Born Today In 1912, Father of Computer Science and WWII Code Breaker Alan Turing

Alan Turing was born today, June 23, in 1912. He 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 formalization 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.

The London 2012 Olympic Torch stopped off at Turing's statue in Manchester on his 100th birthday.

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 2 years and saved over 14 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.

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 January 23 Turing's house was broken into by a burglar. 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 February 27 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 March 31, 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 chemical castration treatment, with DES, as an alternative to prison.

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.  

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. 

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. The Alan Turing law is now an informal term for a 2017 law in the United Kingdom that retroactively pardoned men cautioned or convicted under historical legislation that outlawed homosexual acts.

In 2014, the world's first work of public art to recognize Turing as gay was commissioned in Bletchley, close by to Bletchley Park where his war-time work was carried out. The commission was announced to mark International Day Against Homophobia and Transphobia. The work was unveiled at a ceremony today in 2014, and is placed alongside busy Watling Street, the old main road to London, where Turing himself would have passed by on many occasions. 

The historical drama film The Imitation Game, directed by Morten Tyldum and starring Benedict Cumberbatch as Turing and Keira Knightley as Joan Clarke, was released in November 2014. It is about Turing breaking the Enigma code with other codebreakers in Bletchley Park.