forces.
The effect was electric. Churchill wrote a memo to General Ismay which read: " ACTION THIS DAY. Make sure they have all they want on extreme priority and report to me that this has been done." On 18 November the chief of the secret service reported that every possible measure was being taken. More than two hundred bombes were in operation by the end of the war.
While working at Bletchley, Turing, a talented long-distance runner, occasionally ran the 40 miles( 64 km) to London when he was needed for high-level meetings, and he was capable of world-class marathon standards.
In 1945, Turing was awarded the QBE by King George VI for his wartime services, but his work remained secret for many years.
Hut 8 and Naval Enigma
Turing decided to tackle the particularly difficult problem of German naval Enigma " because no one else was doing anything about it and I could have it to myself ". In December 1939, Turing solved the essential part of the naval indicator system, which was more complex than the indicator systems used by the other services. That same night he also conceived of the idea of Banburismus. a sequential statistical technique( what Abraham Wald later called sequential analysis) toAssist in breaking naval Enigma, " though I was not sure that it would work in practice, and was not in fact sure until some days had actually broken ". For this he invented a measure of weight of evidence that he called the Ban. Banburismus could rule out certain sequences of the Enigma rotors, substantially reducing the time needed to test settings on the bombes. Alexander wrote as follows about his contribution:
There should be no question in anyone ' s mind that Turing ' s work was the biggest factor in Hut 8 ' s success. In the early days he was the only cryptographer who thought the problem worth tackling and not only was he primarily responsible for the main theoretical work within the Hut but he also shared with Welchman and Keen the chief credit for the invention of the Bombe. It is always difficult to say that anyone is absolutely indispensable but if anyone was indispensable to Hut 8 it was Turing. The pioneer ' s work always tends to be forgotten when experience and routine later make everything seem easy and many of us in Hut 8 felt that the magnitude of Turing ' s contribution was never fully realized by the outside world In 1941, Turing proposed marriage to Hut 8 co-worker 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.
Early computers and the Turing test
From 1945 to 1947, Turing lived in Richmond,
London while he worked on the design of the ACE( Automatic Computing Engine) at the National Physical Laboratory( NPL). He presented a
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