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American Revolutionary War | Aftermath | Aftermath |
American Revolutionary War | Territory | Territory
The expanse of territory that was now the U.S. included millions of sparsely settled acres south of the Great Lakes between the Appalachian Mountains and the Mississippi River, much of which was part of Canada. The tentative colonial migration west became a flood during the war.Herring 2011 [2008], p. 41
Britain's extended post-war policy for the U.S. continued to try to establish an Indian barrier state below the Great Lakes as late as 1814 during the War of 1812. The formally acquired western American lands continued to be populated by Indigenous tribes that had mostly been British allies. In practice the British refused to abandon the forts on territory they formally transferred. Instead, they provisioned military allies for continuing frontier raids and sponsored the Northwest Indian War (1785–1795). British sponsorship of local warfare on the U.S. continued until the Anglo-American Jay Treaty, authored by Hamilton, went into effect on February 29, 1796.Benn 1993, p. 17
Of the European powers with American colonies adjacent to the newly created U.S., Spain was most threatened by American independence, and it was correspondingly the most hostile to it. Its territory adjacent to the U.S. was relatively undefended, so Spanish policy developed a combination of initiatives. Spanish soft power diplomatically challenged the British territorial cession west to the Mississippi River and the previous northern boundaries of Spanish Florida.Herring 2011 [2008], p. 46 It imposed a high tariff on American goods, then blocked American settler access to the port of New Orleans. At the same time, the Spanish also sponsored war within the U.S. by Indian proxies in its Southwest Territory ceded by France to Britain, then Britain to the Americans. |
American Revolutionary War | Casualties and losses | Casualties and losses
thumb|upright|alt=A cemetery; grave stones in the foreground in staggered, irregular rows; behind them grass covered mounds of dead; an American flag in the background along a tree line.|Mass graves from the Battles of Saratoga in Salem, New York
The total loss of life throughout the conflict is largely unknown. As was typical in wars of the era, diseases such as smallpox claimed more lives than battle. Between 1775 and 1782, a smallpox epidemic throughout North America killed an estimated 130,000. Historian Joseph Ellis suggests that Washington having his troops inoculated against the disease was one of his most important decisions.Ellis 2004, p. 87
Up to 70,000 American Patriots died during active military service.Peckham 1974, p. Of these, approximately 6,800 were killed in battle, while at least 17,000 died from disease. The majority of the latter died while prisoners of war of the British, mostly in the prison ships in New York Harbor.Burrows 2008b, p. 201 The number of Patriots seriously wounded or disabled by the war has been estimated from 8,500 to 25,000.Chambers 1999 p. 849
The French suffered 2,112 killed in combat in the United States.Dawson 2017, "Frenchmen who died" The Spanish lost 124 killed and 247 wounded in West Florida.White 2010, "Essay"
A British report in 1781 puts their total Army deaths at 6,046 in North America (1775–1779). Approximately 7,774 Germans died in British service in addition to 4,888 deserters; among those labeled German deserters, however, it is estimated that 1,800 were killed in combat. |
American Revolutionary War | Legacy | Legacy
thumb|The U.S. motto Novus ordo seclorum, meaning "A New Age Now Begins", is paraphrased from Thomas Paine's Common Sense, published January 10, 1776. "We have it in our power to begin the world over again", Paine wrote in it.McDonald, Forrest. Novus Ordo Seclorum: The Intellectual Origins of the Constitution, pp. 6–7, Lawrence: University Press of Kansas, 1985. .
The American Revolution set an example to overthrow both monarchy and colonial governments. The United States has the world's oldest written constitution, which was used as a model in other countries, sometimes word-for-word. The Revolution inspired revolutions in France, Haiti, Latin America, and elsewhere.Bailyn, 2007, pp. 35, 134–149
Although the Revolution eliminated many forms of inequality, it did little to change the status of women, despite the role they played in winning independence. Most significantly, it failed to end slavery. While many were uneasy over the contradiction of demanding liberty for some, yet denying it to others, the dependence of southern states on slave labor made abolition too great a challenge. Between 1774 and 1780, many of the states banned the importation of slaves, but the institution itself continued.Morgan, 2012 [1956], pp. 96–97 In 1782, Virginia passed a law permitting manumission and over the next eight years more than 10,000 slaves were given their freedom.Morgan, 2012 [1956], p. 97 The number of abolitionist movements greatly increased, and by 1804 all the northern states had outlawed it.Wood, 1992, pp. 3–8, 186–187 However, slavery continued to be a serious social and political issue and caused divisions that would ultimately end in civil war. |
American Revolutionary War | Historiography | Historiography
The body of historical writings on the American Revolution cite many motivations for the Patriot revolt.Paul David Nelson, "British Conduct of the American Revolutionary War: A Review of Interpretations." Journal of American History 65.3 (1978): 623–653. American Patriots stressed the denial of their constitutional rights as Englishmen, especially "no taxation without representation." Contemporaries credit the American Enlightenment with laying the intellectual, moral, and ethical foundations for the American Revolution among the Founding Fathers, who were influenced by the classical liberalism of John Locke and other Enlightenment writers and philosophers.
Two Treatises of Government has long been cited as a major influence on Revolutionary-era American thinking, but historians David Lundberg and Henry F. May contend that Locke's Essay Concerning Human Understanding was far more widely read.See David Lundberg and Henry F. May, "The Enlightened Reader in America", American Quarterly, vol. 28, no. 2 (1976): 267. Historians since the 1960s have emphasized that the Patriot constitutional argument was made possible by the emergence of an American nationalism that united the Thirteen Colonies. In turn, that nationalism was rooted in a Republican value system that demanded consent of the governed and deeply opposed aristocratic control. In Britain, on the other hand, republicanism was largely a fringe ideology since it challenged the aristocratic control of the British monarchy and political system. Political power was not controlled by an aristocracy or nobility in the 13 colonies; instead, the colonial political system was based on the winners of free elections, which were open at the time to the majority of white men. In analysis of the Revolution, historians in recent decades have often cited three motivations behind it:Robin Winks, ed. Historiography (1999) 5:95
The Atlantic history view places the American story in a broader context, including subsequent revolutions in France and Haiti. It tends to reintegrate the historiographies of the American Revolution and the British Empire.Eliga H. Gould, Peter S. Onuf, eds. Empire and Nation: The American Revolution in the Atlantic World (2005)
The "new social history" approach looks at community social structure to find cleavages that were magnified into colonial cleavages.
The ideological approach that centers on republicanism in the United States. Republicanism dictated there would be no royalty, aristocracy or national church but allowed for continuation of the British common law, which American lawyers and jurists understood and approved and used in their everyday practice. Historians have examined how the rising American legal profession adopted British common law to incorporate republicanism by selective revision of legal customs and by introducing more choices for courts.Ellen Holmes Pearson. "Revising Custom, Embracing Choice: Early American Legal Scholars and the Republicanization of the Common Law", in Gould and Onuf, eds. Empire and Nation: The American Revolution in the Atlantic World (2005) pp. 93–113Anton-Hermann Chroust, Rise of the Legal Profession in America (1965) vol. 2. |
American Revolutionary War | Revolutionary War commemoration stamps | Revolutionary War commemoration stamps
After the first U.S. postage stamp was issued in 1849, the U.S. Postal Service frequently issued commemorative stamps celebrating people and events of the Revolutionary War. The first such stamp was the Liberty Bell issue of 1926. |
American Revolutionary War | See also | See also
1776 in the United States: events, births, deaths, and other years
Timeline of the American Revolution |
American Revolutionary War | Topics of the Revolution | Topics of the Revolution
Committee of safety (American Revolution)
Diplomacy in the American Revolutionary War
Financial costs of the American Revolutionary War
Flags of the American Revolution
Naval operations in the American Revolutionary War |
American Revolutionary War | Social history of the Revolution | Social history of the Revolution
Black Patriot
Christianity in the United States#American Revolution
The Colored Patriots of the American Revolution
History of Poles in the United States#American Revolution
List of clergy in the American Revolution
List of Patriots (American Revolution)
Quakers in the American Revolution
Scotch-Irish Americans#American Revolution |
American Revolutionary War | Others in the American Revolution | Others in the American Revolution
Nova Scotia in the American Revolution
Watauga Association |
American Revolutionary War | Lists of Revolutionary military | Lists of Revolutionary military
List of American Revolutionary War battles
List of British Forces in the American Revolutionary War
List of Continental Forces in the American Revolutionary War
List of infantry weapons in the American Revolution
List of United States militia units in the American Revolutionary War |
American Revolutionary War | Legacy and related | Legacy and related
American Revolution Statuary
Commemoration of the American Revolution
Founders Online
Independence Day (United States)
The Last Men of the Revolution
List of plays and films about the American Revolution
Museum of the American Revolution
Tomb of the Unknown Soldier of the American Revolution
List of wars of independence
Bibliography of the American Revolutionary War |
American Revolutionary War | Notes | Notes |
American Revolutionary War | Citations | Citations
Year dates enclosed in [brackets] denote year of original printing |
American Revolutionary War | Bibliography | Bibliography
Britannica.com
Dictionary of American Biography
Encyclopædia Britannica
, p. 73
– Highly regarded examination of British strategy and leadership. An introduction by John W. Shy with his biographical sketch of Mackesy.
Robinson Library
(See also:British Warships in the Age of Sail)
Canada's Digital Collections Program
History.org
Maryland State House
The History Place
Totallyhistory.com
U.S. Merchant Marine
U.S. National Archives
Valley Forge National Historic Park
Yale Law School, Massachusetts Act |
American Revolutionary War | Further reading | Further reading
Allison, David, and Larrie D. Ferreiro, eds. The American Revolution: A World War (Smithsonian, 2018) excerpt
Bobrick, Benson. Angel in the Whirlwind: The Triumph of the American Revolution. Penguin, 1998 (paperback reprint)
Brands, H. W. Our First Civil War: Patriots and Loyalists in the American Revolution. New York: Anchor Books 2022.
Chartrand, Rene. The French Army in the American War of Independence (1994). Short (48 pp), very well illustrated descriptions.
Commager, Henry Steele and Richard B. Morris, eds. The Spirit of 'Seventy-Six': The Story of the American Revolution as told by Participants. (Indianapolis: Bobbs-Merrill, 1958). online
Foner, Eric, "Whose Revolution?: The history of the United States' founding from below" (review of Woody Holton, Liberty Is Sweet: The Hidden History of the American Revolution, Simon & Schuster, 2021, 800 pp.), The Nation, vol. 314, no. 8 (18–25 April 2022), pp. 32–37. Highlighted are the struggles and tragic fates of America's Indians and Black slaves. For example, "In 1779 [George] Washington dispatched a contingent of soldiers to upstate New York to burn Indian towns and crops and seize hostages 'of every age and sex.' The following year, while serving as governor of Virginia, [Thomas] Jefferson ordered troops under the command of George Rogers Clark to enter the Ohio Valley and bring about the expulsion or 'extermination' of local Indians." (pp. 34–35.)
Kwasny, Mark V. Washington's Partisan War, 1775–1783. Kent, Ohio: 1996. . Militia warfare.
Library of Congress
May, Robin. The British Army in North America 1775–1783 (1993). Short (48pp), very well illustrated descriptions.
Neimeyer, Charles Patrick. America Goes to War: A Social History of the Continental Army (1995)
Royal Navy Museum
Stoker, Donald, Kenneth J. Hagan, and Michael T. McMaster, eds. Strategy in the American War of Independence: a global approach (Routledge, 2009) excerpt.
Symonds, Craig L. A Battlefield Atlas of the American Revolution (1989), newly drawn maps emphasizing the movement of military units
U.S. Army, "The Winning of Independence, 1777–1783" American Military History Volume I, 2005.
U.S. National Park Service
}
Zlatich, Marko; Copeland, Peter. General Washington's Army (1): 1775–78 (1994). Short (48pp), very well illustrated descriptions.
——. General Washington's Army (2): 1779–83 (1994). Short (48pp), very well illustrated descriptions. |
American Revolutionary War | External links | External links
"The American Revolutionary War" at United States Military Academy. .
Library of Congress Guide to the American Revolution
Bibliographies of the War of American Independence compiled by the United States Army Center of Military History (archived)
Category:Conflicts in 1775
Category:Conflicts in 1776
Category:Conflicts in 1777
Category:Conflicts in 1778
Category:Conflicts in 1779
Category:Conflicts in 1780
Category:Conflicts in 1781
Category:Conflicts in 1782
Category:Conflicts in 1783
Category:Civil wars in the United States
Category:Rebellions against the British Empire
Category:Wars between the United Kingdom and the United States
Category:Wars of independence |
American Revolutionary War | Table of Content | Short description, Prelude to war, Taxation and legislation, Break with the British Crown, Political reactions, Declaration of Independence, War breaks out, Early engagements, British New York counter-offensive, Patriot resurgence, British northern strategy fails, Foreign intervention, Stalemate in the North, War in the South, Western campaign, British defeat, Strategy and commanders, American strategy, Continental Army, Continental Navy, France, British strategy, British Army, German troops, Revolution as civil war, Loyalists, Women, African Americans, Native Americans, Peace negotiations, Aftermath, Territory, Casualties and losses, Legacy, Historiography, Revolutionary War commemoration stamps, See also, Topics of the Revolution, Social history of the Revolution, Others in the American Revolution, Lists of Revolutionary military, Legacy and related, Notes, Citations, Bibliography, Further reading, External links |
Ampere | Short description | The ampere ( , ; symbol: A), often shortened to amp,SI supports only the use of symbols and deprecates the use of abbreviations for units. is the unit of electric current in the International System of Units (SI). One ampere is equal to 1 coulomb (C) moving past a point per second. It is named after French mathematician and physicist André-Marie Ampère (1775–1836), considered the father of electromagnetism along with Danish physicist Hans Christian Ørsted.
As of the 2019 revision of the SI, the ampere is defined by fixing the elementary charge to be exactly , which means an ampere is an electric current equivalent to elementary charges moving every seconds or elementary charges moving in a second. Prior to the redefinition the ampere was defined as the current passing through two parallel wires 1 metre apart that produces a magnetic force of newtons per metre.
The earlier CGS system has two units of current, one structured similarly to the SI's and the other using Coulomb's law as a fundamental relationship, with the CGS unit of charge defined by measuring the force between two charged metal plates. The CGS unit of current is then defined as one unit of charge per second. |
Ampere | History | History
The ampere is named for French physicist and mathematician André-Marie Ampère (1775–1836), who studied electromagnetism and laid the foundation of electrodynamics. In recognition of Ampère's contributions to the creation of modern electrical science, an international convention, signed at the 1881 International Exposition of Electricity, established the ampere as a standard unit of electrical measurement for electric current.
The ampere was originally defined as one tenth of the unit of electric current in the centimetre–gram–second system of units. That unit, now known as the abampere, was defined as the amount of current that generates a force of two dynes per centimetre of length between two wires one centimetre apart. The size of the unit was chosen so that the units derived from it in the MKSA system would be conveniently sized.
The "international ampere" was an early realization of the ampere, defined as the current that would deposit of silver per second from a silver nitrate solution. Later, more accurate measurements revealed that this current is .
Since power is defined as the product of current and voltage, the ampere can alternatively be expressed in terms of the other units using the relationship , and thus 1 A = 1 W/V. Current can be measured by a multimeter, a device that can measure electrical voltage, current, and resistance. |
Ampere | Former definition in the SI | Former definition in the SI
Until 2019, the SI defined the ampere as follows:
The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed one metre apart in vacuum, would produce between these conductors a force equal to newtons per metre of length.
Ampère's force law states that there is an attractive or repulsive force between two parallel wires carrying an electric current. This force is used in the formal definition of the ampere.
The SI unit of charge, the coulomb, was then defined as "the quantity of electricity carried in 1 second by a current of 1 ampere". Conversely, a current of one ampere is one coulomb of charge going past a given point per second:
In general, charge was determined by steady current flowing for a time as .
This definition of the ampere was most accurately realised using a Kibble balance, but in practice the unit was maintained via Ohm's law from the units of electromotive force and resistance, the volt and the ohm, since the latter two could be tied to physical phenomena that are relatively easy to reproduce, the Josephson effect and the quantum Hall effect, respectively.
Techniques to establish the realisation of an ampere had a relative uncertainty of approximately a few parts in 10, and involved realisations of the watt, the ohm and the volt. |
Ampere | Present definition | Present definition
The 2019 revision of the SI defined the ampere by taking the fixed numerical value of the elementary charge to be when expressed in the unit C, which is equal to A⋅s, where the second is defined in terms of , the unperturbed ground state hyperfine transition frequency of the caesium-133 atom.
The SI unit of charge, the coulomb, "is the quantity of electricity carried in 1 second by a current of 1 ampere".. Conversely, a current of one ampere is one coulomb of charge going past a given point per second:
In general, charge is determined by steady current flowing for a time as .
Constant, instantaneous and average current are expressed in amperes (as in "the charging current is 1.2 A") and the charge accumulated (or passed through a circuit) over a period of time is expressed in coulombs (as in "the battery charge is "). The relation of the ampere (C/s) to the coulomb is the same as that of the watt (J/s) to the joule. |
Ampere | Units derived from the ampere | Units derived from the ampere
The international system of units (SI) is based on seven SI base units the second, metre, kilogram, kelvin, ampere, mole, and candela representing seven fundamental types of physical quantity, or "dimensions", (time, length, mass, temperature, electric current, amount of substance, and luminous intensity respectively) with all other SI units being defined using these. These SI derived units can either be given special names e.g. watt, volt, lux, etc. or defined in terms of others, e.g. metre per second. The units with special names derived from the ampere are:
Quantity Unit Symbol Meaning In SI base units Electric charge coulomb C ampere second A⋅s Electric potential difference volt V joule per coulomb kg⋅m2⋅s−3⋅A−1 Electrical resistance ohm Ω volt per ampere kg⋅m2⋅s−3⋅A−2 Electrical conductance siemens S ampere per volt or inverse ohm s3⋅A2⋅kg−1⋅m−2 Electrical inductance henry H ohm second kg⋅m2⋅s−2⋅A−2 Electrical capacitance farad F coulomb per volt s4⋅A2⋅kg−1⋅m−2 Magnetic flux weber Wb volt second kg⋅m2⋅s−2⋅A−1 Magnetic flux density tesla T weber per square metre kg⋅s−2⋅A−1
There are also some SI units that are frequently used in the context of electrical engineering and electrical appliances, but are defined independently of the ampere, notably the hertz, joule, watt, candela, lumen, and lux. |
Ampere | SI prefixes | SI prefixes
Like other SI units, the ampere can be modified by adding a prefix that multiplies it by a power of 10. |
Ampere | See also | See also
|
Ampere | References | References |
Ampere | External links | External links
The NIST Reference on Constants, Units, and Uncertainty
NIST Definition of ampere and μ0
Category:SI base units
Category:Units of electric current |
Ampere | Table of Content | Short description, History, Former definition in the SI, Present definition, Units derived from the ampere, SI prefixes, See also, References, External links |
Algorithm | Short description | thumb|Flowchart of using successive subtractions to find the greatest common divisor of number r and s|alt=In a loop, subtract the larger number against the smaller number. Halt the loop when the subtraction will make a number negative. Assess two numbers, whether one of them is equal to zero or not. If yes, take the other number as the greatest common divisor. If no, put the two numbers in the subtraction loop again.
In mathematics and computer science, an algorithm () is a finite sequence of mathematically rigorous instructions, typically used to solve a class of specific problems or to perform a computation. Algorithms are used as specifications for performing calculations and data processing. More advanced algorithms can use conditionals to divert the code execution through various routes (referred to as automated decision-making) and deduce valid inferences (referred to as automated reasoning).
In contrast, a heuristic is an approach to solving problems without well-defined correct or optimal results.David A. Grossman, Ophir Frieder, Information Retrieval: Algorithms and Heuristics, 2nd edition, 2004, For example, although social media recommender systems are commonly called "algorithms", they actually rely on heuristics as there is no truly "correct" recommendation.
As an effective method, an algorithm can be expressed within a finite amount of space and time"Any classical mathematical algorithm, for example, can be described in a finite number of English words" (Rogers 1987:2). and in a well-defined formal languageWell defined concerning the agent that executes the algorithm: "There is a computing agent, usually human, which can react to the instructions and carry out the computations" (Rogers 1987:2). for calculating a function."an algorithm is a procedure for computing a function (concerning some chosen notation for integers) ... this limitation (to numerical functions) results in no loss of generality", (Rogers 1987:1). Starting from an initial state and initial input (perhaps empty),"An algorithm has zero or more inputs, i.e., quantities which are given to it initially before the algorithm begins" (Knuth 1973:5). the instructions describe a computation that, when executed, proceeds through a finite"A procedure which has all the characteristics of an algorithm except that it possibly lacks finiteness may be called a 'computational method (Knuth 1973:5). number of well-defined successive states, eventually producing "output""An algorithm has one or more outputs, i.e., quantities which have a specified relation to the inputs" (Knuth 1973:5). and terminating at a final ending state. The transition from one state to the next is not necessarily deterministic; some algorithms, known as randomized algorithms, incorporate random input.Whether or not a process with random interior processes (not including the input) is an algorithm is debatable. Rogers opines that: "a computation is carried out in a discrete stepwise fashion, without the use of continuous methods or analog devices ... carried forward deterministically, without resort to random methods or devices, e.g., dice" (Rogers 1987:2). |
Algorithm | Etymology | Etymology
Around 825 AD, Persian scientist and polymath Muḥammad ibn Mūsā al-Khwārizmī wrote kitāb al-ḥisāb al-hindī ("Book of Indian computation") and kitab al-jam' wa'l-tafriq al-ḥisāb al-hindī ("Addition and subtraction in Indian arithmetic"). In the early 12th century, Latin translations of these texts involving the Hindu–Arabic numeral system and arithmetic appeared, for example Liber Alghoarismi de practica arismetrice, attributed to John of Seville, and Liber Algorismi de numero Indorum, attributed to Adelard of Bath.Blair, Ann, Duguid, Paul, Goeing, Anja-Silvia and Grafton, Anthony. Information: A Historical Companion, Princeton: Princeton University Press, 2021. p. 247 Here, alghoarismi or algorismi is the Latinization of Al-Khwarizmi's name; the text starts with the phrase Dixit Algorismi, or "Thus spoke Al-Khwarizmi".
The word algorism in English came to mean the use of place-value notation in calculations; it occurs in the Ancrene Wisse from circa 1225. By the time Geoffrey Chaucer wrote The Canterbury Tales in the late 14th century, he used a variant of the same word in describing augrym stones, stones used for place-value calculation. In the 15th century, under the influence of the Greek word ἀριθμός (arithmos, "number"; cf. "arithmetic"), the Latin word was altered to algorithmus. By 1596, this form of the word was used in English, as algorithm, by Thomas Hood. |
Algorithm | Definition | Definition
One informal definition is "a set of rules that precisely defines a sequence of operations", which would include all computer programs (including programs that do not perform numeric calculations), and any prescribed bureaucratic procedure
or cook-book recipe. In general, a program is an algorithm only if it stops eventuallyStone requires that "it must terminate in a finite number of steps" (Stone 1973:7–8).—even though infinite loops may sometimes prove desirable. define an algorithm to be an explicit set of instructions for determining an output, that can be followed by a computing machine or a human who could only carry out specific elementary operations on symbols.Boolos and Jeffrey 1974, 1999:19
Most algorithms are intended to be implemented as computer programs. However, algorithms are also implemented by other means, such as in a biological neural network (for example, the human brain performing arithmetic or an insect looking for food), in an electrical circuit, or a mechanical device. |
Algorithm | History | History |
Algorithm | Ancient algorithms | Ancient algorithms
Step-by-step procedures for solving mathematical problems have been recorded since antiquity. This includes in Babylonian mathematics (around 2500 BC), Egyptian mathematics (around 1550 BC), Indian mathematics (around 800 BC and later),Hayashi, T. (2023, January 1). Brahmagupta. Encyclopedia Britannica. the Ifa Oracle (around 500 BC), Greek mathematics (around 240 BC), Chinese mathematics (around 200 BC and later), and Arabic mathematics (around 800 AD).
The earliest evidence of algorithms is found in ancient Mesopotamian mathematics. A Sumerian clay tablet found in Shuruppak near Baghdad and dated to describes the earliest division algorithm. During the Hammurabi dynasty , Babylonian clay tablets described algorithms for computing formulas. Algorithms were also used in Babylonian astronomy. Babylonian clay tablets describe and employ algorithmic procedures to compute the time and place of significant astronomical events.
Algorithms for arithmetic are also found in ancient Egyptian mathematics, dating back to the Rhind Mathematical Papyrus . Algorithms were later used in ancient Hellenistic mathematics. Two examples are the Sieve of Eratosthenes, which was described in the Introduction to Arithmetic by Nicomachus, and the Euclidean algorithm, which was first described in Euclid's Elements ().Examples of ancient Indian mathematics included the Shulba Sutras, the Kerala School, and the Brāhmasphuṭasiddhānta.
The first cryptographic algorithm for deciphering encrypted code was developed by Al-Kindi, a 9th-century Arab mathematician, in A Manuscript On Deciphering Cryptographic Messages. He gave the first description of cryptanalysis by frequency analysis, the earliest codebreaking algorithm. |
Algorithm | Computers | Computers |
Algorithm | Weight-driven clocks | Weight-driven clocks
Bolter credits the invention of the weight-driven clock as "the key invention [of Europe in the Middle Ages]," specifically the verge escapement mechanismBolter 1984:24 producing the tick and tock of a mechanical clock. "The accurate automatic machine"Bolter 1984:26 led immediately to "mechanical automata" in the 13th century and "computational machines"—the difference and analytical engines of Charles Babbage and Ada Lovelace in the mid-19th century.Bolter 1984:33–34, 204–206. Lovelace designed the first algorithm intended for processing on a computer, Babbage's analytical engine, which is the first device considered a real Turing-complete computer instead of just a calculator. Although the full implementation of Babbage's second device was not realized for decades after her lifetime, Lovelace has been called "history's first programmer". |
Algorithm | Electromechanical relay | Electromechanical relay
Bell and Newell (1971) write that the Jacquard loom, a precursor to Hollerith cards (punch cards), and "telephone switching technologies" led to the development of the first computers.Bell and Newell diagram 1971:39, cf. Davis 2000 By the mid-19th century, the telegraph, the precursor of the telephone, was in use throughout the world. By the late 19th century, the ticker tape () was in use, as were Hollerith cards (c. 1890). Then came the teleprinter () with its punched-paper use of Baudot code on tape.
Telephone-switching networks of electromechanical relays were invented in 1835. These led to the invention of the digital adding device by George Stibitz in 1937. While working in Bell Laboratories, he observed the "burdensome" use of mechanical calculators with gears. "He went home one evening in 1937 intending to test his idea... When the tinkering was over, Stibitz had constructed a binary adding device".Melina Hill, Valley News Correspondent, A Tinkerer Gets a Place in History, Valley News West Lebanon NH, Thursday, March 31, 1983, p. 13.Davis 2000:14 |
Algorithm | Formalization | Formalization
thumb|Ada Lovelace's diagram from "Note G", the first published computer algorithm
In 1928, a partial formalization of the modern concept of algorithms began with attempts to solve the Entscheidungsproblem (decision problem) posed by David Hilbert. Later formalizations were framed as attempts to define "effective calculability"Kleene 1943 in Davis 1965:274 or "effective method".Rosser 1939 in Davis 1965:225 Those formalizations included the Gödel–Herbrand–Kleene recursive functions of 1930, 1934 and 1935, Alonzo Church's lambda calculus of 1936, Emil Post's Formulation 1 of 1936, and Alan Turing's Turing machines of 1936–37 and 1939. |
Algorithm | Representations | Representations
Algorithms can be expressed in many kinds of notation, including natural languages, pseudocode, flowcharts, drakon-charts, programming languages or control tables (processed by interpreters). Natural language expressions of algorithms tend to be verbose and ambiguous and are rarely used for complex or technical algorithms. Pseudocode, flowcharts, drakon-charts, and control tables are structured expressions of algorithms that avoid common ambiguities of natural language. Programming languages are primarily for expressing algorithms in a computer-executable form but are also used to define or document algorithms. |
Algorithm | Turing machines | Turing machines
There are many possible representations and Turing machine programs can be expressed as a sequence of machine tables (see finite-state machine, state-transition table, and control table for more), as flowcharts and drakon-charts (see state diagram for more), as a form of rudimentary machine code or assembly code called "sets of quadruples", and more. Algorithm representations can also be classified into three accepted levels of Turing machine description: high-level description, implementation description, and formal description.Sipser 2006:157 A high-level description describes the qualities of the algorithm itself, ignoring how it is implemented on the Turing machine. An implementation description describes the general manner in which the machine moves its head and stores data to carry out the algorithm, but does not give exact states. In the most detail, a formal description gives the exact state table and list of transitions of the Turing machine. |
Algorithm | Flowchart representation | Flowchart representation
The graphical aid called a flowchart offers a way to describe and document an algorithm (and a computer program corresponding to it). It has four primary symbols: arrows showing program flow, rectangles (SEQUENCE, GOTO), diamonds (IF-THEN-ELSE), and dots (OR-tie). Sub-structures can "nest" in rectangles, but only if a single exit occurs from the superstructure. |
Algorithm | Algorithmic analysis | Algorithmic analysis
It is often important to know how much time, storage, or other cost an algorithm may require. Methods have been developed for the analysis of algorithms to obtain such quantitative answers (estimates); for example, an algorithm that adds up the elements of a list of n numbers would have a time requirement of , using big O notation. The algorithm only needs to remember two values: the sum of all the elements so far, and its current position in the input list. If the space required to store the input numbers is not counted, it has a space requirement of , otherwise is required.
Different algorithms may complete the same task with a different set of instructions in less or more time, space, or 'effort' than others. For example, a binary search algorithm (with cost ) outperforms a sequential search (cost ) when used for table lookups on sorted lists or arrays. |
Algorithm | Formal versus empirical | Formal versus empirical
The analysis, and study of algorithms is a discipline of computer science. Algorithms are often studied abstractly, without referencing any specific programming language or implementation. Algorithm analysis resembles other mathematical disciplines as it focuses on the algorithm's properties, not implementation. Pseudocode is typical for analysis as it is a simple and general representation. Most algorithms are implemented on particular hardware/software platforms and their algorithmic efficiency is tested using real code. The efficiency of a particular algorithm may be insignificant for many "one-off" problems but it may be critical for algorithms designed for fast interactive, commercial, or long-life scientific usage. Scaling from small n to large n frequently exposes inefficient algorithms that are otherwise benign.
Empirical testing is useful for uncovering unexpected interactions that affect performance. Benchmarks may be used to compare before/after potential improvements to an algorithm after program optimization.
Empirical tests cannot replace formal analysis, though, and are non-trivial to perform fairly. |
Algorithm | Execution efficiency | Execution efficiency
To illustrate the potential improvements possible even in well-established algorithms, a recent significant innovation, relating to FFT algorithms (used heavily in the field of image processing), can decrease processing time up to 1,000 times for applications like medical imaging. In general, speed improvements depend on special properties of the problem, which are very common in practical applications.Haitham Hassanieh, Piotr Indyk, Dina Katabi, and Eric Price, "ACM-SIAM Symposium On Discrete Algorithms (SODA) , Kyoto, January 2012. See also the sFFT Web Page . Speedups of this magnitude enable computing devices that make extensive use of image processing (like digital cameras and medical equipment) to consume less power. |
Algorithm | Design | Design
Algorithm design is a method or mathematical process for problem-solving and engineering algorithms. The design of algorithms is part of many solution theories, such as divide-and-conquer or dynamic programming within operation research. Techniques for designing and implementing algorithm designs are also called algorithm design patterns, with examples including the template method pattern and the decorator pattern. One of the most important aspects of algorithm design is resource (run-time, memory usage) efficiency; the big O notation is used to describe e.g., an algorithm's run-time growth as the size of its input increases. |
Algorithm | Structured programming | Structured programming
Per the Church–Turing thesis, any algorithm can be computed by any Turing complete model. Turing completeness only requires four instruction types—conditional GOTO, unconditional GOTO, assignment, HALT. However, Kemeny and Kurtz observe that, while "undisciplined" use of unconditional GOTOs and conditional IF-THEN GOTOs can result in "spaghetti code", a programmer can write structured programs using only these instructions; on the other hand "it is also possible, and not too hard, to write badly structured programs in a structured language".John G. Kemeny and Thomas E. Kurtz 1985 Back to Basic: The History, Corruption, and Future of the Language, Addison-Wesley Publishing Company, Inc. Reading, MA, . Tausworthe augments the three Böhm-Jacopini canonical structures:Tausworthe 1977:101 SEQUENCE, IF-THEN-ELSE, and WHILE-DO, with two more: DO-WHILE and CASE.Tausworthe 1977:142 An additional benefit of a structured program is that it lends itself to proofs of correctness using mathematical induction.Knuth 1973 section 1.2.1, expanded by Tausworthe 1977 at pages 100ff and Chapter 9.1 |
Algorithm | Legal status | Legal status
By themselves, algorithms are not usually patentable. In the United States, a claim consisting solely of simple manipulations of abstract concepts, numbers, or signals does not constitute "processes" (USPTO 2006), so algorithms are not patentable (as in Gottschalk v. Benson). However practical applications of algorithms are sometimes patentable. For example, in Diamond v. Diehr, the application of a simple feedback algorithm to aid in the curing of synthetic rubber was deemed patentable. The patenting of software is controversial, and there are criticized patents involving algorithms, especially data compression algorithms, such as Unisys's LZW patent. Additionally, some cryptographic algorithms have export restrictions (see export of cryptography). |
Algorithm | Classification | Classification |
Algorithm | By implementation | By implementation
Recursion
A recursive algorithm invokes itself repeatedly until meeting a termination condition and is a common functional programming method. Iterative algorithms use repetitions such as loops or data structures like stacks to solve problems. Problems may be suited for one implementation or the other. The Tower of Hanoi is a puzzle commonly solved using recursive implementation. Every recursive version has an equivalent (but possibly more or less complex) iterative version, and vice versa.
Serial, parallel or distributed
Algorithms are usually discussed with the assumption that computers execute one instruction of an algorithm at a time on serial computers. Serial algorithms are designed for these environments, unlike parallel or distributed algorithms. Parallel algorithms take advantage of computer architectures where multiple processors can work on a problem at the same time. Distributed algorithms use multiple machines connected via a computer network. Parallel and distributed algorithms divide the problem into subproblems and collect the results back together. Resource consumption in these algorithms is not only processor cycles on each processor but also the communication overhead between the processors. Some sorting algorithms can be parallelized efficiently, but their communication overhead is expensive. Iterative algorithms are generally parallelizable, but some problems have no parallel algorithms and are called inherently serial problems.
Deterministic or non-deterministic
Deterministic algorithms solve the problem with exact decisions at every step; whereas non-deterministic algorithms solve problems via guessing. Guesses are typically made more accurate through the use of heuristics.
Exact or approximate
While many algorithms reach an exact solution, approximation algorithms seek an approximation that is close to the true solution. Such algorithms have practical value for many hard problems. For example, the Knapsack problem, where there is a set of items, and the goal is to pack the knapsack to get the maximum total value. Each item has some weight and some value. The total weight that can be carried is no more than some fixed number X. So, the solution must consider the weights of items as well as their value.
Quantum algorithm
Quantum algorithms run on a realistic model of quantum computation. The term is usually used for those algorithms that seem inherently quantum or use some essential feature of Quantum computing such as quantum superposition or quantum entanglement. |
Algorithm | By design paradigm | By design paradigm
Another way of classifying algorithms is by their design methodology or paradigm. Some common paradigms are:
Brute-force or exhaustive search
Brute force is a problem-solving method of systematically trying every possible option until the optimal solution is found. This approach can be very time-consuming, testing every possible combination of variables. It is often used when other methods are unavailable or too complex. Brute force can solve a variety of problems, including finding the shortest path between two points and cracking passwords.
Divide and conquer
A divide-and-conquer algorithm repeatedly reduces a problem to one or more smaller instances of itself (usually recursively) until the instances are small enough to solve easily. Merge sorting is an example of divide and conquer, where an unordered list is repeatedly split into smaller lists, which are sorted in the same way and then merged. In a simpler variant of divide and conquer called prune and search or decrease-and-conquer algorithm, which solves one smaller instance of itself, and does not require a merge step. An example of a prune and search algorithm is the binary search algorithm.
Search and enumeration
Many problems (such as playing chess) can be modelled as problems on graphs. A graph exploration algorithm specifies rules for moving around a graph and is useful for such problems. This category also includes search algorithms, branch and bound enumeration, and backtracking.
Randomized algorithm
Such algorithms make some choices randomly (or pseudo-randomly). They find approximate solutions when finding exact solutions may be impractical (see heuristic method below). For some problems, the fastest approximations must involve some randomness.For instance, the volume of a convex polytope (described using a membership oracle) can be approximated to high accuracy by a randomized polynomial time algorithm, but not by a deterministic one: see Whether randomized algorithms with polynomial time complexity can be the fastest algorithm for some problems is an open question known as the P versus NP problem. There are two large classes of such algorithms:
Monte Carlo algorithms return a correct answer with high probability. E.g. RP is the subclass of these that run in polynomial time.
Las Vegas algorithms always return the correct answer, but their running time is only probabilistically bound, e.g. ZPP.
Reduction of complexity
This technique transforms difficult problems into better-known problems solvable with (hopefully) asymptotically optimal algorithms. The goal is to find a reducing algorithm whose complexity is not dominated by the resulting reduced algorithms. For example, one selection algorithm finds the median of an unsorted list by first sorting the list (the expensive portion), and then pulling out the middle element in the sorted list (the cheap portion). This technique is also known as transform and conquer.
Back tracking
In this approach, multiple solutions are built incrementally and abandoned when it is determined that they cannot lead to a valid full solution. |
Algorithm | Optimization problems | Optimization problems
For optimization problems there is a more specific classification of algorithms; an algorithm for such problems may fall into one or more of the general categories described above as well as into one of the following:
Linear programming
When searching for optimal solutions to a linear function bound by linear equality and inequality constraints, the constraints can be used directly to produce optimal solutions. There are algorithms that can solve any problem in this category, such as the popular simplex algorithm.George B. Dantzig and Mukund N. Thapa. 2003. Linear Programming 2: Theory and Extensions. Springer-Verlag. Problems that can be solved with linear programming include the maximum flow problem for directed graphs. If a problem also requires that any of the unknowns be integers, then it is classified in integer programming. A linear programming algorithm can solve such a problem if it can be proved that all restrictions for integer values are superficial, i.e., the solutions satisfy these restrictions anyway. In the general case, a specialized algorithm or an algorithm that finds approximate solutions is used, depending on the difficulty of the problem.
Dynamic programming
When a problem shows optimal substructures—meaning the optimal solution can be constructed from optimal solutions to subproblems—and overlapping subproblems, meaning the same subproblems are used to solve many different problem instances, a quicker approach called dynamic programming avoids recomputing solutions. For example, Floyd–Warshall algorithm, the shortest path between a start and goal vertex in a weighted graph can be found using the shortest path to the goal from all adjacent vertices. Dynamic programming and memoization go together. Unlike divide and conquer, dynamic programming subproblems often overlap. The difference between dynamic programming and simple recursion is the caching or memoization of recursive calls. When subproblems are independent and do not repeat, memoization does not help; hence dynamic programming is not applicable to all complex problems. Using memoization dynamic programming reduces the complexity of many problems from exponential to polynomial.
The greedy method
Greedy algorithms, similarly to a dynamic programming, work by examining substructures, in this case not of the problem but of a given solution. Such algorithms start with some solution and improve it by making small modifications. For some problems, they always find the optimal solution but for others they may stop at local optima. The most popular use of greedy algorithms is finding minimal spanning trees of graphs without negative cycles. Huffman Tree, Kruskal, Prim, Sollin are greedy algorithms that can solve this optimization problem.
The heuristic method
In optimization problems, heuristic algorithms find solutions close to the optimal solution when finding the optimal solution is impractical. These algorithms get closer and closer to the optimal solution as they progress. In principle, if run for an infinite amount of time, they will find the optimal solution. They can ideally find a solution very close to the optimal solution in a relatively short time. These algorithms include local search, tabu search, simulated annealing, and genetic algorithms. Some, like simulated annealing, are non-deterministic algorithms while others, like tabu search, are deterministic. When a bound on the error of the non-optimal solution is known, the algorithm is further categorized as an approximation algorithm. |
Algorithm | Examples | Examples
One of the simplest algorithms finds the largest number in a list of numbers of random order. Finding the solution requires looking at every number in the list. From this follows a simple algorithm, which can be described in plain English as:
High-level description:
If a set of numbers is empty, then there is no highest number.
Assume the first number in the set is the largest.
For each remaining number in the set: if this number is greater than the current largest, it becomes the new largest.
When there are no unchecked numbers left in the set, consider the current largest number to be the largest in the set.
(Quasi-)formal description:
Written in prose but much closer to the high-level language of a computer program, the following is the more formal coding of the algorithm in pseudocode or pidgin code:
Input: A list of numbers L.
Output: The largest number in the list L.
if L.size = 0 return null
largest ← L[0]
for each item in L, do
if item > largest, then
largest ← item
return largest |
Algorithm | See also | See also
Abstract machine
ALGOL
Algorithm aversion
Algorithm engineering
Algorithm characterizations
Algorithmic bias
Algorithmic composition
Algorithmic entities
Algorithmic synthesis
Algorithmic technique
Algorithmic topology
Computational mathematics
Garbage in, garbage out
Introduction to Algorithms (textbook)
Government by algorithm
List of algorithms
List of algorithm general topics
Medium is the message
Regulation of algorithms
Theory of computation
Computability theory
Computational complexity theory |
Algorithm | Notes | Notes |
Algorithm | Bibliography | Bibliography
Bell, C. Gordon and Newell, Allen (1971), Computer Structures: Readings and Examples, McGraw–Hill Book Company, New York. .
Includes a bibliography of 56 references.
,
: cf. Chapter 3 Turing machines where they discuss "certain enumerable sets not effectively (mechanically) enumerable".
Campagnolo, M.L., Moore, C., and Costa, J.F. (2000) An analog characterization of the subrecursive functions. In Proc. of the 4th Conference on Real Numbers and Computers, Odense University, pp. 91–109
Reprinted in The Undecidable, p. 89ff. The first expression of "Church's Thesis". See in particular page 100 (The Undecidable) where he defines the notion of "effective calculability" in terms of "an algorithm", and he uses the word "terminates", etc.
Reprinted in The Undecidable, p. 110ff. Church shows that the Entscheidungsproblem is unsolvable in about 3 pages of text and 3 pages of footnotes.
Davis gives commentary before each article. Papers of Gödel, Alonzo Church, Turing, Rosser, Kleene, and Emil Post are included; those cited in the article are listed here by author's name.
Davis offers concise biographies of Leibniz, Boole, Frege, Cantor, Hilbert, Gödel and Turing with von Neumann as the show-stealing villain. Very brief bios of Joseph-Marie Jacquard, Babbage, Ada Lovelace, Claude Shannon, Howard Aiken, etc.
,
Yuri Gurevich, Sequential Abstract State Machines Capture Sequential Algorithms, ACM Transactions on Computational Logic, Vol 1, no 1 (July 2000), pp. 77–111. Includes bibliography of 33 sources.
, 3rd edition 1976[?], (pbk.)
, . Cf. Chapter "The Spirit of Truth" for a history leading to, and a discussion of, his proof.
Presented to the American Mathematical Society, September 1935. Reprinted in The Undecidable, p. 237ff. Kleene's definition of "general recursion" (known now as mu-recursion) was used by Church in his 1935 paper An Unsolvable Problem of Elementary Number Theory that proved the "decision problem" to be "undecidable" (i.e., a negative result).
Reprinted in The Undecidable, p. 255ff. Kleene refined his definition of "general recursion" and proceeded in his chapter "12. Algorithmic theories" to posit "Thesis I" (p. 274); he would later repeat this thesis (in Kleene 1952:300) and name it "Church's Thesis"(Kleene 1952:317) (i.e., the Church thesis).
Kosovsky, N.K. Elements of Mathematical Logic and its Application to the theory of Subrecursive Algorithms, LSU Publ., Leningrad, 1981
A.A. Markov (1954) Theory of algorithms. [Translated by Jacques J. Schorr-Kon and PST staff] Imprint Moscow, Academy of Sciences of the USSR, 1954 [i.e., Jerusalem, Israel Program for Scientific Translations, 1961; available from the Office of Technical Services, U.S. Dept. of Commerce, Washington] Description 444 p. 28 cm. Added t.p. in Russian Translation of Works of the Mathematical Institute, Academy of Sciences of the USSR, v. 42. Original title: Teoriya algerifmov. [QA248.M2943 Dartmouth College library. U.S. Dept. of Commerce, Office of Technical Services, number OTS .]
Minsky expands his "...idea of an algorithm – an effective procedure..." in chapter 5.1 Computability, Effective Procedures and Algorithms. Infinite machines.
Reprinted in The Undecidable, pp. 289ff. Post defines a simple algorithmic-like process of a man writing marks or erasing marks and going from box to box and eventually halting, as he follows a list of simple instructions. This is cited by Kleene as one source of his "Thesis I", the so-called Church–Turing thesis.
Reprinted in The Undecidable, p. 223ff. Herein is Rosser's famous definition of "effective method": "...a method each step of which is precisely predetermined and which is certain to produce the answer in a finite number of steps... a machine which will then solve any problem of the set with no human intervention beyond inserting the question and (later) reading the answer" (p. 225–226, The Undecidable)
Cf. in particular the first chapter titled: Algorithms, Turing Machines, and Programs. His succinct informal definition: "...any sequence of instructions that can be obeyed by a robot, is called an algorithm" (p. 4).
. Corrections, ibid, vol. 43(1937) pp. 544–546. Reprinted in The Undecidable, p. 116ff. Turing's famous paper completed as a Master's dissertation while at King's College Cambridge UK.
Reprinted in The Undecidable, pp. 155ff. Turing's paper that defined "the oracle" was his PhD thesis while at Princeton.
United States Patent and Trademark Office (2006), 2106.02 **>Mathematical Algorithms: 2100 Patentability, Manual of Patent Examining Procedure (MPEP). Latest revision August 2006
Zaslavsky, C. (1970). Mathematics of the Yoruba People and of Their Neighbors in Southern Nigeria. The Two-Year College Mathematics Journal, 1(2), 76–99. https://doi.org/10.2307/3027363 |
Algorithm | Further reading | Further reading
Jon Kleinberg, Éva Tardos(2006): Algorithm Design, Pearson/Addison-Wesley, ISBN 978-0-32129535-4
Knuth, Donald E. (2000). Selected Papers on Analysis of Algorithms . Stanford, California: Center for the Study of Language and Information.
Knuth, Donald E. (2010). Selected Papers on Design of Algorithms . Stanford, California: Center for the Study of Language and Information.
|
Algorithm | External links | External links
Dictionary of Algorithms and Data Structures – National Institute of Standards and Technology
Algorithm repositories
The Stony Brook Algorithm Repository – State University of New York at Stony Brook
Collected Algorithms of the ACM – Associations for Computing Machinery
The Stanford GraphBase – Stanford University
Category:Articles with example pseudocode
Category:Mathematical logic
Category:Theoretical computer science |
Algorithm | Table of Content | Short description, Etymology, Definition, History, Ancient algorithms, Computers, Weight-driven clocks, Electromechanical relay, Formalization, Representations, Turing machines, Flowchart representation, Algorithmic analysis, Formal versus empirical, Execution efficiency, Design, Structured programming, Legal status, Classification, By implementation, By design paradigm, Optimization problems, Examples, See also, Notes, Bibliography, Further reading, External links |
Annual plant | short description |
right|thumb|240px|Peas are an annual plant.
An annual plant is a plant that completes its life cycle, from germination to the production of seeds, within one growing season, and then dies. Globally, 6% of all plant species and 15% of herbaceous plants (excluding trees and shrubs) are annuals. The annual life cycle has independently emerged in over 120 different plant families throughout the entire angiosperm phylogeny. |
Annual plant | The evolutionary and ecological drivers of the annual life cycle | The evolutionary and ecological drivers of the annual life cycle
Traditionally, there has been a prevailing assumption that annuals have evolved from perennial ancestors. However, recent research challenges this notion, revealing instances where perennials have evolved from annual ancestors. Intriguingly, models propose that transition rates from an annual to a perennial life cycle are twice as fast as the reverse transition.
The life-history theory posits that annual plants are favored when adult mortality is higher than seedling (or seed) mortality, i.e., annuals will dominate environments with disturbances or high temporal variability, reducing adult survival. This hypothesis finds support in observations of increased prevalence of annuals in regions with hot-dry summers, with elevated adult mortality and high seed persistence. Furthermore, the evolution of the annual life cycle under hot-dry summer in different families makes it one of the best examples of convergent evolution. Additionally, annual prevalence is also positively affected by year-to-year variability.
Globally, the prevalence of annual plants shows an upward trend with an increasing human footprint. Moreover, domestic grazing has been identified as contributing to the heightened abundance of annuals in grasslands. Disturbances linked to activities like grazing and agriculture, particularly following European settlement, have facilitated the invasion of annual species from Europe and Asia into the New World.
In various ecosystems, the dominance of annual plants is often a temporary phase during secondary succession, particularly in the aftermath of disturbances. For instance, after fields are abandoned, annuals may initially colonize them but are eventually replaced by long-lived species. However, in certain Mediterranean systems, a unique scenario unfolds: when annuals establish dominance, perennials do not necessarily supplant them. This peculiarity is attributed to alternative stable states in the system—both annual dominance and perennial states prove stable, with the ultimate system state dependent on the initial conditions. |
Annual plant | Traits of annuals and their implication for agriculture | Traits of annuals and their implication for agriculture
Annual plants commonly exhibit a higher growth rate, allocate more resources to seeds, and allocate fewer resources to roots than perennials. In contrast to perennials, which feature long-lived plants and short-lived seeds, annual plants compensate for their lower longevity by maintaining a higher persistence of soil seed banks. These differences in life history strategies profoundly affect ecosystem functioning and services. For instance, annuals, by allocating less resources belowground, play a more minor role in reducing erosion, storing organic carbon, and achieving lower nutrient- and water-use efficiencies than perennials.
The distinctions between annual and perennial plants are notably evident in agricultural contexts. Despite constituting a minor part of global biomass, annual species stand out as the primary food source for humankind, likely owing to their greater allocation of resources to seed production, thereby enhancing agricultural productivity. In the Anthropocene epoch, marked by human impact on the environment, there has been a substantial increase in the global cover of annuals. This shift is primarily attributed to the conversion of natural systems, often dominated by perennials, into annual cropland. Currently, annual plants cover approximately 70% of croplands and contribute to around 80% of worldwide food consumption. |
Annual plant | Molecular genetics | Molecular genetics
In 2008, it was discovered that the inactivation of only two genes in one species of annual plant leads to its conversion into a perennial plant. Researchers deactivated the SOC1 and FUL genes (which control flowering time) of Arabidopsis thaliana. This switch established phenotypes common in perennial plants, such as wood formation. |
Annual plant | See also | See also
- Plant that flowers & sets seeds once, then dies.
Ephemeral plant |
Annual plant | References | References |
Annual plant | External links | External links
|
Annual plant | Table of Content | short description, The evolutionary and ecological drivers of the annual life cycle, Traits of annuals and their implication for agriculture, Molecular genetics, See also, References, External links |
Anthophyta | short description | The anthophytes are a paraphyletic grouping of plant taxa bearing flower-like reproductive structures. The group, once thought to be a clade, contained the angiosperms – the extant flowering plants, such as roses and grasses – as well as the Gnetales and the extinct Bennettitales.
Detailed morphological and molecular studies have shown that the group is not actually monophyletic, with proposed floral homologies of the gnetophytes and the angiosperms having evolved in parallel. This makes it easier to reconcile molecular clock data that suggests that the angiosperms diverged from the gymnosperms around 320-300 mya.
Some more recent studies have used the word anthophyte to describe a hypothetical group which includes the angiosperms and a variety of extinct seed plant groups (with various suggestions including at least some of the following groups: glossopterids, corystosperms, Petriellales Pentoxylales, Bennettitales and Caytoniales), but not the Gnetales. |
Anthophyta | References | References
Category:Historically recognized plant taxa |
Anthophyta | Table of Content | short description, References |
Atlas (disambiguation) | Wiktionary | An atlas is a collection of maps.
Atlas may also refer to: |
Atlas (disambiguation) | Arts, entertainment and media | Arts, entertainment and media |
Atlas (disambiguation) | Fictional characters | Fictional characters
Atlas (DC Comics), several fictional characters
Atlas (Teen Titans)
Atlas, an Astro Boy (1980) character
Atlas (BioShock)
Atlas, a BattleMech in the BattleTech universe
Atlas, an antagonist in Mega Man ZX Advent
Atlas, a Portal 2 character
Atlas, a PS238 character
Erik Josten, a.k.a. Atlas, a Marvel Comics supervillain
The Atlas, a strong driving force from No Man's Sky |
Atlas (disambiguation) | Literature | Literature
Atlas, a photography book by Gerhard Richter
The Atlas (novel), by William T. Vollmann
Atlas (magazine)
The Atlas (newspaper), published in England from 1826 to 1869 |
Atlas (disambiguation) | Music | Music |
Atlas (disambiguation) | Bands | Bands
Atlas (band), a New Zealand rock band |
Atlas (disambiguation) | Albums | Albums
Atlas (Kinky album)
Atlas (Laurel Halo album)
Atlas (Parkway Drive album)
Atlas (Real Estate album)
Atlas (RÜFÜS album)
Atlas (The Score album) |
Atlas (disambiguation) | Opera | Opera
Atlas (opera), 1991, by Meredith Monk
Atlas: An Opera in Three Parts, a 1993 recording of Monk's opera |
Atlas (disambiguation) | Songs | Songs
"Atlas" (Battles song), 2007
"Atlas" (Bicep song), 2020
"Atlas" (Coldplay song), 2013
"Atlas", by Delphic
"Atlas", from the album The Tide, the Thief & River's End by Caligula's Horse
"Atlas", by Parkway Drive
"Atlas", from Man Overboard by Man Overboard
"Atlas", by Jake Chudnow, used as the main theme in the YouTube series Mind Field
“Atlas”, by Coheed and Cambria
“Atlas”, by Good Kid |
Atlas (disambiguation) | Gaming | Gaming
The Atlas (video game), a 1991 multiplatform strategy video game
Atlas (video game), a massively-multiplayer online video game released for early access in 2018
Atlas Corporation, an arms manufacturer in the video game series Borderlands
Atlas Corporation, a private military company in the video game Call of Duty: Advanced Warfare |
Atlas (disambiguation) | Other uses in arts, entertainment and media | Other uses in arts, entertainment and media
Atlas (1961 film), an action-adventure film
Atlas (2024 film), an American science fiction thriller film
Atlas (comic book series), by Dylan Horrocks
Atlas (statue), a statue by Lee Lawrie in Rockefeller Center |
Atlas (disambiguation) | Businesses and organizations | Businesses and organizations
Atlas Air, an American cargo airline
Atlas Aircraft, a 1940s aircraft manufacturer
Atlas Aviation, an aircraft maintenance firm
Atlas Blue, a Moroccan low-cost airline
Atlas (appliance company), in Belarus
Atlas Car and Manufacturing Company, a locomotive manufacturer
Atlas Comics (1950s), a publisher
Atlas/Seaboard Comics, a 1970s line of comics
Atlas Consortium, a group of technology companies
Atlas Copco, a Swedish company founded in 1873
Atlas Corporation, an investment company
Atlas Drop Forge Company, a parts subsidiary of REO Motor Car Company
Atlas Elektronik, a German naval/marine electronics and systems business
Atlas Entertainment, a film production company
Atlas Group, a Pakistani business group
Atlas Media Corp., a non-fiction entertainment company
Atlas Aircraft Corporation, a South African military aircraft manufacturer
Atlas Model Railroad, American maker of model trains and accessories
Atlas Network, formerly Atlas Economic Research Foundation
Atlas Powder Company, an American explosives and chemicals company
Atlas Press, a UK publisher
Atlas Press (tool company)
Atlas (restaurant), a Michelin-starred restaurant in Atlanta
Atlas Solutions, an online advertising subsidiary of Meta Platforms
Atlas Van Lines, a moving company
Atlas Werke, a defunct German shipbuilding company
RTV Atlas, a broadcaster in Montenegro |
Atlas (disambiguation) | Military | Military
Airbus A400M Atlas, a military aircraft produced since 2007
Armstrong Whitworth Atlas, a British military aircraft produced 1927–1933
HMLAT-303, a United States Marine Corps helicopter training squadron
Atlas Aircraft Corporation, a South African military aircraft manufacturer
French ship Atlas, several French Navy ships
HMS Atlas, several Royal Navy ships
USS Atlas, several U.S. Navy ships
ATLAS (simulation) (Army Tactical Level Advanced Simulation), a Thai military system |
Atlas (disambiguation) | Mythological and legendary figures | Mythological and legendary figures
Atlas (mythology), a Titan in ancient Greek mythology
Atlas of Atlantis, the first legendary king of Atlantis
Atlas of Mauretania, a legendary king |
Atlas (disambiguation) | People | People
Atlas (name), including lists of people with the given name or surname
Atlas (graffiti artist) |
Atlas (disambiguation) | Places | Places |
Atlas (disambiguation) | United States | United States
Atlas, Illinois
Atlas, Texas
Atlas, West Virginia
Atlas, Wisconsin
Atlas District, in Washington, D.C.
Atlas Peak AVA, a California wine region
Atlas Township, Michigan |
Atlas (disambiguation) | Other places | Other places
Atlas Cinema, a historic movie theatre in Istanbul, Turkey
Atlas Mountains, a set of mountain ranges in northwestern Africa
Atlas, Nilüfer, a village in Bursa Province, Turkey |
Atlas (disambiguation) | Science and technology | Science and technology |
Atlas (disambiguation) | Astronomy | Astronomy
Atlas (comet) (C/2019 Y4)
Atlas (crater), on the near side of the Moon
Atlas (moon), a satellite of Saturn
Atlas (star), a triple star system in the constellation of Taurus and a member of the Pleiades
Advanced Topographic Laser Altimeter System (ATLAS), a space-based lidar instrument on ICESat-2
Asteroid Terrestrial-impact Last Alert System (ATLAS) |
Atlas (disambiguation) | Computing | Computing
Atlas (computer), a 1960s supercomputer
Atlas Supervisor, its operating system
Atlas (robot)
ATLAS (software), a tool to scan American citizenship records for candidates for denaturalization
Atlas, a computer used at the Lawrence Livermore National Laboratory in 2006
Abbreviated Test Language for All Systems (ATLAS), a computer language for equipment testing
Advanced Technology Leisure Application Simulator (ATLAS), a hydraulic motion simulator used in theme parks
ASP.NET AJAX (formerly "Atlas"), a set of ASP.NET extensions
ATLAS Transformation Language, a programming language for model transformation
Atlas.ti, a qualitative analysis program
Automatically Tuned Linear Algebra Software (ATLAS)
ERA Atlas, a version of the UNIVAC 1101, a 1950s American computer |
Atlas (disambiguation) | Mathematics | Mathematics
Atlas (topology), a set of charts
A set of charts which covers a manifold
A smooth structure, a maximal smooth atlas for a topological manifold |
Atlas (disambiguation) | Physics | Physics
Argonne Tandem Linear Accelerator System (ATLAS), at the Argonne National Laboratory
ATLAS experiment, a particle detector for the Large Hadron Collider at CERN
Atomic-terrace low-angle shadowing (ATLAS), a nanofabrication technique |
Atlas (disambiguation) | Biology and healthcare | Biology and healthcare
Atlas (anatomy), a vertebra in the cervical spine
Atlas personality, the personality of someone whose childhood was characterized by excessive responsibilities |
Atlas (disambiguation) | Animals and plants | Animals and plants
Atlas bear
Atlas beetle
Atlas cedar
Atlas moth
Atlas pied flycatcher, a bird
Atlas turtle
Atlas, a book about flora and/or fauna of a region, such as atlases of the flora and fauna of Britain and Ireland |
Atlas (disambiguation) | Sport | Sport
Atlas Delmenhorst, a German association football club
Atlas F.C., a Mexican professional football club
Club Atlético Atlas, an Argentine amateur football club
KK Atlas, a former Serbian men's professional basketball club |
Atlas (disambiguation) | Transport | Transport |
Atlas (disambiguation) | Aerospace | Aerospace
Atlas (rocket family)
SM-65 Atlas intercontinental ballistic missile (ICBM)
AeroVelo Atlas, a human-powered helicopter
Birdman Atlas, an ultralight aircraft
La Mouette Atlas, a French hang glider design |
Atlas (disambiguation) | Automotive | Automotive
Atlas (1951 automobile), a French mini-car
Atlas (light trucks), a Greek motor vehicle manufacturer
Atlas (Pittsburgh automobile), produced 1906–1907
Atlas (Springfield automobile), produced 1907–1913
Atlas, a British van by the Standard Motor Company produced 1958–1962
Atlas Motor Buggy, an American highwheeler produced in 1909
Ford Atlas, a concept pickup truck that previewed the then-new 2015 F-150
Geely Atlas, a sport utility vehicle
General Motors Atlas engine
Honda Atlas Cars Pakistan, a car manufacturer
Nissan Atlas, a Japanese light truck
Volkswagen Atlas, a sport utility vehicle |
Atlas (disambiguation) | Ships and boats | Ships and boats
Atlas (ship), various merchant ships
ST Atlas, a Swedish tugboat |
Atlas (disambiguation) | Trains | Trains
Atlas, an 1863–1885 South Devon Railway Dido class locomotive
Atlas, a 1927–1962 LMS Royal Scot Class locomotive |
Atlas (disambiguation) | Other uses | Other uses
Atlas (architecture)
Atlas (storm), which hit the Midwestern United States in October 2013
Agrupación de Trabajadores Latinoamericanos Sindicalistas (ATLAS), a 1950s Latin American trade union confederation
Atlas languages, Berber languages spoken in the Atlas Mountains of Morocco
ATLAS Network, a network of European special police units
Atlas power station, İskenderun, Hatay Province, Turkey
Atlas Uranium Mill, Moab, Utah, United States
Atlas folio, a book size |
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