::Alan Turing


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Alan Mathison Turing, OBE, FRS ({{#invoke:IPAc-en|main}}; 23 June 1912 – 7 June 1954) was a British pioneering computer scientist, mathematician, logician, cryptanalyst and theoretical biologist. He was highly influential in the development of computer science, providing a formalisation of the concepts of algorithm and computation with the Turing machine, which can be considered a model of a general purpose computer.<ref name="frs">{{#invoke:Citation/CS1|citation |CitationClass=journal }}</ref><ref name=AFP/><ref>{{#invoke:Footnotes|harvard_citation_no_bracket}}</ref> Turing is widely considered to be the father of theoretical computer science and artificial intelligence.<ref>{{#invoke:Footnotes|harvard_citation_no_bracket}}</ref>

During the Second World War, Turing worked for the Government Code and Cypher School (GC&CS) at Bletchley Park, Britain's codebreaking centre. For a time he led Hut 8, the section responsible for German naval cryptanalysis. He devised a number of techniques for breaking German ciphers, including improvements to the pre-war Polish bombe method and an electromechanical machine that could find settings for the Enigma machine. Turing played a pivotal role in cracking intercepted coded messages that enabled the Allies to defeat the Nazis in many crucial engagements, including the Battle of the Atlantic; it has been estimated that this work shortened the war in Europe by as many as two to four years.<ref>See {{#invoke:citation/CS1|citation |CitationClass=news }} A number of sources state that Winston Churchill said that Turing made the single biggest contribution to Allied victory in the war against Nazi Germany. However both The Churchill Centre and Turing's biographer Andrew Hodges have said they know of no documentary evidence to support this claim nor of the date or context in which Churchill supposedly said it, and the Churchill Centre lists it among their Churchill 'Myths'. See {{#invoke:citation/CS1|citation |CitationClass=web }} and {{#invoke:citation/CS1|citation |CitationClass=web }} A BBC News profile piece that repeated the Churchill claim has subsequently been amended to say there is no evidence for it. See {{#invoke:citation/CS1|citation |CitationClass=news }}</ref>

After the war, he worked at the National Physical Laboratory, where he designed the ACE, among the first designs for a stored-program computer. In 1948 Turing joined Max Newman's Computing Laboratory at the University of Manchester, where he helped develop the Manchester computers<ref>{{#invoke:Footnotes|harvard_citation_no_bracket}}</ref> and became interested in mathematical biology. He wrote a paper on the chemical basis of morphogenesis, and predicted oscillating chemical reactions such as the Belousov–Zhabotinsky reaction, first observed in the 1960s.

Turing was prosecuted in 1952 for homosexual acts, when such behaviour was still a criminal act in the UK. He accepted treatment with oestrogen injections (chemical castration) as an alternative to prison. Turing died in 1954, 16 days before his 42nd birthday, from cyanide poisoning. An inquest determined his death as suicide, but it has been noted that the known evidence is equally consistent with accidental poisoning.<ref>{{#invoke:citation/CS1|citation |CitationClass=news }}</ref> In 2009, following an Internet campaign, British Prime Minister Gordon Brown made an official public apology on behalf of the British government for "the appalling way he was treated". Queen Elizabeth II granted him a posthumous pardon in 2013.<ref name=BBC-pardon24Dec/><ref name=turingpardoncryptome24dec2013>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref name=turingindependent24dec2013>{{#invoke:citation/CS1|citation |CitationClass=news }}</ref>

Alan Turing sections
Intro  Early life and family  Education  Cryptanalysis  Early computers and the Turing test  Pattern formation and mathematical biology  Conviction for indecency  Death  Recognition and tributes  Government apology and pardon  Centenary celebrations  Portrayal in adaptations  Awards and honours  Notes  References  Further reading  External links  

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