TESTED TO DESTRUCTION

See Also: COMPUTERS; THE SECOND WORLD WAR

Alan Turing read mathematics at the University of Cambridge. Exposure to John von Neumann's work on the logical foundations of quantum mechanics helped him to attain his intellectual maturity. Through studying Bertrand Russell and A.N. Whitehead's Principia mathematica (1913) he was drawn from pure mathematics into mathematical logic.

In 1935 the topologist Max Newman introduced him to the problem of whether there was a definite process or processes through which all mathematical problems could be determined. The following year the London Mathematical Society published a paper by Turing in which he set out the idea for a 'Turing machine'. This was effectively a program, while a 'universal Turing machine' would be a computer. For Turing the crux of his argument was to demonstrate that there were tasks that the former machine could not carry out. However, to subsequent generations the fact that the device had been envisaged came to be seen as having been the publication's essence.

In the period that preceded the outbreak of the Second World War, the government's crypt-analytical department recruited Turing on an informal basis. Following the conflict's start, he worked at the Government Code & Cypher School s Bletchley Park facility. There, he played a leading role in breaking the German Navy's Enigma code and the German High Command's Fish cypher. This work helped to turn the Battle of the Atlantic in the Allies' favour.

The School had telecommunications engineers from the Post Office Research Station at Dollis Hill build equipment that enabled the code breaking to be transferred from mechanical devices to electronic machines. Turing appreciated that if the 'universal Turing machine' was to become a reality it would be through the use of the latter technology. He spent time teaching himself electrical engineering.

In 1945 J. Presper Eckert and John Mauchly published their idea for the EDVAC computer. This stole Turing's thunder. However, the development prompted the National Physical Laboratory to establish a new numerical division to house its own rival programme. Turing took up a position on the project team at the Teddington-based research facility. He held his superior John Womersley in contempt. However, the latter appreciated the intellectual value of his subordinate's work and ensured that he received the opportunity to develop his ideas. Turing designed the Automatic Computing Engine. This was built in the manor house that is part of the Laboratory's site. The mathematician devised the stored program to run on it.

In 1945 Newman was appointed to be a professor of pure mathematics at the University of Manchester. He persuaded the Royal Society to make a grant of money that underwrote the building of a computer. This was far less ambitious than the N.P.L. one. The Mancunian effort was focused upon the single basic point of whether or not a device could be fabricated. Having set out the project, the academic then kept his distance from the actual fabrication of the machine. This work was led by Frederick Williams, a former radar engineer.

A.C.E.'s construction became bogged down for a protracted period by the issue of storage. Turing found the wait to be frustrating. He spent much of his time in Cambridge. He studied physiology and neurology. He submitted work to his employers that contended that neural nets might be capable of learning. They proved to be unresponsive to the concept. He became increasingly disillusioned with the Laboratory.

In summer 1948 the Manchester machine gave the first demonstration of an electronic computer. That autumn Turing resigned from the Laboratory. The Mancunian group hired him.

Two years after the Manchester computer had first operated, the Teddington one began to work. Using the program that Turing had written, it soon proved itself to be a far superior machine to its northern counterpart.

The same year Mind published an article by Turing in which he argued that the brain's actions could be recreated within a machine. In the piece he set out what became known as the 'Turing test'. A device would pass this if a human could have a remote interaction with it but not detect that it was a machine. The following year he was elected to a Fellowship of the Royal Society.

In 1952 Turing reported a robbery at his home in Manchester. The ensuing police investigation uncovered evidence of the mathematician's affair with a nineteen-year-old man. The academic was prosecuted for gross indecency and found guilty. He agreed to undertake a programme of oestrogen injections. This was intended to moderate his 'unnatural' desires. Since the war he had retained a degree of exposure to intelligence work. This was terminated abruptly following his conviction.

Turing committed suicide in 1954. He had been fascinated by the Walt Disney movie Snow White and The Seven Dwarfs (1937). There is a story that a partially eaten apple that had been dipped in a cyanide solution was found by his bed.

In 2009 Prime Minister Gordon Brown made an official apology about the way in which Turing had been treated. Four years later the Liberal Democrat peer Lord Sharkey sponsored the Alan Turing (Statutory Pardon) Bill. The government stated that it would not oppose the measure. As a student, the peer had been taught mathematics by Robin Gandy, who had been a friend of Turing.

Location: 2 Warrington Crescent, Maida Vale, W9 1ER. Turing's birthplace.

The National Physical Laboratory, Hampton Road, Teddington, TW11 0LW

The London Mathematical Society, 57-58 Russell Square, WC1B 4HS (purple, brown)

Website: www.gchq.gov.uk www.lms.ac.uk www.manchester.ac.uk www.npl.co.uk

www.turing.org.uk (Maintained by Andrew Hodges, a Turing biographer.)

David Backhouse 2024