 won its 3-year long court battle against Paperback Software International and Mosaic Software Inc. in 1990. However, when it sued Borland over its Quattro Pro spreadsheet in Lotus v. Borland, a 6-year battle that ended at the Supreme Court in 1996, the final ruling appeared to support narrowing the applicability of copyright law to software; this is because the lower court's decision that it was not a copyright violation to merely have a compatible command menu or language was upheld, but only via stalemate. In 1995, the First Circuit found that command menus are an uncopyrightable "method of operation" under section 102(b) of the Copyright Act. The 1-2-3 menu structure (example, slash File Erase) was itself an advanced version of single letter menus introduced in VisiCalc. When the case came before the Supreme Court, the justices would end up deadlocked 4-4. This meant that Borland had emerged victorious, but the extent to which copyright law would be applicable to computer software went unaddressed and undefined. Decline Microsoft's early spreadsheet Multiplan eventually gave way to Excel, which debuted on the Macintosh in 1985. It arrived on PCs with the release of Windows 2.x in 1987, but as Windows was not yet popular, it posed no serious threat to Lotus's stranglehold on spreadsheet sales. However, Lotus suffered technical setbacks in this period. Version 3 of Lotus 1-2-3, fully converted from its original macro assembler to the more portable C language, was delayed by more than a year as the totally new 1-2-3 had to be made portable across platforms and fully compatible with existing macro sets and file formats. The inability to fit the larger code size of compiled C into lower-powered machines forced the company to split its spreadsheet offerings, with 1-2-3 release 3 only for higher-end machines, and a new version 2.2, based on the 2.01 assembler code base, available for PCs without extended memory. By the time these versions were released in 1989, Microsoft had eroded much of Lotus's market share. During the early 1990s, Windows grew in popularity, and along with it, Excel, which gradually displaced Lotus from its leading position. A planned total revamp of 1-2-3 for Windows fell apart, and all that the company could manage, was a Windows adaptation of their existing spreadsheet with no changes except using a graphical interface. Additionally, several versions of 1-2-3 had different features and slightly different interfaces. 1-2-3's intended successor, Lotus Symphony, was Lotus's entry into the anticipated "integrated software" market. It intended to expand the rudimentary all-in-one 1-2-3 into a fully-fledged spreadsheet, graph, database and word processor for DOS, but none of the integrated packages ever really succeeded. 1-2-3 migrated to the Windows platform, as part of Lotus SmartSuite. IBM's continued development and marketing of Lotus SmartSuite and OS/2 during the 1990s placed it in direct competition with Microsoft Office and Microsoft Windows, respectively. As a result, Microsoft "punished the IBM PC Company with higher prices, a late license for Windows 95, and the withholding of technical and marketing support." Microsoft did not grant IBM the OEM rights for Windows 95 until 15 minutes prior to the release of Windows 95 on 24 August 1995. Because of this uncertainty, IBM machines were sold without Windows 95, while Compaq, HP, and other companies sold machines with Windows 95 from day one. On 11 June 2013, IBM announced it would withdraw the Lotus brand: IBM Lotus 1-2-3 Millennium Edition V9.x, IBM Lotus SmartSuite 9.x V9.8.0, and Organizer V6.1.0. IBM stated, "Customers will no longer be able to receive support for these offerings after 30 September 2014. No service extensions will be offered. There will be no replacement programs." User features The name "1-2-3" stemmed from the product's integration of three main capabilities: along with its core spreadsheet functionality, 1-2-3 also offered integral charting/graphing and rudimentary database operations. Data features included sorting data in any defined rectangle, by order of information in one or two columns in the rectangular area. Justifying text in a range into paragraphs allowed it to be used as a primitive word processor. It had keyboard-driven pop-up menus as well as one-key commands, making it fast to operate. It was also user-friendly, introducing an early instance of context-sensitive help accessed by the F1 key. Macros in version one and add-ins (introduced in version 2.0) contributed much to 1-2-3's popularity, allowing dozens of outside vendors to sell macro packages and add-ins ranging from dedicated financial worksheets like F9 to full-fledged word processors. In the single-tasking MS-DOS, 1-2-3 was sometimes used as a complete office suite. All major graphics standards were supported; initially CGA and Hercules, and later EGA, AT&T, and VGA. Early versions used the filename extension "WKS". In version 2.0, the extension changed first to "WK1", then "WK2". This later became "WK3" for version 3.0 and "WK4" for version 4.0. Version 2 introduced macros with syntax and commands similar in complexity to an advanced BASIC interpreter, as well as string variable expressions. Later versions supported multiple worksheets and were written in C. The charting/graphing routines were written in Forth by Jeremy Sagan (son of Carl Sagan) and the printing routines by Paul Funk (founder of Funk Software). PC version history DOS Real Mode (8088+) These editions of 1-2-3 for DOS were primarily written in x86 assembly language. Release 1 was the first release for DOS-based PCs. Introduced in January 1983. Release 1A in April 1983 Officially supported ASCII, unofficially supported the IBM extended character set (but not LICS). Release 2 brought add-in support, better memory management and expanded memory support, supported x87 math coprocessors, and introduced support for the Lotus International Character Set (LICS). Introduced in September 1985. The Japanese version Lotus 1-2-3 Release 2J for NEC PC-98 computers was released on 1986-09-05. Release 2.01 in July 1986. Introduced an option to switch between LICS and the IBM extended character set. The Japanese version Lotus 1-2-3 Release 2.1J for NEC PC-98 computers was released in October 1987. A version Lotus 1-2-3 Release 2.1J+ followed in February 1989. Release 2.2 brought improved speed, automated macro tools, and presentation-quality graphics. Introduced in 1989. The Japanese version Lotus 1-2-3 Release 2.2J was released in February 1990. Release 2.3 brought WYSIWYG editing to the 2.x line. Introduced in 1991. The Japanese version Lotus 1-2-3 Release 2.3J was released in September 1991. Release 2.4 added icons and additional tools, and was the last release supporting 2D (only) spreadsheets. Introduced in 1992. The Japanese version Lotus 1-2-3 Release 2.4J was released in September 1993. In July 1995, Lotus released Lotus 1-2-3 Release 2.5J for DOS. Protected Mode (80286+) These editions of 1-2-3 for DOS were primarily written in C. Release 3 introduced the concept of 3D spreadsheets, utilized extended memory, supported having multiple files open simultaneously, and required an 80286-based PC or higher. It also introduced support for the Lotus Multi-Byte Character Set (LMBCS). Introduced in March 1989. Releases 3.1 and 3.1+ added WYSIWYG capabilities, the ability to swap to disk allowing for larger files (up to 64 MB), and could be run as a DOS program under Windows 3.0 and OS/2. Introduced in 1990. Release 3.4 added icons, improved performance, and enhanced graph capabilities, making it functionally similar to Release 2.4. Introduced in 1992. Lotus 1-2-3 for Home, 1992 Release 4 was the last release for DOS. More an upgrade to Release 3.4 than in line with Release 3 for Windows, it contains an improved interface and new features, including Version Manager, a spell checker, context-sensitive help, and cell comments. Introduced in May 1994. OS/2 Lotus 1-2-3/G Release 1. OS/2 text mode application introduced support for the Lotus Multi-Byte Character Set (LMBCS) together with the Release 3.0 for DOS in summer 1989. Release 1.1. Introduced in 1991. Release 2. Introduced in 1992. Release 2.1. Introduced in 1994. Windows Win16 (Windows 3.x) Lotus 1-2-3/W Release 1 was the first release for Windows, requiring Windows 3.0 or higher, was 16-bit, and was functionally equivalent to Release 3.x for DOS. Introduced in 1991. The Japanese version Lotus 1-2-3/Windows R1.0J was released on 1991-11-15. The version Lotus 1-2-3/Windows R1.1J was released on 1992-6-2. Release 4 was an extensive improvement that added groupware capabilities, improved integration with Lotus Notes, advanced graphics, context-sensitive menus and icons, and in-cell editing. Introduced in June 1993. A Japanese Lotus 1-2-3/Windows Release 4J was released 1993-07-16. Release 5 added additional groupware capabilities, chart maps, and improved database access. This was the last 16-bit version for Windows 3.1x, and was available as part
|
and a minor inconvenience for home users, but proved a serious nuisance in an office setting. Starting with Release 3.0, Lotus no longer used copy protection. However, it was then necessary to "initialize" the System disk with one's name and company name so as to customize the copy of the program. Release 2.2 and higher had this requirement. This was an irreversible process unless one had made an exact copy of the original disk so as to be able to change names to transfer the program to someone else. The reliance on the specific hardware of the IBM PC led to 1-2-3 being utilized as one of the two stress test applications, along with Microsoft Flight Simulator, for true 100% compatibility when PC clones appeared in the early 1980s. 1-2-3 required two disk drives and at least 192K of memory, which made it incompatible with the IBM PCjr; Lotus produced a version for the PCjr that was on two cartridges but otherwise identical. By early 1984 the software was a killer app for the IBM PC and compatibles, while hurting sales of computers that could not run it. "They're looking for 1-2-3. Boy, are they looking for 1-2-3!" InfoWorld wrote. Noting that computer purchasers did not want PC compatibility as much as compatibility with certain PC software, the magazine suggested "let's tell it like it is. Let's not say 'PC compatible,' or even 'MS-DOS compatible.' Instead, let's say '1-2-3 compatible.'" PC clones' advertising did often prominently state that they were compatible with 1-2-3. An Apple II software company promised that its spreadsheet had "the power of 1-2-3". Because spreadsheets use large amounts of memory, 1‐2‐3 helped popularize greater RAM capacities in PCs, and especially the advent of expanded memory, which allowed greater than 640k to be accessed. Rivals Lotus 1-2-3 inspired imitators, the first of which was Mosaic Software's "The Twin", written in the fall of 1985 largely in the C language, followed by VP-Planner, which was backed by Adam Osborne. These were able to not only read 1-2-3 files, but also execute many or most macro programs by incorporating the same command structure. Copyright law had first been understood to only cover the source code of a program. After the success of lawsuits which claimed that the very "look and feel" of a program were covered, Lotus sought to ban any program which had a compatible command and menu structure. Program commands had not been considered to be covered before, but the commands of 1-2-3 were embedded in the words of the menu displayed on the screen. 1-2-3 won its 3-year long court battle against Paperback Software International and Mosaic Software Inc. in 1990. However, when it sued Borland over its Quattro Pro spreadsheet in Lotus v. Borland, a 6-year battle that ended at the Supreme Court in 1996, the final ruling appeared to support narrowing the applicability of copyright law to software; this is because the lower court's decision that it was not a copyright violation to merely have a compatible command menu or language was upheld, but only via stalemate. In 1995, the First Circuit found that command menus are an uncopyrightable "method of operation" under section 102(b) of the Copyright Act. The 1-2-3 menu structure (example, slash File Erase) was itself an advanced version of single letter menus introduced in VisiCalc. When the case came before the Supreme Court, the justices would end up deadlocked 4-4. This meant that Borland had emerged victorious, but the extent to which copyright law would be applicable to computer software went unaddressed and undefined. Decline Microsoft's early spreadsheet Multiplan eventually gave way to Excel, which debuted on the Macintosh in 1985. It arrived on PCs with the release of Windows 2.x in 1987, but as Windows was not yet popular, it posed no serious threat to Lotus's stranglehold on spreadsheet sales. However, Lotus suffered technical setbacks in this period. Version 3 of Lotus 1-2-3, fully converted from its original macro assembler to the more portable C language, was delayed by more than a year as the totally new 1-2-3 had to be made portable across platforms and fully compatible with existing macro sets and file formats. The inability to fit the larger code size of compiled C into lower-powered machines forced the company to split its spreadsheet offerings, with 1-2-3 release 3 only for higher-end machines, and a new version 2.2, based on the 2.01 assembler code base, available for PCs without extended memory. By the time these versions were released in 1989, Microsoft had eroded much of Lotus's market share. During the early 1990s, Windows grew in popularity, and along with it, Excel, which gradually displaced Lotus from its leading position. A planned total revamp of 1-2-3 for Windows fell apart, and all that the company could manage, was a Windows adaptation of their existing spreadsheet with no changes except using a graphical interface. Additionally, several versions of 1-2-3 had different features and slightly different interfaces. 1-2-3's intended successor, Lotus Symphony, was Lotus's entry into the anticipated "integrated software" market. It intended to expand the rudimentary all-in-one 1-2-3 into a fully-fledged spreadsheet, graph, database and word processor for DOS, but none of the integrated packages ever really succeeded. 1-2-3 migrated to the Windows platform, as part of Lotus SmartSuite. IBM's continued development and marketing of Lotus SmartSuite and OS/2 during the 1990s placed it in direct competition with Microsoft Office and Microsoft Windows, respectively. As a result, Microsoft "punished the IBM PC Company with higher prices, a late license for Windows 95, and the withholding of technical and marketing support." Microsoft did not grant IBM the OEM rights for Windows 95 until 15 minutes prior to the release of Windows 95 on 24 August 1995. Because of this uncertainty, IBM machines were sold without Windows 95, while Compaq, HP, and other companies sold machines with Windows 95 from day one. On 11 June 2013, IBM announced it would withdraw the Lotus brand: IBM Lotus 1-2-3 Millennium Edition V9.x, IBM Lotus SmartSuite 9.x V9.8.0, and Organizer V6.1.0. IBM stated, "Customers will no longer be able to receive support for these offerings after 30 September 2014. No service extensions will be offered. There will be no replacement programs." User features The name "1-2-3" stemmed from the product's integration of three main capabilities: along with its core spreadsheet functionality, 1-2-3 also offered integral charting/graphing and rudimentary database operations. Data features included sorting data in any defined rectangle, by order of information in one or two columns in the rectangular area. Justifying text in a range into paragraphs allowed it to be used as a primitive word processor. It had keyboard-driven pop-up menus as well as one-key commands, making it fast to operate. It was also user-friendly, introducing an early instance of context-sensitive help accessed by the F1 key. Macros in version one and add-ins (introduced in version 2.0) contributed much to 1-2-3's popularity, allowing dozens of outside vendors to sell macro packages and add-ins ranging from dedicated financial worksheets like F9 to full-fledged word processors. In the single-tasking MS-DOS, 1-2-3 was sometimes used as a complete office suite. All major graphics standards were supported; initially CGA and Hercules, and later EGA, AT&T, and VGA. Early versions used the filename extension "WKS". In version 2.0, the extension changed first to "WK1", then "WK2". This later became "WK3" for version 3.0 and "WK4" for version 4.0. Version 2 introduced macros with syntax and commands similar in complexity to an advanced BASIC interpreter, as well as string variable expressions. Later versions supported multiple worksheets and were written in C. The charting/graphing routines were written in Forth by Jeremy Sagan (son of Carl Sagan) and the printing routines by Paul Funk (founder of Funk Software). PC version history DOS Real Mode (8088+) These editions of 1-2-3 for DOS were primarily written in x86 assembly language. Release 1 was the first release for DOS-based PCs. Introduced in January 1983. Release 1A in April 1983 Officially supported ASCII, unofficially supported the IBM extended character set (but not LICS). Release 2 brought add-in support, better memory management and expanded memory support, supported x87 math coprocessors, and introduced support for the Lotus International Character Set (LICS). Introduced in September 1985. The Japanese version Lotus 1-2-3 Release 2J for NEC PC-98 computers was released on 1986-09-05. Release 2.01 in July 1986. Introduced an option to switch between LICS and the IBM extended character set. The Japanese version Lotus 1-2-3 Release 2.1J for NEC PC-98 computers was released in October 1987. A version Lotus 1-2-3 Release 2.1J+ followed in February 1989. Release 2.2 brought improved speed, automated macro tools, and presentation-quality graphics. Introduced in 1989. The Japanese version Lotus 1-2-3 Release 2.2J was
|
office space located at the Texas State University in San Marcos, Texas; President Johnson's college alma mater. Lyndon B. Johnson Tropical Medical Center, a hospital in American Samoa Lyndon B. Johnson General Hospital, part of Harris Health System in Houston, Texas Lyndon B. Johnson Space Center in Houston, Texas Lyndon Baines Johnson Department of Education Building, in Washington, D.C. Lyndon Baines Johnson Library and Museum, presidential museum in Austin, Texas Military vessels USS Lyndon B. Johnson (DDG-1002) Parks and topographical features Lyndon B. Johnson National Historical Park, Johnson City, Texas Lake Lyndon B. Johnson, a lake in Texas Lyndon B. Johnson National Grassland, in Texas Lyndon Baines Johnson Memorial Grove on the Potomac, in Washington, D.C. FELDA L.B. Johnson, a
|
of memorials to Lyndon B. Johnson, the 36th president of the United States. Buildings Lyndon B. Johnson Student Center, a complex including teaching theaters, shops, a student pool hall, and office space located at the Texas State University in San Marcos, Texas; President Johnson's college alma mater. Lyndon B. Johnson Tropical Medical Center, a hospital in American Samoa Lyndon B. Johnson General Hospital, part of Harris Health System in Houston, Texas Lyndon B. Johnson Space Center in Houston, Texas Lyndon Baines Johnson Department of Education Building,
|
Johannes Blaskowitz reached an agreement on the capitulation of all German forces in the Netherlands. The capitulation document was signed the next day (no typewriter had been available the prior day) in the auditorium of Wageningen University, located next door. After liberation in 1945, Liberation Day was celebrated every five years. In 1990 the day was declared a national holiday when liberation would be remembered and celebrated every year. Festivals are held in most places in the Netherlands with parades of veterans and musical festivals throughout the whole country. See also Battle of the Netherlands Liberation of the Netherlands Liberation Day Liberation of Arnhem Victory in Europe Day External links Nationaal Comité 4 en 5 mei WWII:
|
in 1945, Liberation Day was celebrated every five years. In 1990 the day was declared a national holiday when liberation would be remembered and celebrated every year. Festivals are held in most places in the Netherlands with parades of veterans and musical festivals throughout the whole country. See also Battle of the Netherlands Liberation of the Netherlands Liberation Day Liberation of Arnhem Victory in Europe Day External links Nationaal Comité 4 en 5 mei WWII: Liberation of the Netherlands - Canada at War 1st Polish armoured division liberating Netherlands 4th Canadian armoured division liberating Netherlands Dutch society May observances National days Wageningen History of Wageningen L Annual events
|
such as from an unwanted blinking light on a consumer product, to a community level, as when a new urban development affects existing communities through its poorly planned street lighting. Light pollution can be understood not only as a phenomenon resulting from a specific source or kind of pollution, but also as a contributor to the wider, collective impact of various sources of pollution. Although this type of pollution can exist throughout the day, its effects are magnified during the night with the contrast of darkness. It has been estimated that 83 percent of the world's people live under light-polluted skies and that 23 percent of the world's land area is affected by skyglow. The area affected by artificial illumination continues to increase. A major side-effect of urbanization, light pollution is blamed for compromising health, disrupting ecosystems, and spoiling aesthetic environments. Solutions to light pollution are often easy steps like adjusting light fixtures or using more appropriate lightbulbs. However, because it is a human-made phenomenon, addressing its impacts on humans and the wider ecological systems of Earth involves vast societal complexities that overlay light pollution with political, social, and economic considerations. Definitions Light pollution is the presence of anthropogenic artificial light in otherwise dark conditions. The term is most commonly used in relation to in the outdoor environment and surrounding, but is also used to refer to artificial light indoors. Adverse consequences are multiple; some of them may not be known yet. Light pollution competes with starlight in the night sky for urban residents, interferes with astronomical observatories, and, like any other form of pollution, disrupts ecosystems and has adverse health effects. Light pollution is a side-effect of industrial civilization. Its sources include building exterior and interior lighting, advertising, outdoor area lighting (such as car parks), offices, factories, streetlights, and illuminated sporting venues. It is most severe in highly industrialized, densely populated areas of North America, Europe, and Asia and in major cities in the Middle East and North Africa like Tehran and Cairo, but even relatively small amounts of light can be noticed and create problems. Awareness of the deleterious effects of light pollution began in the second half of the 19th century, but efforts to address effects did not begin until the 1950s. In the 1980s a global dark-sky movement emerged with the founding of the International Dark-Sky Association (IDA). There are now such educational and advocacy organizations in many countries worldwide. Results Energy conservation advocates contend that light pollution must be addressed by changing the habits of society, so that lighting is used more efficiently, with less waste and less creation of unwanted or unneeded illumination. Several industry groups also recognize light pollution as an important issue. For example, the Institution of Lighting Engineers in the United Kingdom provides its members with information about light pollution, the problems it causes, and how to reduce its impact. Although, recent research point that the energy efficiency is not enough to reduce the light pollution because of the rebound effect. Since people may disagree over whether any particular lighting source is irritating or how important its effects on non-human life are, it is common for one person to consider as light pollution something that another finds desirable. One example is found in advertising, when an advertiser wishes for particular lights to be bright and visible while others find them annoying. Other types of light pollution are less disputed. For instance, light that accidentally crosses a property boundary and annoys a neighbour is generally considered wasted and pollutive. For this reason and others, decisions about how to manage artificial light are often marked by disputes. Differences of opinion over what light is reasonable and who should have authority and responsibility sometimes make it necessary for parties to negotiate. Where it is desired that such decisions be supported by objective data, light levels can be quantified by field measurement or mathematical modeling, the results of which are typically rendered in isophote maps or light contour maps. To deal with light pollution, authorities have taken a variety of measures depending on the interests, beliefs, and understandings of the society involved. These measures range from doing nothing at all to implementing strict laws and regulations specifying how lights may be installed and used. Types Light pollution is caused by inefficient or unnecessary use of artificial light. Specific categories of light pollution include light trespass, over-illumination, glare, light clutter, and skyglow. A single offending light source often falls into more than one of these categories. Light trespass Light trespass occurs when unwanted light enters one's property, for instance, by shining over a neighbour's fence. A common light trespass problem occurs when a strong light enters the window of one's home from the outside, causing problems such as sleep deprivation. A number of cities in the U.S. have developed standards for outdoor lighting to protect the rights of their citizens against light trespass. To assist them, the International Dark-Sky Association has developed a set of model lighting ordinances. The Dark-Sky Association was started to reduce the light going up into the sky which reduces the visibility of stars (see Skyglow below). This is any light that is emitted more than 90° above nadir. By limiting light at this 90° mark they have also reduced the light output in the 80–90° range which creates most of the light trespass issues. U.S. federal agencies may also enforce standards and process complaints within their areas of jurisdiction. For instance, in the case of light trespass by white strobe lighting from communication towers in excess of FAA minimum lighting requirements the Federal Communications Commission maintains an Antenna Structure Registration database information which citizens may use to identify offending structures and provides a mechanism for processing citizen inquiries and complaints. The U.S. Green Building Council (USGBC) has also incorporated a credit for reducing the amount of light trespass and sky glow into their environmentally friendly building standard known as LEED. Light trespass can be reduced by selecting light fixtures that limit the amount of light emitted more than 80° above the nadir. The IESNA definitions include full cutoff (0%), cutoff (10%), and semi-cutoff (20%). (These definitions also include limits on light emitted above 90° to reduce sky glow.) Over-illumination Over-illumination is the excessive use of light. In the USA commercial building lighting consumes in excess of 81.68 terawatts (1999 data) of electricity, according to the DOE. Even among developed countries there are large differences in patterns of light use. American cities emit three to five times more light to space per capita compared to German cities. Over-illumination stems from several factors: Consensus-based standards or norms that are not based on vision science; Not using timers, occupancy sensors or other controls to extinguish lighting when not needed; Improper design, by specifying higher levels of light than needed for a given visual task; Incorrect choice of fixtures or light bulbs, which do not direct light into areas as needed; Improper selection of hardware to utilize more energy than needed to accomplish the lighting task; Incomplete training of building managers and occupants to use lighting systems efficiently; Inadequate lighting maintenance resulting in increased stray light and energy costs; "Daylight lighting" demanded by citizens to reduce crime or by shop owners to attract customers; Substitution of old lamps with more efficient LEDs using the same electrical power; and Indirect lighting techniques, such as illuminating a vertical wall to bounce light onto the ground. Most of these issues can be readily corrected with available, inexpensive technology, and with the resolution of landlord/tenant practices that create barriers to rapid correction of these matters. Most importantly, public awareness would need to improve for industrialized countries to realize the large payoff in reducing over-illumination. In certain cases, an over-illumination lighting technique may be needed. For example, indirect lighting is often used to obtain a "softer" look, since hard direct lighting is generally found less desirable for certain surfaces, such as skin. The indirect lighting method is perceived as cozier and suits bars, restaurants, and living quarters. It is also possible to block the direct lighting effect by adding softening filters or other solutions, though intensity will be reduced. Glare Glare can be categorized into different types. One such classification is described in a book by Bob Mizon, coordinator for the British Astronomical Association's Campaign for Dark Skies, as follows: Blinding glare describes effects such as that caused by staring into the Sun. It is completely blinding and leaves temporary or permanent vision deficiencies. Disability glare describes effects such as being blinded by oncoming car lights, or light scattering in fog or in the eye, reducing contrast, as well as reflections from print and other dark areas that render them bright, with a significant reduction in sight capabilities. Discomfort glare does not typically cause a dangerous situation in itself, though it is annoying and irritating at best. It can potentially cause fatigue if experienced over extended periods. According to Mario Motta, president of the Massachusetts Medical Society, "...glare from bad lighting is a public-health hazard—especially the older you become. Glare light scattering in the eye causes loss of contrast and leads to unsafe driving conditions, much like the glare on a dirty windshield from low-angle sunlight or the high beams from an oncoming car." In essence bright and/or badly shielded lights around roads can partially blind drivers or pedestrians and contribute to accidents. The blinding effect is caused in large part by reduced contrast due to light scattering in the eye by excessive brightness, or to the reflection of light from dark areas in the field of vision, with luminance similar to the background luminance. This kind of glare is a particular instance of disability glare, called veiling glare. (This is not the same as loss of accommodation of night vision which is caused by the direct effect of the light itself on the eye.) Light clutter Light clutter refers to excessive groupings of lights. Groupings of lights may generate confusion, distract from obstacles (including those that they may be intended to illuminate), and potentially cause accidents. Clutter is particularly noticeable on roads where the street lights are badly designed, or where brightly lit advertisements surround the roadways. Depending on the motives of the person or organization that installed the lights, their placement and design can even be intended to distract drivers, and can contribute to accidents. From satellites Another source of light pollution are artificial satellites. With future increase in numbers of satellite constellations, like OneWeb and Starlink, it is feared especially by the astronomical community, such as the IAU that light pollution will increase significantly, beside other problems of satellite overcrowding. Public discourse surrounding the anticipated growth of satellite constellation, like OneWeb and Starlink, includes multiple petitions by astronomers and citizen scientists, and has raised questions about which regulatory bodies hold jurisdiction over human actions that obscure starlight. Measurement Issues to measuring light pollution Measuring the effect of sky glow on a global scale is a complex procedure. The natural atmosphere is not completely dark, even in the absence of terrestrial sources of light and illumination from the Moon. This is caused by two main sources: airglow and scattered light. At high altitudes, primarily above the mesosphere, there is enough UV radiation from the sun at very short wavelengths to cause ionization. When the ions collide with electrically neutral particles they recombine and emit photons in the process, causing airglow. The degree of ionization is sufficiently large to allow a constant emission of radiation even during the night when the upper atmosphere is in the Earth's shadow. Lower in the atmosphere all the solar photons with energies above the ionization potential of N2 and O2 have already been absorbed by the higher layers and thus no appreciable ionization occurs. Apart from emitting light, the sky also scatters incoming light, primarily from distant stars and the Milky Way, but also the zodiacal light, sunlight that is reflected and backscattered from interplanetary dust particles. The amount of airglow and zodiacal light is quite varied (depending, amongst other things on sunspot activity and the Solar cycle) but given optimal conditions, the darkest possible sky has a brightness of about 22 magnitude/square arc second. If a full moon is present, the sky brightness increases to about 18 magnitude/sq. arcsecond depending on local atmospheric transparency, 40 times brighter than the darkest sky. In densely populated areas a sky brightness of 17 magnitude/sq. an arcsecond is not uncommon, or as much as 100 times brighter than is natural. Satellite imagery measuring To precisely measure how bright the sky gets, night time satellite imagery of the earth is used as raw input for the number and intensity of light sources. These are put into a physical model of scattering due to air molecules and aerosoles to calculate cumulative sky brightness. Maps that show the enhanced sky brightness have been prepared for the entire world. Bortle scale The Bortle scale is a nine-level measuring system used to track how much light pollution there is in the sky. Five or less is the amount required to see the Milky Way whilst one is "pristine", the darkest possible. Global impact Europe Inspection of the area surrounding Madrid reveals that the effects of light pollution caused by a single large conglomeration can be felt up to away from the center. Global effects of light pollution are also made obvious. Research in the late 1990s showed that entire area consisting of southern England, Netherlands, Belgium, West Germany, and northern France have a sky brightness of at least two to four times normal. The only places in continental Europe where the sky can attain its natural darkness are in northern Scandinavia and in islands far from the continent. North America In North America the situation is comparable. There is a significant problem with light pollution ranging from the Canadian Maritime Provinces to the American Southwest. The International Dark-Sky Association works to designate areas that have high-quality night skies. These areas are supported by communities and organizations that are dedicated to reducing light pollution (e.g. Dark-sky preserve). The National Park Service Natural Sounds and Night Skies Division has measured night sky quality in national park units across the U.S. Sky quality in the U.S. ranges from pristine (Capitol Reef National Park and Big Bend National Park) to severely degraded (Santa Monica Mountains National Recreation Area and Biscayne National Park). The National Park Service Night Sky Program monitoring database is available online (2015). East Asia Light pollution in Hong Kong was declared the 'worst on the planet' in March 2013. In June 2016, it was estimated that one third of the world's population could no longer see the Milky Way, including 80% of Americans and 60% of Europeans. Singapore was found to be the most light-polluted country in the world. Consequences Public health impact Medical research on the effects of excessive light on the human body suggests that a variety of adverse health effects may be caused by light pollution or excessive light exposure, and some lighting design textbooks use human health as an explicit criterion for proper interior lighting. Health effects of over-illumination or improper spectral composition of light may include: increased headache incidence, worker fatigue, medically defined stress, decrease in sexual function and increase in anxiety. Likewise, animal models have been studied demonstrating unavoidable light to produce adverse effect on mood and anxiety. For those who need to be awake at night, light at night also has an acute effect on alertness and mood. In 2007, "shift work that involves circadian disruption" was listed as a probable carcinogen by the World Health Organization's International Agency for Research on Cancer. (IARC Press release No. 180). Multiple studies have documented a correlation between night shift work and the increased incidence of breast and prostate cancer. One study which examined the link between exposure to artificial light at night (ALAN) and levels of breast cancer in South Korea found that regions which had the highest levels of ALAN reported the highest number of cases of breast cancer. Seoul, which had the highest levels of light pollution, had 34.4% more cases of breast cancer than Ganwon-do, which had the lowest levels of light pollution. This suggested a high correlation between ALAN and the prevalence of breast cancer. It was also found that there was no correlation between other types of cancer such as cervical or lung cancer and ALAN levels. A more recent discussion (2009), written by Professor Steven Lockley, Harvard Medical School, can be found in the CfDS handbook "Blinded by the Light?". Chapter 4, "Human health implications of light pollution" states that "...light intrusion, even if dim, is likely to have measurable effects on sleep disruption and melatonin suppression. Even if these effects are relatively small from night to night, continuous chronic circadian, sleep and hormonal disruption may have longer-term health risks". The New York Academy of Sciences hosted a meeting in 2009 on Circadian Disruption and Cancer. Red light suppresses melatonin the least. In June 2009, the American Medical Association developed a policy in support of control of light pollution. News about the decision emphasized glare as a public health hazard leading to unsafe driving conditions. Especially in the elderly, glare produces loss of contrast, obscuring night vision. A new 2021 study published in the Southern Economic Journal indicates that light pollution may increase by 13% in preterm births before 23 weeks of gestation. Ecological impact When artificial light affects organisms and ecosystems it is called ecological light pollution. While light at night can be beneficial, neutral, or damaging for individual species, its presence invariably disturbs ecosystems. For example, some species of spiders avoid lit areas, while other species are happy to build their spider web directly on a lamp post. Since lamp posts attract many flying insects, the spiders that don't mind light gain an advantage over the spiders that avoid it. This is a simple example of the way in which species frequencies and food webs can be disturbed by the introduction of light at night. Light pollution poses a serious threat in particular to nocturnal wildlife, having negative impacts on plant and animal physiology. It can confuse animal navigation, alter competitive interactions, change predator-prey relations, and cause physiological harm. The rhythm of life is orchestrated by the natural diurnal patterns of light and dark, so disruption to these patterns impacts the ecological dynamics. Studies suggest that light pollution around lakes prevents zooplankton, such as Daphnia, from eating surface algae, causing algal blooms that can kill off the lakes' plants and lower water quality. Light pollution may also affect ecosystems in other ways. For example, entomologists have documented that nighttime light may interfere with the ability of moths and other nocturnal insects to navigate. It can also negative impact on insect development and reproduction. Night-blooming flowers that depend on moths for pollination may be affected by night lighting, as there is no replacement pollinator that would not be affected by the artificial light. This can lead to species decline of plants that are unable to reproduce, and change an area's longterm ecology. Among nocturnal insects, fireflies (Coleoptera: Lampyridae, Phengodidae and Elateridae) are especially interesting study objects for light pollution, once they depend on their own light to reproduce and, consequently, are very sensitive to environmental levels of light. Fireflies are well known and interesting to the general public (unlike many other insects) and are easily spotted by non-experts, and, due to their sensibility and rapid response to environmental changes good bioindicators for artificial night lighting. Significant declines in some insect populations have been suggested as being at least partially mediated by artificial lights at night. A 2009 study also suggests deleterious impacts on animals and ecosystems because of perturbation of polarized light or artificial polarization of light (even during the day, because direction of natural polarization of sun light and its reflection is a source of information for a lot of animals). This form of pollution is named polarized light pollution (PLP). Unnatural polarized light sources can trigger maladaptive behaviors in polarization-sensitive taxa and alter ecological interactions. Lights on tall structures can disorient migrating birds.
|
outdoor area lighting (such as car parks), offices, factories, streetlights, and illuminated sporting venues. It is most severe in highly industrialized, densely populated areas of North America, Europe, and Asia and in major cities in the Middle East and North Africa like Tehran and Cairo, but even relatively small amounts of light can be noticed and create problems. Awareness of the deleterious effects of light pollution began in the second half of the 19th century, but efforts to address effects did not begin until the 1950s. In the 1980s a global dark-sky movement emerged with the founding of the International Dark-Sky Association (IDA). There are now such educational and advocacy organizations in many countries worldwide. Results Energy conservation advocates contend that light pollution must be addressed by changing the habits of society, so that lighting is used more efficiently, with less waste and less creation of unwanted or unneeded illumination. Several industry groups also recognize light pollution as an important issue. For example, the Institution of Lighting Engineers in the United Kingdom provides its members with information about light pollution, the problems it causes, and how to reduce its impact. Although, recent research point that the energy efficiency is not enough to reduce the light pollution because of the rebound effect. Since people may disagree over whether any particular lighting source is irritating or how important its effects on non-human life are, it is common for one person to consider as light pollution something that another finds desirable. One example is found in advertising, when an advertiser wishes for particular lights to be bright and visible while others find them annoying. Other types of light pollution are less disputed. For instance, light that accidentally crosses a property boundary and annoys a neighbour is generally considered wasted and pollutive. For this reason and others, decisions about how to manage artificial light are often marked by disputes. Differences of opinion over what light is reasonable and who should have authority and responsibility sometimes make it necessary for parties to negotiate. Where it is desired that such decisions be supported by objective data, light levels can be quantified by field measurement or mathematical modeling, the results of which are typically rendered in isophote maps or light contour maps. To deal with light pollution, authorities have taken a variety of measures depending on the interests, beliefs, and understandings of the society involved. These measures range from doing nothing at all to implementing strict laws and regulations specifying how lights may be installed and used. Types Light pollution is caused by inefficient or unnecessary use of artificial light. Specific categories of light pollution include light trespass, over-illumination, glare, light clutter, and skyglow. A single offending light source often falls into more than one of these categories. Light trespass Light trespass occurs when unwanted light enters one's property, for instance, by shining over a neighbour's fence. A common light trespass problem occurs when a strong light enters the window of one's home from the outside, causing problems such as sleep deprivation. A number of cities in the U.S. have developed standards for outdoor lighting to protect the rights of their citizens against light trespass. To assist them, the International Dark-Sky Association has developed a set of model lighting ordinances. The Dark-Sky Association was started to reduce the light going up into the sky which reduces the visibility of stars (see Skyglow below). This is any light that is emitted more than 90° above nadir. By limiting light at this 90° mark they have also reduced the light output in the 80–90° range which creates most of the light trespass issues. U.S. federal agencies may also enforce standards and process complaints within their areas of jurisdiction. For instance, in the case of light trespass by white strobe lighting from communication towers in excess of FAA minimum lighting requirements the Federal Communications Commission maintains an Antenna Structure Registration database information which citizens may use to identify offending structures and provides a mechanism for processing citizen inquiries and complaints. The U.S. Green Building Council (USGBC) has also incorporated a credit for reducing the amount of light trespass and sky glow into their environmentally friendly building standard known as LEED. Light trespass can be reduced by selecting light fixtures that limit the amount of light emitted more than 80° above the nadir. The IESNA definitions include full cutoff (0%), cutoff (10%), and semi-cutoff (20%). (These definitions also include limits on light emitted above 90° to reduce sky glow.) Over-illumination Over-illumination is the excessive use of light. In the USA commercial building lighting consumes in excess of 81.68 terawatts (1999 data) of electricity, according to the DOE. Even among developed countries there are large differences in patterns of light use. American cities emit three to five times more light to space per capita compared to German cities. Over-illumination stems from several factors: Consensus-based standards or norms that are not based on vision science; Not using timers, occupancy sensors or other controls to extinguish lighting when not needed; Improper design, by specifying higher levels of light than needed for a given visual task; Incorrect choice of fixtures or light bulbs, which do not direct light into areas as needed; Improper selection of hardware to utilize more energy than needed to accomplish the lighting task; Incomplete training of building managers and occupants to use lighting systems efficiently; Inadequate lighting maintenance resulting in increased stray light and energy costs; "Daylight lighting" demanded by citizens to reduce crime or by shop owners to attract customers; Substitution of old lamps with more efficient LEDs using the same electrical power; and Indirect lighting techniques, such as illuminating a vertical wall to bounce light onto the ground. Most of these issues can be readily corrected with available, inexpensive technology, and with the resolution of landlord/tenant practices that create barriers to rapid correction of these matters. Most importantly, public awareness would need to improve for industrialized countries to realize the large payoff in reducing over-illumination. In certain cases, an over-illumination lighting technique may be needed. For example, indirect lighting is often used to obtain a "softer" look, since hard direct lighting is generally found less desirable for certain surfaces, such as skin. The indirect lighting method is perceived as cozier and suits bars, restaurants, and living quarters. It is also possible to block the direct lighting effect by adding softening filters or other solutions, though intensity will be reduced. Glare Glare can be categorized into different types. One such classification is described in a book by Bob Mizon, coordinator for the British Astronomical Association's Campaign for Dark Skies, as follows: Blinding glare describes effects such as that caused by staring into the Sun. It is completely blinding and leaves temporary or permanent vision deficiencies. Disability glare describes effects such as being blinded by oncoming car lights, or light scattering in fog or in the eye, reducing contrast, as well as reflections from print and other dark areas that render them bright, with a significant reduction in sight capabilities. Discomfort glare does not typically cause a dangerous situation in itself, though it is annoying and irritating at best. It can potentially cause fatigue if experienced over extended periods. According to Mario Motta, president of the Massachusetts Medical Society, "...glare from bad lighting is a public-health hazard—especially the older you become. Glare light scattering in the eye causes loss of contrast and leads to unsafe driving conditions, much like the glare on a dirty windshield from low-angle sunlight or the high beams from an oncoming car." In essence bright and/or badly shielded lights around roads can partially blind drivers or pedestrians and contribute to accidents. The blinding effect is caused in large part by reduced contrast due to light scattering in the eye by excessive brightness, or to the reflection of light from dark areas in the field of vision, with luminance similar to the background luminance. This kind of glare is a particular instance of disability glare, called veiling glare. (This is not the same as loss of accommodation of night vision which is caused by the direct effect of the light itself on the eye.) Light clutter Light clutter refers to excessive groupings of lights. Groupings of lights may generate confusion, distract from obstacles (including those that they may be intended to illuminate), and potentially cause accidents. Clutter is particularly noticeable on roads where the street lights are badly designed, or where brightly lit advertisements surround the roadways. Depending on the motives of the person or organization that installed the lights, their placement and design can even be intended to distract drivers, and can contribute to accidents. From satellites Another source of light pollution are artificial satellites. With future increase in numbers of satellite constellations, like OneWeb and Starlink, it is feared especially by the astronomical community, such as the IAU that light pollution will increase significantly, beside other problems of satellite overcrowding. Public discourse surrounding the anticipated growth of satellite constellation, like OneWeb and Starlink, includes multiple petitions by astronomers and citizen scientists, and has raised questions about which regulatory bodies hold jurisdiction over human actions that obscure starlight. Measurement Issues to measuring light pollution Measuring the effect of sky glow on a global scale is a complex procedure. The natural atmosphere is not completely dark, even in the absence of terrestrial sources of light and illumination from the Moon. This is caused by two main sources: airglow and scattered light. At high altitudes, primarily above the mesosphere, there is enough UV radiation from the sun at very short wavelengths to cause ionization. When the ions collide with electrically neutral particles they recombine and emit photons in the process, causing airglow. The degree of ionization is sufficiently large to allow a constant emission of radiation even during the night when the upper atmosphere is in the Earth's shadow. Lower in the atmosphere all the solar photons with energies above the ionization potential of N2 and O2 have already been absorbed by the higher layers and thus no appreciable ionization occurs. Apart from emitting light, the sky also scatters incoming light, primarily from distant stars and the Milky Way, but also the zodiacal light, sunlight that is reflected and backscattered from interplanetary dust particles. The amount of airglow and zodiacal light is quite varied (depending, amongst other things on sunspot activity and the Solar cycle) but given optimal conditions, the darkest possible sky has a brightness of about 22 magnitude/square arc second. If a full moon is present, the sky brightness increases to about 18 magnitude/sq. arcsecond depending on local atmospheric transparency, 40 times brighter than the darkest sky. In densely populated areas a sky brightness of 17 magnitude/sq. an arcsecond is not uncommon, or as much as 100 times brighter than is natural. Satellite imagery measuring To precisely measure how bright the sky gets, night time satellite imagery of the earth is used as raw input for the number and intensity of light sources. These are put into a physical model of scattering due to air molecules and aerosoles to calculate cumulative sky brightness. Maps that show the enhanced sky brightness have been prepared for the entire world. Bortle scale The Bortle scale is a nine-level measuring system used to track how much light pollution there is in the sky. Five or less is the amount required to see the Milky Way whilst one is "pristine", the darkest possible. Global impact Europe Inspection of the area surrounding Madrid reveals that the effects of light pollution caused by a single large conglomeration can be felt up to away from the center. Global effects of light pollution are also made obvious. Research in the late 1990s showed that entire area consisting of southern England, Netherlands, Belgium, West Germany, and northern France have a sky brightness of at least two to four times normal. The only places in continental Europe where the sky can attain its natural darkness are in northern Scandinavia and in islands far from the continent. North America In North America the situation is comparable. There is a significant problem with light pollution ranging from the Canadian Maritime Provinces to the American Southwest. The International Dark-Sky Association works to designate areas that have high-quality night skies. These areas are supported by communities and organizations that are dedicated to reducing light pollution (e.g. Dark-sky preserve). The National Park Service Natural Sounds and Night Skies Division has measured night sky quality in national park units across the U.S. Sky quality in the U.S. ranges from pristine (Capitol Reef National Park and Big Bend National Park) to severely degraded (Santa Monica Mountains National Recreation Area and Biscayne National Park). The National Park Service Night Sky Program monitoring database is available online (2015). East Asia Light pollution in Hong Kong was declared the 'worst on the planet' in March 2013. In June 2016, it was estimated that one third of the world's population could no longer see the Milky Way, including 80% of Americans and 60% of Europeans. Singapore was found to be the most light-polluted country in the world. Consequences Public health impact Medical research on the effects of excessive light on the human body suggests that a variety of adverse health effects may be caused by light pollution or excessive light exposure, and some lighting design textbooks use human health as an explicit criterion for proper interior lighting. Health effects of over-illumination or improper spectral composition of light may include: increased headache incidence, worker fatigue, medically defined stress, decrease in sexual function and increase in anxiety. Likewise, animal models have been studied demonstrating unavoidable light to produce adverse effect on mood and anxiety. For those who need to be awake at night, light at night also has an acute effect on alertness and mood. In 2007, "shift work that involves circadian disruption" was listed as a probable carcinogen by the World Health Organization's International Agency for Research on Cancer. (IARC Press release No. 180). Multiple studies have documented a correlation between night shift work and the increased incidence of breast and prostate cancer. One study which examined the link between exposure to artificial light at night (ALAN) and levels of breast cancer in South Korea found that regions which had the highest levels of ALAN reported the highest number of cases of breast cancer. Seoul, which had the highest levels of light pollution, had 34.4% more cases of breast cancer than Ganwon-do, which had the lowest levels of light pollution. This suggested a high correlation between ALAN and the prevalence of breast cancer. It was also found that there was no correlation between other types of cancer such as cervical or lung cancer and ALAN levels. A more recent discussion (2009), written by Professor Steven Lockley, Harvard Medical School, can be found in the CfDS handbook "Blinded by the Light?". Chapter 4, "Human health implications of light pollution" states that "...light intrusion, even if dim, is likely to have measurable effects on sleep disruption and melatonin suppression. Even if these effects are relatively small from night to night, continuous chronic circadian, sleep and hormonal disruption may have longer-term health risks". The New York Academy of Sciences hosted a meeting in 2009 on Circadian Disruption and Cancer. Red light suppresses melatonin the least. In June 2009, the American Medical Association developed a policy in support of control of light pollution. News about the decision emphasized glare as a public health hazard leading to unsafe driving conditions. Especially in the elderly, glare produces loss of contrast, obscuring night vision. A new 2021 study published in the Southern Economic Journal indicates that light pollution may increase by 13% in preterm births before 23 weeks of gestation. Ecological impact When artificial light affects organisms and ecosystems it is called ecological light pollution. While light at night can be beneficial, neutral, or damaging for individual species, its presence invariably disturbs ecosystems. For example, some species of spiders avoid lit areas, while other species are happy to build their spider web directly on a lamp post. Since lamp posts attract many flying insects, the spiders that don't mind light gain an advantage over the spiders that avoid it. This is a simple example of the way in which species frequencies and food webs can be disturbed by the introduction of light at night. Light pollution poses a serious threat in particular to nocturnal wildlife, having negative impacts on plant and animal physiology. It can confuse animal navigation, alter competitive interactions, change predator-prey relations, and cause physiological harm. The rhythm of life is orchestrated by the natural diurnal patterns of light and dark, so disruption to these patterns impacts the ecological dynamics. Studies suggest that light pollution around lakes prevents zooplankton, such as Daphnia, from eating surface algae, causing algal blooms that can kill off the lakes' plants and lower water quality. Light pollution may also affect ecosystems in other ways. For example, entomologists have documented that nighttime light may interfere with the ability of moths and other nocturnal insects to navigate. It can also negative impact on insect development and reproduction. Night-blooming flowers that depend on moths for pollination may be affected by night lighting, as there is no replacement pollinator that would not be affected by the artificial light. This can lead to species decline of plants that are unable to reproduce, and change an area's longterm ecology. Among nocturnal insects, fireflies (Coleoptera: Lampyridae, Phengodidae and Elateridae) are especially interesting study objects for light pollution, once they depend on their own light to reproduce and, consequently, are very sensitive to environmental levels of light. Fireflies are well known and interesting to the general public (unlike many other insects) and are easily spotted by non-experts, and, due to their sensibility and rapid response to environmental changes good bioindicators for artificial night lighting. Significant declines in some insect populations have been suggested as being at least partially mediated by artificial lights at night. A 2009 study also suggests deleterious impacts on animals and ecosystems because of perturbation of polarized light or artificial polarization of light (even during the day, because direction of natural polarization of sun light and its reflection is a source of information for a lot of animals). This form of pollution is named polarized light pollution (PLP). Unnatural polarized light sources can trigger maladaptive behaviors in polarization-sensitive taxa and alter ecological interactions. Lights on tall structures can disorient migrating birds. Estimates by the U.S. Fish and Wildlife Service of the number of birds killed after being attracted to tall towers range from four to five million per year to an order of magnitude higher. The Fatal Light Awareness Program (FLAP) works with building owners in Toronto, Ontario, Canada and other cities to reduce mortality of birds by turning out lights during migration periods. Similar disorientation has also been noted for bird species migrating close to offshore production and drilling facilities. Studies carried out by Nederlandse Aardolie Maatschappij b.v. (NAM) and Shell have led to the development and trial of new lighting technologies in the North Sea. In early 2007, the lights were installed on the Shell production platform L15. The experiment proved a great success since the number of birds circling the platform declined by 50 to 90%. Birds migrate at night for several reasons. Save water from dehydration in hot day flying and part of the bird's navigation system works with stars in some way. With city light outshining the night sky, birds (and also about mammals) no longer navigate by stars. Sea turtle hatchlings emerging from nests on beaches are another casualty of light pollution. It is a common misconception that hatchling sea turtles are attracted to the moon. Rather, they find the ocean by moving away from the dark silhouette of dunes and their vegetation, a behavior with which artificial lights interfere. The breeding activity and reproductive phenology of toads, however, are cued by moonlight. Juvenile seabirds may also be disoriented by lights as they leave their nests and fly out to sea. Amphibians and reptiles are also affected by light pollution. Introduced light sources during normally dark periods can disrupt levels of melatonin production. Melatonin is a hormone that regulates photoperiodic physiology and behaviour. Some species of frogs and salamanders utilize a light-dependent "compass" to orient their migratory behaviour to breeding sites. Introduced light can also cause developmental irregularities, such as retinal damage, reduced juvenile growth, premature metamorphosis, reduced sperm production, and genetic mutation. In September 2009, the 9th European Dark-Sky Symposium in Armagh, Northern Ireland had a session on the environmental effects
|
the corotating frame of reference). The points , , and are positions of unstable equilibrium. Any object orbiting at , , or will tend to fall out of orbit; it is therefore rare to find natural objects there, and spacecraft inhabiting these areas must employ station keeping in order to maintain their position. Natural objects at Lagrange points Due to the natural stability of and , it is common for natural objects to be found orbiting in those Lagrange points of planetary systems. Objects that inhabit those points are generically referred to as 'trojans' or 'trojan asteroids'. The name derives from the names that were given to asteroids discovered orbiting at the Sun–Jupiter and points, which were taken from mythological characters appearing in Homer's Iliad, an epic poem set during the Trojan War. Asteroids at the point, ahead of Jupiter, are named after Greek characters in the Iliad and referred to as the "Greek camp". Those at the point are named after Trojan characters and referred to as the "Trojan camp". Both camps are considered to be types of trojan bodies. As the Sun and Jupiter are the two most massive objects in the Solar System, there are more Sun–Jupiter trojans than for any other pair of bodies. However, smaller numbers of objects are known at the Lagrange points of other orbital systems: The Sun–Earth and points contain interplanetary dust and at least two asteroids, and . The Earth–Moon and points contain concentrations of interplanetary dust, known as Kordylewski clouds. Stability at these specific points is greatly complicated by solar gravitational influence. The Sun–Neptune and points contain several dozen known objects, the Neptune trojans. Mars has four accepted Mars trojans: 5261 Eureka, , , and . Saturn's moon Tethys has two smaller moons of Saturn in its and points, Telesto and Calypso. Another Saturn moon, Dione also has two Lagrangian co-orbitals, Helene at its point and Polydeuces at . The moons wander azimuthally about the Lagrangian points, with Polydeuces describing the largest deviations, moving up to 32° away from the Saturn–Dione point. One version of the giant impact hypothesis postulates that an object named Theia formed at the Sun–Earth or point and crashed into Earth after its orbit destabilized, forming the Moon. In binary stars, the Roche lobe has its apex located at ; if one of the stars expands past its Roche lobe, then it will lose matter to its companion star, known as Roche lobe overflow. Objects which are on horseshoe orbits are sometimes erroneously described as trojans, but do not occupy Lagrange points. Known objects on horseshoe orbits include 3753 Cruithne with Earth, and Saturn's moons Epimetheus and Janus. Physical and mathematical details Lagrangian points are the constant-pattern solutions of the restricted three-body problem. For example, given two massive bodies in orbits around their common barycenter, there are five positions in space where a third body, of comparatively negligible mass, could be placed so as to maintain its position relative to the two massive bodies. As seen in a rotating reference frame that matches the angular velocity of the two co-orbiting bodies, the gravitational fields of two massive bodies combined providing the centripetal force at the Lagrangian points, allowing the smaller third body to be relatively stationary with respect to the first two. The location of L1 is the solution to the following equation, gravitation providing the centripetal force: where r is the distance of the L1 point from the smaller object, R is the distance between the two main objects, and M1 and M2 are the masses of the large and small object, respectively. (The quantity in parentheses on the right is the distance of L1 from the center of mass.) Solving this for r involves solving a quintic function, but if the mass of the smaller object (M2) is much smaller than the mass of the larger object (M1) then and are at approximately equal distances r from the smaller object, equal to the radius of the Hill sphere, given by: We may also write this as: Since the tidal effect of a body is proportional to its mass divided by the distance cubed, this means that the tidal effect of the smaller body at the L or at the L point is about three times of that body. We may also write: where ρ and ρ are the average densities of the two bodies and and are their diameters. The ratio of diameter to distance gives the angle subtended by the body, showing that viewed from these two Lagrange points, the apparent sizes of the two bodies will be similar, especially if the density of the smaller one is about thrice that of the larger, as in the case of the earth and the sun. This distance can be described as being such that the orbital period, corresponding to a circular orbit with this distance as radius around M2 in the absence of M1, is that of M2 around M1, divided by ≈ 1.73: The location of L2 is the solution to the following equation, gravitation providing the centripetal force: with parameters defined as for the L1 case. Again, if the mass of the smaller object (M2) is much smaller than the mass of the larger object (M1) then L2 is at approximately the radius of the Hill sphere, given by: The same remarks about tidal influence and apparent size apply as for the L point. For example, the angular radius of the sun as viewed from L2 is arcsin(/) ≈ 0.264°, whereas that of the earth is arcsin(6371/) ≈ 0.242°. Looking toward the sun from L2 one sees an annular eclipse. It is necessary for a spacecraft, like Gaia, to follow a Lissajous orbit or a halo orbit around L2 in order for its solar panels to get full sun. L3 The location of L3 is the solution to the following equation, gravitation providing the centripetal force: with parameters M1, M2, and R defined as for the L1 and L2 cases, and r now indicates the distance of L3 from the position of the smaller object, if it were rotated 180 degrees about the larger object, while positive r implying L3 is closer to the larger object than the smaller object. If the mass of the smaller object (M2) is much smaller than the mass of the larger object (M1), then: and The reason these points are in balance is that at and the distances to the two masses are equal. Accordingly, the gravitational forces from the two massive bodies are in the same ratio as the masses of the two bodies, and so the resultant force acts through the barycenter of the system; additionally, the geometry of the triangle ensures that the resultant acceleration is to the distance from the barycenter in the same ratio as for the two massive bodies. The barycenter being both the center of mass and center of rotation of the three-body system, this resultant force is exactly that required to keep the smaller body at the Lagrange point in orbital equilibrium with the other two larger bodies of the system (indeed, the third body needs to have negligible mass). The general triangular configuration was discovered by Lagrange working on the three-body problem. Radial acceleration The radial acceleration a of an object in orbit at a point along the line passing through both bodies is given by: where r is the distance from the large body M1, R is the distance between the two main objects, and sgn(x) is the sign function of x. The terms in this function represent respectively: force from M1; force from M2; and centripetal force. The points L3, L1, L2 occur where the acceleration is zero — see chart at right. Positive acceleration is acceleration towards the right of the chart and negative acceleration is towards the left; that is why acceleration has opposite signs on opposite sides of the gravity wells. Stability Although the , , and points are nominally unstable, there are quasi-stable periodic orbits called halo orbits around these points in a three-body system. A full n-body dynamical system such as the Solar System does not contain these periodic orbits, but does contain quasi-periodic (i.e. bounded but not precisely repeating) orbits following Lissajous-curve trajectories. These quasi-periodic Lissajous orbits are what most of Lagrangian-point space missions have used until now. Although they are not perfectly stable, a modest effort of station keeping keeps a spacecraft in a desired Lissajous orbit for a long time. For Sun–Earth- missions, it is preferable for the spacecraft to be in a large-amplitude () Lissajous orbit around than to stay at , because the line between Sun and Earth has increased solar interference on Earth–spacecraft communications. Similarly, a large-amplitude Lissajous orbit around keeps a probe out of Earth's shadow and therefore ensures continuous illumination of its solar panels. The and points are stable provided that the mass of the primary body (e.g. the Earth) is at least 25 times the mass of the secondary body (e.g. the Moon), and the mass of the secondary is at least 10 times that of the tertiary (e.g. the satellite). The Earth is over 81 times the mass of the Moon (the Moon is 1.23% of the mass of the Earth). Although the and points are found at the top of a "hill", as in the effective potential contour plot above, they are nonetheless stable. The reason for the stability is a second-order effect: as a body moves away from the exact Lagrange position, Coriolis acceleration (which depends on the velocity of an orbiting object and cannot be modeled as a contour map) curves the trajectory into a path around (rather than away from) the point. Because the source of stability is the Coriolis force, the resulting orbits can be stable, but generally are not planar, but "three-dimensional": they lie on a warped surface intersecting the ecliptic plane. The kidney-shaped orbits typically shown nested around and are the projections of the orbits on a plane (e.g. the ecliptic) and not the full 3-D orbits. Solar System values This table lists sample values of L1, L2, and L3 within the Solar System. Calculations assume the two bodies orbit in a perfect circle with separation equal to the semimajor axis and no other bodies are nearby. Distances are measured from the larger body's center of mass with L3 showing a negative location. The percentage columns show how the distances compare with the semimajor axis. E.g. for the Moon, L1 is located from Earth's center, which is 84.9% of the Earth–Moon distance or 15.1% in front of the Moon; L2 is located from Earth's center, which is 116.8% of the Earth–Moon distance or 16.8% beyond the Moon; and L3 is located from Earth's center, which
|
Earth–Moon system. When a body at these points is perturbed, it moves away from the point, but the factor opposite of that which is increased or decreased by the perturbation (either gravity or angular momentum-induced speed) will also increase or decrease, bending the object's path into a stable, kidney bean-shaped orbit around the point (as seen in the corotating frame of reference). The points , , and are positions of unstable equilibrium. Any object orbiting at , , or will tend to fall out of orbit; it is therefore rare to find natural objects there, and spacecraft inhabiting these areas must employ station keeping in order to maintain their position. Natural objects at Lagrange points Due to the natural stability of and , it is common for natural objects to be found orbiting in those Lagrange points of planetary systems. Objects that inhabit those points are generically referred to as 'trojans' or 'trojan asteroids'. The name derives from the names that were given to asteroids discovered orbiting at the Sun–Jupiter and points, which were taken from mythological characters appearing in Homer's Iliad, an epic poem set during the Trojan War. Asteroids at the point, ahead of Jupiter, are named after Greek characters in the Iliad and referred to as the "Greek camp". Those at the point are named after Trojan characters and referred to as the "Trojan camp". Both camps are considered to be types of trojan bodies. As the Sun and Jupiter are the two most massive objects in the Solar System, there are more Sun–Jupiter trojans than for any other pair of bodies. However, smaller numbers of objects are known at the Lagrange points of other orbital systems: The Sun–Earth and points contain interplanetary dust and at least two asteroids, and . The Earth–Moon and points contain concentrations of interplanetary dust, known as Kordylewski clouds. Stability at these specific points is greatly complicated by solar gravitational influence. The Sun–Neptune and points contain several dozen known objects, the Neptune trojans. Mars has four accepted Mars trojans: 5261 Eureka, , , and . Saturn's moon Tethys has two smaller moons of Saturn in its and points, Telesto and Calypso. Another Saturn moon, Dione also has two Lagrangian co-orbitals, Helene at its point and Polydeuces at . The moons wander azimuthally about the Lagrangian points, with Polydeuces describing the largest deviations, moving up to 32° away from the Saturn–Dione point. One version of the giant impact hypothesis postulates that an object named Theia formed at the Sun–Earth or point and crashed into Earth after its orbit destabilized, forming the Moon. In binary stars, the Roche lobe has its apex located at ; if one of the stars expands past its Roche lobe, then it will lose matter to its companion star, known as Roche lobe overflow. Objects which are on horseshoe orbits are sometimes erroneously described as trojans, but do not occupy Lagrange points. Known objects on horseshoe orbits include 3753 Cruithne with Earth, and Saturn's moons Epimetheus and Janus. Physical and mathematical details Lagrangian points are the constant-pattern solutions of the restricted three-body problem. For example, given two massive bodies in orbits around their common barycenter, there are five positions in space where a third body, of comparatively negligible mass, could be placed so as to maintain its position relative to the two massive bodies. As seen in a rotating reference frame that matches the angular velocity of the two co-orbiting bodies, the gravitational fields of two massive bodies combined providing the centripetal force at the Lagrangian points, allowing the smaller third body to be relatively stationary with respect to the first two. The location of L1 is the solution to the following equation, gravitation providing the centripetal force: where r is the distance of the L1 point from the smaller object, R is the distance between the two main objects, and M1 and M2 are the masses of the large and small object, respectively. (The quantity in parentheses on the right is the distance of L1 from the center of mass.) Solving this for r involves solving a quintic function, but if the mass of the smaller object (M2) is much smaller than the mass of the larger object (M1) then and are at approximately equal distances r from the smaller object, equal to the radius of the Hill sphere, given by: We may also write this as: Since the tidal effect of a body is proportional to its mass divided by the distance cubed, this means that the tidal effect of the smaller body at the L or at the L point is about three times of that body. We may also write: where ρ and ρ are the average densities of the two bodies and and are their diameters. The ratio of diameter to distance gives the angle subtended by the body, showing that viewed from these two Lagrange points, the apparent sizes of the two bodies will be similar, especially if the density of the smaller one is about thrice that of the larger, as in the case of the earth and the sun. This distance can be described as being such that the orbital period, corresponding to a circular orbit with this distance as radius around M2 in the absence of M1, is that of M2 around M1, divided by ≈ 1.73: The location of L2 is the solution to the following equation, gravitation providing the centripetal force: with parameters defined as for the L1 case. Again, if the mass of the smaller object (M2) is much smaller than the mass of the larger object (M1) then L2 is at approximately the radius of the Hill sphere, given by: The same remarks about tidal influence and apparent size apply as for the L point. For example, the angular radius of the sun as viewed from L2 is arcsin(/) ≈ 0.264°, whereas that of the earth is arcsin(6371/) ≈ 0.242°. Looking toward the sun from L2 one sees an annular eclipse. It is necessary for a spacecraft, like Gaia, to follow a Lissajous orbit
|
In addition, a letter written by Saint Augustine of Hippo in 415 AD tells the story of a dreamer, Doctor Gennadius, and refers to lucid dreaming. 17th century Philosopher and physician Sir Thomas Browne (1605–1682) was fascinated by dreams and described his own ability to lucid dream in his Religio Medici, stating: "...yet in one dream I can compose a whole Comedy, behold the action, apprehend the jests and laugh my self awake at the conceits thereof". Samuel Pepys in his diary entry for 15 August 1665 records a dream, stating: "I had my Lady Castlemayne in my arms and was admitted to use all the dalliance I desired with her, and then dreamt that this could not be awake, but that it was only a dream". 19th century In 1867, the French sinologist Marie-Jean-Léon, Marquis d'Hervey de Saint Denys anonymously published Les Rêves et Les Moyens de Les Diriger; Observations Pratiques ('Dreams and the ways to direct them; practical observations'), in which he describes his own experiences of lucid dreaming, and proposes that it is possible for anyone to learn to dream consciously. 20th century In 1913, Dutch psychiatrist and writer Frederik (Willem) van Eeden (1860–1932) coined the term 'lucid dream' in an article entitled "A Study of Dreams". Some have suggested that the term is a misnomer because Van Eeden was referring to a phenomenon more specific than a lucid dream. Van Eeden intended the term lucid to denote "having insight", as in the phrase a lucid interval applied to someone in temporary remission from a psychosis, rather than as a reference to the perceptual quality of the experience, which may or may not be clear and vivid. Scientific research In 1968, Celia Green analyzed the main characteristics of such dreams, reviewing previously published literature on the subject and incorporating new data from participants of her own. She concluded that lucid dreams were a category of experience quite distinct from ordinary dreams and said they were associated with rapid eye movement sleep (REM sleep). Green was also the first to link lucid dreams to the phenomenon of false awakenings. In 1975, Dr Keith Hearne had the idea to exploit the nature of Rapid Eye Movements (REM) to allow a dreamer to send a message directly from dreams to the waking world. Working with an experienced lucid dreamer (Alan Worsley), he eventually succeeded in recording (via the use of an electrooculogram or EOG) a pre-defined set of eye movements signalled from within Worsley's lucid dream. This occurred at around 8 am on the morning of April 12, 1975. Hearne's EOG experiment was formally recognized through publication in the journal for The Society for Psychical Research. Lucid dreaming was subsequently researched by asking dreamers to perform pre-determined physical responses while experiencing a dream, including eye movement signals. In 1980, Stephen LaBerge at Stanford University developed such techniques as part of his doctoral dissertation. In 1985, LaBerge performed a pilot study that showed that time perception while counting during a lucid dream is about the same as during waking life. Lucid dreamers counted out ten seconds while dreaming, signaling the start and the end of the count with a pre-arranged eye signal measured with electrooculogram recording. LaBerge's results were confirmed by German researchers D. Erlacher and M. Schredl in 2004. In a further study by Stephen LaBerge, four subjects were compared either singing while dreaming or counting while dreaming. LaBerge found that the right hemisphere was more active during singing and the left hemisphere was more active during counting. Neuroscientist J. Allan Hobson has hypothesized what might be occurring in the brain while lucid. The first step to lucid dreaming is recognizing one is dreaming. This recognition might occur in the dorsolateral prefrontal cortex, which is one of the few areas deactivated during REM sleep and where working memory occurs. Once this area is activated and the recognition of dreaming occurs, the dreamer must be cautious to let the dream continue but be conscious enough to remember that it is a dream. While maintaining this balance, the amygdala and parahippocampal cortex might be less intensely activated. To continue the intensity of the dream hallucinations, it is expected the pons and the parieto-occipital junction stay active. Using electroencephalography (EEG) and other polysomnographical measurements, LaBerge and others have shown that lucid dreams begin in the Rapid Eye Movement (REM) stage of sleep. LaBerge also proposes that there are higher amounts of beta-1 frequency band (13–19 Hz) brain wave activity experienced by lucid dreamers, hence there is an increased amount of activity in the parietal lobes making lucid dreaming a conscious process. Paul Tholey, a German Gestalt psychologist and a professor of psychology and sports science, originally studied dreams in order to resolve the question of whether one dreams in colour or black and white. In his phenomenological research, he outlined an epistemological frame using critical realism. Tholey instructed his subjects to continuously suspect waking life to be a dream, in order that such a habit would manifest itself during dreams. He called this technique for inducing lucid dreams the Reflexionstechnik (reflection technique). Subjects learned to have such lucid dreams; they observed their dream content and reported it soon after awakening. Tholey could examine the cognitive abilities of dream figures. Nine trained lucid dreamers were directed to set other dream figures arithmetic and verbal tasks during lucid dreaming. Dream figures who agreed to perform the tasks proved more successful in verbal than in arithmetic tasks. Tholey discussed his scientific results with Stephen LaBerge, who has a similar approach. A study was conducted by Stephen LaBerge and other scientists to see if it were possible to attain the ability to lucid dream through a drug. In 2018, galantamine was given to 121 patients in a double-blind, placebo-controlled trial, the only one of its kind. Some participants found as much as a 42 percent increase in their ability to lucid dream, compared to self-reports from the past six months, and ten people experienced a lucid dream for the first time. It is theorized that galantamine allows acetylcholine to build up, leading to greater recollection and awareness during dreaming. Two-way communication Teams of cognitive scientists established real-time two-way communication with people undergoing a lucid dream. During dreaming they were able to consciously communicate with experimenters via eye movements or facial muscle signals, were able to comprehend complex questions and use working memory. Such interactive lucid dreaming could be a new approach for the scientific exploration of the dream state and could have applications for learning and creativity. Alternative theories Other researchers suggest that lucid dreaming is not a state of sleep, but of brief wakefulness, or "micro-awakening". Experiments by Stephen LaBerge used "perception of the outside world" as a criterion for wakefulness while studying lucid dreamers, and their sleep state was corroborated with physiological measurements. LaBerge's subjects experienced their lucid dream while in a state of REM, which critics felt may mean that the subjects are fully awake. J Allen Hobson responded that lucid dreaming must be a state of both waking and dreaming. Philosopher Norman Malcolm has argued against the possibility of checking the accuracy of dream reports, pointing out that "the only criterion of the truth of a statement that someone has had a certain dream is, essentially, his saying so." Definition Paul Tholey laid the epistemological basis for the research of lucid dreams, proposing seven different conditions of clarity that a dream must fulfill in order to be defined as a lucid dream: Awareness of the dream state (orientation) Awareness of the capacity to make decisions Awareness of memory functions Awareness of self Awareness of the dream environment Awareness of the meaning of the dream Awareness of concentration and focus (the subjective clarity of that state) Later, in 1992, a study by Deirdre Barrett examined whether lucid dreams contained four "corollaries" of lucidity: The dreamer is aware that they are dreaming Objects disappear after waking Physical laws need not apply in the
|
study was conducted by Stephen LaBerge and other scientists to see if it were possible to attain the ability to lucid dream through a drug. In 2018, galantamine was given to 121 patients in a double-blind, placebo-controlled trial, the only one of its kind. Some participants found as much as a 42 percent increase in their ability to lucid dream, compared to self-reports from the past six months, and ten people experienced a lucid dream for the first time. It is theorized that galantamine allows acetylcholine to build up, leading to greater recollection and awareness during dreaming. Two-way communication Teams of cognitive scientists established real-time two-way communication with people undergoing a lucid dream. During dreaming they were able to consciously communicate with experimenters via eye movements or facial muscle signals, were able to comprehend complex questions and use working memory. Such interactive lucid dreaming could be a new approach for the scientific exploration of the dream state and could have applications for learning and creativity. Alternative theories Other researchers suggest that lucid dreaming is not a state of sleep, but of brief wakefulness, or "micro-awakening". Experiments by Stephen LaBerge used "perception of the outside world" as a criterion for wakefulness while studying lucid dreamers, and their sleep state was corroborated with physiological measurements. LaBerge's subjects experienced their lucid dream while in a state of REM, which critics felt may mean that the subjects are fully awake. J Allen Hobson responded that lucid dreaming must be a state of both waking and dreaming. Philosopher Norman Malcolm has argued against the possibility of checking the accuracy of dream reports, pointing out that "the only criterion of the truth of a statement that someone has had a certain dream is, essentially, his saying so." Definition Paul Tholey laid the epistemological basis for the research of lucid dreams, proposing seven different conditions of clarity that a dream must fulfill in order to be defined as a lucid dream: Awareness of the dream state (orientation) Awareness of the capacity to make decisions Awareness of memory functions Awareness of self Awareness of the dream environment Awareness of the meaning of the dream Awareness of concentration and focus (the subjective clarity of that state) Later, in 1992, a study by Deirdre Barrett examined whether lucid dreams contained four "corollaries" of lucidity: The dreamer is aware that they are dreaming Objects disappear after waking Physical laws need not apply in the dream The dreamer has a clear memory of the waking world Barrett found less than a quarter of lucidity accounts exhibited all four. Subsequently, Stephen LaBerge studied the prevalence of being able to control the dream scenario among lucid dreams, and found that while dream control and dream awareness are correlated, neither requires the other. LaBerge found dreams that exhibit one clearly without the capacity for the other; also, in some dreams where the dreamer is lucid and aware they could exercise control, they choose simply to observe. Prevalence and frequency In 2016, a meta-analytic study by David Saunders and colleagues on 34 lucid dreaming studies, taken from a period of 50 years, demonstrated that 55% of a pooled sample of 24,282 people claimed to have experienced lucid dreams at least once or more in their lifetime. Furthermore, for those that stated they did experience lucid dreams, approximately 23% reported to experience them on a regular basis, as often as once a month or more. In a 2004 study on lucid dream frequency and personality, a moderate correlation between nightmare frequency and frequency of lucid dreaming was demonstrated. Some lucid dreamers also reported that nightmares are a trigger for dream lucidity. Previous studies have reported that lucid dreaming is more common among adolescents than adults. A 2015 study by Julian Mutz and Amir-Homayoun Javadi showed that people who had practiced meditation for a long time tended to have more lucid dreams. The authors claimed that "Lucid dreaming is a hybrid state of consciousness with features of both waking and dreaming" in a review they published in Neuroscience of Consciousness in 2017. Mutz and Javadi found that during lucid dreaming, there is an increase in activity of the dorsolateral prefrontal cortex, the bilateral frontopolar prefrontal cortex, the precuneus, the inferior parietal lobules, and the supramarginal gyrus. All are brain functions related to higher cognitive functions including working memory, planning, and self-consciousness. The researchers also found that during a lucid dream, "levels of self-determination" were similar to those that people experienced during states of wakefulness. They also found that lucid dreamers can only control limited aspects of their dream at once. Mutz and Javadi also have stated that by studying lucid dreaming further, scientists could learn more about various types of consciousness, which happen to be less easy to separate and research at other times. Suggested applications Treating nightmares It has been suggested that those who suffer from nightmares could benefit from the ability to be aware they are indeed dreaming. A pilot study performed in 2006 showed that lucid dreaming therapy treatment was successful in reducing nightmare frequency. This treatment consisted of exposure to the idea, mastery of the technique, and lucidity exercises. It was not clear what aspects of the treatment were responsible for the success of overcoming nightmares, though the treatment as a whole was said to be successful. Australian psychologist Milan Colic has explored the application of principles from narrative therapy to clients' lucid dreams, to reduce the impact not only of nightmares during sleep but also depression, self-mutilation, and other problems in waking life. Colic found that therapeutic conversations could reduce the distressing content of dreams, while understandings about life—and even characters—from lucid dreams could be applied to their lives with marked therapeutic benefits. Psychotherapists have applied lucid dreaming as a part of therapy. Studies have shown that, by inducing a lucid dream, recurrent nightmares can be alleviated. It is unclear whether this alleviation is due to lucidity or the ability to alter the dream itself. A 2006 study performed by Victor Spoormaker and Van den Bout evaluated the validity of lucid dreaming treatment (LDT) in chronic nightmare sufferers. LDT is composed of exposure, mastery and lucidity exercises. Results of lucid dreaming treatment revealed that the nightmare frequency of the treatment groups had decreased. In another study, Spoormaker, Van den Bout, and Meijer (2003) investigated lucid dreaming treatment for nightmares by testing eight subjects who received a one-hour individual session, which consisted of lucid dreaming exercises. The results of the study revealed that the nightmare frequency had decreased and the sleep quality had slightly increased. Holzinger, Klösch, and Saletu managed a psychotherapy study under the working name of ‘Cognition during dreaming—a therapeutic intervention in nightmares’, which included 40 subjects, men and women, 18–50 years old, whose life quality was significantly altered by nightmares. The test subjects were administered Gestalt group therapy and 24 of them were also taught to enter the state of lucid dreaming by Holzinger. This was purposefully taught in order to change the course of their nightmares. The subjects then reported the diminishment of their nightmare prevalence from 2–3 times a week to 2–3 times per month. Creativity In her book The Committee of Sleep, Deirdre Barrett describes how some experienced lucid dreamers have learned to remember specific practical goals such as artists looking for inspiration seeking a show of their own work once they become lucid or computer programmers looking for a screen with their desired code. However, most of these dreamers had many experiences of failing to recall waking objectives before gaining this level of control. Exploring the World of Lucid Dreaming by Stephen LaBerge and Howard Rheingold (1990) discusses creativity within dreams and lucid dreams, including testimonials from a number of people who claim they have used the practice of lucid dreaming to help them solve a number of creative issues, from an aspiring parent thinking of potential baby names to a surgeon practicing surgical techniques. The authors discuss how creativity in dreams could stem from "conscious access to the contents of our unconscious minds"; access to "tacit knowledge"—the things we know but can't explain, or things we know but are unaware that we know. The Dreams Behind the Music book by Craig Webb (2016) details lucid dreams of a number of musical artists, including how they are able not just to hear, but also compose, mix, arrange, practice, and perform music while conscious within their dreams. In popular culture Films Films like Dreamscape (1984), Waking Life (2001), Vanilla Sky (2001), Paprika (2006), Inception (2010), Lucid Dream (2017) and 118 (2019) refer to lucid dreaming. Songs The spoken bridge in the 1991 song Silent Lucidity by Queensrÿche instructs the listener on how to achieve lucid dreaming. 1999 hit song "Higher" by American rock band Creed was directly inspired by lead singer Scott Stapp's lucid dreaming experience. In the hit 2018 song by Juice Wrld, "Lucid Dreams," Juice uses the analogy of a lucid dream he can't control to describe the memory of
|
subjective, personal point of view Lyric, from the Greek language, a song that is played with a lyre Lyric describes, in the classification of the human voice in European classical music, a specific vocal weight and a range at the upper end of the given voice part RTÉ lyric fm, a radio station in Ireland Lyric (group), a rhythm and blues girl group
|
given voice part RTÉ lyric fm, a radio station in Ireland Lyric (group), a rhythm and blues girl group "Lyric" (song), a single released in June 2003 by Zwan Lyric Hearing, an extended wear hearing aid The Lyric (magazine), a North American poetry magazine The Lyric (album), a 2005 jazz album by Jim Tomlinson and Stacey Kent See also
|
loss. Currently, in the area of phosphor LED development, much effort is being spent on optimizing these devices to higher light output and higher operation temperatures. For instance, the efficiency can be raised by adapting better package design or by using a more suitable type of phosphor. Conformal coating process is frequently used to address the issue of varying phosphor thickness. Some phosphor-based white LEDs encapsulate InGaN blue LEDs inside phosphor-coated epoxy. Alternatively, the LED might be paired with a remote phosphor, a preformed polycarbonate piece coated with the phosphor material. Remote phosphors provide more diffuse light, which is desirable for many applications. Remote phosphor designs are also more tolerant of variations in the LED emissions spectrum. A common yellow phosphor material is cerium-doped yttrium aluminium garnet (Ce3+:YAG). White LEDs can also be made by coating near-ultraviolet (NUV) LEDs with a mixture of high-efficiency europium-based phosphors that emit red and blue, plus copper and aluminium-doped zinc sulfide (ZnS:Cu, Al) that emits green. This is a method analogous to the way fluorescent lamps work. This method is less efficient than blue LEDs with YAG:Ce phosphor, as the Stokes shift is larger, so more energy is converted to heat, but yields light with better spectral characteristics, which render color better. Due to the higher radiative output of the ultraviolet LEDs than of the blue ones, both methods offer comparable brightness. A concern is that UV light may leak from a malfunctioning light source and cause harm to human eyes or skin. Other white LEDs Another method used to produce experimental white light LEDs used no phosphors at all and was based on homoepitaxially grown zinc selenide (ZnSe) on a ZnSe substrate that simultaneously emitted blue light from its active region and yellow light from the substrate. A new style of wafers composed of gallium-nitride-on-silicon (GaN-on-Si) is being used to produce white LEDs using 200-mm silicon wafers. This avoids the typical costly sapphire substrate in relatively small 100- or 150-mm wafer sizes. The sapphire apparatus must be coupled with a mirror-like collector to reflect light that would otherwise be wasted. It was predicted that since 2020, 40% of all GaN LEDs are made with GaN-on-Si. Manufacturing large sapphire material is difficult, while large silicon material is cheaper and more abundant. LED companies shifting from using sapphire to silicon should be a minimal investment. Organic light-emitting diodes (OLEDs) In an organic light-emitting diode (OLED), the electroluminescent material composing the emissive layer of the diode is an organic compound. The organic material is electrically conductive due to the delocalization of pi electrons caused by conjugation over all or part of the molecule, and the material therefore functions as an organic semiconductor. The organic materials can be small organic molecules in a crystalline phase, or polymers. The potential advantages of OLEDs include thin, low-cost displays with a low driving voltage, wide viewing angle, and high contrast and color gamut. Polymer LEDs have the added benefit of printable and flexible displays. OLEDs have been used to make visual displays for portable electronic devices such as cellphones, digital cameras, lighting and televisions. Types LEDs are made in different packages for different applications. A single or a few LED junctions may be packed in one miniature device for use as an indicator or pilot lamp. An LED array may include controlling circuits within the same package, which may range from a simple resistor, blinking or color changing control, or an addressable controller for RGB devices. Higher-powered white-emitting devices will be mounted on heat sinks and will be used for illumination. Alphanumeric displays in dot matrix or bar formats are widely available. Special packages permit connection of LEDs to optical fibers for high-speed data communication links. Miniature These are mostly single-die LEDs used as indicators, and they come in various sizes from 2 mm to 8 mm, through-hole and surface mount packages. Typical current ratings range from around 1 mA to above 20 mA. Multiple LED dies attached to a flexible backing tape form an LED strip light. Common package shapes include round, with a domed or flat top, rectangular with a flat top (as used in bar-graph displays), and triangular or square with a flat top. The encapsulation may also be clear or tinted to improve contrast and viewing angle. Infrared devices may have a black tint to block visible light while passing infrared radiation. Ultra-high-output LEDs are designed for viewing in direct sunlight. 5 V and 12 V LEDs are ordinary miniature LEDs that have a series resistor for direct connection to a 5V or 12V supply. High-power High-power LEDs (HP-LEDs) or high-output LEDs (HO-LEDs) can be driven at currents from hundreds of mA to more than an ampere, compared with the tens of mA for other LEDs. Some can emit over a thousand lumens. LED power densities up to 300 W/cm2 have been achieved. Since overheating is destructive, the HP-LEDs must be mounted on a heat sink to allow for heat dissipation. If the heat from an HP-LED is not removed, the device fails in seconds. One HP-LED can often replace an incandescent bulb in a flashlight, or be set in an array to form a powerful LED lamp. Some well-known HP-LEDs in this category are the Nichia 19 series, Lumileds Rebel Led, Osram Opto Semiconductors Golden Dragon, and Cree X-lamp. As of September 2009, some HP-LEDs manufactured by Cree now exceed 105 lm/W. Examples for Haitz's law—which predicts an exponential rise in light output and efficacy of LEDs over time—are the CREE XP-G series LED, which achieved 105lm/W in 2009 and the Nichia 19 series with a typical efficacy of 140lm/W, released in 2010. AC-driven LEDs developed by Seoul Semiconductor can operate on AC power without a DC converter. For each half-cycle, part of the LED emits light and part is dark, and this is reversed during the next half-cycle. The efficiency of this type of HP-LED is typically 40lm/W. A large number of LED elements in series may be able to operate directly from line voltage. In 2009, Seoul Semiconductor released a high DC voltage LED, named 'Acrich MJT', capable of being driven from AC power with a simple controlling circuit. The low-power dissipation of these LEDs affords them more flexibility than the original AC LED design. Application-specific variations Flashing Flashing LEDs are used as attention seeking indicators without requiring external electronics. Flashing LEDs resemble standard LEDs but they contain an integrated voltage regulator and a multivibrator circuit that causes the LED to flash with a typical period of one second. In diffused lens LEDs, this circuit is visible as a small black dot. Most flashing LEDs emit light of one color, but more sophisticated devices can flash between multiple colors and even fade through a color sequence using RGB color mixing. Flashing SMD LEDs in the 0805 and other size formats have been available since early 2019. Bi-color Bi-color LEDs contain two different LED emitters in one case. There are two types of these. One type consists of two dies connected to the same two leads antiparallel to each other. Current flow in one direction emits one color, and current in the opposite direction emits the other color. The other type consists of two dies with separate leads for both dies and another lead for common anode or cathode so that they can be controlled independently. The most common bi-color combination is red/traditional green, however, other available combinations include amber/traditional green, red/pure green, red/blue, and blue/pure green. RGB tri-color Tri-color LEDs contain three different LED emitters in one case. Each emitter is connected to a separate lead so they can be controlled independently. A four-lead arrangement is typical with one common lead (anode or cathode) and an additional lead for each color. Others, however, have only two leads (positive and negative) and have a built-in electronic controller. RGB LEDs consist of one red, one green, and one blue LED. By independently adjusting each of the three, RGB LEDs are capable of producing a wide color gamut. Unlike dedicated-color LEDs, however, these do not produce pure wavelengths. Modules may not be optimized for smooth color mixing. Decorative-multicolor Decorative-multicolor LEDs incorporate several emitters of different colors supplied by only two lead-out wires. Colors are switched internally by varying the supply voltage. Alphanumeric Alphanumeric LEDs are available in seven-segment, starburst, and dot-matrix format. Seven-segment displays handle all numbers and a limited set of letters. Starburst displays can display all letters. Dot-matrix displays typically use 5×7 pixels per character. Seven-segment LED displays were in widespread use in the 1970s and 1980s, but rising use of liquid crystal displays, with their lower power needs and greater display flexibility, has reduced the popularity of numeric and alphanumeric LED displays. Digital RGB Digital RGB addressable LEDs contain their own "smart" control electronics. In addition to power and ground, these provide connections for data-in, data-out, clock and sometimes a strobe signal. These are connected in a daisy chain. Data sent to the first LED of the chain can control the brightness and color of each LED independently of the others. They are used where a combination of maximum control and minimum visible electronics are needed such as strings for Christmas and LED matrices. Some even have refresh rates in the kHz range, allowing for basic video applications. These devices are known by their part number (WS2812 being common) or a brand name such as NeoPixel. Filament An LED filament consists of multiple LED chips connected in series on a common longitudinal substrate that forms a thin rod reminiscent of a traditional incandescent filament. These are being used as a low-cost decorative alternative for traditional light bulbs that are being phased out in many countries. The filaments use a rather high voltage, allowing them to work efficiently with mains voltages. Often a simple rectifier and capacitive current limiting are employed to create a low-cost replacement for a traditional light bulb without the complexity of the low voltage, high current converter that single die LEDs need. Usually, they are packaged in bulb similar to the lamps they were designed to replace, and filled with inert gas at slightly lower than ambient pressure to remove heat efficiently and prevent corrosion. Chip-on-board arrays Surface-mounted LEDs are frequently produced in chip on board (COB) arrays, allowing better heat dissipation than with a single LED of comparable luminous output. The LEDs can be arranged around a cylinder, and are called "corn cob lights" because of the rows of yellow LEDs. Considerations for use Power sources The current in an LED or other diodes rises exponentially with the applied voltage (see Shockley diode equation), so a small change in voltage can cause a large change in current. Current through the LED must be regulated by an external circuit such as a constant current source to prevent damage. Since most common power supplies are (nearly) constant-voltage sources, LED fixtures must include a power converter, or at least a current-limiting resistor. In some applications, the internal resistance of small batteries is sufficient to keep current within the LED rating. Electrical polarity Unlike a traditional incandescent lamp, an LED will light only when voltage is applied in the forward direction of the diode. No current flows and no light is emitted if voltage is applied in the reverse direction. If the reverse voltage exceeds the breakdown voltage, a large current flows and the LED will be damaged. If the reverse current is sufficiently limited to avoid damage, the reverse-conducting LED is a useful noise diode. Safety and health Certain blue LEDs and cool-white LEDs can exceed safe limits of the so-called blue-light hazard as defined in eye safety specifications such as "ANSI/IESNA RP-27.1–05: Recommended Practice for Photobiological Safety for Lamp and Lamp Systems". One study showed no evidence of a risk in normal use at domestic illuminance, and that caution is only needed for particular occupational situations or for specific populations. In 2006, the International Electrotechnical Commission published IEC 62471 Photobiological safety of lamps and lamp systems, replacing the application of early laser-oriented standards for classification of LED sources. While LEDs have the advantage over fluorescent lamps, in that they do not contain mercury, they may contain other hazardous metals such as lead and arsenic. In 2016 the American Medical Association (AMA) issued a statement concerning the possible adverse influence of blueish street lighting on the sleep-wake cycle of city-dwellers. Industry critics claim exposure levels are not high enough to have a noticeable effect. Advantages Efficiency: LEDs emit more lumens per watt than incandescent light bulbs. The efficiency of LED lighting fixtures is not affected by shape and size, unlike fluorescent light bulbs or tubes. Color: LEDs can emit light of an intended color without using any color filters as traditional lighting methods need. This is more efficient and can lower initial costs. Size: LEDs can be very small (smaller than 2 mm2) and are easily attached to printed circuit boards. Warmup time: LEDs light up very quickly. A typical red indicator LED achieves full brightness in under a microsecond. LEDs used in communications devices can have even faster response times. Cycling: LEDs are ideal for uses subject to frequent on-off cycling, unlike incandescent and fluorescent lamps that fail faster when cycled often, or high-intensity discharge lamps (HID lamps) that require a long time before restarting. Dimming: LEDs can very easily be dimmed either by pulse-width modulation or lowering the forward current. This pulse-width modulation is why LED lights, particularly headlights on cars, when viewed on camera or by some people, seem to flash or flicker. This is a type of stroboscopic effect. Cool light: In contrast to most light sources, LEDs radiate very little heat in the form of IR that can cause damage to sensitive objects or fabrics. Wasted energy is dispersed as heat through the base of the LED. Slow failure: LEDs mainly fail by dimming over time, rather than the abrupt failure of incandescent bulbs. Lifetime: LEDs can have a relatively long useful life. One report estimates 35,000 to 50,000 hours of useful life, though time to complete failure may be shorter or longer. Fluorescent tubes typically are rated at about 10,000 to 25,000 hours, depending partly on the conditions of use, and incandescent light bulbs at 1,000 to 2,000 hours. Several DOE demonstrations have shown that reduced maintenance costs from this extended lifetime, rather than energy savings, is the primary factor in determining the payback period for an LED product. Shock resistance: LEDs, being solid-state components, are difficult to damage with external shock, unlike fluorescent and incandescent bulbs, which are fragile. Focus: The solid package of the LED can be designed to focus its light. Incandescent and fluorescent sources often require an external reflector to collect light and direct it in a usable manner. For larger LED packages total internal reflection (TIR) lenses are often used to the same effect. However, when large quantities of light are needed many light sources are usually deployed, which are difficult to focus or collimate towards the same target. Disadvantages Temperature dependence: LED performance largely depends on the ambient temperature of the operating environment – or thermal management properties. Overdriving an LED in high ambient temperatures may result in overheating the LED package, eventually leading to device failure. An adequate heat sink is needed to maintain long life. This is especially important in automotive, medical, and military uses where devices must operate over a wide range of temperatures, and require low failure rates. Voltage sensitivity: LEDs must be supplied with a voltage above their threshold voltage and a current below their rating. Current and lifetime change greatly with a small change in applied voltage. They thus require a current-regulated supply (usually just a series resistor for indicator LEDs). Color rendition: Most cool-white LEDs have spectra that differ significantly from a black body radiator like the sun or an incandescent light. The spike at 460 nm and dip at 500 nm can make the color of objects appear differently under cool-white LED illumination than sunlight or incandescent sources, due to metamerism, red surfaces being rendered particularly poorly by typical phosphor-based cool-white LEDs. The same is true with green surfaces. The quality of color rendition of an LED is measured by the Color Rendering Index (CRI). Area light source: Single LEDs do not approximate a point source of light giving a spherical light distribution, but rather a lambertian distribution. So, LEDs are difficult to apply to uses needing a spherical light field; however, different fields of light can be manipulated by the application of different optics or "lenses". LEDs cannot provide divergence below a few degrees. Light pollution: Because white LEDs emit more short wavelength light than sources such as high-pressure sodium vapor lamps, the increased blue and green sensitivity of scotopic vision means that white LEDs used in outdoor lighting cause substantially more sky glow. Efficiency droop: The efficiency of LEDs decreases as the electric current increases. Heating also increases with higher currents, which compromises LED lifetime. These effects put practical limits on the current through an LED in high power applications. Impact on wildlife: LEDs are much more attractive to insects than sodium-vapor lights, so much so that there has been speculative concern about the possibility of disruption to food webs. LED lighting near beaches, particularly intense blue and white colors, can disorient turtle hatchlings and make them wander inland instead. The use of "turtle-safe lighting" LEDs that emit only at narrow portions of the visible spectrum is encouraged by conservancy groups in order to reduce harm. Use in winter conditions: Since they do not give off much heat in comparison to incandescent lights, LED lights used for traffic control can have snow obscuring them, leading to accidents. Thermal runaway: Parallel strings of LEDs will not share current evenly due to the manufacturing tolerances in their forward voltage. Running two or more strings from a single current source may result in LED failure as the devices warm up. If forward voltage binning is not possible, a circuit is required to ensure even distribution of current between parallel strands. Applications LED uses fall into four major categories: Visual signals where light goes more or less directly from the source to the human eye, to convey a message or meaning Illumination where light is reflected from objects to give visual response of these objects Measuring and interacting with processes involving no human vision Narrow band light sensors where LEDs operate in a reverse-bias mode and respond to incident light, instead of emitting light Indicators and signs The low energy consumption, low maintenance and small size of LEDs has led to uses as status indicators and displays on a variety of equipment and installations. Large-area LED displays are used as stadium displays, dynamic decorative displays, and dynamic message signs on freeways. Thin, lightweight message displays are used at airports and railway stations, and as destination displays for trains, buses, trams, and ferries. One-color light is well suited for traffic lights and signals, exit signs, emergency vehicle lighting, ships' navigation lights, and LED-based Christmas lights Because of their long life, fast switching times, and visibility in broad daylight due to their high output and focus, LEDs have been used in automotive brake lights and turn signals. The use in brakes improves safety, due to a great reduction in the time needed to light fully, or faster rise time, about 0.1 second faster than an incandescent bulb. This gives drivers behind more time to react. In a dual intensity circuit (rear markers and brakes) if the LEDs are not pulsed at a fast enough frequency, they can create a phantom array, where ghost images of the LED appear if the eyes quickly scan across the array. White LED headlamps are beginning to appear. Using LEDs has styling advantages because LEDs can form much thinner lights than incandescent lamps with parabolic reflectors. Due to the relative cheapness of low output LEDs, they are also used in many temporary uses such as glowsticks, throwies, and the photonic textile Lumalive. Artists have also used LEDs for LED art. Lighting With the development of high-efficiency and high-power LEDs, it has become possible to use LEDs in lighting and illumination. To encourage the shift to LED lamps and other high-efficiency lighting, in 2008 the US Department of Energy created the L Prize competition. The Philips Lighting North America LED bulb won the first competition on August 3, 2011, after successfully completing 18 months of intensive field, lab, and product testing. Efficient lighting is needed for sustainable architecture. As of 2011, some LED bulbs provide up to 150 lm/W and even inexpensive low-end models typically exceed 50 lm/W, so that a 6-watt LED could achieve the same results as a standard 40-watt incandescent bulb. The lower heat output of LEDs also reduces demand on air conditioning systems. Worldwide, LEDs are rapidly adopted to displace less effective sources such as incandescent lamps and CFLs and reduce electrical energy consumption and its associated emissions. Solar powered LEDs are used as street lights and in architectural lighting. The mechanical robustness and long lifetime are used in automotive lighting on cars, motorcycles, and bicycle lights. LED street lights are employed on poles and in parking garages. In 2007, the Italian village of Torraca was the first place to convert its street lighting to LEDs. Cabin lighting on recent Airbus and Boeing jetliners uses LED lighting. LEDs are also being used in airport and heliport lighting. LED airport fixtures currently include medium-intensity runway lights, runway centerline lights, taxiway centerline and edge lights, guidance signs, and obstruction lighting. LEDs are also used as a light source for DLP projectors, and to backlight LCD televisions (referred to as LED TVs) and laptop displays. RGB LEDs raise the color gamut by as much as 45%. Screens for TV and computer displays can be made thinner using LEDs for backlighting. LEDs are small, durable and need little power, so they are used in handheld devices such as flashlights. LED strobe lights or camera flashes operate at a safe, low voltage, instead of the 250+ volts commonly found in xenon flashlamp-based lighting. This is especially useful in cameras on mobile phones, where space is at a premium and bulky voltage-raising circuitry is undesirable. LEDs are used for infrared illumination in night vision uses including security cameras. A ring of LEDs around a video camera, aimed forward into a retroreflective background, allows chroma keying in video productions. LEDs are used in mining operations, as cap lamps to provide light for miners. Research has been done to improve LEDs for mining, to reduce glare and to increase illumination, reducing risk of injury to the miners. LEDs are increasingly finding uses in medical and educational applications, for example as mood enhancement. NASA has even sponsored research for the use of LEDs to promote health for astronauts. Data communication and other signalling Light can be used to transmit data and analog signals. For example, lighting white LEDs can be used in systems assisting people to navigate in closed spaces while searching necessary rooms or objects. Assistive listening devices in many theaters and similar spaces use arrays of infrared LEDs to send sound to listeners' receivers. Light-emitting diodes (as well as semiconductor lasers) are used to send data over many types of fiber optic cable, from digital audio over TOSLINK cables to the very high bandwidth fiber links that form the Internet backbone. For some time, computers were commonly equipped with IrDA interfaces, which allowed them to send and receive data to nearby machines via infrared. Because LEDs can cycle on and off millions of times per second, very high data bandwidth can be achieved. For that reason, Visible Light Communication (VLC) has been proposed as an alternative to the increasingly competitive radio bandwidth. By operating in the visible part of the electromagnetic spectrum, data can be transmitted without occupying the frequencies of radio communications. The main characteristic of VLC, lies on the incapacity of light to surpass physical opaque barriers. This characteristic can be considered a weak point of VLC, due to the susceptibility of interference from physical objects, but is also one of its many strengths: unlike radio waves, light waves are confined in the enclosed spaces they are transmitted, which enforces a physical safety barrier that requires a receptor of that signal to have physical access to the place where the transmission is occurring. A promising application of VLC lies on the Indoor Positioning System (IPS), an analogous to the GPS built to operate in enclosed spaces where the satellite transmissions that allow the GPS operation are hard to reach. For instance, commercial buildings, shopping malls, parking garages, as well as subways and tunnel systems are all possible applications for VLC-based indoor positioning systems. Additionally, once the VLC lamps are able to perform lighting at the same time as data transmission, it can simply occupy the installation of traditional single-function lamps. Other applications for VLC involve communication between appliances of a smart home or office. With increasing IoT-capable devices, connectivity through traditional radio waves might be subjected to interference. However, light bulbs with VLC capabilities would be able to transmit data and commands for such devices. Machine vision systems Machine vision systems often require bright and homogeneous illumination, so features of interest are easier to process. LEDs are often used. Barcode scanners are the most common example of machine vision applications, and many of those scanners use red LEDs instead of lasers. Optical computer mice use LEDs as a light source for the miniature camera within the mouse. LEDs are useful for machine vision because they provide a compact, reliable source of light. LED lamps can be turned on and off to suit the needs of the vision system, and the shape of the beam produced can be tailored to match the system's requirements. Biological detection The discovery of radiative recombination in Aluminum Gallium Nitride (AlGaN) alloys by U.S. Army Research Laboratory (ARL) led to the conceptualization of UV light emitting diodes (LEDs) to be incorporated in light induced fluorescence sensors used for biological agent detection. In 2004, the Edgewood Chemical Biological Center (ECBC) initiated the effort to create a biological detector named TAC-BIO. The program capitalized on Semiconductor UV Optical Sources (SUVOS) developed by the Defense Advanced Research Projects Agency (DARPA). UV induced fluorescence is one of the most robust techniques used for rapid real time detection of biological aerosols. The first UV sensors were lasers lacking in-field-use practicality. In order to address this, DARPA incorporated SUVOS technology to create a low cost, small, lightweight, low power device. The TAC-BIO detector's response time was one minute from when it sensed a biological agent. It was also demonstrated that the detector could be operated unattended indoors and outdoors for weeks at a time. Aerosolized biological particles will fluoresce and scatter light under a UV light beam. Observed fluorescence is dependent on the applied wavelength and the biochemical fluorophores within the biological agent. UV induced fluorescence offers a rapid, accurate, efficient and logistically practical way for biological agent detection. This is because the use of UV fluorescence is reagent less, or a process that does not require an added chemical to produce a reaction, with no consumables, or produces no chemical byproducts. Additionally, TAC-BIO can reliably discriminate between threat and non-threat aerosols. It was claimed to be sensitive enough to detect low concentrations, but not so sensitive that it would cause false positives. The particle counting algorithm used in the device converted raw data into information by counting the photon pulses per unit of time from the fluorescence and scattering detectors, and comparing the value to a set threshold. The original TAC-BIO was introduced in 2010, while the second generation TAC-BIO GEN II, was designed in 2015 to be more cost efficient as plastic parts were used. Its small, light-weight design allows it to be mounted to vehicles, robots, and unmanned aerial vehicles. The second generation device could also be utilized as an environmental detector to monitor air quality in hospitals, airplanes, or even in households to detect fungus and mold. Other applications The light from LEDs can be modulated very quickly so they are used extensively in optical fiber and free space optics communications. This includes remote controls, such as for television sets, where infrared LEDs are often used. Opto-isolators use an LED combined with a photodiode or phototransistor to provide a signal path with electrical isolation between two circuits. This is especially useful in medical equipment where the signals from a low-voltage sensor circuit (usually battery-powered) in contact with a living organism must be electrically isolated
|
driven at currents from hundreds of mA to more than an ampere, compared with the tens of mA for other LEDs. Some can emit over a thousand lumens. LED power densities up to 300 W/cm2 have been achieved. Since overheating is destructive, the HP-LEDs must be mounted on a heat sink to allow for heat dissipation. If the heat from an HP-LED is not removed, the device fails in seconds. One HP-LED can often replace an incandescent bulb in a flashlight, or be set in an array to form a powerful LED lamp. Some well-known HP-LEDs in this category are the Nichia 19 series, Lumileds Rebel Led, Osram Opto Semiconductors Golden Dragon, and Cree X-lamp. As of September 2009, some HP-LEDs manufactured by Cree now exceed 105 lm/W. Examples for Haitz's law—which predicts an exponential rise in light output and efficacy of LEDs over time—are the CREE XP-G series LED, which achieved 105lm/W in 2009 and the Nichia 19 series with a typical efficacy of 140lm/W, released in 2010. AC-driven LEDs developed by Seoul Semiconductor can operate on AC power without a DC converter. For each half-cycle, part of the LED emits light and part is dark, and this is reversed during the next half-cycle. The efficiency of this type of HP-LED is typically 40lm/W. A large number of LED elements in series may be able to operate directly from line voltage. In 2009, Seoul Semiconductor released a high DC voltage LED, named 'Acrich MJT', capable of being driven from AC power with a simple controlling circuit. The low-power dissipation of these LEDs affords them more flexibility than the original AC LED design. Application-specific variations Flashing Flashing LEDs are used as attention seeking indicators without requiring external electronics. Flashing LEDs resemble standard LEDs but they contain an integrated voltage regulator and a multivibrator circuit that causes the LED to flash with a typical period of one second. In diffused lens LEDs, this circuit is visible as a small black dot. Most flashing LEDs emit light of one color, but more sophisticated devices can flash between multiple colors and even fade through a color sequence using RGB color mixing. Flashing SMD LEDs in the 0805 and other size formats have been available since early 2019. Bi-color Bi-color LEDs contain two different LED emitters in one case. There are two types of these. One type consists of two dies connected to the same two leads antiparallel to each other. Current flow in one direction emits one color, and current in the opposite direction emits the other color. The other type consists of two dies with separate leads for both dies and another lead for common anode or cathode so that they can be controlled independently. The most common bi-color combination is red/traditional green, however, other available combinations include amber/traditional green, red/pure green, red/blue, and blue/pure green. RGB tri-color Tri-color LEDs contain three different LED emitters in one case. Each emitter is connected to a separate lead so they can be controlled independently. A four-lead arrangement is typical with one common lead (anode or cathode) and an additional lead for each color. Others, however, have only two leads (positive and negative) and have a built-in electronic controller. RGB LEDs consist of one red, one green, and one blue LED. By independently adjusting each of the three, RGB LEDs are capable of producing a wide color gamut. Unlike dedicated-color LEDs, however, these do not produce pure wavelengths. Modules may not be optimized for smooth color mixing. Decorative-multicolor Decorative-multicolor LEDs incorporate several emitters of different colors supplied by only two lead-out wires. Colors are switched internally by varying the supply voltage. Alphanumeric Alphanumeric LEDs are available in seven-segment, starburst, and dot-matrix format. Seven-segment displays handle all numbers and a limited set of letters. Starburst displays can display all letters. Dot-matrix displays typically use 5×7 pixels per character. Seven-segment LED displays were in widespread use in the 1970s and 1980s, but rising use of liquid crystal displays, with their lower power needs and greater display flexibility, has reduced the popularity of numeric and alphanumeric LED displays. Digital RGB Digital RGB addressable LEDs contain their own "smart" control electronics. In addition to power and ground, these provide connections for data-in, data-out, clock and sometimes a strobe signal. These are connected in a daisy chain. Data sent to the first LED of the chain can control the brightness and color of each LED independently of the others. They are used where a combination of maximum control and minimum visible electronics are needed such as strings for Christmas and LED matrices. Some even have refresh rates in the kHz range, allowing for basic video applications. These devices are known by their part number (WS2812 being common) or a brand name such as NeoPixel. Filament An LED filament consists of multiple LED chips connected in series on a common longitudinal substrate that forms a thin rod reminiscent of a traditional incandescent filament. These are being used as a low-cost decorative alternative for traditional light bulbs that are being phased out in many countries. The filaments use a rather high voltage, allowing them to work efficiently with mains voltages. Often a simple rectifier and capacitive current limiting are employed to create a low-cost replacement for a traditional light bulb without the complexity of the low voltage, high current converter that single die LEDs need. Usually, they are packaged in bulb similar to the lamps they were designed to replace, and filled with inert gas at slightly lower than ambient pressure to remove heat efficiently and prevent corrosion. Chip-on-board arrays Surface-mounted LEDs are frequently produced in chip on board (COB) arrays, allowing better heat dissipation than with a single LED of comparable luminous output. The LEDs can be arranged around a cylinder, and are called "corn cob lights" because of the rows of yellow LEDs. Considerations for use Power sources The current in an LED or other diodes rises exponentially with the applied voltage (see Shockley diode equation), so a small change in voltage can cause a large change in current. Current through the LED must be regulated by an external circuit such as a constant current source to prevent damage. Since most common power supplies are (nearly) constant-voltage sources, LED fixtures must include a power converter, or at least a current-limiting resistor. In some applications, the internal resistance of small batteries is sufficient to keep current within the LED rating. Electrical polarity Unlike a traditional incandescent lamp, an LED will light only when voltage is applied in the forward direction of the diode. No current flows and no light is emitted if voltage is applied in the reverse direction. If the reverse voltage exceeds the breakdown voltage, a large current flows and the LED will be damaged. If the reverse current is sufficiently limited to avoid damage, the reverse-conducting LED is a useful noise diode. Safety and health Certain blue LEDs and cool-white LEDs can exceed safe limits of the so-called blue-light hazard as defined in eye safety specifications such as "ANSI/IESNA RP-27.1–05: Recommended Practice for Photobiological Safety for Lamp and Lamp Systems". One study showed no evidence of a risk in normal use at domestic illuminance, and that caution is only needed for particular occupational situations or for specific populations. In 2006, the International Electrotechnical Commission published IEC 62471 Photobiological safety of lamps and lamp systems, replacing the application of early laser-oriented standards for classification of LED sources. While LEDs have the advantage over fluorescent lamps, in that they do not contain mercury, they may contain other hazardous metals such as lead and arsenic. In 2016 the American Medical Association (AMA) issued a statement concerning the possible adverse influence of blueish street lighting on the sleep-wake cycle of city-dwellers. Industry critics claim exposure levels are not high enough to have a noticeable effect. Advantages Efficiency: LEDs emit more lumens per watt than incandescent light bulbs. The efficiency of LED lighting fixtures is not affected by shape and size, unlike fluorescent light bulbs or tubes. Color: LEDs can emit light of an intended color without using any color filters as traditional lighting methods need. This is more efficient and can lower initial costs. Size: LEDs can be very small (smaller than 2 mm2) and are easily attached to printed circuit boards. Warmup time: LEDs light up very quickly. A typical red indicator LED achieves full brightness in under a microsecond. LEDs used in communications devices can have even faster response times. Cycling: LEDs are ideal for uses subject to frequent on-off cycling, unlike incandescent and fluorescent lamps that fail faster when cycled often, or high-intensity discharge lamps (HID lamps) that require a long time before restarting. Dimming: LEDs can very easily be dimmed either by pulse-width modulation or lowering the forward current. This pulse-width modulation is why LED lights, particularly headlights on cars, when viewed on camera or by some people, seem to flash or flicker. This is a type of stroboscopic effect. Cool light: In contrast to most light sources, LEDs radiate very little heat in the form of IR that can cause damage to sensitive objects or fabrics. Wasted energy is dispersed as heat through the base of the LED. Slow failure: LEDs mainly fail by dimming over time, rather than the abrupt failure of incandescent bulbs. Lifetime: LEDs can have a relatively long useful life. One report estimates 35,000 to 50,000 hours of useful life, though time to complete failure may be shorter or longer. Fluorescent tubes typically are rated at about 10,000 to 25,000 hours, depending partly on the conditions of use, and incandescent light bulbs at 1,000 to 2,000 hours. Several DOE demonstrations have shown that reduced maintenance costs from this extended lifetime, rather than energy savings, is the primary factor in determining the payback period for an LED product. Shock resistance: LEDs, being solid-state components, are difficult to damage with external shock, unlike fluorescent and incandescent bulbs, which are fragile. Focus: The solid package of the LED can be designed to focus its light. Incandescent and fluorescent sources often require an external reflector to collect light and direct it in a usable manner. For larger LED packages total internal reflection (TIR) lenses are often used to the same effect. However, when large quantities of light are needed many light sources are usually deployed, which are difficult to focus or collimate towards the same target. Disadvantages Temperature dependence: LED performance largely depends on the ambient temperature of the operating environment – or thermal management properties. Overdriving an LED in high ambient temperatures may result in overheating the LED package, eventually leading to device failure. An adequate heat sink is needed to maintain long life. This is especially important in automotive, medical, and military uses where devices must operate over a wide range of temperatures, and require low failure rates. Voltage sensitivity: LEDs must be supplied with a voltage above their threshold voltage and a current below their rating. Current and lifetime change greatly with a small change in applied voltage. They thus require a current-regulated supply (usually just a series resistor for indicator LEDs). Color rendition: Most cool-white LEDs have spectra that differ significantly from a black body radiator like the sun or an incandescent light. The spike at 460 nm and dip at 500 nm can make the color of objects appear differently under cool-white LED illumination than sunlight or incandescent sources, due to metamerism, red surfaces being rendered particularly poorly by typical phosphor-based cool-white LEDs. The same is true with green surfaces. The quality of color rendition of an LED is measured by the Color Rendering Index (CRI). Area light source: Single LEDs do not approximate a point source of light giving a spherical light distribution, but rather a lambertian distribution. So, LEDs are difficult to apply to uses needing a spherical light field; however, different fields of light can be manipulated by the application of different optics or "lenses". LEDs cannot provide divergence below a few degrees. Light pollution: Because white LEDs emit more short wavelength light than sources such as high-pressure sodium vapor lamps, the increased blue and green sensitivity of scotopic vision means that white LEDs used in outdoor lighting cause substantially more sky glow. Efficiency droop: The efficiency of LEDs decreases as the electric current increases. Heating also increases with higher currents, which compromises LED lifetime. These effects put practical limits on the current through an LED in high power applications. Impact on wildlife: LEDs are much more attractive to insects than sodium-vapor lights, so much so that there has been speculative concern about the possibility of disruption to food webs. LED lighting near beaches, particularly intense blue and white colors, can disorient turtle hatchlings and make them wander inland instead. The use of "turtle-safe lighting" LEDs that emit only at narrow portions of the visible spectrum is encouraged by conservancy groups in order to reduce harm. Use in winter conditions: Since they do not give off much heat in comparison to incandescent lights, LED lights used for traffic control can have snow obscuring them, leading to accidents. Thermal runaway: Parallel strings of LEDs will not share current evenly due to the manufacturing tolerances in their forward voltage. Running two or more strings from a single current source may result in LED failure as the devices warm up. If forward voltage binning is not possible, a circuit is required to ensure even distribution of current between parallel strands. Applications LED uses fall into four major categories: Visual signals where light goes more or less directly from the source to the human eye, to convey a message or meaning Illumination where light is reflected from objects to give visual response of these objects Measuring and interacting with processes involving no human vision Narrow band light sensors where LEDs operate in a reverse-bias mode and respond to incident light, instead of emitting light Indicators and signs The low energy consumption, low maintenance and small size of LEDs has led to uses as status indicators and displays on a variety of equipment and installations. Large-area LED displays are used as stadium displays, dynamic decorative displays, and dynamic message signs on freeways. Thin, lightweight message displays are used at airports and railway stations, and as destination displays for trains, buses, trams, and ferries. One-color light is well suited for traffic lights and signals, exit signs, emergency vehicle lighting, ships' navigation lights, and LED-based Christmas lights Because of their long life, fast switching times, and visibility in broad daylight due to their high output and focus, LEDs have been used in automotive brake lights and turn signals. The use in brakes improves safety, due to a great reduction in the time needed to light fully, or faster rise time, about 0.1 second faster than an incandescent bulb. This gives drivers behind more time to react. In a dual intensity circuit (rear markers and brakes) if the LEDs are not pulsed at a fast enough frequency, they can create a phantom array, where ghost images of the LED appear if the eyes quickly scan across the array. White LED headlamps are beginning to appear. Using LEDs has styling advantages because LEDs can form much thinner lights than incandescent lamps with parabolic reflectors. Due to the relative cheapness of low output LEDs, they are also used in many temporary uses such as glowsticks, throwies, and the photonic textile Lumalive. Artists have also used LEDs for LED art. Lighting With the development of high-efficiency and high-power LEDs, it has become possible to use LEDs in lighting and illumination. To encourage the shift to LED lamps and other high-efficiency lighting, in 2008 the US Department of Energy created the L Prize competition. The Philips Lighting North America LED bulb won the first competition on August 3, 2011, after successfully completing 18 months of intensive field, lab, and product testing. Efficient lighting is needed for sustainable architecture. As of 2011, some LED bulbs provide up to 150 lm/W and even inexpensive low-end models typically exceed 50 lm/W, so that a 6-watt LED could achieve the same results as a standard 40-watt incandescent bulb. The lower heat output of LEDs also reduces demand on air conditioning systems. Worldwide, LEDs are rapidly adopted to displace less effective sources such as incandescent lamps and CFLs and reduce electrical energy consumption and its associated emissions. Solar powered LEDs are used as street lights and in architectural lighting. The mechanical robustness and long lifetime are used in automotive lighting on cars, motorcycles, and bicycle lights. LED street lights are employed on poles and in parking garages. In 2007, the Italian village of Torraca was the first place to convert its street lighting to LEDs. Cabin lighting on recent Airbus and Boeing jetliners uses LED lighting. LEDs are also being used in airport and heliport lighting. LED airport fixtures currently include medium-intensity runway lights, runway centerline lights, taxiway centerline and edge lights, guidance signs, and obstruction lighting. LEDs are also used as a light source for DLP projectors, and to backlight LCD televisions (referred to as LED TVs) and laptop displays. RGB LEDs raise the color gamut by as much as 45%. Screens for TV and computer displays can be made thinner using LEDs for backlighting. LEDs are small, durable and need little power, so they are used in handheld devices such as flashlights. LED strobe lights or camera flashes operate at a safe, low voltage, instead of the 250+ volts commonly found in xenon flashlamp-based lighting. This is especially useful in cameras on mobile phones, where space is at a premium and bulky voltage-raising circuitry is undesirable. LEDs are used for infrared illumination in night vision uses including security cameras. A ring of LEDs around a video camera, aimed forward into a retroreflective background, allows chroma keying in video productions. LEDs are used in mining operations, as cap lamps to provide light for miners. Research has been done to improve LEDs for mining, to reduce glare and to increase illumination, reducing risk of injury to the miners. LEDs are increasingly finding uses in medical and educational applications, for example as mood enhancement. NASA has even sponsored research for the use of LEDs to promote health for astronauts. Data communication and other signalling Light can be used to transmit data and analog signals. For example, lighting white LEDs can be used in systems assisting people to navigate in closed spaces while searching necessary rooms or objects. Assistive listening devices in many theaters and similar spaces use arrays of infrared LEDs to send sound to listeners' receivers. Light-emitting diodes (as well as semiconductor lasers) are used to send data over many types of fiber optic cable, from digital audio over TOSLINK cables to the very high bandwidth fiber links that form the Internet backbone. For some time, computers were commonly equipped with IrDA interfaces, which allowed them to send and receive data to nearby machines via infrared. Because LEDs can cycle on and off millions of times per second, very high data bandwidth can be achieved. For that reason, Visible Light Communication (VLC) has been proposed as an alternative to the increasingly competitive radio bandwidth. By operating in the visible part of the electromagnetic spectrum, data can be transmitted without occupying the frequencies of radio communications. The main characteristic of VLC, lies on the incapacity of light to surpass physical opaque barriers. This characteristic can be considered a weak point of VLC, due to the susceptibility of interference from physical objects, but is also one of its many strengths: unlike radio waves, light waves are confined in the enclosed spaces they are transmitted, which enforces a physical safety barrier that requires a receptor of that signal to have physical access to the place where the transmission is occurring. A promising application of VLC lies on the Indoor Positioning System (IPS), an analogous to the GPS built to operate in enclosed spaces where the satellite transmissions that allow the GPS operation are hard to reach. For instance, commercial buildings, shopping malls, parking garages, as well as subways and tunnel systems are all possible applications for VLC-based indoor positioning systems. Additionally, once the VLC lamps are able to perform lighting at the same time as data transmission, it can simply occupy the installation of traditional single-function lamps. Other applications for VLC involve communication between appliances of a smart home or office. With increasing IoT-capable devices, connectivity through traditional radio waves might be subjected to interference. However, light bulbs with VLC capabilities would be able to transmit data and commands for such devices. Machine vision systems Machine vision systems often require bright and homogeneous illumination, so features of interest are easier to process. LEDs are often used. Barcode scanners are the most common example of machine vision applications, and many of those scanners use red LEDs instead of lasers. Optical computer mice use LEDs as a light source for the miniature camera within the mouse. LEDs are useful for machine vision because they provide a compact, reliable source of light. LED lamps can be turned on and off to suit the needs of the vision system, and the shape of the beam produced can be tailored to match the system's requirements. Biological detection The discovery of radiative recombination in Aluminum Gallium Nitride (AlGaN) alloys by U.S. Army Research Laboratory (ARL) led to the conceptualization of UV light emitting diodes (LEDs) to be incorporated in light induced fluorescence sensors used for biological agent detection. In 2004, the Edgewood Chemical Biological Center (ECBC) initiated the effort to create a biological detector named TAC-BIO. The program capitalized on Semiconductor UV Optical Sources (SUVOS) developed by the Defense Advanced Research Projects Agency (DARPA). UV induced fluorescence is one of the most robust techniques used for rapid real time detection of biological aerosols. The first UV sensors were lasers lacking in-field-use practicality. In order to address this, DARPA incorporated SUVOS technology to create a low cost, small, lightweight, low power device. The TAC-BIO detector's response time was one minute from when it sensed a biological agent. It was also demonstrated that the detector could be operated unattended indoors and outdoors for weeks at a time. Aerosolized biological particles will fluoresce and scatter light under a UV light beam. Observed fluorescence is dependent on the applied wavelength and the biochemical fluorophores within the biological agent. UV induced fluorescence offers a rapid, accurate, efficient and logistically practical way for biological agent detection. This is because the use of UV fluorescence is reagent less, or a process that does not require an added chemical to produce a reaction, with no consumables, or produces no chemical byproducts. Additionally, TAC-BIO can reliably discriminate between threat and non-threat aerosols. It was claimed to be sensitive enough to detect low concentrations, but not so sensitive that it would cause false positives. The particle counting algorithm used in the device converted raw data into information by counting the photon pulses per unit of time from the fluorescence and scattering detectors, and comparing the value to a set threshold. The original TAC-BIO was introduced in 2010, while the second generation TAC-BIO GEN II, was designed in 2015 to be more cost efficient as plastic parts were used. Its small, light-weight design allows it to be mounted to vehicles, robots, and unmanned aerial vehicles. The second generation device could also be utilized as an environmental detector to monitor air quality in hospitals, airplanes, or even in households to detect fungus and mold. Other applications The light from LEDs can be modulated very quickly so they are used extensively in optical fiber and free space optics communications. This includes remote controls, such as for television sets, where infrared LEDs are often used. Opto-isolators use an LED combined with a photodiode or phototransistor to provide a signal path with electrical isolation between two circuits. This is especially useful in medical equipment where the signals from a low-voltage sensor circuit (usually battery-powered) in contact with a living organism must be electrically isolated from any possible electrical failure in a recording or monitoring device operating at potentially dangerous voltages. An optoisolator also lets information be transferred between circuits that do not share a common ground potential. Many sensor systems rely on light as the signal source. LEDs are often ideal as a light source due to the requirements of the sensors. The Nintendo Wii's sensor bar uses infrared LEDs. Pulse oximeters use them for measuring oxygen saturation. Some flatbed scanners use arrays of RGB LEDs rather than the typical cold-cathode fluorescent lamp as the light source. Having independent control of three illuminated colors allows the scanner to calibrate itself for more accurate color balance, and there is no need for warm-up. Further, its sensors only need be monochromatic, since at any one time the page being scanned is only lit by one color of light. Since LEDs can also be used as photodiodes, they can be used for both photo emission and detection. This could be used, for example, in a touchscreen that registers reflected light from
|
from French and Standard German, other diacritics are usually preserved: French: , , , etc. German: , (from German ), etc. In German loanwords, the digraphs and indicate the diphthong , which does not appear in native words. Orthography of vowels {| class="wikitable" |+ Monophthongs ! Spelling ! IPA ! Example |- | rowspan="2" style="vertical-align: middle;" | a | | |- | rowspan="2" style="vertical-align: middle;" | | |- | aa | |- | ä | rowspan="2" style="vertical-align: middle;" | | |- | rowspan="2" style="vertical-align: middle;" | e | |- | rowspan="2" style="vertical-align: middle;" | | |- | ë | |- | é | | |- | ee | | |- | rowspan="2" style="vertical-align: middle;" | i | | |- | rowspan="2" style="vertical-align: middle;" | | |- | ii | |- | rowspan="2" style="vertical-align: middle;" | o | | |- | rowspan="2" | | |- | oo | |- | rowspan="2" style="vertical-align: middle;" | u | | |- | rowspan="2" style="vertical-align: middle;" | | |- | uu | |} {| class="wikitable" |+ Diphthongs ! Spelling ! IPA ! Example |- | ai | rowspan="2" style="vertical-align: middle;" | | |- | ei | |- | äi | | |- | rowspan="2" style="vertical-align: middle;" | au | | |- | | |- | éi | | |- | | rowspan="2" | | |- | ier | |- | ou | | |- | ue | rowspan="2" | | |- | uer | |} {| class="wikitable" |+ r-vocalization ! Spelling ! IPA ! Example |- | ar | rowspan="2" | | |- | aar | |- | är | rowspan="2" | | |- | äer | |- | er | | |- | ir | rowspan="2" | | |- | ier | |- | or | rowspan="2" | | |- | oer | |- | ur | rowspan="2" | | |- | uer | |} Eifeler Regel Like many other varieties of Western High German, Luxembourgish has a rule of final n-deletion in certain contexts. The effects of this rule (known as the "Eifel Rule") are indicated in writing, and therefore must be taken into account when spelling words and morphemes ending in or . For example: "when I go", but "when we go" "thirty-five", but "forty-five". Phonology Consonants The consonant inventory of Luxembourgish is quite similar to that of Standard German. occurs only in loanwords from Standard German. Just as for many native speakers of Standard German, it tends to be simplified to word-initially. For example, Pflicht ('obligation') is realised as or, in careful speech, . is realised as when it occurs after , e.g. zwee ('two'). appears only in a few words, such as spadséieren ('to go for a walk'). occurs only in loanwords from English. have two types of allophones: alveolo-palatal and uvular . The latter occur before back vowels, and the former occur in all other positions. The allophone appears only in a few words, and speakers increasingly fail to distinguish between the alveolo-palatal allophones of and the postalveolar phonemes . Younger speakers tend to vocalize a word-final to . Vowels The front rounded vowels appear only in loanwords from French and Standard German. In loanwords from French, nasal also occur. has two allophones: Before velars: close-mid front unrounded , which, for some speakers, may be open-mid , especially before . The same variation in height applies to , which may be as open as . All other positions: mid central vowel, more often slightly rounded than unrounded . Phonetically, the long mid vowels are raised close-mid (near-close) and may even overlap with . before is realised as . is the long variant of , not , which does not have a long counterpart. appears only in loanwords from Standard German. The first elements of may be phonetically short in fast speech or in unstressed syllables. The and contrasts arose from the former lexical tone contrast; the shorter were used in words with Accent 1, and the lengthened were used in words with Accent 2. Grammar Nominal syntax Luxembourgish has three genders (masculine, feminine, and neuter), and three cases (nominative, accusative, and dative). These are marked morphologically on determiners and pronouns. As in German, there is no morphological gender distinction in the plural. The forms of the articles and of some selected determiners are given below: As seen above, Luxembourgish has plural forms of en ("a, an"), namely eng in the nominative/accusative and engen in the dative. They are not used as indefinite articles, which—as in German and English—do not exist in the plural, but they do occur in the compound pronouns wéi en ("what, which") and sou en ("such"). For example: wéi eng Saachen ("what things"); sou eng Saachen ("such things"). Moreover, they are used before numbers to express an estimation: eng 30.000 Spectateuren ("some 30,000 spectators"). Distinct nominative forms survive in a few nominal phrases such as der Däiwel ("the devil") and eiser Herrgott ("our Lord"). Rare examples of the genitive are also found: Enn des Mounts ("end of the month"), Ufanks der Woch ("at the beginning of the week"). The functions of the genitive are normally expressed using a combination of the dative and a possessive determiner: e.g. dem Mann säi Buch (lit. "to the man his book", i.e. "the man's book"). This is known as a periphrastic genitive, and is a phenomenon also commonly seen in dialectal and colloquial German, and in Dutch. The forms of the personal pronouns are given in the following table (unstressed forms appear in parentheses): The 2pl form is also used as a polite singular (like French vous, see T-V distinction); the forms are capitalised in writing: Wéi hues du de Concert fonnt? ("How did you [informal sg.] like the concert?") Wéi hutt dir de Concert fonnt? ("How did you [informal pl.] like the concert?") Wéi hutt Dir de Concert fonnt? ("How did you [formal sg. or pl.] like the concert?") Like most varieties of colloquial German, but even more invariably, Luxembourgish uses definite articles with personal names. They are obligatory and not to be translated: De Serge ass an der Kichen. ("Serge is in the kitchen.") A feature Luxembourgish shares with only some western dialects of German is that women and girls are most often referred to with forms of the neuter pronoun hatt: Dat ass d'Nathalie. Hatt ass midd, well et vill a sengem Gaart geschafft huet. ("That's Nathalie. She is tired because she has worked a lot in her garden.") Adjectives Luxembourgish morphology distinguishes two types of adjective: attributive and predicative. Predicative adjectives appear with verbs like sinn ("to be"), and receive no extra ending: De Mann ass grouss. (masculine, "The man is tall.") D'Fra ass grouss. (feminine, "The woman is tall.") D'Meedchen ass grouss. (neuter, "The girl is tall.") D'Kanner si grouss. (plural, "The children are tall.") Attributive adjectives are placed before the noun they describe, and change their ending according to the grammatical gender, number, and case: de grousse Mann (masculine) déi grouss Fra (feminine) dat grousst Meedchen (neuter) déi grouss Kanner (plural) Curiously, the definite article changes with the use of an attributive adjective: feminine d' goes to déi (or di), neuter d' goes to dat, and plural d' changes to déi. The comparative in Luxembourgish is formed analytically, i.e. the adjective itself is not altered (compare the use of -er in German and English; tall → taller, klein → kleiner). Instead it is formed using the adverb méi: e.g. schéin → méi schéin Lëtzebuerg ass méi schéi wéi Esch. ("Luxembourg is prettier than Esch.") The superlative involves a synthetic form consisting of the adjective and the suffix -st: e.g. schéin → schéinst (compare German schönst, English prettiest). Attributive modification requires the emphatic definite article and the inflected superlative adjective: dee schéinste Mann ("the most handsome man") déi schéinst Fra ("the prettiest woman") Predicative modification uses either the same adjectival structure or the adverbial structure am+ -sten: e.g. schéin → am schéinsten: Lëtzebuerg ass dee schéinsten / deen allerschéinsten / am schéinsten. ("Luxembourg is the most beautiful (of all).") Some common adjectives have exceptional comparative and superlative forms: gutt, besser, am beschten ("good, better, best") vill, méi, am meeschten ("much, more, most") wéineg, manner, am mannsten ("few, fewer, fewest") Several other adjectives also have comparative forms. However, these are not commonly used as normal comparatives, but in special senses: al ("old") → eeler Leit ("elderly people"), but: méi al Leit ("older people, people older than X") fréi ("early") → de fréiere President ("the former president"), but: e méi fréien Termin ("an earlier appointment") laang ("long") → viru längerer
|
(lit. "everything what you always wanted know about Luxembourg") Vocabulary Luxembourgish has borrowed many French words. For example, the word for a bus driver is Buschauffeur (as in Dutch and Swiss German), which would be Busfahrer in German and chauffeur de bus in French. Some words are different from Standard German, but have equivalents in German dialects. An example is Gromperen (potatoes – German: Kartoffeln). Other words are exclusive to Luxembourgish. Selected common phrases Note: Words spoken in sound clip do not reflect all words on this list. Neologisms Neologisms in Luxembourgish include both entirely new words, and the attachment of new meanings to old words in everyday speech. The most recent neologisms come from the English language in the fields of telecommunications, computer science, and the Internet. Recent neologisms in Luxembourgish include: direct loans from English: Browser, Spam, CD, Fitness, Come-back, Terminal, Hip, Cool, Tip-top also found in German: Sichmaschinn (search engine, German: Suchmaschine), schwaarzt Lach (black hole, German: Schwarzes Loch), Handy (mobile phone), Websäit (webpage, German: Webseite) native Luxembourgish déck as an emphatic like ganz and voll, e.g. Dëse Kuch ass déck gutt! ("This cake is really good!") recent expressions, used mainly by teenagers: oh mëllen! ("oh crazy"), en décke gelénkt ("you've been tricked") or cassé (French for "(you've been) owned") Academic projects Between 2000 and 2002, Luxembourgish linguist Jérôme Lulling compiled a lexical database of 125,000-word forms as the basis for the first Luxembourgish spellchecker (Projet C.ORT.IN.A). The LaF (Lëtzebuergesch als Friemsprooch – Luxembourgish as a Foreign Language) is a set of four language proficiency certifications for Luxembourgish and follows the ALTE framework of language examination standards. The tests are administered by the Institut National des Langues Luxembourg. The "Centre for Luxembourg Studies" at the University of Sheffield was founded in 1995 on the initiative of Professor Gerald Newton. It is supported by the government of Luxembourg which funds an endowed chair in Luxembourg Studies at the university. The first class of students to study the language outside of the country as undergraduate students began their studies at the 'Centre for Luxembourg Studies' at Sheffield in the academic year 2011–2012. Claims of endangered status UNESCO declared Luxembourgish to be an endangered language in 2019, adding it to its Atlas of the World's Languages in Danger. Additionally, some local media have argued that the Luxembourgish language is at risk of disappearing, and that it should be considered an endangered language. Even though the government claims that more people than ever are able to speak Luxembourgish, these are absolute numbers and often include the many naturalized citizens who have passed the Sproochentest, a language test that certifies the knowledge of merely A.2. in speaking and B.1. in understanding. Luxembourgish language expert and historian Alain Atten argues that not only the absolute number of Luxembourgish speakers should be considered when defining the status of a language, but also the proportion of speakers in a country. Noting that the proportion of native Luxembourgish speakers has decreased in recent decades, Atten believes that Luxembourgish will inevitably disappear, stating: "It is simple math, if there are about 70% foreigners and about 30% Luxembourgers (which is the case in Luxembourg City), then it can impossibly be said that luxembourgish is thriving. That would be very improbable." Alain Atten also points out that the situation is even more dramatic, since the cited percentages take only the residents of Luxembourg into account, excluding the 200,000 cross-border-workers present in the country on a daily basis. This group plays a major role in the daily use of languages in Luxembourg, thus further lowering the percentage of Luxembourgish speakers present in the country. The following numbers are based on statistics by STATEC (those since 2011) and show that the percentage of the population that is able to speak Luxembourgish has been constantly diminishing for years (Note that the 200,000 cross-border workers are not included in this statistic): It has also been argued that two very similar languages, Alsatian and Lorraine Franconian, which were very broadly spoken by the local populations at the beginning of the 20th century in Alsace and in Lorraine respectively, have been nearly completely supplanted by French, and that a similar fate could also be possible for Luxembourgish. Another example of the replacement of Luxembourgish by French occurred in Arelerland (historically a part of Luxembourg, today in Belgium), where the vast majority of the local population spoke Luxembourgish as a native language well into the 20th century. Today, Luxembourgish is nearly extinct in this region, having been replaced by French. According to some Luxembourgish news media and members of Actioun Lëtzebuergesch (an association for the preservation and promotion of the language), the biggest threat to the existence of Luxembourgish is indeed French, since French is the predominant language of most official documents and street signs in Luxembourg, thus considerably weakening the possibilitiy for Luxembourgish learners to practice the newly learned language. In most cases this passively forces expats to learn French instead of Luxembourgish. In 2021 it was announced that public announcements in Luxembourgish (and in German as well) at Luxembourg Airport would cease; it would only be using French and English for future public announcements. This will cause Luxembourgish disappear from use at Luxembourg Airport, after being used for many decades. Actioun Lëtzebuergesch declared itself to be hugely upset by this new governmental measure, citing that other airports in the world seem to have no problems making public announcements in multiple languages. According to a poll conducted by AL, 92.84% of the Luxembourgish population wished to have public announcements to be made in Luxembourgish at Luxembourg Airport. Additionally, all written signs at Luxembourg Airport are only in French and English. This non-use of Luxembourgish and German (two official languages of Luxembourg) have fueled claims of a language discrimination, some pointing out that other airports seem to have no difficulties using up to 4 different languages in written signs. (Palma de Mallorca Airport for example uses Mallorquí, Spanish, English, and German, the latter two not even being official languages of the country) Further fears of Luxembourgish disappearing or being replaced by French have been fueled in 2021 when ASTI (Association de Soutien aux Travailleurs Immigrés) stated that it would wish to see Luxembourgish be removed as the national language of Luxembourg (as written in the constitution), claiming that the national language of Luxembourg should by law be defined as the one that is most used in the local population, hinting that French would be the better choice. See also Erna Hennicot-Schoepges Literature of Luxembourg Luxembourgish Swadesh List Multilingualism in Luxembourg Notes and references Notes References Bibliography Bruch, Robert. (1955) Précis de grammaire luxembourgeoise. Bulletin Linguistique et Ethnologique de l'Institut Grand-Ducal, Luxembourg, Linden. (2nd edition of 1968) Schanen, François and Lulling, Jérôme. (2003) Introduction à l'orthographe luxembourgeoise. (text available in French and Luxembourgish) Further reading In English NEWTON, Gerald (ed.), Luxembourg and Lëtzebuergesch: Language and Communication at the Crossroads of Europe, Oxford, 1996, In French BRAUN, Josy, et al. (en coll. avec Projet Moien), Grammaire de la langue luxembourgeoise. Luxembourg, Ministère de l'Éducation nationale et de la Formation professionnelle 2005. SCHANEN, François, Parlons Luxembourgeois, Langue et culture linguistique d'un petit pays au coeur de l'Europe. Paris, L'Harmattan 2004, SCHANEN, François / ZIMMER, Jacqui, 1,2,3 Lëtzebuergesch Grammaire. Band 1: Le groupe verbal. Band 2: Le groupe nominal. Band 3:L'orthographe. Esch-sur-Alzette, éditions Schortgen, 2005 et 2006 SCHANEN, François / ZIMMER, Jacqui, Lëtzebuergesch Grammaire luxembourgeoise. En un volume. Esch-sur-Alzette, éditions Schortgen, 2012. In Luxembourgish SCHANEN, François, Lëtzebuergesch Sproocherubriken. Esch-sur-Alzette, éditions Schortgen, 2013. Meyer, Antoine, E' Schrek ob de' lezeburger Parnassus, Lezeburg (Luxembourg), Lamort, 1829 In German BRUCH, Robert, Grundlegung einer Geschichte des Luxemburgischen, Luxembourg, Publications scientifiques et littéraires du Ministère de l'Éducation nationale, 1953, vol. I; Das Luxemburgische im westfränkischen Kreis, Luxembourg, Publications scientifiques et littéraires du Ministère de l'Éducation nationale, 1954, vol. II MOULIN, Claudine and Nübling, Damaris (publisher): Perspektiven einer linguistischen Luxemburgistik. Studien zu Diachronie und Synchronie., Universitätsverlag Winter, Heidelberg, 2006. This book has been published with the support of the Fonds National de la Recherche BERG, Guy, Mir wëlle bleiwe wat mir sin: Soziolinguistische und sprachtypologische Betrachtungen zur luxemburgischen Mehrsprachigkeit., Tübingen, 1993 (Reihe Germanistische Linguistik 140). (phrasebook) REMUS, Joscha, Lëtzebuergesch Wort für Wort. Kauderwelsch Band 104. Bielefeld, Reise Know-How Verlag 1997. WELSCHBILLIG Myriam, SCHANEN François, Jérôme Lulling, Luxdico Deutsch:
|
in 1917. His next film was released under the Soviet patronage. During 1918–1920 he covered the Russian Civil War with a documentary crew. In 1919 he headed the first Soviet film courses at the National Film School. Kuleshov may well be the very first film theorist as he was a leader in the Soviet montage theory – developing his theories of editing before those of Sergei Eisenstein (briefly a student of Kuleshov). He contributed the article "Kinematografichesky naturshchik" to the first issue of Zrelishcha in 1922. Among his other notable students were Vsevolod Pudovkin, Boris Barnet, Mikhail Romm, Sergey Komarov, Porfiri Podobed, Vladimir Fogel and Aleksandra Khokhlova who became his wife. For Kuleshov, the essence of the cinema was editing, the juxtaposition of one shot with another. To illustrate this principle, he created what has come to be known as the Kuleshov Effect. In this now-famous editing exercise, shots of an actor were intercut with various meaningful images (a casket, a bowl of soup, etc.) in order to show how editing changes viewers' interpretations of images. Another one of his famous inventions was creative geography, also known as artificial landscape. Those techniques were described in his book The Basics of Film Direction (1941) which was later translated into many languages. In addition to his theoretical and teaching work, Kuleshov directed a number of feature-length films. Among his most notable works are an action-comedy The Extraordinary Adventures of Mr. West in the Land of the Bolsheviks (1924), a psychological drama By the Law (1926) adapted from the short story by Jack London and a biographical drama The Great Consoler (1933) based on O. Henry's life and works. In 1934 and 1935 Kuleshov went to Tajikistan to direct there Dokhunda, a movie based on the novel by Tajik national poet Sadriddin Ayni, but the project was regarded with suspicion by the authorities as possibly exciting Tajik nationalism, and stopped. No footage survives. After directing his last film in 1943, Kuleshov served as an artistic director and an academic rector at VGIK where he worked for the next 25 years. He was a member of the jury at the 27th Venice International Film Festival, as well as a special guest during other international film festivals. Lev Kuleshov died in Moscow in 1970. He was buried at the Novodevichy Cemetery. He was survived by his
|
was intimately involved in development of the style of film making known as Soviet montage, especially its psychological underpinning, including the use of editing and the cut to emotionally influence the audience, a principle known as the Kuleshov effect. He also developed the theory of creative geography, which is the use of the action around a cut to connect otherwise disparate settings into a cohesive narrative. Life and career Lev Kuleshov was born in 1899 into an intellectual Russian family. His father Vladimir Sergeevich Kuleshov was of noble heritage; he studied art in the Moscow School of Painting, Sculpture and Architecture, despite his own father's disapproval. He then married a village schoolteacher Pelagia Alexandrovna Shubina who was raised in an orphanage, which only led to more confrontation. They gave birth to two sons: Boris and Lev. At the time Lev Kuleshov was born, the family became financially broke, lost their estate and moved to Tambov, living a modest life. In 1911 Vladimir Kuleshov died; three years later Lev and his mother moved to Moscow where his elder brother was studying and working as an engineer. Lev Kuleshov decided to follow the steps of his father and entered the Moscow School of Painting, although he didn't finish it. In 1916 he applied to work at the film company led by Aleksandr Khanzhonkov. He produced scenery for Yevgeni Bauer's pictures, such as The King of Paris, For Happiness and others. With time Kuleshov became more interested in film theory. He co-directed his first movie Twilight in 1917. His next film was released under the Soviet patronage. During 1918–1920 he covered the Russian Civil War with a documentary crew. In 1919 he headed the first Soviet film courses at the National Film School. Kuleshov may well be the very first film theorist as he was a leader in the Soviet montage theory – developing his theories of editing before those of Sergei Eisenstein (briefly a student of Kuleshov). He contributed the article "Kinematografichesky naturshchik" to the first issue of Zrelishcha in 1922. Among his other notable students were Vsevolod Pudovkin, Boris Barnet, Mikhail Romm, Sergey Komarov, Porfiri Podobed, Vladimir Fogel and Aleksandra Khokhlova who became his wife. For Kuleshov, the essence of the cinema was editing, the juxtaposition of one shot with another. To illustrate this principle, he created what has come to be known as the Kuleshov Effect. In this now-famous editing exercise,
|
of service, and the cost of designing a new system with a similar availability level is high. Examples include systems to handle customers' accounts in banks, computer reservations systems, air traffic control, energy distribution (power grids), nuclear power plants, military defense installations, and systems such as the TOPS database. The way that the system works is not well understood. Such a situation can occur when the designers of the system have left the organization, and the system has either not been fully documented or documentation has been lost. The user expects that the system can easily be replaced when this becomes necessary. Newer systems perform undesirable (especially for individual or non-institutional users) secondary functions such as a) tracking and reporting of user activity and/or b) automatic updating that creates "back-door" security vulnerabilities and leaves end users dependent on the good faith and honesty of the vendor providing the updates. This problem is especially acute when these secondary functions of a newer system cannot be disabled. Problems posed by legacy computing Legacy systems are considered to be potentially problematic by some software engineers for several reasons. If legacy software runs on only antiquated hardware, the cost of maintaining the system may eventually outweigh the cost of replacing both the software and hardware unless some form of emulation or backward compatibility allows the software to run on new hardware. These systems can be hard to maintain, improve, and expand because there is a general lack of understanding of the system; the staff who were experts on it have retired or forgotten what they knew about it, and staff who entered the field after it became "legacy" never learned about it in the first place. This can be worsened by lack or loss of documentation. Comair airline company fired its CEO in 2004 due to the failure of an antiquated legacy crew scheduling system that ran into a limitation not known to anyone in the company. Legacy systems may have vulnerabilities in older operating systems or applications due to lack of security patches being available or applied. There can also be production configurations that cause security problems. These issues can put the legacy system at risk of being compromised by attackers or knowledgeable insiders. Integration with newer systems may also be difficult because new software may use completely different technologies. Integration across technology is quite common in computing, but integration between newer technologies and substantially older ones is not common. There may simply not be sufficient demand for integration technology to be developed. Some of this "glue" code is occasionally developed by vendors and enthusiasts of particular legacy technologies. Budgetary constraints often lead corporations to not address the need of replacement or migration of a legacy system. However, companies often don't consider the increasing supportability costs (people, software and hardware, all mentioned above) and do not take into consideration the enormous loss of capability or business continuity if the legacy system were to fail. Once these considerations are well understood, then based on the proven ROI of a new, more secure, updated technology stack platform is not as costly as the alternative—and the budget is found. Due to the fact that most legacy programmers are entering retirement age and the number of young engineers replacing them is very small, there is an alarming shortage of available workforce. This in turn results in difficulty in maintaining legacy systems, as well as an increase in costs of procuring experienced programmers. Improvements on legacy software systems Where it is impossible to replace legacy systems through the practice of application retirement, it is still possible to enhance (or "re-face") them. Most development often goes into adding new interfaces to a legacy system. The most prominent technique is to provide a Web-based interface to a terminal-based mainframe application. This may reduce staff productivity due to slower response times and slower mouse-based operator actions, yet it is often seen as an "upgrade", because the interface style is familiar to unskilled users and is easy for them to use. John McCormick discusses such strategies that involve middleware. Printing improvements are problematic because legacy software systems often add no formatting instructions, or they use protocols that are not usable in modern PC/Windows
|
still possible to enhance (or "re-face") them. Most development often goes into adding new interfaces to a legacy system. The most prominent technique is to provide a Web-based interface to a terminal-based mainframe application. This may reduce staff productivity due to slower response times and slower mouse-based operator actions, yet it is often seen as an "upgrade", because the interface style is familiar to unskilled users and is easy for them to use. John McCormick discusses such strategies that involve middleware. Printing improvements are problematic because legacy software systems often add no formatting instructions, or they use protocols that are not usable in modern PC/Windows printers. A print server can be used to intercept the data and translate it to a more modern code. Rich Text Format (RTF) or PostScript documents may be created in the legacy application and then interpreted at a PC before being printed. Biometric security measures are difficult to implement on legacy systems. A workable solution is to use a Telnet or HTTP proxy server to sit between users and the mainframe to implement secure access to the legacy application. The change being undertaken in some organizations is to switch to automated business process (ABP) software which generates complete systems. These systems can then interface to the organizations' legacy systems and use them as data repositories. This approach can provide a number of significant benefits: the users are insulated from the inefficiencies of their legacy systems, and the changes can be incorporated quickly and easily in the ABP software. Model-driven reverse and forward engineering approaches can be also used for the improvement of legacy software. NASA example Andreas Hein, from the Technical University of Munich, researched the use of legacy systems in space exploration. According to Hein, legacy systems are attractive for reuse if an organization has the capabilities for verification, validation, testing, and operational history. These capabilities must be integrated into various software life cycle phases such as development, implementation, usage, or maintenance. For software systems, the capability to use and maintain the system are crucial. Otherwise the system will become less and less understandable and maintainable. According to Hein, verification, validation, testing, and operational history increases the confidence in a system's reliability and quality. However, accumulating this history is often expensive. NASA's now retired Space Shuttle program used a large amount of 1970s-era technology. Replacement was cost-prohibitive because of the expensive requirement for flight certification. The original hardware completed the expensive integration and certification requirement for flight, but any new equipment would have had to go through that entire process again. This long and detailed process required extensive tests of the new components in their new configurations before a single unit could be used in the Space Shuttle program. Thus any new system that started the certification process becomes a de facto legacy system by the time it is approved for flight. Additionally, the entire Space Shuttle system, including ground and launch vehicle assets, was designed to work together as a closed system. Since the specifications did not change, all of the certified systems and components performed well in the roles for which they were designed. Even before the Shuttle was scheduled to be retired in 2010, NASA found it advantageous to keep using many pieces of 1970s technology rather than to upgrade those systems and recertify the new components. Perspectives on legacy code Some in the software engineering prefer to describe "legacy code" without the connotation of being obsolete. Among the most prevalent neutral conceptions are source code inherited from someone else and source code inherited from an older version of the software. Eli Lopian, CEO of Typemock, has defined it as "code that developers are afraid to change". Michael Feathers introduced a definition of legacy code as code without tests, which reflects the perspective of legacy code being difficult to work with in part due to a lack of automated regression tests. He also defined characterization tests to start putting legacy code under test. Ginny Hendry characterized creation of code as a challenge to current coders to create code that is "like other legacies in our lives—like the antiques, heirlooms, and stories that are cherished and lovingly passed down from one generation to the next. What if legacy code was something we took pride in?". Additional uses of the term Legacy in computing The term legacy support is often used in conjunction with legacy systems. The term may refer to a feature of modern software. For example, Operating systems with "legacy support" can detect and
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.