Alan Turing
More info
- Born
- Died
- Known for
- The Turing machine, cryptanalysis at Bletchley Park, the Turing test
- Nationality
- British
The man who defined what a computer is before anyone had built one — and therefore also what one can never do.
In "On Computable Numbers" in 1936, Turing introduced the abstract machine that carries his name, in order to settle Hilbert's Entscheidungsproblem. The answer was no: there are questions no algorithm can decide, the halting problem among them. The same paper describes, almost in passing, a universal machine able to simulate any other — the stored-program principle.
During the war he worked at Bletchley Park breaking Enigma. In 1950 he formulated the imitation game, now the Turing test. He was prosecuted in 1952 for homosexuality, sentenced to hormone treatment, and died two years later of cyanide poisoning. Computing's foremost prize carries his name.