title: Strike Back (TV series)

text: Richard Armitage plays the first series protagonist, SAS Sergeant John Porter, a character who is brought back into service by Section 20 seven years after he resigns from a botched rescue mission.<ref name="brady/armitage sky"></ref> Armitage describes the character as "sort of like Lucas North [the character he played on the BBC espionage series "Spooks"], only on some kind of go-faster drug." Following the announcement of the second series, Armitage had to drop out of the role, following his commitment to appear as Thorin Oakenshield in "The Hobbit" films. He was replaced by Sullivan Stapleton, who plays former United States Delta Force Sergeant Damian Scott, and Philip Winchester who plays British SBS Sergeant Michael Stonebridge. Stapleton was originally contracted to appear in two series but stayed on until series 5.


title: Strike Back (TV series)

text: In the first series, Andrew Lincoln plays Hugh Collinson, Porter's comrade in the 2003 mission and Section 20 boss. Jodhi May plays Lieutenant Layla Thompson, an "ambitious woman working in a male-dominated field that she's climbed to the top of". Over the course of the first series she grows to distrust Collinson. Shelley Conn plays Sergeant Danni Prendiville, a Section 20 officer who has an affair with Porter. Colin Salmon appears as civil servant James Middleton, and Orla Brady plays kidnapped Sky war correspondent Katie Dartmouth.


title: Strike Back (TV series)

text: In series two, Amanda Mealing plays Collinson's successor, Colonel Eleanor Grant, described as a "smart, tough military leader who is skilled with a gun and diplomacy, but knows when to break a rule or two." Eva Birthistle plays Captain Kate Marshall, a "crack commando" who oversees Section 20's military personnel, and with whom Stonebridge had an extra-marital affair. Rhashan Stone plays Major Oliver Sinclair, Grant's right-hand man, and Section 20's second-in-command. Michelle Lukes plays Sergeant Julia Richmond, one of the newer recruits of Section 20 with the ability to speak seven languages. Jimi Mistry plays "Project Dawn" villain Latif, the Pakistani terrorist and mastermind behind the eponymous plot.


title: Strike Back (TV series)

text: In the third series "Vengeance", Rachel Dalton, played by Rhona Mitra, replaces Grant who was killed off at the conclusion of "Project Dawn". Richmond becomes more active in the field in this series. The primary antagonists of "Vengeance" are guns-for-hire Karl Matlock, played by Vincent Regan. and Conrad Knox, a billionaire who is using his humanitarian work as a front to build his own militia, played by Charles Dance.


title: Strike Back (TV series)

text: The sixth series "" introduces a new set of characters to replace Scott and Stonebridge; they include Daniel MacPherson as Sergeant Samuel Wyatt, Warren Brown as Sgt Thomas ‘Mac’ McAllister, Roxanne McKee as Captain Natalie Reynolds (for one series only) and Alin Sumarwata as Lance Corporal Gracie Novin.


title: Strike Back (TV series)

text: The television series is based on a novel of the same name by Chris Ryan, a former SAS soldier who was known as the only member of his unit, Bravo Two Zero, to evade capture by Iraqi forces during the Gulf War in 1991, and was regarded as the most difficult escape for a British soldier. Ryan became a novelist after leaving the SAS. Andy Harries, the chief executive of his production company, Left Bank Pictures, saw the novel "Strike Back" at an airport while on holiday, but never got around to reading it. Regardless, he still managed to pitch the idea of a series from the novel to Sky's Head of Drama Elaine Pyke, who commissioned it. Harries said of the experience, "I read the back of the book just to remind myself, I remember Elaine saying 'what's the story' and I said 'Don't worry about that, it's really the thrust of the piece.'" The commission became part of Sky's £10 million commitment to producing original dramas based on novels following the network's success in adapting the "Discworld" novels from Terry Pratchett. It was also a part of Sky's attempt to replicate the pace of American-based action series including "24". Chris Ryan became involved in the project by acting as a series consultant and script advisor. Harries also served as a producer on the show.


title: Strike Back (TV series)

text: A second series of "Strike Back" was commissioned by Sky in August 2010, for a longer run of 10 episodes. Later, in February 2011, it was announced that Sky entered an international co-production deal with the American television network Cinemax, as the network wanted to introduce a new original drama series. The first episodes of the series was written by "The X-Files" alum Frank Spotnitz. Spotnitz was brought in to start the second series with the purpose to re-imagine the show, as the producers needed it to work in the absence of first series lead Richard Armitage, due to the actor's commitment to "The Hobbit" film series in New Zealand.


title: Strike Back (TV series)

text: In the first series, Armitage had to "bulk up for the role." The actor spent ten weeks with a trainer in the UK, before moving to Johannesburg, where the first series was shot, and participated in more training, however he had to spend ten days after arriving to acclimatise to the city's high altitudes. Before the second series, more main cast members took up intensive bootcamp style training in South Africa by former SAS and SBS operators. The two leads Stapleton and Winchester underwent the most intensive training. The actors were trained in many aspects including running, teamwork, tactical manoeuvres with and without weapons and other various military tactics. Winchester recalled his training experience, "[Sullivan Stapleton] and I would meet every morning at 6am. We would run to a chosen location and on the way we had to memorise street names and directions and then our trainers would say 'that car that you just passed what was the licence plate number?' Our trainers were ex-SAS guys who made us study everything in detail, for example, we learnt step by step how to enter a room in twos, then alone. At the same time, we had to be constantly aware of where our weapon was trained."


title: Strike Back (TV series)

text: The series uses a vast array of firearms and other weapons, including side arms, assault and sniper rifles, rocket-propelled grenades, hand grenades and other explosives as well as knives and other weapons. In training, cast members started by carrying weights that mimicked the weapons so they could get used to carrying them during filming. They were later taught how to handle various firearms used in the series to make it appear as real as possible, they were taught to disassemble and re-assemble, fire and reload the weapons used before scenes/shooting. Former SAS and SBS servicemen gave many of the cast weapons training, and were also on hand during the filming to oversee and advise the cast members on the proper handling and use of the various weapons and tactics used in different scenes.


title: Strike Back (TV series)

text: Filming the first series began in South Africa in August 2009, and was shot with 35mm film. 35mm cameras were used because the crew regard them as "the best and most flexible capture medium" available. Three Kodak film stocks were used for filming the series, along with a variety of Arri cameras. Each scene uses a minimum of two cameras, but the crew regularly use four camera angles.


title: Strike Back (TV series)

text: Having worked in South Africa several times in the past, Mancub decided to use the country as the filming location for the series, as he felt it could replicate anywhere in the world. The first series was largely filmed in the Gauteng province, including its capital, Johannesburg. Local crew members were used to collaborate with the British crew. Starting with "Project Dawn", Cape Town was largely used as a filming location, with other episodes filmed in Durban and Springbok, Northern Cape. Before filming "Project Dawn", the production crew were scouting other filming locations throughout Europe, South America and the United States. The series would additionally be shot in Budapest, Hungary. Some other scenes were also shot in the UK. The first two episodes of "Vengeance" were originally scheduled to film in Mozambique, but a week before filming was due to start the country had "a massive freedom fighter rally."


title: Strike Back (TV series)

text: The series aired on Sky One in the United Kingdom. The first series began airing on 5 May 2010, originally showing two episodes for three weeks. According to overnight viewing figures, the premiere episode was seen by 398,000 viewers and a 1.7 per cent audience share, becoming one of the most viewed non-terrestrial broadcasts, and more than tripled Sky One's average audience in their slots from the previous three months. "Project Dawn" began on 21 August 2011, but was showing just one episode a week that time. Overnight ratings saw a substantial increase over the first series premiere, having been seen by 616,000 viewers, with a 2.6 per cent audience share. "Vengeance" premiered on 2 September 2012, however overnight ratings decreased to 385,000, and was beaten by new episodes of "The Simpsons" and "Sinbad", which aired on the same channel.


title: Strike Back (TV series)

text: The United States did not initially air the first series, but on 25 October 2013 it was aired with the title Strike Back: Origins. The first series to air in the US was "Project Dawn", and was known as "Season One" in the country, it began airing on Cinemax on 12 August 2011. The premiere attracted 567,000 viewers on its first telecast, and an additional 500,000 viewed the two following encores. Despite the limited availability of the network on American television (only 16.7 million homes have Cinemax available), it was the best ratings performance for the network since a broadcast of the film "Titanic" in 2005. "Vengeance" premiered with two back-to-back episodes, on 17 August 2012. It attracted 390,000 viewers, with encores increasing viewership to over half a million. "Vengeance" averaged 310,000 viewers with an 18 to 49 rating of 0.13.


title: Strike Back (TV series)

text: The series was also made available in other countries. In Australia, the first series aired on ABC1, with "Project Dawn" airing on Channel Seven. In Canada the show airs on HBO Canada, while in France, it is shown on Canal+. In Belgium, the second series of the show began airing on La Deux on 28 April 2013 while the channel did not show the first series.


title: Strike Back (TV series)

text: "Strike Back" received generally positive reviews from television critics. It has an overall metacritic rating of 71, indicating generally favourable reviews based on 30 critics. Its first season received a rating of 64, increasing to 78 in season 3.


title: Strike Back (TV series)

text: "Strike Back" was nominated for six accolades, winning two. In 2010, the first series was nominated for Best Digital Choice for the National Television Awards. In 2012, the series was nominated for a Primetime Emmy Award for Outstanding Main Title Design, and Eva Birthistle was nominated for Best Actress in a Supporting Role TV in the ninth annual Irish Film & Television Awards in 2012. In the same year, "Strike Back" won a UK Screen Association Conch Award for Best Audio on TV Drama of the Year. Additionally the series won a Royal Television Society Award for Best Special Effects, with South African company Big Bang Stunts & Effects being the recipient. It was also nominated for Best Sound in Drama in 2010.


title: Strike Back (TV series)

text: The first series of "Strike Back" was released on a two-disc set on DVD and Blu-ray Disc on 7June 2010 in the United Kingdom (Region 2), just two weeks after the conclusion of the series on television. In Australia (Region4), the DVD was released on 3May 2011, while the Blu-ray was released later on 2June. The release consisted of all six episodes, which were edited to three feature-length episodes, along with special features, namely cast interviews and behind the scenes featurette.


title: Strike Back (TV series)

text: The second series, "Project Dawn", was released on a three-disc set on DVD and Blu-ray on 14November 2011. Along with the ten episodes, the set includes the special featurettes "Top Secrets: Making Strike Back: Project Dawn", "Firearms Training", and "Scott Vs Igor Fight Scene" featurettes, as well as broadcast titles. On the same day of its release, a collection of both series were also released on DVD and Blu-ray. In the United States (Region1), the series, labelled "Strike Back: Cinemax Season One", was released on 7August 2012. The American release includes audio commentaries from various cast and crew members on five episodes, along with a DVD and digital copy on the Blu-ray edition. "Vengeance" was released on DVD on 5November 2012 in the UK. The fifth series was available only in the UK until 1March 2016, at which time the North American DVD and Blu-ray disc versions were released. Series 1–5 are available in the UK as PAL DVDs, and series 2–5 (North American Cinemax series 1–4) have all been available in North America as NTSC DVDs and Blu-ray discs since 1March 2016. A manufacture-on-demand DVD of the final series, "The Last Shot", was released via the Warner Archive Collection on August25, 2020.


title: Strike Back (TV series)

text: It was announced in October 2015 that plans to make a "Strike Back" feature film are in the early planning stages, with the two leads, Winchester and Stapleton, to reprise their roles.


title: E. L. James

text: Erika Mitchell (born 7 March 1963), known by her pen name E. L. James, is a British author. She wrote the best-selling erotic romance trilogy "Fifty Shades of Grey", "Fifty Shades Darker", and "Fifty Shades Freed", along with the companion novels "", "", and "". Prior to this, she wrote the "Twilight" fan fiction "Master of the Universe" that served as the basis for the "Fifty Shades" trilogy under the web name Snowqueens Icedragon. In 2019 she published her first book unconnected with the fictional world of "Fifty Shades", "The Mister", to negative critical reaction.


title: E. L. James

text: The "Fifty Shades" novels have sold over 125 million copies worldwide, over 35 million copies in the United States and set the record in the United Kingdom as the fastest selling paperback of all time. In 2012, "Time" magazine named her one of "The World's 100 Most Influential People". The novels were subsequently adapted into the films "Fifty Shades of Grey", "Fifty Shades Darker", and "Fifty Shades Freed".


title: E. L. James

text: Erika Mitchell was born on 7 March 1963 in Willesden, Middlesex to a Chilean mother and a Scottish father who was a BBC cameraman. She was brought up in Buckinghamshire.


title: E. L. James

text: James was educated at the independent Pipers Corner School and at Wycombe High School, a state grammar school for girls in the town of High Wycombe in Buckinghamshire, followed by the University of Kent in South East England where she studied History.


title: E. L. James

text: After leaving university, James became a studio manager's assistant at the National Film and Television School in Beaconsfield. She married Niall Leonard, a novelist and screenwriter from Northern Ireland, in 1987. They have two sons. As of 2012, they reside in Brentford, West London.


title: E. L. James

text: James says the idea for the "Fifty Shades" trilogy began as a response to the vampire novel series "Twilight". In late 2008, James saw the movie "Twilight", and then became intensely absorbed with the novels that the movie was based on. She read the novels several times over in a period of a few days, and then, for the first time in her life, sat down to write a book: basically a sequel to the "Twilight" novels. Between January and August 2009, she wrote two such books in quick succession. She says she then discovered the phenomenon of fan fiction, and this inspired her to publish her novels as Kindle books under the pen name "Snowqueens Icedragon". Beginning in August 2009, she then began to write the "Fifty Shades" books.


title: E. L. James

text: James has spoken of her shock at the success of the books. "The explosion of interest has taken me completely by surprise" she said. James has described the "Fifty Shades" trilogy as "my midlife crisis, writ large. All my fantasies in there, and that's it." She did not start to write until January 2009, as she revealed while still active on FanFiction.Net: "I started writing in January 2009 after I finished the Twilight saga, and I haven't stopped since. I discovered Fan Fiction in August 2009. Since then I have written my two fics and plan on doing at least one more. After that ... who knows?" In August 2013, James topped the "Forbes" list of the highest-earning authors due to her book sales with earnings of $95m which included $5m for the film rights to "Fifty Shades of Grey". On 1 June 2015 James announced the upcoming release of "Grey: Fifty Shades of Grey as Told by Christian", which was released into stores on 18 June 2015. "Darker: Fifty Shades Darker as Told by Christian" was released 28 November 2017.


title: Erythropoietin

text: Erythropoietin (; EPO), also known as erythropoetin, haematopoietin, or haemopoietin, is a glycoprotein cytokine secreted mainly by the kidneys in response to cellular hypoxia; it stimulates red blood cell production (erythropoiesis) in the bone marrow. Low levels of EPO (around 10 mU/mL) are constantly secreted in sufficient quantities to compensate for normal red blood cell turnover. Common causes of cellular hypoxia resulting in elevated levels of EPO (up to 10 000 mU/mL) include any anemia, and hypoxemia due to chronic lung disease.


title: Erythropoietin

text: Erythropoietin is produced by interstitial fibroblasts in the kidney in close association with the peritubular capillary and proximal convoluted tubule. It is also produced in perisinusoidal cells in the liver. Liver production predominates in the fetal and perinatal period; renal production predominates in adulthood. It is homologous with thrombopoietin.


title: Erythropoietin

text: Exogenous erythropoietin, recombinant human erythropoietin (rhEPO), is produced by recombinant DNA technology in cell culture and are collectively called erythropoiesis-stimulating agents (ESA): two examples are epoetin alfa and epoetin beta. ESAs are used in the treatment of anemia in chronic kidney disease, anemia in myelodysplasia, and in anemia from cancer chemotherapy. Risks of therapy include death, myocardial infarction, stroke, venous thromboembolism, and tumor recurrence. Risk increases when EPO treatment raises hemoglobin levels over 11 g/dL to 12 g/dL: this is to be avoided.


title: Erythropoietin

text: rhEPO has been used illicitly as a performance-enhancing drug. It can often be detected in blood, due to slight differences from the endogenous protein; for example, in features of posttranslational modification.


title: Erythropoietin

text: EPO is highly glycosylated (40% of total molecular weight), with half-life in blood around 5 h. EPO's half-life may vary between endogenous and various recombinant versions. Additional glycosylation or other alterations of EPO via recombinant technology have led to the increase of EPO's stability in blood (thus requiring less frequent injections).


title: Erythropoietin

text: Erythropoietin is an essential hormone for red blood cell production. Without it, definitive erythropoiesis does not take place. Under hypoxic conditions, the kidney will produce and secrete erythropoietin to increase the production of red blood cells by targeting CFU-E, proerythroblast and basophilic erythroblast subsets in the differentiation. Erythropoietin has its primary effect on red blood cell progenitors and precursors (which are found in the bone marrow in humans) by promoting their survival through protecting these cells from apoptosis, or cell death.


title: Erythropoietin

text: Erythropoietin is the primary erythropoietic factor that cooperates with various other growth factors (e.g., IL-3, IL-6, glucocorticoids, and SCF) involved in the development of erythroid lineage from multipotent progenitors. The burst-forming unit-erythroid (BFU-E) cells start erythropoietin receptor expression and are sensitive to erythropoietin. Subsequent stage, the colony-forming unit-erythroid (CFU-E), expresses maximal erythropoietin receptor density and is completely dependent on erythropoietin for further differentiation. Precursors of red cells, the proerythroblasts and basophilic erythroblasts also express erythropoietin receptor and are therefore affected by it.


title: Erythropoietin

text: Erythropoietin was reported to have a range of actions beyond stimulation of erythropoiesis including vasoconstriction-dependent hypertension, stimulating angiogenesis, and promoting cell survival via activation of EPO receptors resulting in anti-apoptotic effects on ischemic tissues. However this proposal is controversial with numerous studies showing no effect. It is also inconsistent with the low levels of EPO receptors on those cells. Clinical trials in humans with ischemic heart, neural and renal tissues have not demonstrated the same benefits seen in animals. In addition some research studies have shown its neuroprotective effect on diabetic neuropathy, however these data were not confirmed in clinical trials that have been conducted on the deep peroneal, superficial peroneal, tibial and sural nerves.


title: Erythropoietin

text: Erythropoietin has been shown to exert its effects by binding to the erythropoietin receptor (EpoR). EPO binds to the erythropoietin receptor on the red cell progenitor surface and activates a JAK2 signalling cascade. This initiates the STAT5, PIK3 and Ras MAPK pathways. This results in differentiation, survival and proliferation of the erythroid cell. SOCS1, SOCS3 and CIS are also expressed which act as negative regulators of the cytokine signal.


title: Erythropoietin

text: High level erythropoietin receptor expression is localized to erythroid progenitor cells. While there are reports that EPO receptors are found in a number of other tissues, such as heart, muscle, kidney and peripheral/central nervous tissue, those results are confounded by nonspecificity of reagents such as anti-EpoR antibodies. In controlled experiments, a functional EPO receptor is not detected in those tissues. In the bloodstream, red cells themselves do not express erythropoietin receptor, so cannot respond to EPO. However, indirect dependence of red cell longevity in the blood on plasma erythropoietin levels has been reported, a process termed neocytolysis. In addition, there is conclusive evidence that EPO receptor expression is upregulated in brain injury.


title: Erythropoietin

text: Erythropoietin levels in blood are quite low in the absence of anemia, at around 10 mU/mL. However, in hypoxic stress, EPO production may increase up to 1000-fold, reaching 10 000 mU/mL of blood. In adults, EPO is synthesized mainly by interstitial cells in the peritubular capillary bed of the renal cortex, with additional amounts being produced in the liver, and the pericytes in the brain. Regulation is believed to rely on a feedback mechanism measuring blood oxygenation and iron availability. Constitutively synthesized transcription factors for EPO, known as hypoxia-inducible factors, are hydroxylated and proteosomally digested in the presence of oxygen and iron. During normoxia GATA2 inhibits the promoter region for EPO. GATA2 levels decrease during hypoxia and allow the promotion of EPO production.


title: Erythropoietin

text: Erythropoietin production can be induced by HIF-2α as well as by PGC-1α. Erythropoietin also activates these factors, resulting in


title: Erythropoietin

text: Erythropoietins available for use as therapeutic agents are produced by recombinant DNA technology in cell culture, and include Epogen/Procrit (epoetin alfa) and Aranesp (darbepoetin alfa); they are used in treating anemia resulting from chronic kidney disease, chemotherapy induced anemia in patients with cancer, inflammatory bowel disease (Crohn's disease and ulcerative colitis) and myelodysplasia from the treatment of cancer (chemotherapy and radiation). The package inserts include boxed warnings of increased risk of death, myocardial infarction, stroke, venous thromboembolism, and tumor recurrence, particularly when used to increase the hemoglobin levels to more than 11 g/dL to 12 g/dL.


title: Erythropoietin

text: In 1905, Paul Carnot proposed the idea that a hormone regulates the production of red blood cells. After conducting experiments on rabbits subject to bloodletting, Carnot and his graduate student Clotilde-Camille Deflandre attributed an increase in red blood cells in rabbit subjects to a hemotropic factor called hemopoietin. Eva Bonsdorff and Eeva Jalavisto called the hemopoietic substance 'erythropoietin'. K.R. Reissman and Allan J. Erslev demonstrated that a certain substance, circulated in the blood, is able to stimulate red blood cell production and increase hematocrit. This substance was purified and confirmed as erythropoietin.


title: Erythropoietin

text: In 1977, Goldwasser and Kung purified EPO. Pure EPO allowed the amino acid sequence to be partially identified and the gene to be isolated. Synthetic EPO was first successfully used to correct anemia in 1987. In 1985, Lin "et al" isolated the human erythropoietin gene from a genomic phage library and used it to produce EPO. In 1989, the US Food and Drug Administration (FDA) approved the hormone Epogen for use in certain anemias.


title: Erythropoietin

text: Gregg L. Semenza and Peter J. Ratcliffe studied the EPO gene and its oxygen-dependent regulation. Along with William Kaelin Jr., they were awarded the 2019 Nobel Prize in Physiology or Medicine for their discovery of hypoxia-inducible factor (HIF), which regulates the EPO gene, as well as other genes, in response to hypoxia.


title: Erythropoietin

text: In December 2007, Retacrit and Silapo (both epoetin zeta) were approved for use in the European Union.


title: Erythropoietin

text: As a performance-enhancing drug, EPO has been banned since the early 1990s, but a first test was not available until the 2000 Summer Olympics. Before this test was available, some athletes were sanctioned after confessing to having used EPO, for example in the Festina affair, when a car with doping products for the Festina cycling team was found.


title: Erythropoietin

text: The first doping test in cycling was used in the 2001 La Flèche Wallonne. The first rider to test positive in that race was Bo Hamburger, although he was later acquitted because his B-sample was not conclusive.


title: Erythropoietin

text: The U.S. Postal Service Pro Cycling Team, under the leadership of Lance Armstrong and Johan Bruyneel, ran a sophisticated doping program that lasted for many years during the late 1990s and early 2000s. Erythropoietin was a common substance used by the cyclists.


title: Erythropoietin

text: A 2007 study showed that EPO has a significant effect on exercise performance, but a 2017 study showed that the effects of EPO administered to amateur cyclists was not distinguishable from a placebo.


title: Erythropoietin

text: In March 2019, American mixed martial artist and former UFC Bantamweight Champion T.J. Dillashaw tested positive for EPO in a drug test administered by USADA, and was stripped of the UFC bantamweight title and suspended for 2 years.


title: Omar Khayyam

text: Ghiyāth al-Dīn Abū al-Fatḥ ʿUmar ibn Ibrāhīm Nīsābūrī (18 May 1048 – 4 December 1131), commonly known as Omar Khayyam (), was a polymath, known for his contributions to mathematics, astronomy, philosophy, and Persian poetry. He was born in Nishapur, the initial capital of the Seljuk Empire. As a scholar, he was contemporary with the rule of the Seljuk dynasty around the time of the First Crusade.


title: Omar Khayyam

text: As a mathematician, he is most notable for his work on the classification and solution of cubic equations, where he provided geometric solutions by the intersection of conics. Khayyam also contributed to the understanding of the parallel axiom. As an astronomer, he calculated the duration of the solar year with remarkable precision and accuracy, and designed the Jalali calendar, a solar calendar with a very precise 33-year intercalation cycle that provided the basis for the Persian calendar that is still in use after nearly a millennium.


title: Omar Khayyam

text: There is a tradition of attributing poetry to Omar Khayyam, written in the form of quatrains ("rubāʿiyāt" ). This poetry became widely known to the English-reading world in a translation by Edward FitzGerald ("Rubaiyat of Omar Khayyam", 1859), which enjoyed great success in the Orientalism of the "fin de siècle".


title: Omar Khayyam

text: Omar Khayyam was born, of Khorasani Persian ancestry, in Nishapur in 1048. In medieval Persian texts he is usually simply called "Omar Khayyam". Although open to doubt, it has often been assumed that his forebears followed the trade of tent-making, since "Khayyam" means "tent-maker" in Arabic. The historian Bayhaqi, who was personally acquainted with Omar, provides the full details of his horoscope: "he was Gemini, the sun and Mercury being in the ascendant[...]". This was used by modern scholars to establish his date of birth as 18 May 1048.


title: Omar Khayyam

text: Khayyam's boyhood was spent in Nishapur, a leading metropolis under the Great Seljuq Empire, and it had been a major center of the Zoroastrian religion. His full name, as it appears in the Arabic sources, was "Abu’l Fath Omar ibn Ibrahim al-Khayyam". His gifts were recognized by his early tutors who sent him to study under Imam Muwaffaq Nishaburi, the greatest teacher of the Khorasan region who tutored the children of the highest nobility. Omar made a great friendship with him through the years. Khayyam was also taught by the Zoroastrian mathematician, Abu Hassan Bahmanyar bin Marzban. After studying science, philosophy, mathematics and astronomy at Nishapur, about the year 1068 he traveled to the province of Bukhara, where he frequented the renowned library of the Ark. In about 1070 he moved to Samarkand, where he started to compose his famous treatise on algebra under the patronage of Abu Tahir Abd al-Rahman ibn ʿAlaq, the governor and chief judge of the city. Omar Khayyam was kindly received by the Karakhanid ruler Shams al-Mulk Nasr, who according to Bayhaqi, would "show him the greatest honour, so much so that he would seat [Omar] beside him on his throne".


title: Omar Khayyam

text: In 1073–4 peace was concluded with Sultan Malik-Shah I who had made incursions into Karakhanid dominions. Khayyam entered the service of Malik-Shah in 1074–5 when he was invited by the Grand Vizier Nizam al-Mulk to meet Malik-Shah in the city of Marv. Khayyam was subsequently commissioned to set up an observatory in Isfahan and lead a group of scientists in carrying out precise astronomical observations aimed at the revision of the Persian calendar. The undertaking began probably in 1076 and ended in 1079 when Omar Khayyam and his colleagues concluded their measurements of the length of the year, reporting it as 365.24219858156 days. Given that the length of the year is changing in the sixth decimal place over a person's lifetime, this is outstandingly accurate. For comparison the length of the year at the end of the 19th century was 365.242196 days, while today it is 365.242190 days.


title: Omar Khayyam

text: After the death of Malik-Shah and his vizier (murdered, it is thought, by the Ismaili order of Assassins), Omar fell from favor at court, and as a result, he soon set out on his pilgrimage to Mecca. A possible ulterior motive for his pilgrimage reported by Al-Qifti, was a public demonstration of his faith with a view to allaying suspicions of skepticism and confuting the allegations of unorthodoxy (including possible sympathy or adherence to Zoroastrianism) levelled at him by a hostile clergy. He was then invited by the new Sultan Sanjar to Marv, possibly to work as a court astrologer. He was later allowed to return to Nishapur owing to his declining health. Upon his return, he seems to have lived the life of a recluse.


title: Omar Khayyam

text: Omar Khayyam died at the age of 83 in his hometown of Nishapur on 4 December 1131, and he is buried in what is now the Mausoleum of Omar Khayyam. One of his disciples Nizami Aruzi relates the story that sometime during 1112–3 Khayyam was in Balkh in the company of Al-Isfizari (one of the scientists who had collaborated with him on the Jalali calendar) when he made a prophecy that "my tomb shall be in a spot where the north wind may scatter roses over it". Four years after his death, Aruzi located his tomb in a cemetery in a then large and well-known quarter of Nishapur on the road to Marv. As it had been foreseen by Khayyam, Aruzi found the tomb situated at the foot of a garden-wall over which pear trees and peach trees had thrust their heads and dropped their flowers so that his tombstone was hidden beneath them.


title: Omar Khayyam

text: Khayyam was famous during his life as a mathematician. His surviving mathematical works include: "A commentary on the difficulties concerning the postulates of Euclid's Elements" (, completed in December 1077), "On the division of a quadrant of a circle" (, undated but completed prior to the treatise on algebra), and "On proofs for problems concerning Algebra" (, most likely completed in 1079). He furthermore wrote a treatise on the binomial theorem and extracting the n root of natural numbers, which has been lost.


title: Omar Khayyam

text: A part of Khayyam's commentary on Euclid's Elements deals with the parallel axiom. The treatise of Khayyam can be considered the first treatment of the axiom not based on petitio principii, but on a more intuitive postulate. Khayyam refutes the previous attempts by other mathematicians to "prove" the proposition, mainly on grounds that each of them had postulated something that was by no means easier to admit than the Fifth Postulate itself. Drawing upon Aristotle's views, he rejects the usage of movement in geometry and therefore dismisses the different attempt by Al-Haytham. Unsatisfied with the failure of mathematicians to prove Euclid's statement from his other postulates, Omar tried to connect the axiom with the Fourth Postulate, which states that all right angles are equal to one another.


title: Omar Khayyam

text: Khayyam was the first to consider the three distinct cases of acute, obtuse, and right angle for the summit angles of a Khayyam-Saccheri quadrilateral. After proving a number of theorems about them, he showed that Postulate V follows from the right angle hypothesis, and refuted the obtuse and acute cases as self-contradictory. His elaborate attempt to prove the parallel postulate was significant for the further development of geometry, as it clearly shows the possibility of non-Euclidean geometries. The hypotheses of acute, obtuse, and right angles are now known to lead respectively to the non-Euclidean hyperbolic geometry of Gauss-Bolyai-Lobachevsky, to that of Riemannian geometry, and to Euclidean geometry.


title: Omar Khayyam

text: Tusi's commentaries on Khayyam's treatment of parallels made its way to Europe. John Wallis, professor of geometry at Oxford, translated Tusi's commentary into Latin. Jesuit geometer Girolamo Saccheri, whose work ("euclides ab omni naevo vindicatus", 1733) is generally considered the first step in the eventual development of non-Euclidean geometry, was familiar with the work of Wallis. The American historian of mathematics David Eugene Smith mentions that Saccheri "used the same lemma as the one of Tusi, even lettering the figure in precisely the same way and using the lemma for the same purpose". He further says that "Tusi distinctly states that it is due to Omar Khayyam, and from the text, it seems clear that the latter was his inspirer."


title: Omar Khayyam

text: This treatise on Euclid contains another contribution dealing with the theory of proportions and with the compounding of ratios. Khayyam discusses the relationship between the concept of ratio and the concept of number and explicitly raises various theoretical difficulties. In particular, he contributes to the theoretical study of the concept of irrational number. Displeased with Euclid's definition of equal ratios, he redefined the concept of a number by the use of a continuous fraction as the means of expressing a ratio. Rosenfeld and Youschkevitch (1973) argue that "by placing irrational quantities and numbers on the same operational scale, [Khayyam] began a true revolution in the doctrine of number." Likewise, it was noted by D. J. Struik that Omar was "on the road to that extension of the number concept which leads to the notion of the real number."


title: Omar Khayyam

text: Rashed and Vahabzadeh (2000) have argued that because of his thoroughgoing geometrical approach to algebraic equations, Khayyam can be considered the precursor of Descartes in the invention of analytic geometry. In "The Treatise on the Division of a Quadrant of a Circle" Khayyam applied algebra to geometry. In this work, he devoted himself mainly to investigating whether it is possible to divide a circular quadrant into two parts such that the line segments projected from the dividing point to the perpendicular diameters of the circle form a specific ratio. His solution, in turn, employed several curve constructions that led to equations containing cubic and quadratic terms.


title: Omar Khayyam

text: Khayyam seems to have been the first to conceive a general theory of cubic equations and the first to geometrically solve every type of cubic equation, so far as positive roots are concerned. The treatise on algebra contains his work on cubic equations. It is divided into three parts: (i) equations which can be solved with compass and straight edge, (ii) equations which can be solved by means of conic sections, and (iii) equations which involve the inverse of the unknown.


title: Omar Khayyam

text: Khayyam produced an exhaustive list of all possible equations involving lines, squares, and cubes. He considered three binomial equations, nine trinomial equations, and seven tetranomial equations. For the first and second degree polynomials, he provided numerical solutions by geometric construction. He concluded that there are fourteen different types of cubics that cannot be reduced to an equation of a lesser degree. For these he could not accomplish the construction of his unknown segment with compass and straight edge. He proceeded to present geometric solutions to all types of cubic equations using the properties of conic sections. The prerequisite lemmas for Khayyam's geometrical proof include Euclid VI, Prop 13, and Apollonius II, Prop 12. The positive root of a cubic equation was determined as the abscissa of a point of intersection of two conics, for instance, the intersection of two parabolas, or the intersection of a parabola and a circle, etc. However, he acknowledged that the arithmetic problem of these cubics was still unsolved, adding that "possibly someone else will come to know it after us". This task remained open until the sixteenth century, where algebraic solution of the cubic equation was found in its generality by Cardano, Del Ferro, and Tartaglia in Renaissance Italy.


title: Omar Khayyam

text: In effect, Khayyam's work is an effort to unify algebra and geometry. This particular geometric solution of cubic equations has been further investigated by M. Hachtroudi and extended to solving fourth-degree equations. Although similar methods had appeared sporadically since Menaechmus, and further developed by the 10th-century mathematician Abu al-Jud, Khayyam's work can be considered the first systematic study and the first exact method of solving cubic equations. The mathematician Woepcke (1851) who offered translations of Khayyam's algebra into French praised him for his "power of generalization and his rigorously systematic procedure."


title: Omar Khayyam

text: In his algebraic treatise, Khayyam alludes to a book he had written on the extraction of the formula_1th root of the numbers using a law he had discovered which did not depend on geometric figures. This book was most likely titled "The difficulties of arithmetic" (), and is not extant. Based on the context, some historians of mathematics such as D. J. Struik, believe that Omar must have known the formula for the expansion of the binomial formula_2, where is a positive integer. The case of power 2 is explicitly stated in Euclid's elements and the case of at most power 3 had been established by Indian mathematicians. Khayyam was the mathematician who noticed the importance of a general binomial theorem. The argument supporting the claim that Khayyam had a general binomial theorem is based on his ability to extract roots. One of Khayyam's predecessors, Al-Karaji, had already discovered the triangular arrangement of the coefficients of binomial expansions that Europeans later came to know as Pascal's triangle; Khayyam popularized this triangular array in Iran, so that it is now known as Omar Khayyam's triangle.


title: Omar Khayyam

text: In 1074–5, Omar Khayyam was commissioned by Sultan Malik-Shah to build an observatory at Isfahan and reform the Persian calendar. There was a panel of eight scholars working under the direction of Khayyam to make large-scale astronomical observations and revise the astronomical tables. Recalibrating the calendar fixed the first day of the year at the exact moment of the passing of the Sun's center across vernal equinox. This marks the beginning of spring or Nowrūz, a day in which the Sun enters the first degree of Aries before noon.


title: Omar Khayyam

text: The Jalālī calendar was a true solar calendar where the duration of each month is equal to the time of the passage of the Sun across the corresponding sign of the Zodiac. The calendar reform introduced a unique 33-year intercalation cycle. As indicated by the works of Khazini, Khayyam's group implemented an intercalation system based on quadrennial and quinquennial leap years. Therefore, the calendar consisted of 25 ordinary years that included 365 days, and 8 leap years that included 366 days. The calendar remained in use across Greater Iran from the 11th to the 20th centuries. In 1911 the Jalali calendar became the official national calendar of Qajar Iran. In 1925 this calendar was simplified and the names of the months were modernized, resulting in the . The Jalali calendar is more accurate than the Gregorian calendar of 1582, with an error of one day accumulating over 5,000 years, compared to one day every 3,330 years in the Gregorian calendar.


title: Omar Khayyam

text: One of his pupils Nizami Aruzi of Samarcand relates that Khayyam apparently did not have a belief in astrology and divination: "I did not observe that he ("scil." Omar Khayyam) had any great belief in astrological predictions, nor have I seen or heard of any of the great [scientists] who had such belief." While working for Sultan Sanjar as an astrologer he was asked to predict the weather – a job that he apparently did not do well. George Saliba (2002) explains that the term , used in various sources in which references to Omar's life and work could be found, has sometimes been incorrectly translated to mean astrology. He adds: "from at least the middle of the tenth century, according to Farabi's enumeration of the sciences, that this science, , was already split into two parts, one dealing with astrology and the other with theoretical mathematical astronomy."


title: Omar Khayyam

text: He has a short treatise devoted to Archimedes' principle (in full title, "On the Deception of Knowing the Two Quantities of Gold and Silver in a Compound Made of the Two"). For a compound of gold adulterated with silver, he describes a method to measure more exactly the weight per capacity of each element. It involves weighing the compound both in air and in water, since weights are easier to measure exactly than volumes. By repeating the same with both gold and silver one finds exactly how much heavier than water gold, silver and the compound were. This treatise was extensively examined by Eilhard Wiedemann who believed that Khayyam's solution was more accurate and sophisticated than that of Khazini and Al-Nayrizi who also dealt with the subject elsewhere.


title: Omar Khayyam

text: Another short treatise is concerned with music theory in which he discusses the connection between music and arithmetic. Khayyam's contribution was in providing a systematic classification of musical scales, and discussing the mathematical relationship among notes, minor, major and tetrachords.


title: Omar Khayyam

text: The earliest allusion to Omar Khayyam's poetry is from the historian Imad ad-Din al-Isfahani, a younger contemporary of Khayyam, who explicitly identifies him as both a poet and a scientist (, 1174). One of the earliest specimens of Omar Khayyam's Rubiyat is from Fakhr al-Din Razi. In his work (ca. 1160), he quotes one of his poems (corresponding to quatrain LXII of FitzGerald's first edition). Daya in his writings (, ca. 1230) quotes two quatrains, one of which is the same as the one already reported by Razi. An additional quatrain is quoted by the historian Juvayni (, ca. 1226–1283). In 1340 Jajarmi includes thirteen quatrains of Khayyam in his work containing an anthology of the works of famous Persian poets (), two of which have hitherto been known from the older sources. A comparatively late manuscript is the Bodleian MS. Ouseley 140, written in Shiraz in 1460, which contains 158 quatrains on 47 folia. The manuscript belonged to William Ouseley (1767–1842) and was purchased by the Bodleian Library in 1844.There are occasional quotes of verses attributed to Omar in texts attributed to authors of the 13th and 14th centuries, but these are of doubtful authenticity, so that skeptical scholars point out that the entire tradition may be pseudepigraphic.


title: Omar Khayyam

text: Hans Heinrich Schaeder in 1934 commented that the name of Omar Khayyam "is to be struck out from the history of Persian literature" due to the lack of any material that could confidently be attributed to him.


title: Omar Khayyam

text: De Blois (2004) presents a bibliography of the manuscript tradition, concluding pessimistically that the situation has not changed significantly since Schaeder's time.


title: Omar Khayyam

text: Five of the quatrains later attributed to Omar are found as early as 30 years after his death, quoted in "Sindbad-Nameh". While this establishes that these specific verses were in circulation in Omar's time or shortly later, it doesn't imply that the verses must be his. De Blois concludes that at the least the process of attributing poetry to Omar Khayyam appears to have begun already in the 13th century. Edward Granville Browne (1906) notes the difficulty of disentangling authentic from spurious quatrains: "while it is certain that Khayyam wrote many quatrains, it is hardly possible, save in a few exceptional cases, to assert positively that he wrote any of those ascribed to him".


title: Omar Khayyam

text: In addition to the Persian quatrains, there are twenty-five Arabic poems attributed to Khayyam which are attested by historians such as al-Isfahani, Shahrazuri (, ca. 1201–1211), Qifti (, 1255), and Hamdallah Mustawfi (, 1339).


title: Omar Khayyam

text: Boyle and Frye (1975) emphasize that there are a number of other Persian scholars who occasionally wrote quatrains, including Avicenna, Ghazzali, and Tusi. He concludes that it is also possible that for Khayyam poetry was an amusement of his leisure hours: "these brief poems seem often to have been the work of scholars and scientists who composed them, perhaps, in moments of relaxation to edify or amuse the inner circle of their disciples".


title: Omar Khayyam

text: The poetry attributed to Omar Khayyam has contributed greatly to his popular fame in the modern period as a direct result of the extreme popularity of the translation of such verses into English by Edward FitzGerald (1859). FitzGerald's "Rubaiyat of Omar Khayyam" contains loose translations of quatrains from the Bodleian manuscript. It enjoyed such success in the fin de siècle period that a bibliography compiled in 1929 listed more than 300 separate editions, and many more have been published since.


title: Omar Khayyam

text: Khayyam considered himself intellectually to be a student of Avicenna. According to Al-Bayhaqi, he was reading the metaphysics in Avicenna's "the Book of Healing" before he died. There are six philosophical papers believed to have been written by Khayyam. One of them, "On existence" (), was written originally in Persian and deals with the subject of existence and its relationship to universals. Another paper, titled "The necessity of contradiction in the world, determinism and subsistence" (), is written in Arabic and deals with free will and determinism. The titles of his other works are "On being and necessity" (), "The Treatise on Transcendence in Existence" (), "On the knowledge of the universal principles of existence" (), and "Abridgement concerning natural phenomena" ().


title: Omar Khayyam

text: A literal reading of Khayyam's quatrains leads to the interpretation of his philosophic attitude toward life as a combination of pessimism, nihilism, Epicureanism, fatalism, and agnosticism. This view is taken by Iranologists such as Arthur Christensen, H. Schaeder, Richard N. Frye, E. D. Ross, E. H. Whinfield and George Sarton. Conversely, the Khayyamic quatrains have also been described as mystical Sufi poetry. In addition to his Persian quatrains, J. C. E. Bowen (1973) mentions that Khayyam's Arabic poems also "express a pessimistic viewpoint which is entirely consonant with the outlook of the deeply thoughtful rationalist philosopher that Khayyam is known historically to have been." Edward FitzGerald emphasized the religious skepticism he found in Khayyam. In his preface to the "Rubáiyát" he claimed that he "was hated and dreaded by the Sufis", and denied any pretense at divine allegory: "his Wine is the veritable Juice of the Grape: his Tavern, where it was to be had: his "Saki", the Flesh and Blood that poured it out for him." Sadegh Hedayat is one of the most notable proponents of Khayyam's philosophy as agnostic skepticism, and according to Jan Rypka (1934), he even considered Khayyam an atheist. Hedayat (1923) states that "while Khayyam believes in the transmutation and transformation of the human body, he does not believe in a separate soul; if we are lucky, our bodily particles would be used in the making of a jug of wine." Omar Khayyam's poetry has been cited in the context of New Atheism, such as in "The Portable Atheist" by Christopher Hitchens.


title: Omar Khayyam

text: Al-Qifti (ca. 1172–1248) appears to confirm this view of Omar's philosophy. In his work "The History of Learned Men" he reports that Omar's poems were only outwardly in the Sufi style, but were written with an anti-religious agenda. He also mentions that he was at one point indicted for impiety, but went on a pilgrimage to prove he was pious. The report has it that upon returning to his native city he concealed his deepest convictions and practised a strictly religious life, going morning and evening to the place of worship.


title: Omar Khayyam

text: In the context of a piece entitled "On the Knowledge of the Principles of Existence", Khayyam endorses the Sufi path. Csillik (1960) suggests the possibility that Omar Khayyam could see in Sufism an ally against orthodox religiosity. Other commentators do not accept that Omar's poetry has an anti-religious agenda and interpret his references to wine and drunkenness in the conventional metaphorical sense common in Sufism. The French translator J. B. Nicolas held that Omar's constant exhortations to drink wine should not be taken literally, but should be regarded rather in the light of Sufi thought where rapturous intoxication by "wine" is to be understood as a metaphor for the enlightened state or divine rapture of "baqaa". The view of Omar Khayyam as a Sufi was defended by Bjerregaard (1915), Idries Shah (1999), and Dougan (1991) who attributes the reputation of hedonism to the failings of FitzGerald's translation, arguing that Omar's poetry is to be understood as "deeply esoteric". On the other hand, Iranian experts such as Mohammad Ali Foroughi and Mojtaba Minovi rejected the hypothesis that Omar Khayyam was a Sufi. Foroughi stated that Khayyam's ideas may have been consistent with that of Sufis at times but there is no evidence that he was formally a Sufi. Aminrazavi (2007) states that "Sufi interpretation of Khayyam is possible only by reading into his "Rubāʿīyyāt" extensively and by stretching the content to fit the classical Sufi doctrine." Furthermore, Frye (1975) emphasizes that Khayyam was intensely disliked by a number of celebrated Sufi mystics who belonged to the same century. This includes Shams Tabrizi (spiritual guide of Rumi), Najm al-Din Daya who described Omar Khayyam as "an unhappy philosopher, atheist, and materialist", and Attar who regarded him not as a fellow-mystic but a free-thinking scientist who awaited punishments hereafter.


title: Omar Khayyam

text: Seyyed Hossein Nasr argues that it is "reductive" to use a literal interpretation of his verses (many of which are of uncertain authenticity to begin with) to establish Omar Khayyam's philosophy. Instead, he adduces Khayyam's interpretive translation of Avicenna's treatise "Discourse on Unity" (), where he expresses orthodox views on Divine Unity in agreement with the author. The prose works believed to be Omar's are written in the Peripatetic style and are explicitly theistic, dealing with subjects such as the existence of God and theodicy. As noted by Bowen these works indicate his involvement in the problems of metaphysics rather than in the subtleties of Sufism. As evidence of Khayyam's faith and/or conformity to Islamic customs, Aminrazavi mentions that in his treatises he offers salutations and prayers, praising God and Muhammad. In most biographical extracts, he is referred to with religious honorifics such as , "The Patron of Faith" (), and "The Evidence of Truth" (). He also notes that biographers who praise his religiosity generally avoid making reference to his poetry, while the ones who mention his poetry often do not praise his religious character. For instance, Al-Bayhaqi's account, which antedates by some years other biographical notices, speaks of Omar as a very pious man who professed orthodox views down to his last hour.


title: Omar Khayyam

text: On the basis of all the existing textual and biographical evidence, the question remains somewhat open, and as a result Khayyam has received sharply conflicting appreciations and criticisms.


title: Omar Khayyam

text: The various biographical extracts referring to Omar Khayyam describe him as unequalled in scientific knowledge and achievement during his time. Many called him by the epithet "King of the Wise" (). Shahrazuri (d. 1300) esteems him highly as a mathematician, and claims that he may be regarded as "the successor of Avicenna in the various branches of philosophic learning". Al-Qifti (d. 1248), even though disagreeing with his views, concedes he was "unrivalled in his knowledge of natural philosophy and astronomy". Despite being hailed as a poet by a number of biographers, according to Richard N. Frye "it is still possible to argue that Khayyam's status as a poet of the first rank is a comparatively late development."


title: Omar Khayyam

text: Thomas Hyde was the first European to call attention to Omar and to translate one of his quatrains into Latin ("Historia religionis veterum Persarum eorumque magorum", 1700). Western interest in Persia grew with the Orientalism movement in the 19th century. Joseph von Hammer-Purgstall (1774–1856) translated some of Khayyam's poems into German in 1818, and Gore Ouseley (1770–1844) into English in 1846, but Khayyam remained relatively unknown in the West until after the publication of Edward FitzGerald's "Rubaiyat of Omar Khayyam" in 1859. FitzGerald's work at first was unsuccessful but was popularised by Whitley Stokes from 1861 onward, and the work came to be greatly admired by the Pre-Raphaelites. In 1872 FitzGerald had a third edition printed which increased interest in the work in America. By the 1880s, the book was extremely well known throughout the English-speaking world, to the extent of the formation of numerous "Omar Khayyam Clubs" and a "fin de siècle cult of the Rubaiyat". Khayyam's poems have been translated into many languages; many of the more recent ones are more literal than that of FitzGerald.


title: Omar Khayyam

text: FitzGerald's translation was a factor in rekindling interest in Khayyam as a poet even in his native Iran. Sadegh Hedayat in his "Songs of Khayyam" ("Taranehha-ye Khayyam", 1934) reintroduced Omar's poetic legacy to modern Iran. Under the Pahlavi dynasty, a new monument of white marble, designed by the architect Houshang Seyhoun, was erected over his tomb. A statue by Abolhassan Sadighi was erected in Laleh Park, Tehran in the 1960s, and a bust by the same sculptor was placed near Khayyam's mausoleum in Nishapur. In 2009, the state of Iran donated a pavilion to the United Nations Office in Vienna, inaugurated at Vienna International Center. In 2016, three statues of Khayyam were unveiled: one at the University of Oklahoma, one in Nishapur and one in Florence, Italy. Over 150 composers have used the "Rubaiyat" as their source of inspiration. The earliest such composer was Liza Lehmann.


title: Omar Khayyam

text: FitzGerald rendered Omar's name as "Tentmaker", and the anglicized name of "Omar the Tentmaker" resonated in English-speaking popular culture for a while. Thus, Nathan Haskell Dole published a novel called "Omar, the Tentmaker: A Romance of Old Persia" in 1898. "Omar the Tentmaker of Naishapur" is a historical novel by John Smith Clarke, published in 1910. "Omar the Tentmaker" is also the title of a 1914 play by Richard Walton Tully in an oriental setting, adapted as a silent film in 1922. US General Omar Bradley was given the nickname "Omar the Tent-Maker" in World War II.


title: Omar Khayyam

text: The quatrain by Omar Khayyam known as "The Moving Finger", in the form of its translation by the English poet Edward Fitzgerald is one of the most popular quatrains in the Anglosphere. It reads:


title: Omar Khayyam

text: The title of the novel "The Moving Finger" written by Agatha Christie and published in 1942 was inspired by this quatrain of the translation of "Rubaiyat of Omar Khayyam" by Edward Fitzgerald. Martin Luther King also cites this quatrain of Omar Khayyam in one of his speeches "":


title: Omar Khayyam

text: In one of his apologetic speeches about the Clinton–Lewinsky scandal, Bill Clinton, the 42nd president of the US, also cites this quatrain.


title: Omar Khayyam

text: The French-Lebanese writer Amin Maalouf based the first half of his historical fiction novel "Samarkand" on Khayyam's life and the creation of his Rubaiyat. The sculptor Eduardo Chillida produced four massive iron pieces titled "Mesa de Omar Khayyam" (Omar Khayyam's Table) in the 1980s.


title: Omar Khayyam

text: The lunar crater Omar Khayyam was named in his honour in 1970, as was the minor planet 3095 Omarkhayyam discovered by Soviet astronomer Lyudmila Zhuravlyova in 1980.


title: Omar Khayyam

text: Google has released two Google Doodles commemorating him. The first was on his 964th birthday on 18 May 2012. The second was on his 971st birthday on 18 May 2019.


title: Rachel Ticotin

text: Rachel Ticotin Strauss is an American film and television actress. She has appeared in films such as "Fort Apache, The Bronx"; "Total Recall", "Falling Down", and "Con Air". She has appeared in the NBC legal drama "" as Lt. Arleen Gonzales, and guest starred in the "Warriors" episode of "Blue Bloods" in 2013 (season 3, episode 15), appearing as "Carmen Castillo".


title: Rachel Ticotin

text: Ticotin (pronounced "tick-oh-tin") was born in the Bronx, New York City, the daughter of Iris Torres, a Puerto Rican educator, and Abe Ticotin, a Russian-Jewish used-car salesman. Her sister, Nancy Ticotin, is also an actress. She also has three brothers, Marcus, Daniel, and David A. Ticotin, a first assistant director who lives in Calabasas, California, with his wife Alexis and their children. Her brother Daniel, now known as Sahaj, is a musician and lead singer for the rock group Ra. Ticotin grew up, and received her primary and secondary education, in the Bronx. Her parents enrolled her in the Ballet Hispanico of New York, where she took ballet lessons.


title: Rachel Ticotin

text: In 1978, Ticotin made her film debut as a dancer in the film "King of the Gypsies." She also acted in the off-Broadway production of Miguel Piñero's "The Sun Always Shines for the Cool". During this period, she received an onscreen credit as a production assistant on Brian De Palma's "Dressed to Kill". Her first big break came when, working as a production assistant alongside her brother David in 1981, she was given a significant role as "Isabella", Paul Newman's love interest in the movie "Fort Apache, The Bronx". That same year, she was listed as one of 12 promising new actors in John Willis' "Screen World" Vol. 33.


title: Rachel Ticotin

text: In 1983, she landed a regular role on NBC's television drama "Love and Honor". Other television series in which she has appeared include: "Ohara" (1987), "Women on the Inside" (1991), "Crime & Punishment" (1993), and "Disney's Gargoyles" (1994).


title: Rachel Ticotin

text: Ticotin's film work includes: "Critical Condition" (1987) as Rachel Atwood, "Total Recall" (1990) as Melina alongside Arnold Schwarzenegger and Sharon Stone, "Where the Day Takes You" (1992) as Officer Landers, "Falling Down" (1993) as Detective Sandra Torres, "First Time Felon" (1997) as Mcbride alongside Omar Epps, and "Con Air" (1997) alongside Nicolas Cage, in which she earned an ALMA Award for her role as prison guard Sally Bishop. In 1995, she played the role of Doña Inez, the Mexican mother of Don Juan in the tongue-in-cheek romantic comedy "Don Juan DeMarco", with Johnny Depp playing the title role.


title: Rachel Ticotin

text: Ticotin has participated in over 40 films and television series, appearing in "Man on Fire" (2004) as Mariana and "The Sisterhood of the Traveling Pants" (2005). Ticotin was cast as Vangie Gonzalez Taylor in the second season of PBS's television series "American Family" alongside Edward James Olmos, Esai Morales, Raquel Welch, and Kate del Castillo. Ticotin also appeared on television in season two of the ABC series "Lost" as Captain Teresa Cortez, mother of Michelle Rodriguez's character Ana Lucia Cortez.


title: Rachel Ticotin

text: In September 2010, she joined the cast of the NBC legal drama "" as Lt. Arleen Gonzales in place of Wanda De Jesus, who originally played the role. Ticotin reshot the scenes originally performed by De Jesus.


title: Rachel Ticotin

text: She was married to actor David Caruso from 1984 to 1987, with whom she has a daughter (Greta), born in 1984. Since 1998, she has been married to actor Peter Strauss.


title: Stand by Me (Ben E. King song)

text: "Stand by Me" is a song originally performed in 1961 by American singer-songwriter Ben E. King and written by him, along with Jerry Leiber and Mike Stoller, who together used the pseudonym Elmo Glick. According to King, the title is derived from, and was inspired by, a spiritual written by Sam Cooke and J. W. Alexander called "Stand by Me Father," recorded by the Soul Stirrers with Johnnie Taylor singing lead. The third line of the second verse of the former work derives from Psalm 46:2c/3c.


title: Stand by Me (Ben E. King song)

text: It was featured on the soundtrack of the 1986 film of the same name, and a corresponding music video, featuring King along with actors River Phoenix and Wil Wheaton, was released to promote the film. It was also featured in a 1987 European commercial of Levi's 501 jeans, contributing to greater success in Europe. In 2012, its royalties were estimated to have topped $22.8 million (£17 million), making it the sixth highest-earning song as of its era. 50% of the royalties were paid to King. In 2015, King's original version was inducted into the National Recording Registry by the Library of Congress, as "culturally, historically, or aesthetically significant", just under five weeks before his death. Later in the year, the 2015 lineup of the Drifters recorded it in tribute.


title: Stand by Me (Ben E. King song)

text: There have been over 400 recorded versions of the song, performed by many artists, notably Otis Redding, John Lennon, Cassius Clay (later Muhammad Ali), 4 the Cause, Tracy Chapman, musicians of the Playing for Change project, Florence and the Machine, and the Kingdom Choir. A-League club Melbourne Victory FC play this song before home matches, while fans raise their scarves above their heads and sing the lyrics.


title: Stand by Me (Ben E. King song)

text: In 1960, Ben E. King was inspired to update the early 20th-century gospel hymn "Stand by Me" by Charles Albert Tindley, which was based around psalm 46, "will not we fear, though the Earth be removed, and though the mountains be carried into the midst of the sea."


title: Stand by Me (Ben E. King song)

text: According to the documentary "History of Rock 'n' Roll", King had no intention of recording the song himself. King had written it for the Drifters, who passed on recording it. After the "Spanish Harlem" recording session in 1960, King had some studio time left over. The session's producers, Jerry Leiber and Mike Stoller, asked if he had any more songs. King played it on the piano for them. They liked it and called the studio musicians back in to record it.


title: Stand by Me (Ben E. King song)

text: I remember arriving at our office as Jerry and Ben were working on lyrics for a new song. King had the beginnings of a melody that he was singing "a cappella". I went to the piano and worked up the harmonies, developing a bass pattern that became the signature of the song. Ben and Jerry quickly finished the lyrics ... .


title: Stand by Me (Ben E. King song)

text: Ben E. had the beginnings of a song—both words and music. He worked on the lyrics together with Jerry, and I added elements to the music, particularly the bass line. To some degree, it's based on a gospel song called "Lord Stand By Me". I have a feeling that Jerry and Ben E. were inspired by it. Ben, of course, had a strong background in church music. He's a 50% writer on the song, and Jerry and I are 25% each... When I walked in, Jerry and Ben E. were working on the lyrics to a song. They were at an old oak desk we had in the office. Jerry was sitting behind it, and Benny was sitting on the top. They looked up and said they were writing a song. I said, "Let me hear it."... Ben began to sing the song a cappella. I went over to the upright piano and found the chord changes behind the melody he was singing. It was in the key of A. Then I created a bass line. Jerry said, "Man that's it!" We used my bass pattern for a starting point and, later, we used it as the basis for the string arrangement created by Stanley Applebaum.


title: Stand by Me (Ben E. King song)

text: The personnel on the song included Romeo Penque on sax, Ernie Hayes on piano, Al Caiola and Charles McCracken on guitars, Lloyd Trotman on double bass, Phil Kraus on percussion, and Gary Chester on drums, plus a wordless mixed chorus and strings. Songwriting credits on the single were shown as King and Elmo Glick—a pseudonym used by Leiber and Stoller.


title: Stand by Me (Ben E. King song)

text: King's record went to number 1 on the R&B charts and was a Top Ten hit on the US charts twice—in its original release, entering the Billboard chart on May 13, 1961 and peaking at number 4 on June 16, 1961, and a 1986 re-release coinciding with its use as the theme song for the film of the same name following its appearance in the film, when it peaked at number 9 on December 20, 1986 – January 3, 1987. The song is also heard in the televised advertisement of Levi's 501 jeans. In the commercial, a man wearing a black denim jeans is able to enter a nightclub whose policy is "no blue jeans". "Stand by Me" also topped the charts in Canada, Ireland, and the United Kingdom upon its re-release. In the latter country, the song topped the UK Singles Chart in January 1987, mostly because of the jeans TV commercial, originally peaking at number 27 on the UK Singles Chart on its original release in Britain in 1961.


title: Stand by Me (Ben E. King song)

text: The song was not released on an album until it had been out as a single for two years. The song appeared on King's "Don't Play That Song!" album.


title: Stand by Me (Ben E. King song)

text: The song was ranked 122nd on "Rolling Stone"<nowiki>'</nowiki>s list of the 500 Greatest Songs of All Time. In 1999, BMI named it as the fourth most-performed song of the 20th century, with about seven million performances.


title: Stand by Me (Ben E. King song)

text: On March 27, 2012, the Songwriters Hall of Fame announced that the song would receive its 2012 Towering Song Award and that King would be honored with the 2012 Towering Performance Award for his recording of it. In February 2019, the Smooth Radio network in the United Kingdom called it one "of the best love songs of the 1960s".


title: Stand by Me (Ben E. King song)

text: The song uses a version of the common chord progression now called the 50s progression, which has been called the "'Stand by Me' changes" after the song.


title: Stand by Me (Ben E. King song)

text: John Lennon recorded his version of the song for his 1975 album "Rock 'n' Roll". Lennon's remake became a single three weeks after the album's release and was his last hit prior to his five-year retirement from the music industry. Lennon filmed a performance of the song for "The Old Grey Whistle Test" in 1975. "Cash Box" said of it that "John's serenading guitar chords herald this bright new production of one of rockdom's favorites," and that it displays Lennon's "magical, mysterious voice...at his finest."


title: Stand by Me (Ben E. King song)

text: On the week of May 3, 1975, this version was in its second of two weeks at the peak position number 20 on the US Hot 100, right in front of King's comeback hit "Supernatural Thing – Part I" at number 21. Both tunes fell off the top 40 the next week and off the chart the week after that. Lennon's version stayed on top 100 of the UK Singles Chart for seven weeks, peaking at number 30 on its fourth week on the week of May 18–24, 1975. It peaked at number 13 on Canada's "RPM" Top Singles chart on the week ending May 3, 1975 and stayed on the peak position the following week. It peaked at number 11 on the Official New Zealand Music Chart on the week of July 14, 1975.


title: Stand by Me (Ben E. King song)

text: The single's B-side track is "Move Over Ms. L", initially intended for Lennon's previous album "Walls and Bridges" but was cut from the final lineup due to his dissatisfaction with his early takes. Keith Moon covered "Move Over Ms. L" for his 1975 solo album "Two Sides of the Moon".


title: Stand by Me (Ben E. King song)

text: Before the parent album's official release, during Lennon's March 1974 sessions with Harry Nilsson for Nilsson's album "Pussy Cats", Lennon recorded two takes of the song in collaboration with former Beatles member Paul McCartney. McCartney performed on the drums; Lennon on guitar. The unreleased recordings would eventually be included in a bootleg album "A Toot and a Snore in '74".


title: Stand by Me (Ben E. King song)

text: "Billboard" regarded Lennon's version as "the best version since the original." "Pitchfork" writer Marc Hogan found Lennon's version "more affecting (just barely)" than the original due to the "acoustic guitar and Lennon's fervent vocals". A 2007 book "The Words and Music of John Lennon" by Ben Urish and Ken Bielen called Lennon's version one of the "stronger" tracks of the album. Journalist and book author Robert Webb in 2013 called this version one of the "greatest cover versions".


title: Stand by Me (Ben E. King song)

text: Mickey Gilley released his version of the song in 1980, and it was included in the movie "Urban Cowboy". It was his eighth No. 1 on the US country charts and also reached No. 22 on the US Hot 100. This version also peaked at No. 3 in Canadian "RPM" Country Singles in September 1980 and No. 51 in "RPM" Top Singles the following month. The song would "become one of Gilley's signature songs."


title: Stand by Me (Ben E. King song)

text: Documentary filmmaker Mark Johnson, who also created the Playing for Change project based on an idea he had in the late 1990s and established the eponymous Foundation, witnessed street performer Roger Ridley (died November 16, 2005) singing "Stand by Me" in Santa Monica, California, in March 2005. Johnson was inspired to film Ridley's performance and another thirty-six musicians' individual performances of the song "around the world" and then mix the clips into one music video. The music video was featured in an October 2008 episode of "Bill Moyers Journal", where Johnson was promoting the documentary film "Playing for Change: Peace Through Music", which includes the music video and was shown as part of the 2008 Tribeca Film Festival in New York City. The music video was uploaded via the Playing for Change YouTube channel in November 2008, garnering more than 10 million views in May 2009. The total amount of views of the YouTube video increased to more than 24 million in December 2010, 30 million in March 2011, 40 million in March 2012, 50 million in some time between 2012 and 2014, 60 million in 2014, 74 million in May 2015, 100 million in 2017, and 140 (or 142) million in March 2020.


title: Stand by Me (Ben E. King song)

text: The musicians' performance of the song would be later included in their 2009 debut album "Songs Around the World". The debut album has nine other tracks, comes with the seven-track bonus DVD, and sold about 26,000 units on its first week, 85% of sales from online sales and "nontraditional retail stores (including Starbucks locations)" and 25% from outside the United States.


title: Stand by Me (Ben E. King song)

text: Prince Royce recorded a bachata version of the song as his debut single, changing parts of the lyrics into Spanish. This version peaked number eight on US Hot Latin Tracks and number one on US Tropical Airplay. At the Latin Grammy Awards of 2010, Royce performed the song live along with Ben E. King. Royce's remake received a Lo Nuestro award for "Tropical Song of the Year". Royce performed the song live again at a July 2016 Philips Arena concert in Atlanta, Georgia alongside a male fan, at a 2017 Amway Center concert in Orlando, Florida, as the second song for the 2019 RodeoHouston concert, and at the third night of the 2020 Democratic National Convention. He also made a dance version for his debut album as well.


title: Stand by Me (Ben E. King song)

text: Adriano Celentano's 1962 Italian version, "Pregherò" (meaning "I will pray") reached number 1 on the Italian charts. Muhammad Ali (as Cassius Clay) released a version on his 1963 spoken-word/comedy album "I Am the Greatest". Clay's recording was released as the B-side of the eponymous single in 1964, charting on the "Billboard" "Bubbling Under Hot 100 Singles". It was included on the CD Beat Of The Pops Vol 34.


title: Stand by Me (Ben E. King song)

text: Otis Redding covered the song for his 1964 debut album "Pain in My Heart"; Kenny Lynch's 1964 version stayed on the top 100 UK Singles Chart for seven weeks, peaking at number 39 on the week of May 7–13, 1964, its fourth week. Spyder Turner's 1967 version climbed to number 3 on the US "Billboard" Black Singles chart, number 12 on the "Billboard" Hot 100 chart, and number 10 in Canada.


title: Stand by Me (Ben E. King song)

text: David and Jimmy Ruffin (credited as The Ruffin Brothers) remade the song for their only collaborative album "I Am My Brother's Keeper" (1970). Released as a single, the version stayed at its peak position number 61 on "Billboard" Hot 100 for two weeks on the weeks ending November 28 (its sixth week) and December 5, 1970 (seventh week). It also peaked at number 24 on "Billboard" Soul Singles on the week ending November 21, 1970, its fourth week.


title: Stand by Me (Ben E. King song)

text: Maurice White's 1985 cover from his self titled album reached No. 6 on the US "Billboard" Hot R&B/Hip-Hop Singles chart and No. 11 on the US "Billboard" Adult Contemporary Songs chart. White's version also topped at No. 5 on the RPM Canadian Adult Contemporary Songs chart and No. 8 on the New Zealand Singles chart.


title: Stand by Me (Ben E. King song)

text: Julian Lennon, son of John Lennon, performed the song at a spring 1985 concert, seen in the 1985 home video release "Stand by Me: A Portrait of Julian Lennon". This version later appeared on the soundtrack to the 1986 film, "Playing for Keeps". U2 performed the song with Bruce Springsteen at the John F. Kennedy Stadium (Philadelphia) concert on September 25, 1987, during the Joshua Tree Tour.


title: Stand by Me (Ben E. King song)

text: Anita Mui recorded the Cantonese version for her 1987 Cantonese album "Mung Leui Gung Tseui". In 1988, Mui's version was awarded as one of top ten gold songs by Hong Kong telecommunication stations RTHK and by TVB. After Mui's death in 2003, Hong Kong singers and actors Miriam Yeung, Denise Ho, Alex To, Edmond Leung, band members of Grasshopper, Andy Hui, and William So performed Mui's version at "Anita Mui. 10. Memory. Music. Gather." (), the December 30, 2013 tribute concert for Mui.


title: Stand by Me (Ben E. King song)

text: In a 1995 music video entitled "Disney's Timon & Pumbaa in "Stand by Me"", Timon performs the song with slightly altered lyrics, while every time Timon sings the chorus, Pumbaa survives physical mishaps and ferocious creatures. A trio of frogs then finish the song at the end. It's the only media in the series to use digital ink and paint. It was shown before "Tom and Huck" in theaters.


title: Stand by Me (Ben E. King song)

text: A version of the song was released by American R&B group 4 the Cause as their debut single in 1998. It was a number-one hit in Switzerland, reached number two of the Austrian and German singles charts and number three in New Zealand, and was a top-ten hit in several other countries.


title: Stand by Me (Ben E. King song)

text: Florence and the Machine recorded the song for the soundtrack and trailer of "Final Fantasy XV" in 2016. The band released its EP "Songs from Final Fantasy XV" on August 12, 2016, containing the band's remake. The cover peaked at number fifteen on the Billboard Hot Rock Singles in December 2016. In February 2017, voice actors of "Final Fantasy XV" Ray Chase (Noctis), Adam Croasdell (Ignis), Robbie Daymond (Prompto), and Max Mittelman (Tredd Furia of the 2016 film "") performed King's song all together while streaming their "FFXV" playthrough in a Twitch livestream video, viewed by almost 800 users.


title: Stand by Me (Ben E. King song)

text: Skylar Grey recorded the song which appeared for a Budweiser commercial for Super Bowl LII, with proceeds for the song to go to the American Red Cross.


title: Stand by Me (Ben E. King song)

text: The Kingdom Choir performed the song at the wedding of Prince Harry and Meghan Markle on May 19, 2018. Their version debuted and peaked at number one on the "Billboard" Hot Gospel Songs chart on the week ending June 2, 2018. It also entered the UK Singles Chart and peaked at number 94 on its first and only week, the week of May 25–31, 2018. It is included in their debut album, "Stand by Me", released later that year.


title: Stand by Me (Ben E. King song)

text: On October 24, 2021, Snoop Dogg performed the song alongside the audience at a Big Night Live concert in Boston as a tribute to his mother Beverly Tate, who died at age 70 earlier on the same night.


title: Joan Lin

text: Joan Lin Feng-jiao (born 30 June 1953) is a Taiwanese former actress. She is married to Hong Kong-Chinese actor and martial artist Jackie Chan.


title: Joan Lin

text: Born 30 June 1953 in Taipei, Lin was the second child out of five children. She dropped out of school at the age of 12 due to her family's poverty.


title: Joan Lin

text: In 1972, at age 19, Lin starred in her first film, "" (also known as "Hero of Waterfront"), a Kung fu film. Many of her films are based on the novels of Chiung Yao.


title: Joan Lin

text: Lin, together with Charlie Chin and Chin Han and Brigitte Lin, were the biggest names in the Taiwanese and Hong Kong cinema industries in the 1970s. Dubbed the "Two Chins, Two Lins" (二秦二林) by the media, they were known for starring in several box-office hits, many of which were adaptations of Chiung Yao's novels.


title: Joan Lin

text: In 1979, she won Best Leading Actress at the 16th Golden Horse Awards for her performance in "The Story of a Small Town". During her 10-year career, Lin appeared in more than 70 films.


title: Joan Lin

text: Joan Lin met Hong Kong-born Chinese actor and martial artist Jackie Chan in January 1981 and they secretly married in Los Angeles in 1982. Their only child, Jaycee Chan, was born the day after they got married. Lin has since retired from the film industry.


title: Address Resolution Protocol

text: The Address Resolution Protocol (ARP) is a communication protocol used for discovering the link layer address, such as a MAC address, associated with a given internet layer address, typically an IPv4 address. This mapping is a critical function in the Internet protocol suite. ARP was defined in 1982 by , which is Internet Standard STD 37.


title: Address Resolution Protocol

text: ARP has been implemented with many combinations of network and data link layer technologies, such as IPv4, Chaosnet, DECnet and Xerox PARC Universal Packet (PUP) using IEEE 802 standards, FDDI, X.25, Frame Relay and Asynchronous Transfer Mode (ATM).


title: Address Resolution Protocol

text: In Internet Protocol Version 6 (IPv6) networks, the functionality of ARP is provided by the Neighbor Discovery Protocol (NDP).


title: Address Resolution Protocol

text: The Address Resolution Protocol is a request-response protocol. Its messages are directly encapsulated by a link layer protocol. It is communicated within the boundaries of a single network, never routed across internetworking nodes.


title: Address Resolution Protocol

text: The Address Resolution Protocol uses a simple message format containing one address resolution request or response. The packets are carried at the data link layer of the underlying network as raw payload. In the case of Ethernet, a EtherType value is used to identify ARP frames.


title: Address Resolution Protocol

text: The size of the ARP message depends on the link layer and network layer address sizes. The message header specifies the types of network in use at each layer as well as the size of addresses of each. The message header is completed with the operation code for request (1) and reply (2). The payload of the packet consists of four addresses, the hardware and protocol address of the sender and receiver hosts.


title: Address Resolution Protocol

text: The principal packet structure of ARP packets is shown in the following table which illustrates the case of IPv4 networks running on Ethernet. In this scenario, the packet has 48-bit fields for the sender hardware address (SHA) and target hardware address (THA), and 32-bit fields for the corresponding sender and target protocol addresses (SPA and TPA). The ARP packet size in this case is 28 bytes.


title: Address Resolution Protocol

text: ARP protocol parameter values have been standardized and are maintained by the Internet Assigned Numbers Authority (IANA).


title: Address Resolution Protocol

text: The EtherType for ARP is . This appears in the Ethernet frame header when the payload is an ARP packet and is not to be confused with PTYPE, which appears within this encapsulated ARP packet.


title: Address Resolution Protocol

text: ARP's placement within the Internet protocol suite and the OSI model may be a matter of confusion or even of dispute. mentions ARP within its link layer section without explicitly placing it within that layer. Some older references place ARP in OSI's data link layer while newer editions associate it with the network layer or introduce an intermediate OSI layer 2.5.


title: Address Resolution Protocol

text: Two computers in an office ("Computer 1" and "Computer 2") are connected to each other in a local area network by Ethernet cables and network switches, with no intervening gateways or routers. "Computer 1" has a packet to send to "Computer 2". Through DNS, it determines that "Computer 2" has the IP address .


title: Address Resolution Protocol

text: To send the message, it also requires "Computer 2"s MAC address. First, "Computer 1" uses a cached ARP table to look up for any existing records of "Computer 2"'s MAC address (). If the MAC address is found, it sends an Ethernet frame containing the IP packet onto the link with the destination address . If the cache did not produce a result for , "Computer 1" has to send a broadcast ARP request message (destination MAC address), which is accepted by all computers on the local network, requesting an answer for .


title: Address Resolution Protocol

text: "Computer 2" responds with an ARP response message containing its MAC and IP addresses. As part of fielding the request, "Computer 2" may insert an entry for "Computer 1" into its ARP table for future use.


title: Address Resolution Protocol

text: "Computer 1" receives and caches the response information in its ARP table and can now send the packet.


title: Address Resolution Protocol

text: An ARP probe in IPv4 is an ARP request constructed with the SHA of the probing host, an SPA of all 0s, a THA of all 0s, and a TPA set to the IPv4 address being probed for. If some host on the network regards the IPv4 address (in the TPA) as its own, it will reply to the probe (via the SHA of the probing host) thus informing the probing host of the address conflict. If instead there is no host which regards the IPv4 address as its own, then there will be no reply. When several such probes have been sent, with slight delays, and none receive replies, it can reasonably be expected that no conflict exists. As the original probe packet contains neither a valid SHA/SPA nor a valid THA/TPA pair, there is no risk of any host using the packet to update its cache with problematic data. Before beginning to use an IPv4 address (whether received from manual configuration, DHCP, or some other means), a host implementing this specification must test to see if the address is already in use, by broadcasting ARP probe packets.


title: Address Resolution Protocol

text: ARP may also be used as a simple announcement protocol. This is useful for updating other hosts' mappings of a hardware address when the sender's IP address or MAC address changes. Such an announcement, also called a gratuitous ARP (GARP) message, is usually broadcast as an "ARP request" containing the SPA in the target field (TPA=SPA), with THA set to zero. An alternative way is to broadcast an "ARP reply" with the sender's SHA and SPA duplicated in the target fields (TPA=SPA, THA=SHA).


title: Address Resolution Protocol

text: The "ARP request" and "ARP reply" announcements are both standards-based methods, but the "ARP request" method is preferred. Some devices may be configured for the use of either of these two types of announcements.


title: Address Resolution Protocol

text: An ARP announcement is not intended to solicit a reply; instead, it updates any cached entries in the ARP tables of other hosts that receive the packet. The operation code in the announcement may be either request or reply; the ARP standard specifies that the opcode is only processed after the ARP table has been updated from the address fields.


title: Address Resolution Protocol

text: Many operating systems issue an ARP announcement during startup. This helps to resolve problems which would otherwise occur if, for example, a network card was recently changed (changing the IP-address-to-MAC-address mapping) and other hosts still have the old mapping in their ARP caches.


title: Address Resolution Protocol

text: ARP announcements are also used by some network interfaces to provide load balancing for incoming traffic. In a team of network cards, it is used to announce a different MAC address within the team that should receive incoming packets.


title: Address Resolution Protocol

text: ARP announcements can be used in the Zeroconf protocol to allow automatic assignment of a link-local address to an interface where no other IP address configuration is available. The announcements are used to ensure an address chosen by a host is not in use by other hosts on the network link.


title: Address Resolution Protocol

text: This function can be dangerous from a cybersecurity viewpoint since an attacker can obtain information about the other hosts of its subnet to save in their ARP cache (ARP spoofing) an entry where the attacker MAC is associated, for instance, to the IP of the default gateway, thus allowing him to intercept all the traffic to external networks.


title: Address Resolution Protocol

text: ARP mediation refers to the process of resolving Layer-2 addresses through a virtual private wire service (VPWS) when different resolution protocols are used on the connected circuits, e.g., Ethernet on one end and Frame Relay on the other. In IPv4, each provider edge (PE) device discovers the IP address of the locally attached customer edge (CE) device and distributes that IP address to the corresponding remote PE device. Then each PE device responds to local ARP requests using the IP address of the remote CE device and the hardware address of the local PE device. In IPv6, each PE device discovers the IP address of both local and remote CE devices and then intercepts local Neighbor Discovery (ND) and Inverse Neighbor Discovery (IND) packets and forwards them to the remote PE device.


title: Address Resolution Protocol

text: Inverse Address Resolution Protocol (Inverse ARP or InARP) is used to obtain network layer addresses (for example, IP addresses) of other nodes from data link layer (Layer 2) addresses. Since ARP translates layer-3 addresses to layer-2 addresses, InARP may be described as its inverse. In addition, InARP is implemented as a protocol extension to ARP: it uses the same packet format as ARP, but different operation codes.


title: Address Resolution Protocol

text: InARP is primarily used in Frame Relay (DLCI) and ATM networks, in which layer-2 addresses of virtual circuits are sometimes obtained from layer-2 signaling, and the corresponding layer-3 addresses must be available before those virtual circuits can be used.


title: Address Resolution Protocol

text: The Reverse Address Resolution Protocol (Reverse ARP or RARP), like InARP, translates layer-2 addresses to layer-3 addresses. However, in InARP the requesting station queries the layer-3 address of another node, whereas RARP is used to obtain the layer-3 address of the requesting station itself for address configuration purposes. RARP is obsolete; it was replaced by BOOTP, which was later superseded by the Dynamic Host Configuration Protocol (DHCP).


title: Address Resolution Protocol

text: Because ARP does not provide methods for authenticating ARP replies on a network, ARP replies can come from systems other than the one with the required Layer 2 address. An ARP "proxy" is a system that answers the ARP request on behalf of another system for which it will forward traffic, normally as a part of the network's design, such as for a dialup internet service. By contrast, in ARP "spoofing" the answering system, or "spoofer", replies to a request for another system's address with the aim of intercepting data bound for that system. A malicious user may use ARP spoofing to perform a man-in-the-middle or denial-of-service attack on other users on the network. Various software exists to both detect and perform ARP spoofing attacks, though ARP itself does not provide any methods of protection from such attacks.


title: Address Resolution Protocol

text: IPv6 uses the Neighbor Discovery Protocol and its extensions such as Secure Neighbor Discovery, rather than ARP.


title: Address Resolution Protocol

text: Computers can maintain lists of known addresses, rather than using an active protocol. In this model, each computer maintains a database of the mapping of Layer 3 addresses (e.g., IP addresses) to Layer 2 addresses (e.g., Ethernet MAC addresses). This data maintained primarily by interpreting ARP packets from the local network link. Thus, it is often called the "ARP cache". Since at least the 1980s, networked computers have a utility called "arp" for interrogating or manipulating this database.


title: Address Resolution Protocol

text: Historically, other methods were used to maintain the mapping between addresses, such as static configuration files, or centrally maintained lists.


title: Address Resolution Protocol

text: Embedded systems such as networked cameras and networked power distribution devices, which lack a user interface, can use so-called "ARP stuffing" to make an initial network connection, although this is a misnomer, as ARP is not involved.


title: Address Resolution Protocol

text: Such devices typically have a method to disable this process once the device is operating normally, as the capability can make it vulnerable to attack.


title: 11:11 (numerology)

text: In numerology, some New Age believers often link 11:11 to chance or coincidence. It is an example of synchronicity. For instance, those who are seeing 11:11 on a clock often claim it as an auspicious sign or signaling a spirit presence.


title: 11:11 (numerology)

text: Post-hoc reasoning and confirmation bias provides a context for such claims, and skeptics have pointed out that the assertions of people like Uri Geller that 11:11 is somehow important in world events do not hold up to even cursory scrutiny.


title: 11:11 (numerology)

text: For various reasons, people ascribe different kinds of significance to dates and numbers. For example, "the eleventh hour of the eleventh day of the eleventh month," 11:00 a.m. (Paris time) 11 November 1918, when the armistice ending World War I came into effect.


title: 11:11 (numerology)

text: 11 November 2011, or "11/11/11" saw an increase in the number of marriages taking place in different areas throughout the world, including the U.S. and across the Asian continent.


title: The Lives of Others

text: The Lives of Others (, ) is a 2006 German drama film written and directed by Florian Henckel von Donnersmarck marking his feature film directorial debut. The plot is about the monitoring of East Berlin residents by agents of the Stasi, East Germany's secret police. It stars Ulrich Mühe as Stasi Captain Gerd Wiesler, Ulrich Tukur as his superior Anton Grubitz, Sebastian Koch as the playwright Georg Dreyman, and Martina Gedeck as Dreyman's lover, a prominent actress named Christa-Maria Sieland.


title: The Lives of Others

text: The film was released in Germany on 23 March 2006. At the same time, the screenplay was published by Suhrkamp Verlag. "The Lives of Others" won the Academy Award for Best Foreign Language Film. The film had earlier won seven Deutscher Filmpreis awards—including those for best film, best director, best screenplay, best actor, and best supporting actor—after setting a new record with 11 nominations. It also won the BAFTA Award for Best Film Not in the English Language and European Film Award for Best Film, while was nominated for the Golden Globe Award for Best Foreign Language Film. "The Lives of Others" cost US$2 million and grossed more than US$77 million worldwide .


title: The Lives of Others

text: Released 17 years after the fall of the Berlin Wall, marking the end of the German Democratic Republic, it was the first notable drama film about the subject after a series of comedies such as "Good Bye, Lenin!" and "Sonnenallee". This approach was widely applauded in Germany even as some criticized the humanization of Wiesler's character. The film's authenticity was considered praiseworthy given that the director grew up outside of East Germany and was 16 when the Berlin Wall fell.


title: The Lives of Others

text: In 1984 East Germany, Stasi "Hauptmann" Gerd Wiesler, code name HGW XX/7, is ordered to spy on the playwright Georg Dreyman, who had so far escaped state scrutiny due to his Communist views and international recognition. Wiesler and his team bug Dreyman's apartment, set up surveillance equipment in an attic and begin reporting Dreyman's activities. Wiesler learns that Dreyman has been put under surveillance at the request of the Minister of Culture, Bruno Hempf, who covets Dreyman's girlfriend, actress Christa-Maria Sieland. After an intervention by Wiesler leads to Dreyman's discovering Sieland's relationship with Hempf, he implores her not to meet him again. Sieland flees to a nearby bar where Wiesler, posing as a fan, urges her to be true to herself. She returns home and reconciles with Dreyman.


title: The Lives of Others

text: At Dreyman's birthday party, his friend Albert Jerska, a blacklisted theatrical director, gives him sheet music for "Sonate vom Guten Menschen" ("Sonata for a Good Man"). Shortly afterwards, Jerska hangs himself. A grieving Dreyman decides to publish an anonymous article in "Der Spiegel", a prominent West German newsweekly. Dreyman's article accuses the state of concealing the country's elevated suicide rates. When Dreyman and his friends feign a defection attempt to determine whether or not his flat is bugged, a now-sympathetic Wiesler does not alert the border guards or his superior Lt. Col. Anton Grubitz and the conspirators believe they are safe. Since all East German typewriters are registered and identifiable, an editor of "Der Spiegel" smuggles Dreyman an ultra-flat typewriter with a red ribbon. Dreyman hides the typewriter under a floorboard of his apartment but is seen by Sieland.