Alan Turing (June 23, 1912 - June 7, 1954) was a British mathematician, logician, and cryptographer. Turing is often considered to be a father of modern computer science.
With the Turing Test, Turing made a significant and characteristically provocative contribution to the debate regarding artificial intelligence: whether it will ever be possible to say that a machine is conscious and can think. He provided an influential formalisation of the concept of algorithm and computation with the Turing machine, formulating the now widely accepted "Turing" version of the Church-Turing thesis, namely that any practical computing model has either the equivalent or a subset of the capabilities of a Turing machine. During World War II, Turing worked at Bletchley Park, Britain's codebreaking centre and was for a time head of Hut 8, the section responsible for German Naval cryptanalysis. He devised a number of techniques for breaking German ciphers, including the method of the bombe, an electromechanical machine which could find settings for the Enigma machine.
After the war, he worked at the National Physical Laboratory, creating one of the first designs for a stored-program computer, although it was never actually built. In 1947 he moved to the University of Manchester to work, largely on software, on the Manchester Mark I then emerging as one of the world's earliest true computers.
In 1952, Turing was convicted of acts of gross indecency after admitting to a sexual relationship with a man in Manchester. He was placed on probation and required to undergo hormone therapy. When Alan Turing died in 1954, an inquest found that he had committed suicide by eating an apple laced with cyanide.