Alan Mathison Turing was one of the most influential thinkers of the 20th century, and has been called the ‘Father of Computer Science’. He was born in 1912 into an English middle-class family, and was educated at Sherborne school, and King’s College Cambridge. He had a stutter from early childhood, and became aware of his homosexuality during adolescence. While still at Sherborne, he fell in love with an older boy called Christopher Morcom, who shared his interests in maths and science. His relationship with Christopher, who died of tuberculosis two years after they met, had a profound influence on the rest of his life.
At the age of 24 he published his first important work, called ‘On Computable Numbers, with an Application to the Entscheidungsproblem’, which laid the foundation for the development of the programmable computer.
In this work, he solved the problem of ‘decidability’ which had been exercising scientific minds for some years. Earlier research had found that therecould be an infinite number of mathematical formulae and, put simply, the problem was how to reduce any formula to a set of simple instructions which could be used by a machine to mimic the logic performed by the human brain. Turing’s solution was to use the binary system (i.e. only 1 and 0’s) to represent both numbers and logical operations, which could be fed, via punched tape or some other medium, into a mechanical device which he called the ‘Universal Turing Machine’. Essentially this was the first programmable computer. His work came to the attention of mathematicians in the US who were conducting parallel research, and he was invited to collaborate with them, eventually being awarded a PhD in Logic by Princeton.
In 1939 he returned to Britain to join the Code and Cypher School at Bletchley Park whose main purpose was to decode messages passed between the German military command and the front line. These messages were encoded using a very sophisticated machine, called Enigma, which had been developed before World War II. Decoding the Enigma messages was seen as vital to the war effort, but manual decoding was extremely time-consuming and Turing recognized that a ‘Turing machine’ could help with the task. He therefore made a direct appeal to the Prime Minister Winston Churchill to provide extra funds to allow him to set up a machine at Bletchley Park,. His audacity paid off and he was able to construct the machine, called the ‘Bombe’, which significantly speeded up the de-cyphering of Enigma messages. Amongst other things, this enabled the position of German U-boats in the North Atlantic to be predicted, thereby allowing allied convoys to avoid them. At the end of the war, the work of Turing and his team was highly praised by Churchill, who said that the war could not have been won without them.
After the war, he continued to develop his ideas on computing, and at Manchester University in 1948 helped to set up what was probably the world’s first successful prototype computer.
As no voice recordings of Turing survive, it is difficult to know how severely he stuttered, and accounts of people who knew him vary. During his time at Bletchley Park he was regarded as a bit odd by his colleagues, as he did not socialize easily, which may have been due to his stutter, or his natural shyness, or his general unworldliness. However he was also liked, by those who did get to know him, for his gentleness and cheerful outlook.
Whilst he did not flaunt the fact that he was gay, neither did he make a secret of it, and this, together with his naivete, eventually proved to be his downfall. While working in Manchester he frequented such gay venues as existed in the city at that time, and at one of these met a young man with whom he started an affair. An acquaintance of the young man broke into Turing’s house one night, and in the subsequent police investigation Turing spoke of having had sexual relations with the burglar’s friend. Sex between men, even in private, was still a criminal offence in Britain in the 1950’s and in a prevailing atmosphere of paranoia about gay men being a risk to national security Turing had his security clearance taken away. Though he was not sent to prison, he suffered the humiliation of having the details of his private life exposed in the newspapers, and was forced to undergo hormone treatment as a ‘cure’ for his homosexual urges. In fact this treatment did nothing but suppress the libido and trigger depression. It was probably a combination of this depression and the stress of public exposure which led him to take his own life – by eating an apple laced with cyanide – in 1954. He was 41. Alan Turing 1946
Turing’s legacy to the modern world is incalculable. He was fascinated by the working of the human brain, and his research led him into the areas of physics, biology, psychology and philosophy. Many of his ideas were way ahead of his time, and his writings in the few years preceding his death, for example on Artificial Intelligence, are still being studied today by experts in the field of computer science. His misfortune was to have lived in a less tolerant and more hypocritical age than our own. It is a tribute to him that his personal courage, dedication and refusal to compromise have led to today’s information revolution, and will go on influencing our lives for many years to come.
‘Alan Turing – The Enigma’, a biography by Andrew Hodges, 1987
‘Breaking the Code’ by Hugh Whitmore (stage play and TV drama based on Hodges’ book)