Manchester honours Alan Turing

Computer pioneer died 50 years ago today

The city of Manchester this morning honoured Alan Turing - the brilliant mathemetician and codebreaker who committed suicide 50 years ago today.

Manchester University is behind the ceremony which sees a blue plaque dedicated to Turing unveiled on the house in Adlington Road, Wilmslow, where - on 7 June 1954 - Turing ate a cyanide-laced apple.

Turing will be best remembered for his work on the German Enigma codes during his time at Bletchley Park, in addition to the thorny "Fish" cypher. Fish was eventually broken with the aid of Colossus in 1944. Turing was fascinated by artificial intelligence and the concept of the programmable single machine capable of handling any task, and by applying his intelligence to this concept he greatly contributed to the development of Bletchley's codebreaking machines and ultimately, the development of the modern computer concept.

In his personal life, Turing was less assured. At Bletchley he was known as "Prof" - an anarchic and socially-awkward man who eventually proposed marriage to colleague Joan Clarke, only to later retract the offer and admit to Clarke his homosexuality.

The post-war years saw Turing at Manchester University continuing his work - albeit sporadically - on machine code programming and related subjects. Sadly, he was never truly able to see his brilliant vision become a concrete reality, as the US moved apace towards the "modern" computer as we now know it.

In 1952, he was arrested and tried for a homosexual relationship with a young man from Manchester. Turing avoided prison by agreeing to have yearly oestrogen injections to control his libido - a savage punishment at a time that male homosexuality was illegal in Britain.

In fact, Turing's homosexuality had already cost him a secret post with with Bletchley's successor - GCHQ. In the chilly Cold War climate of 1948, his sexual orientation resulted in the loss of his security clearance. Left out in the cold, he bitterly resented his treatment at the hands of the security services, who continued to harrass him sporadically. In 1953, he was visited by police apparently looking for a Norwegian who had visited him - an incident widely believed to have been state-security inspired.

On 8 June, 1954, Turing's cleaner found him dead in his bed. He had died the day before from eating an apple laced with cyanide. Some have attempted to build a conspiracy around the tragedy, although the coroner's verdict of "suicide" seems plausible.

Turing's legacy as one of the founders of computer science cannot be overestimated. For more on the man and his astonishing work, we recommend this site as a starting point. ®

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