The Colonnade Hotel, 2 Warrington Cres, London W9 1ER, Regno Unito
St Michael’s School, 20 Charles Rd, Saint Leonards-on-sea TN38 0QH, Regno Unito
Sherborne School, Abbey Rd, Sherborne DT9 3AP, Regno Unito
Princeton University, Princeton, New Jersey 08544, Stati Uniti
University Of Cambridge, Cambridge CB2, Regno Unito
The Mansion, Bletchley Park, Sherwood Dr, Bletchley, Milton Keynes MK3 6EB, Regno Unito
Ivy House, 68-78 High St, Hampton Hill, Hampton TW12 1NY, Regno Unito
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Copper Folly, 43 Adlington Rd, Wilmslow SK9 2BJ, Regno Unito
Woking Crematorium, Hermitage Rd, Woking GU21 8TJ, Regno Unito
Alan Turing Memorial, Sackville park, Fairfield St, Manchester M1 3HB, Regno Unito
Alan Mathison Turing OBE FRS (23 June 1912 – 7 June 1954) was an English computer scientist, mathematician, logician, cryptanalyst, philosopher, and theoretical biologist. Turing was highly influential in the development of theoretical 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. Turing is widely considered to be the father of theoretical computer science and artificial intelligence.
During the Second World War, Turing worked for the Government Code and Cypher School (GC&CS) at Bletchley Park, Britain's codebreaking centre that produced Ultra intelligence. For a time he led Hut 8, the section which was responsible for German naval cryptanalysis. Here he devised a number of techniques for speeding the breaking of German ciphers, including improvements to the pre-war Polish bombe method, 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, and in so doing helped win the war. Counterfactual history is difficult with respect to the effect Ultra intelligence had on the length of the war, but at the upper end it has been estimated that this work shortened the war in Europe by more than two years and saved over fourteen million lives.
After the war, Turing 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 Machine Laboratory at the Victoria University of Manchester, where he helped develop the Manchester computers 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.
In 1941, Turing proposed marriage to Hut 8 colleague 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.
Princeton University, NJ
In January 1952, Turing, then 39, started a relationship with Arnold Murray, a 19-year-old unemployed man. Turing had met Murray just before Christmas outside the Regal Cinema when walking down Manchester's Oxford Road and invited him to lunch. On 23 January Turing's house was burgled. Murray told Turing that the burglar was an acquaintance of his, and Turing reported the crime to the police. During the investigation he acknowledged a sexual relationship with Murray. Homosexual acts were criminal offences in the United Kingdom at that time, and both men were charged with gross indecency under Section 11 of the Criminal Law Amendment Act 1885. Initial committal proceedings for the trial were held on 27 February during which Turing's solicitor "reserved his defence", i.e., did not argue or provide evidence against the allegations.
Later, convinced by the advice of his brother and his own solicitor, Turing entered a plea of guilty. The case, Regina v. Turing and Murray, was brought to trial on 31 March 1952. Turing was convicted and given a choice between imprisonment and probation, which would be conditional on his agreement to undergo hormonal treatment designed to reduce libido. He accepted the option of treatment via injections of what was then called stilboestrol (now known as diethylstilbestrol or DES), a synthetic oestrogen; this treatment was continued for the course of one year. The treatment rendered Turing impotent and caused gynaecomastia, fulfilling in the literal sense Turing's prediction that "no doubt I shall emerge from it all a different man, but quite who I've not found out". Murray was given a conditional discharge.
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 GC&CS in 1946 (though he kept his academic job). He was denied entry into the United States after his conviction in 1952, but was free to visit other European countries. Turing was never accused of espionage but, in common with all who had worked at Bletchley Park, he was prevented by the Official Secrets Act from discussing his war work.
On 8 June 1954, Turing's housekeeper 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 was 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 ashes were scattered there, just as his father's had been. Andrew Hodges and another biographer, David Leavitt, have both suggested that Turing was re-enacting a scene from the Walt Disney film Snow White and the Seven Dwarfs (1937), 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."
Philosophy professor Jack Copeland has questioned various aspects of the coroner's historical verdict. He suggests an alternative explanation for the cause of Turing's death, this being the accidental inhalation of cyanide fumes from an apparatus for electroplating gold onto spoons, which uses potassium cyanide to dissolve the gold. Turing had such an apparatus set up in his tiny spare room. Copeland notes that the autopsy findings were more consistent with inhalation than with ingestion of the poison. Turing also habitually ate an apple before bed, and it was not unusual for it to be discarded half-eaten. In addition, Turing had reportedly borne his legal setbacks and hormone treatment (which had been discontinued a year previously) "with good humour" and had shown no sign of despondency prior to his death, even setting down a list of tasks he intended to complete upon return to his office after the holiday weekend. Turing's mother believed that the ingestion was accidental, resulting from her son's careless storage of laboratory chemicals. Biographer Andrew Hodges suggests Turing arranged the delivery of the equipment to deliberately allow his mother plausible deniability regarding any suicide claims.