Alan Turing's reputation grows and grows, from the nadir of his conviction for "gross indecency", in 1952, to his present standing as a pioneer of computer science and artificial intelligence, from relative obscurity to hero of the entertaining, if rather inaccurate, film The Imitation Game. Jack Copeland's story focuses on Turing's achievements in maths and science. In his 20s he designed his Universal Turing Machine, introducing the concept of "stored programs", helped to defeat Hitler's U-boats and later worked in the vanguard of artificial intelligence research. Copeland's research is meticulous and his sources exhaustive. His photographs and diagrams of the Enigma machine and Turing's Bombe decoding machine are fascinating. There are few references to Turing's personal life, but the final chapter is an attack on the unchallenged belief that Turing died by suicide at 41. Copeland argues that he was happy in his work, physically fit and at ease with his sexuality.
