“Goodbye” Alan Turing Died 7 June 1954

Alan Mathison Turing, OBE, FRS (23 June 1912 – 7 June 1954), was a British mathematician and computer scientist. He was highly influential in the development of computer science, giving 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 studied mathematics at Cambridge University, and subsequently taught there, working in the world of quantum mechanics. It was at Cambridge that he developed the proof which states that automatic computation cannot solve all mathematical problems, the concept being known as the Turing machine.

In 1936, Turing went to Princeton University in America, returning to England in 1938. He began to work secretly part-time for the British cryptanalytic department, the Government Code and Cypher School. On the outbreak of war he took up full-time work at its headquarters, Bletchley Park.

Here he played a vital role in deciphering the messages encrypted by the German Enigma machine, which provided vital intelligence for the Allies. He took the lead in a team that designed a machine known as a bombe that successfully decoded German messages.

After the war, Turing turned his thoughts to the development of a machine that would logically process information. He worked first for the National Physical Laboratory (1945-1948) but his plans were dismissed by his colleagues and the lab lost out on being the first to design a digital computer. It is thought that Turing’s blueprint would have secured them the honour, as his machine was capable of computation speeds higher than the others. In 1949, he went to ManchesterUniversity where he directed the computing laboratory and developed a body of work that helped to form the basis for the field of artificial intelligence. In 1951 he was elected a fellow of the Royal Society.

In 1952, Turing was arrested and tried for homosexuality, then a criminal offence. To avoid prison, he accepted injections of oestrogen for a year, which were intended to neutralise his libido. In that era, homosexuals were considered a security risk as they were open to blackmail. Turing’s security clearance was withdrawn, meaning he could no longer work for GCHQ, the post-war successor to BletchleyPark.

He committed suicide on 7 June, 1954.