Misplaced Pages

Alan Turing

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.

This is an old revision of this page, as edited by 113.193.96.202 (talk) at 20:07, 22 June 2012 (→Childhood and youth). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Revision as of 20:07, 22 June 2012 by 113.193.96.202 (talk) (→Childhood and youth)(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff) "Turing" redirects here. For other uses, see Turing (disambiguation).
Alan Turing
File:Alan Turing photo.jpgTuring at the time of his election to Fellowship of the Royal Society.
BornAlan Mathison Turing
(1912-06-23)23 June 1912
Maida Vale, London, England,
United Kingdom
Died7 June 1954(1954-06-07) (aged 41)
Wilmslow, Cheshire, England,
United Kingdom
NationalityBritish
Alma materKing's College, Cambridge
Princeton University
Known forHalting problem
Turing machine
Cryptanalysis of the Enigma
Automatic Computing Engine
Turing Award
Turing Test
Turing patterns
AwardsOfficer of the Order of the British Empire
Fellow of the Royal Society
Scientific career
FieldsMathematics, Cryptanalysis, Computer science
InstitutionsUniversity of Cambridge
Government Code and Cypher School
National Physical Laboratory
University of Manchester
Doctoral advisorAlonzo Church
Doctoral studentsRobin Gandy

Alan Mathison Turing, OBE, FRS (/ˈtjʊərɪŋ/ TEWR-ing; 23 June 1912 – 7 June 1954), was an English mathematician, logician, cryptanalyst and computer scientist. 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 played a significant role in the creation of the modern computer. Turing is widely considered to be the father of computer science and artificial intelligence.

During the Second World War, Turing worked for the Government Code and Cypher School (GCCS) at Bletchley Park, Britain's codebreaking centre. For a time he was head of Hut 8, the section responsible for German naval cryptanalysis. He devised a number of techniques for breaking German ciphers, including the method of the bombe, an electromechanical machine that could find settings for the Enigma machine.

After the war he worked at the National Physical Laboratory, where he created one of the first designs for a stored-program computer, the ACE. In 1948 Turing joined Max Newman's Computing Laboratory at Manchester University, where he assisted in the development of the Manchester computers and became interested in mathematical biology. He wrote a paper on the chemical basis of morphogenesis, and he predicted oscillating chemical reactions such as the Belousov–Zhabotinsky reaction, which were first observed in the 1960s.

Turing's homosexuality resulted in a criminal prosecution in 1952, when homosexual acts were still illegal in the United Kingdom. He accepted treatment with female hormones (chemical castration) as an alternative to prison. He died in 1954, just over two weeks before his 42nd birthday, from cyanide poisoning. An inquest determined it was suicide; his mother and some others believed his death was accidental. On 10 September 2009, following an Internet campaign, British Prime Minister Gordon Brown made an official public apology on behalf of the British government for the way in which Turing was treated after the war.

Childhood and youth

Turing was conceived at Chhatrapur, Orissa, in India.<reaque|381}}</ref> later the Colonnade Hotel. He had an elder brother, John. His father's civil service commission was still active, and during Turing's childhood years his parents travelled between Hastings, England and India, leaving their two sons to stay with a retired Army couple. Very early in life, Turing showed signs of the genius he was later to display prominently.

His parents enrolled him at St Michael's, a day school at 20 Charles Road, St Leonards-on-Sea, at the age of six. The headmistress recognised his talent early on, as did many of his subsequent educators. In 1926, at the age of 14, he went on to Sherborne School, a famous independent school in the market town of Sherborne in Dorset. His first day of term coincided with the 1926 General Strike in Britain, but so determined was he to attend his first day that he rode his bicycle unaccompanied more than 60 miles (97 km) from Southampton to school, stopping overnight at an inn.

King's College, Cambridge, where the computer room is named after Turing, who became a student there in 1931 and a Fellow in 1935

Turing's natural inclination toward mathematics and science did not earn him respect with some of the teachers at Sherborne, whose definition of education placed more emphasis on the classics. His headmaster wrote to his parents: "I hope he will not fall between two stools. If he is to stay at public school, he must aim at becoming educated. If he is to be solely a Scientific Specialist, he is wasting his time at a public school". Despite this, Turing continued to show remarkable ability in the studies he loved, solving advanced problems in 1927 without having even studied elementary calculus. In 1928, aged 16, Turing encountered Albert Einstein's work; not only did he grasp it, but he extrapolated Einstein's questioning of Newton's laws of motion from a text in which this was never made explicit.

At Sherborne Turing formed a friendship with fellow pupil Christopher Morcom. This friendship, cut short by Morcom's death in February 1930 from complications of bovine tuberculosis (contracted after drinking infected cow's milk some years previously), would provide inspiration for Turing's future achievements. Turing's religious faith was shattered by Morcom's death and he became an atheist. He adopted the conviction that all phenomena, including the workings of the human brain, must be materialistic, but he still believed in the survival of the spirit after death.

University and work on computability

Alan Turing memorial statue in Sackville Park, Manchester

After Sherborne, Turing went to study at King's College, Cambridge. He was an undergraduate there from 1931 to 1934, graduating with first-class honours in Mathematics. In 1935, at the young age of 22, he was elected a fellow at King's on the strength of a dissertation in which he proved the central limit theorem, despite the fact that he had failed to find out that it had already been proved in 1922 by Jarl Waldemar Lindeberg.

In 1928, German mathematician David Hilbert had called attention to the Entscheidungsproblem (decision problem). In his momentous paper "On Computable Numbers, with an Application to the Entscheidungsproblem" (submitted on 28 May 1936 and delivered 12 November), Turing reformulated Kurt Gödel's 1931 results on the limits of proof and computation, replacing Gödel's universal arithmetic-based formal language with what became known as Turing machines, formal and simple hypothetical devices. He proved that some such machine would be capable of performing any conceivable mathematical computation if it were representable as an algorithm. He went on to prove that there was no solution to the Entscheidungsproblem by first showing that the halting problem for Turing machines is undecidable: in general, it is not possible to decide algorithmically, whether a given Turing machine will ever halt.

While his proof was published shortly after Alonzo Church's equivalent proof in respect of his lambda calculus, Turing was unaware of Church's work at the time that he developed it. Turing's approach is considerably more accessible and intuitive than Church's. It was also novel in its notion of a 'Universal Machine' (now known as a Universal Turing machine), with the idea that such a machine could perform the tasks of any other machine, or in other words, is provably capable of computing anything that is computable. Turing machines are to this day a central object of study in theory of computation. In his memoirs Turing wrote that he was disappointed about the reception of this 1936 paper, which also introduced the notion of definable numbers, and that only two people had reacted – these being Heinrich Scholz and Richard Bevan Braithwaite.

From September 1936 to July 1938 he spent most of his time at the Institute for Advanced Study, Princeton, New Jersey, studying under Alonzo Church. In addition to his purely mathematical work, he studied cryptology and also built three of four stages of an electro-mechanical binary multiplier. In June 1938 he obtained his PhD from Princeton University; his dissertation (Systems of Logic Based on Ordinals) introduced the concept of ordinal logic and the notion of relative computing, where Turing machines are augmented with so-called oracles, allowing a study of problems that cannot be solved by a Turing machine.

Back in Cambridge, he attended lectures by Ludwig Wittgenstein about the foundations of mathematics. The two argued and disagreed, with Turing defending formalism and Wittgenstein arguing that mathematics does not discover any absolute truths but rather invents them. He also started to work part-time with the Government Code and Cypher School (GCCS).

Cryptanalysis

Two cottages in the stable yard at Bletchley Park. Turing worked here in 1939 and 1940, before moving to Hut 8.

During the Second World War, Turing was a leading participant in the breaking of German ciphers at Bletchley Park. The historian and wartime codebreaker Asa Briggs has said:

You needed exceptional talent, you needed genius at Bletchley and Turing's was that genius.

From September 1938, Turing had been working part-time with the Government Code and Cypher School (GCCS), the British code breaking organisation. He concentrated on Cryptanalysis of the Enigma, with Dilly Knox, a senior GCCS codebreaker. Soon after the July 1939 Warsaw meeting at which the Polish Cipher Bureau had provided the British and French with the details of the wiring of Enigma rotors and their method of decrypting Enigma messages, Turing and Knox started to work on a less fragile approach to the problem. The Polish method relied on an insecure indicator procedure that the Germans were likely to change, which they did in May 1940. Turing's approach was more general, using crib-based decryption for which he produced the initial functional specification of the bombe.

On 4 September 1939, the day after the UK declared war on Germany, Turing reported to Bletchley Park, the wartime station of GCCS. Specifying the bombe was the first of five major cryptanalytical advances that Turing made during the war. The others were: deducing the indicator procedure used by the German navy; developing a statistical procedure for making much more efficient use of the bombes dubbed Banburismus; developing a procedure for working out the cam settings of the wheels of the Lorenz SZ 40/42 (Tunny) dubbed Turingery and, towards the end of the war, the development of a portable secure voice scrambler at Hanslope Park that was codenamed Delilah.

By using statistical techniques to optimise the trial of different possibilities in the code breaking process, Turing made an innovative contribution to the subject. He wrote two papers discussing mathematical approaches which were entitled Report on the applications of probability to cryptography and Paper on statistics of repetitions which were of such value to GCCS and its successor GCHQ, that they were not released to the UK National Archives until April 2012, shortly before the centenary of his birth. A GCHQ mathematician said at the time that the fact that the contents had been restricted for some 70 years demonstrated their importance.

Turing had something of a reputation for eccentricity at Bletchley Park. He was known to his colleagues as 'Prof' and his Treatise on Enigma was known as 'The Prof's Book'. Jack Good, a cryptanalyst who worked with him, is quoted by Ronald Lewin as having said of Turing:

in the first week of June each year he would get a bad attack of hay fever, and he would cycle to the office wearing a service gas mask to keep the pollen off. His bicycle had a fault: the chain would come off at regular intervals. Instead of having it mended he would count the number of times the pedals went round and would get off the bicycle in time to adjust the chain by hand. Another of his eccentricities is that he chained his mug to the radiator pipes to prevent it being stolen.

While working at Bletchley, Turing, a talented long-distance runner, occasionally ran the 40 miles (64 km) to London when he was needed for high-level meetings, and he was capable of world-class marathon standards.

In 1945, Turing was awarded the OBE for his wartime services, but his work remained secret for many years.

Turing–Welchman bombe

A complete and working replica of a bombe at the National Codes Centre at Bletchley Park

Within weeks of arriving at Bletchley Park, Turing had specified an electromechanical machine that could help break Enigma more effectively than the Polish bomba kryptologiczna, from which its name was derived. The bombe, with an enhancement suggested by mathematician Gordon Welchman, became one of the primary tools, and the major automated one, used to attack Enigma-enciphered messages.

Jack Good opined:

Turing's most important contribution, I think, was of part of the design of the bombe, the cryptanalytic machine. He had the idea that you could use, in effect, a theorem in logic which sounds to the untrained ear rather absurd; namely that from a contradiction, you can deduce everything.

The bombe searched for possible correct settings used for an Enigma message (i.e. rotor order, rotor settings and plugboard settings), using a suitable crib: a fragment of probable plaintext. For each possible setting of the rotors (which had of the order of 10 states, or 10 for the four-rotor U-boat variant), the bombe performed a chain of logical deductions based on the crib, implemented electrically. The bombe detected when a contradiction had occurred, and ruled out that setting, moving on to the next. Most of the possible settings would cause contradictions and be discarded, leaving only a few to be investigated in detail. The first bombe was installed on 18 March 1940. More than two hundred bombes were in operation by the end of the war.

Hut 8 and Naval Enigma

Statue of Turing by Stephen Kettle at Bletchley Park, commissioned by the American philanthropist Sidney E Frank.

Turing decided to tackle the particularly difficult problem of German naval Enigma "because no one else was doing anything about it and I could have it to myself". In December 1939, Turing solved the essential part of the naval indicator system, which was more complex than the indicator systems used by the other services. That same night he also conceived of the idea of Banburismus, a sequential statistical technique (what Abraham Wald later called sequential analysis) to assist in breaking naval Enigma, "though I was not sure that it would work in practice, and was not in fact sure until some days had actually broken". For this he invented a measure of weight of evidence that he called the Ban. Banburismus could rule out certain sequences of the Enigma rotors, substantially reducing the time needed to test settings on the bombes.

In 1941, Turing proposed marriage to Hut 8 co-worker Joan Clarke, a fellow mathematician and cryptanalyst, but their engagement was short-lived. After admitting his homosexuality to his fiancée, who was reportedly "unfazed" by the revelation, Turing decided that he could not go through with the marriage.

Turing travelled to the United States in November 1942 and worked with U.S. Navy cryptanalysts on Naval Enigma and bombe construction in Washington, visiting their Computing Machine Laboratory at Dayton, Ohio. His reaction to the American Bombe design was far from enthusiastic:

It seems a pity for them to go out of their way to build a machine to do all this stopping if it is not necessary. I am now converted to the extent of thinking that starting from scratch on the design of a Bombe, this method is about as good as our own. The American Bombe program was to produce 336 Bombes, one for each wheel order. I used to smile inwardly at the conception of test (of commutators) can hardly be considered conclusive as they were not testing for the bounce with electronic stop finding devices.

During this trip, he also assisted at Bell Labs with the development of secure speech devices.

He returned to Bletchley Park in March 1943. During his absence, Hugh Alexander had officially assumed the position of head of Hut 8, although Alexander had been de facto head for some time—Turing having little interest in the day-to-day running of the section. Turing became a general consultant for cryptanalysis at Bletchley Park.

Alexander wrote as follows about his contribution:

There should be no question in anyone's mind that Turing's work was the biggest factor in Hut 8's success. In the early days he was the only cryptographer who thought the problem worth tackling and not only was he primarily responsible for the main theoretical work within the Hut but he also shared with Welchman and Keen the chief credit for the invention of the Bombe. It is always difficult to say that anyone is absolutely indispensable but if anyone was indispensable to Hut 8 it was Turing. The pioneer's work always tends to be forgotten when experience and routine later make everything seem easy and many of us in Hut 8 felt that the magnitude of Turing's contribution was never fully realized by the outside world.

Turingery

In July 1942, Turing devised a technique termed Turingery (or jokingly Turingismus) for use against the Lorenz cipher messages produced by the Germans' new Geheimschreiber (secret writer) machine. This was a teleprinter rotor cipher attachment codenamed Tunny at Bletchley Park. Turingery was a method of wheel-breaking, i.e. a procedure for working out the cam settings of Tunny's wheels. He also introduced the Tunny team to Tommy Flowers who, under the guidance of Max Newman, went on to build the Colossus computer, the world's first programmable digital electronic computer, which replaced a simpler prior machine (the Heath Robinson), and whose superior speed allowed the statistical decryption techniques to be applied usefully to the messages. Some have mistakenly said that Turing was a key figure in the design of the Colossus computer. Turingery and the statistical approach of Banburismus undoubtedly fed into the thinking about cryptanalysis of the Lorenz cipher, but he was not directly involved in the Colossus development.

Secure speech device (Delilah)

Following his work at Bell Labs in the US, Turing pursued the idea of electronic enciphering of speech in the telephone system, and in the latter part of the war, he moved to work for the Secret Service's Radio Security Service (later HMGCC) at Hanslope Park. There he further developed his knowledge of electronics with the assistance of engineer Donald Bayley. Together they undertook the design and construction of a portable secure voice communications machine codenamed Delilah. It was intended for different applications, lacking capability for use with long-distance radio transmissions, and in any case, Delilah was completed too late to be used during the war. Though Turing demonstrated it to officials by encrypting and decrypting a recording of a Winston Churchill speech, Delilah was not adopted for use. Turing also consulted with Bell Labs on the development of SIGSALY, a secure voice system that was used in the later years of the war.

Early computers and the Turing test

From 1945 to 1947 Turing lived in Richmond, London while he worked on the design of the ACE (Automatic Computing Engine) at the National Physical Laboratory (NPL). He presented a paper on 19 February 1946, which was the first detailed design of a stored-program computer. Von Neumann's incomplete First Draft of a Report on the EDVAC had predated Turing's paper, but it was much less detailed and, according to John R. Womersley, Superintendent of the NPL Mathematics Division, it "contains a number of ideas which are Dr. Turing’s own". Although ACE was a feasible design, the secrecy surrounding the wartime work at Bletchley Park led to delays in starting the project and he became disillusioned. In late 1947 he returned to Cambridge for a sabbatical year. While he was at Cambridge, the Pilot ACE was built in his absence. It executed its first program on 10 May 1950. Although Turing's ACE was never built, a number of computers around the world owe much to it, for example, the English Electric DEUCE and the American Bendix G-15.

According to the memoirs of the German computer pioneer Heinz Billing from the Max Planck Institute for Physics, published by Genscher, Düsseldorf (1997), there was a meeting between Alan Turing and Konrad Zuse. It took place in Göttingen in 1947. The interrogation had the form of a colloquium. Participants were Womersley, Turing, Porter from England and a few German researchers like Zuse, Walther, and Billing. (For more details see Herbert Bruderer, Konrad Zuse und die Schweiz).

In 1948, he was appointed Reader in the Mathematics Department at the University of Manchester. In 1949, he became Deputy Director of the Computing Laboratory there, working on software for one of the earliest stored-program computers—the Manchester Mark 1. During this time he continued to do more abstract work in mathematics, and in "Computing machinery and intelligence" (Mind, October 1950), Turing addressed the problem of artificial intelligence, and proposed an experiment which became known as the Turing test, an attempt to define a standard for a machine to be called "intelligent". The idea was that a computer could be said to "think" if a human interrogator could not tell it apart, through conversation, from a human being. In the paper, Turing suggested that rather than building a program to simulate the adult mind, it would be better rather to produce a simpler one to simulate a child's mind and then to subject it to a course of education. A reversed form of the Turing test is widely used on the Internet; the CAPTCHA test is intended to determine whether the user is a human or a computer.

In 1948, Turing, working with his former undergraduate colleague, D. G. Champernowne, began writing a chess program for a computer that did not yet exist. In 1952, lacking a computer powerful enough to execute the program, Turing played a game in which he simulated the computer, taking about half an hour per move. The game was recorded. The program lost to Turing's colleague Alick Glennie, although it is said that it won a game against Champernowne's wife.

His Turing test was a significant and characteristically provocative and lasting contribution to the debate regarding artificial intelligence, which continues after more than half a century.

He also invented the LU decomposition method in 1948, used today for solving matrix equations.

Pattern formation and mathematical biology

Turing worked from 1952 until his death in 1954 on mathematical biology, specifically morphogenesis. He published one paper on the subject called The Chemical Basis of Morphogenesis in 1952, putting forth the Turing hypothesis of pattern formation. His central interest in the field was understanding Fibonacci phyllotaxis, the existence of Fibonacci numbers in plant structures. He used reaction–diffusion equations which are central to the field of pattern formation. Later papers went unpublished until 1992 when Collected Works of A.M. Turing was published. His contribution is considered a seminal piece of work in this field.

Conviction for indecency

In January 1952, Turing met a man called Arnold Murray outside a cinema in Manchester. After a lunch date, Turing invited Murray to spend the weekend with him at his house, an invitation which Murray accepted although he did not show up. The pair met again in Manchester the following Monday, when Murray agreed to accompany Turing to the latter's house. A few weeks later Murray visited Turing's house again, and apparently spent the night there.

After Murray helped an accomplice to break into his house, Turing reported the crime to the police. During the investigation, Turing acknowledged a sexual relationship with Murray. Homosexual acts were illegal in the United Kingdom at that time, and so both were charged with gross indecency under Section 11 of the Criminal Law Amendment Act 1885.

Turing was given a choice between imprisonment or probation conditional on his agreement to undergo hormonal treatment designed to reduce libido. He accepted chemical castration via injections of Stilboestrol, a synthetic oestrogen hormone.

Turing's conviction led to the removal of his security clearance, and barred him from continuing with his cryptographic consultancy for the Government Communications Headquarters (GCHQ), the British signals intelligence agency that had evolved from GCCS in 1946. At the time, there was acute public anxiety about spies and homosexual entrapment by Soviet agents, because of the recent exposure of the first two members of the Cambridge Five, Guy Burgess and Donald Maclean, as KGB double agents. Turing was never accused of espionage but, as with all who had worked at Bletchley Park, was prevented from discussing his war work.

Death

"Hyperboloids of wondrous Light
Rolling for aye through Space and Time
Harbour those Waves which somehow Might
Play out God's holy pantomime"

A.M. Turing 1954

On 8 June 1954, Turing's cleaner found him dead; he had died the previous day. A post-mortem examination established that the cause of death was cyanide poisoning. When his body was discovered an apple lay half-eaten beside his bed, and although the apple was not tested for cyanide, it is speculated that this was the means by which a fatal dose was consumed. An inquest determined that he had committed suicide, and he was cremated at Woking Crematorium on 12 June 1954. Turing's mother argued strenuously that the ingestion was accidental, caused by her son's careless storage of laboratory chemicals. Biographer Andrew Hodges suggests that Turing may have killed himself in an ambiguous way quite deliberately, to give his mother some plausible deniability. Hodges and David Leavitt have suggested that Turing was re-enacting a scene from the 1937 film Snow White, his favourite fairy tale, both noting that (in Leavitt's words) he took "an especially keen pleasure in the scene where the Wicked Queen immerses her apple in the poisonous brew."

Recognition and tributes

A Blue Plaque marking Turing's home at Wilmslow, Cheshire

A biography published by the Royal Society shortly after Turing's death (and while his wartime work was still subject to the Official Secrets Act) recorded:

Three remarkable papers written just before the war, on three diverse mathematical subjects, show the quality of the work that might have been produced if he had settled down to work on some big problem at that critical time. For his work at the Foreign Office he was awarded the OBE.

Since 1966, the Turing Award has been given annually by the Association for Computing Machinery to a person for technical contributions to the computing community. It is widely considered to be the computing world's highest honour, equivalent to the Nobel Prize.

Breaking the Code is a 1986 play by Hugh Whitemore about Alan Turing. The play ran in London's West End beginning in November 1986 and on Broadway from 15 November 1987 to 10 April 1988. There was also a 1996 BBC television production. In all cases, Derek Jacobi played Turing. The Broadway production was nominated for three Tony Awards including Best Actor in a Play, Best Featured Actor in a Play, and Best Direction of a Play, and for two Drama Desk Awards, for Best Actor and Best Featured Actor.

On 23 June 1998, on what would have been Turing's 86th birthday, Andrew Hodges, his biographer, unveiled an official English Heritage Blue Plaque at his birthplace and childhood home in Warrington Crescent, London, later the Colonnade Hotel. To mark the 50th anniversary of his death, a memorial plaque was unveiled on 7 June 2004 at his former residence, Hollymeade, in Wilmslow, Cheshire.

On 13 March 2000, Saint Vincent and the Grenadines issued a set of stamps to celebrate the greatest achievements of the 20th century, one of which carries a recognisable portrait of Turing against a background of repeated 0s and 1s, and is captioned: "1937: Alan Turing's theory of digital computing". On 1 April 2003, Turing's work at Bletchley Park was named an IEEE Milestone. On 28 October 2004, a bronze statue of Alan Turing sculpted by John W. Mills was unveiled at the University of Surrey in Guildford, marking the 50th anniversary of Turing's death; it portrays him carrying his books across the campus. In 2006, Boston Pride named Turing their Honorary Grand Marshal.

Turing was one of four mathematicians examined in the 2008 BBC documentary entitled "Dangerous Knowledge". The Princeton Alumni Weekly named Turing the second most significant alumnus in the history of Princeton University, second only to President James Madison. A 1.5-ton, life-size statue of Turing was unveiled on 19 June 2007 at Bletchley Park. Built from approximately half a million pieces of Welsh slate, it was sculpted by Stephen Kettle, having been commissioned by the late American billionaire Sidney Frank.

Turing has been honoured in various ways in Manchester, the city where he worked towards the end of his life. In 1994, a stretch of the A6010 road (the Manchester city intermediate ring road) was named "Alan Turing Way". Part of this road runs alongside the City of Manchester Stadium, where Manchester City play their games. A bridge carrying this road was widened, and carries the name Alan Turing Bridge. A statue of Turing was unveiled in Manchester on 23 June 2001. It is in Sackville Park, between the University of Manchester building on Whitworth Street and the Canal Street gay village. The memorial statue, depicts the "father of Computer Science" sitting on a bench at a central position in the park. The statue was unveiled on Turing's birthday.

Turing memorial statue plaque in Sackville Park, Manchester

Turing is shown holding an apple—a symbol classically used to represent forbidden love, the object that inspired Isaac Newton's theory of gravitation, and the assumed means of Turing's own death. The cast bronze bench carries in relief the text 'Alan Mathison Turing 1912–1954', and the motto 'Founder of Computer Science' as it would appear if encoded by an Enigma machine: 'IEKYF ROMSI ADXUO KVKZC GUBJ'.

A plinth at the statue's feet says 'Father of computer science, mathematician, logician, wartime codebreaker, victim of prejudice'. There is also a Bertrand Russell quotation saying 'Mathematics, rightly viewed, possesses not only truth, but supreme beauty—a beauty cold and austere, like that of sculpture.' The sculptor buried his old Amstrad computer, which was an early popular home computer, under the plinth, as a tribute to "the godfather of all modern computers".

In 1999, Time Magazine named Turing as one of the 100 Most Important People of the 20th century for his role in the creation of the modern computer, and stated: "The fact remains that everyone who taps at a keyboard, opening a spreadsheet or a word-processing program, is working on an incarnation of a Turing machine." Turing is featured in the 1999 Neal Stephenson novel "Cryptonomicon."

In 2002, Turing was ranked twenty-first on the BBC nationwide poll of the 100 Greatest Britons. In 2006 British writer and mathematician Ioan James chose Turing as one of twenty people to feature in his book about famous historical figures who may have had some of the traits of Asperger's syndrome. In 2010, actor/playwright Jade Esteban Estrada portrayed Turing in the solo musical, "ICONS: The Lesbian and Gay History of the World, Vol. 4.". In 2011, in the Guardian's "My hero" series, writer Alan Garner chose Turing as his hero and described how they had met whilst out jogging in the early 1950s. Garner remembered Turing as "funny and witty" and said that he "talked endlessly".

In February 2011, Turing's papers from the Second World War were bought for the nation with an 11th-hour bid by the National Heritage Memorial Fund, allowing them to stay at Bletchley Park.

The logo of Apple Computer is often erroneously referred to as a tribute to Alan Turing, with the bite mark a reference to his method of suicide. Both the designer of the logo and the company deny that there is any homage to Turing in the design of the logo. In Series I, Episode 13 of the British television quiz show QI presenter Stephen Fry recounted a conversation had with Steve Jobs, saying that Jobs' response was, "It isn't true, but God, we wish it were."

Government apology

In August 2009, John Graham-Cumming started a petition urging the British Government to posthumously apologise to Alan Turing for prosecuting him as a homosexual. The petition received thousands of signatures. Prime Minister Gordon Brown acknowledged the petition, releasing a statement on 10 September 2009 apologising and describing the treatment of Turing as "appalling":

Thousands of people have come together to demand justice for Alan Turing and recognition of the appalling way he was treated. While Turing was dealt with under the law of the time and we can't put the clock back, his treatment was of course utterly unfair and I am pleased to have the chance to say how deeply sorry I and we all are for what happened to him ... So on behalf of the British government, and all those who live freely thanks to Alan's work I am very proud to say: we're sorry, you deserved so much better.

In December 2011, William Jones created an e-petition requesting the British Government pardon Alan Turing for his conviction of "gross-indecency":

We ask the HM Government to grant a pardon to Alan Turing for the conviction of "gross indecency". In 1952, he was convicted of "gross indecency" with another man and was forced to undergo so-called "organo-therapy" – chemical castration. Two years later, he killed himself with cyanide, aged just 41. Alan Turing was driven to a terrible despair and early death by the nation he'd done so much to save. This remains a shame on the UK government and UK history. A pardon can go to some way to healing this damage. It may act as an apology to many of the other gay men, not as well known as Alan Turing, who were subjected to these laws.

The petition has over 34,000 signatures, but the request was declined by Lord McNally:

A posthumous pardon was not considered appropriate as Alan Turing was properly convicted of what at the time was a criminal offence. He would have known that his offence was against the law and that he would be prosecuted. It is tragic that Alan Turing was convicted of an offence which now seems both cruel and absurd—particularly poignant given his outstanding contribution to the war effort. However, the law at the time required a prosecution and, as such, long-standing policy has been to accept that such convictions took place and, rather than trying to alter the historical context and to put right what cannot be put right, ensure instead that we never again return to those times.

Tributes by universities

The Alan Turing Building at the University of Manchester

A celebration of Turing's life and achievements arranged by the British Logic Colloquium and the British Society for the History of Mathematics was held on 5 June 2004.

Centenary commemoration

To mark the 100th anniversary of Turing's birth, the Turing Centenary Advisory Committee (TCAC) is coordinating the Alan Turing Year, a year-long programme of events around the world honouring Turing's life and achievements. The TCAC working with the University of Manchester faculty members and a broad spectrum of people from Cambridge University and Bletchley Park, is chaired by S. Barry Cooper, with Alan Turing's nephew Sir John Dermot Turing acting as TCAC Honorary President.

Events are scheduled in many countries around the world including the USA, Brazil, China, Czech Republic, the Philippines, New Zealand, Israel, Spain, Switzerland, Norway, Italy, Portugal and Germany. The keystone events will be a three-day conference in Manchester, UK in June examining Turing's mathematical and code-breaking achievements, and a Turing Centenary Conference in Cambridge organised by King's College, Cambridge and the association Computability in Europe.

On 23 February 2012, the Royal Mail issued a stamp featuring Turing as part its "Britons of Distinction" series.

On 22 June 2012 Manchester City Council, in partnership with the Lesbian & Gay Foundation launched The Alan Turing Memorial Award which will recognise individuals or groups who have made a significant contribution to the fight against homophobia in Manchester.

On 23 June 2012, Google featured an interactive doodle where visitors had to change the instructions of a Turing Machine, so when run, the symbols on the tape would match a provided sequence

The Turing Test, an opera by Julian Wagstaff which ran at the Edinburgh fringe in 2007, will also go on a UK tour in October to mark the 100th anniversary year of Turing's birth. The Turing Test is set in the near future and tells the fictional story of a brilliant young PhD student Stephanie, who is trapped in a bitter battle between two rival scientists racing to build the world's first truly intelligent computer.

See also

Notes

  1. ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1098/rsbm.1955.0019, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi=10.1098/rsbm.1955.0019 instead.
  2. ^ Gray, Paul (29 March 1999). "Alan Turing – Time 100 People of the Century". Time Magazine. The fact remains that everyone who taps at a keyboard, opening a spreadsheet or a word-processing program, is working on an incarnation of a Turing machine.
  3. Homer, Steven and Alan L. (2001). Computability and Complexity Theory. Springer via Google Books limited view. p. 35. ISBN 0-387-95055-9. Retrieved 13 May 2011.
  4. Leavitt 2007, pp. 231–233
  5. Turing, A. M. (1952). "The Chemical Basis of Morphogenesis". Philosophical Transactions of the Royal Society of London, series B. 237 (641): 37–72. doi:10.1098/rstb.1952.0012. {{cite journal}}: Invalid |ref=harv (help)
  6. ^ "PM apology after Turing petition". BBC News. 11 September 2009.
  7. ^ Hodges 1992, p. 5
  8. "The Alan Turing Internet Scrapbook". Retrieved 26 September 2006.
  9. Hodges 1992, p. 6
  10. Jones, G. James (11 December 2001). "Alan Turing – Towards a Digital Mind: Part 1". System Toolbox. Archived from the original on 3 August 2007. Retrieved 27 July 2007. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  11. Hofstadter, Douglas R. (1985). Metamagical Themas: Questing for the Essence of Mind and Pattern. Basic Books. ISBN 0-465-04566-9. OCLC 230812136.
  12. Hodges 1992, p. 26
  13. Hodges 1992, p. 34
  14. Hassall, R. The Sherborne formula: the making of Alan Turing Vivat! 2012/13: 17–29.
  15. Teuscher, Christof (ed.) (2004). Alan Turing: Life and Legacy of a Great Thinker. Springer-Verlag. ISBN 3-540-20020-7. OCLC 53434737 62339998. {{cite book}}: |first= has generic name (help); Check |oclc= value (help)
  16. Paul Gray, Alan Turing Time Magazine's Most Important People of the Century, p.2
  17. The Inspiration of Life and Death, 1928–1932 Alan Turing Scrapbook
  18. See Section 3 of John Aldrich, "England and Continental Probability in the Inter-War Years", Journal Electronique d'Histoire des Probabilités et de la Statistique, vol. 5/2 Decembre 2009 Journal Electronique d'Histoire des Probabilités et de la Statistique
  19. Hodges 1992, pp. 88, 94
  20. Turing, A. M. (1936). "On Computable Numbers, with an Application to the Entscheidungsproblem" (PDF). Proceedings of the London Mathematical Society. 2. 42 (published 1936–37): 230–65. doi:10.1112/plms/s2-42.1.230. {{cite journal}}: Invalid |ref=harv (help) (and Turing, A.M. (1938). "On Computable Numbers, with an Application to the Entscheidungsproblem: A correction". Proceedings of the London Mathematical Society. 2. Vol. 43 (published 1937). pp. 544–6. doi:10.1112/plms/s2-43.6.544.)
  21. Hodges 1992, p. 111
  22. Hodges 1992, p. 138
  23. Turing, A. M. (1938), Systems of Logic Based on Ordinals (PDF)
  24. Hodges 1992, p. 152
  25. Hodges 1992, pp. 153–154
  26. Briggs, Asa, Britain's Greatest Codebreaker, UK Channel 4 {{citation}}: |format= requires |url= (help); Missing or empty |title= (help)
  27. Jack Copeland, "Colossus and the Dawning of the Computer Age", p. 352 in Action This Day, 2001
  28. Copeland 2004, p. 217 harvnb error: multiple targets (3×): CITEREFCopeland2004 (help)
  29. ^ Copeland, 2006 p. 378
  30. Turing, Alan (c. 1941), Report on the applications of probability to cryptography, The National Archives of the UK: HW 25/37
  31. Turing, Alan (c. 1941), Paper on statistics of repetitions, The National Archives of the UK: HW 25/38
  32. Vallance, Chris (19 April 2012). "Alan Turing papers on code breaking released by GCHQ". BBC News. Retrieved 20 April 2012.
  33. Hodges 1992, p. 208
  34. Lewin 1978, p. 57
  35. Brown, Anthony Cave (1975), Bodyguard of Lies: The Extraordinary True Story Behind D-Day, The Lyons Press, ISBN 978-1-59921-383-5
  36. John Graham-Cumming (10 March 2010). "An Olympic honour for Alan Turing". http://www.guardian.co.uk. {{cite news}}: External link in |publisher= (help)
  37. "The Men Who Cracked Enigma", Episode 4 in the UKTV History Channel documentary series "Heroes of World War II"
  38. Professor Jack Good in "The Men Who Cracked Enigma", 2003: with his caveat: "if my memory is correct"
  39. Oakley 2006, p. 40/03B
  40. Copeland, Jack (2004). "Alan Turing, Codebreaker and Computer Pioneer". Retrieved 27 July 2007. {{cite web}}: Unknown parameter |coauthors= ignored (|author= suggested) (help); Unknown parameter |month= ignored (help)
  41. "Bletchley Park Unveils Statue Commemorating Alan Turing". Retrieved 30 June 2007.
  42. ^ Mahon 1945, p. 14
  43. Leavitt 2007, pp. 184–186
  44. Leavitt 2007, pp. 176–178
  45. Hodges 1992, pp. 242–245
  46. "BOMBE PROJECT HISTORY, MAY 44". Retrieved 2 May 2012.
  47. Hodges 1992, pp. 245–253
  48. Alexander & circa 1945, p. 42 harvnb error: no target: CITEREFAlexandercirca_1945 (help)
  49. Copeland 2006, p. 380
  50. Copeland 2006, p. 381
  51. Copeland 2006, p. 72
  52. Gannon 2007, p. 230
  53. Hilton 2006, pp. 197–199
  54. Copeland 2006, pp. 382, 383
  55. Hodges 1992, pp. 245–250
  56. Hodges 1992, p. 273
  57. Hodges 1992, p. 346
  58. Plaque #1619 on Open Plaques
  59. Copeland 2006, p. 108
  60. Randell, B (1980), A History of Computing in the Twentieth Century: Colossus (PDF), retrieved 27 January 2012 citing Womersley, J. R. (13 February 1946), "'ACE' Machine Project", Executive Committee, National Physical Laboratory, Teddington, Middlesex
  61. Turing, Alan M. (1948). "Rounding-Off Errors in Matrix Processes". Quarterly Journal of Mechanics and Applied Mathematics. 1: 287–308. {{cite journal}}: Unknown parameter |month= ignored (help)
  62. Harnad, Stevan (2008) The Annotation Game: On Turing (1950) on Computing, Machinery and Intelligence. In: Epstein, Robert & Peters, Grace (Eds.) Parsing the Turing Test: Philosophical and Methodological Issues in the Quest for the Thinking Computer. Springer
  63. Alan Turing vs Alick Glennie (1952) "Turing Test" Chessgames.com
  64. Saygin, A.P., Cicekli, I., & Akman, V. (2000) Turing Test: 50 years later. Minds and Machines, Vol. 10, pp 463–518.
  65. "SPICE 1 2 3 and beyond ... Intusoft Newsletter, August 2003". Intusoft.com. 16 August 2001. Archived from the original on 11 June 2011. Retrieved 29 May 2011. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  66. "Control Mechanism For Biological Pattern Formation Decoded" ScienceDaily, 30 November 2006
  67. Archived 2003-08-23 at the Wayback Machine
  68. Leavitt 2007, p. 266
  69. Hodges 1992, p. 458
  70. Leavitt 2007, p. 268
  71. "Turing, Alan (1912–1954)". Glbtq.com. Retrieved 29 May 2011.
  72. Leavitt 2007, p. 269
  73. Copeland 2006, p. 143
  74. Turing, A.M. (1954). "AMT/D/4: image 16 Postcard to [[Robin Gandy]]". Turing Digital Archive. Retrieved 3 December 2011. {{cite web}}: URL–wikilink conflict (help)
  75. Hodges 1992, p. 488
  76. Hodges 1992, p. 529
  77. Hodges 1992, pp. 488, 489
  78. Leavitt 2007, p. 140 and Hodges 1992, pp. 149, 489
  79. Steven Geringer (27 July 2007). "ACM'S Turing Award Prize Raised To $250,000". ACM press release. Retrieved 16 October 2008.
  80. "Unveiling the official Blue Plaque on Alan Turing's Birthplace". Retrieved 26 September 2006.
  81. "About this Plaque – Alan Turing". Archived from the original on 13 October 2007. Retrieved 25 September 2006.
  82. Plaque #3276 on Open Plaques
  83. IEEE History Center (2003). "Milestones:Code-breaking at Bletchley Park during World War II, 1939–1945". IEEE Global History Network. IEEE. Retrieved 29 March 2012.
  84. "The Earl of Wessex unveils statue of Alan Turing". Retrieved 10 February 2007.
  85. Archived 2006-06-19 at the Wayback Machine
  86. "Dangerous Knowledge". BBC Four. 11 June 2008. Retrieved 25 September 2009.
  87. Bletchley Park Unveils Statue Commemorating Alan Turing, Bletchley Park press release, 20 June 2007
  88. see "Computer buried in tribute to genius". Manchester Evening News. 15 June 2001. Retrieved 23 June 2009.
  89. "100 great British heroes". BBC News. 21 August 2002.
  90. Ioan M. James (2006). Asperger's Syndrome and High Achievement. Jessica Kingsley. ISBN 978-1-84310-388-2.
  91. Garner, Alan (12 November 2011), "My Hero: Alan Turing", Saturday Guardian Review, p. 5, retrieved 23 November 2011
  92. Josh Halliday (25 February 2011). "Turing papers to stay in UK after 11th-hour auction bid at". The Guardian. UK. Retrieved 29 May 2011.
  93. "Logos that became legends: Icons from the world of advertising". The Independent. UK. 4 January 2008. Archived from the original on 3 October 2009. Retrieved 14 September 2009. {{cite news}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  94. "Interview with Rob Janoff, designer of the Apple logo". creativebits. Retrieved 14 September 2009.
  95. Leavitt 2007, p. 280
  96. Thousands call for Turing apology. BBC News. 31 August 2009. Retrieved 31 August 2009.
  97. Petition seeks apology for Enigma code-breaker Turing. CNN. 1 September 2009. Archived from the original on 5 October 2009. Retrieved 1 September 2009. {{cite book}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  98. ^ Davies, Caroline (11 September 2009). "PM's apology to codebreaker Alan Turing: we were inhumane". The Guardian. UK.
  99. The petition was only open to UK citizens.
  100. Full text of the Prime Minister's apology.
  101. ^ "Grant a pardon to Alan Turing". 6 December 2011. Cite error: The named reference "PardonPetition" was defined multiple times with different content (see the help page).
  102. "Petition to pardon computer pioneer Alan Turing started". BBC News. 6 December 2011.
  103. "Widespread Celebrations But No Pardon For Turing". 6 February 2012.
  104. "Turing Days @ İstanbul Bilgi University". Retrieved 29 October 2011.
  105. Archived 2007-09-20 at the Wayback Machine
  106. "Polya Hall, Stanford University" (PDF). Retrieved 14 June 2011.
  107. "Laboratoire d'Informatique Fondamentale de Lille". Retrieved 3 December 2010.
  108. "Turing at the University of Oregon". Retrieved 1 November 2011.
  109. "Turing at the EPFL". Retrieved 6 January 2012.
  110. "The Northerner: Alan Turing, computer pioneer, has centenary marked by a year of celebrations". M.guardian.co.uk. 23 February 2011. Retrieved 29 May 2011.
  111. Gary Cutlack (2 January 2012). "Codebreaker Alan Turing gets stamp of approval". Gizmodo. Retrieved 2 January 2012.
  112. Anon (22 June 2012). "Centenary award tribute to 'enigma' codebreaker Alan Turing Read more at: http://menmedia.co.uk/manchestereveningnews/news/s/1581770_centenary-award-tribute-to-enigma-codebreaker-alan-turing". Manchester Evening News. Manchester: MEN media. Retrieved 22 June 2012. {{cite news}}: External link in |title= (help)
  113. "Google Home Page". 23 June 2012. Retrieved 23 June 2012.
  114. "The Turing Test — An Opera by Julian Wagstaff". Julianwagstaff.com. 15 August 2007. Retrieved 6 February 2012.
  115. Sophie Curtis (6 February 2012). "Turing Test opera to embark on UK tour". Techworld. Retrieved 6 February 2012.

References

Further reading

External links

Papers

Logic
Major fields
Logics
Theories
Foundations
Lists
topics
other
Philosophy of mind
Philosophers
Theories
Concepts
Related

Template:Persondata

Template:Link FA

Categories: