Alan Turing

Alan Turing was the English mathematician who gave computing its theoretical foundation. In 1936, to settle a question in mathematical logic, he imagined an abstract device — now called a Turing machine — and proved that a single universal machine could carry out the work of any other, given the right program. Every general-purpose computer since is a physical echo of that idea.

During the Second World War he was central to breaking the German Enigma cipher at Bletchley Park, work that helped turn the conflict. He went on to ask whether machines could think — the Turing test still frames that debate — before his life was cut short following a conviction for homosexuality, then a crime in Britain. He stands at the center of the history of programming.