Alan Mathison Turing (1912 to 1954) was a British mathematician and logician whose work laid the theoretical foundation of modern computer science. He was born in London on June 23, 1912, and died at his home in Wilmslow, Cheshire, on June 7, 1954.
In 1936, while still in his twenties, Turing wrote “On Computable Numbers, with an Application to the Entscheidungsproblem,” a paper that defined computation and established mathematical limits on what machines could compute. The abstract device he introduced in that paper, now called the Turing machine, became the standard model for what it means for a function to be computable.
During the Second World War, from 1939 to 1945, Turing worked at Bletchley Park, the British government’s wartime codebreaking center, where he was a chief figure in the effort to break the German Enigma cipher, with particular responsibility for decrypting U-boat communications.
In his 1950 paper “Computing Machinery and Intelligence,” Turing proposed what he called the imitation game, now widely known as the Turing test: a way of judging machine intelligence by whether a human evaluator can distinguish a machine from a person through text conversation alone. The ACM Turing Award, often described as the highest distinction in computing, is named in his honor.