Alan Turing Caricature of the British mathematician Alan Turing In Turing described a theoretical computer a Turing machine in rigorous mathematical terms formalising the previously vague concept of computability During the Second World War he worked as a code breaker at Bletchley Park Britains codebreaking centre In Turing and Cambridge mathematician Gordon Welchman designed the British Bombe which could break any Enigmaenciphered message In later years he worked on Artificial Intelligence devising the Turing test to decide whether a computer can be thought of as truly intelligent Turing committed suicide when prosecuted for his homosexuality a criminal offence at the time