On March 31, 1952, Alan Turing was arrested and came to trial after the police learned of his sexual relationship with a young Manchester man. He made no serious denial or defence, instead of telling everyone that he saw no wrong with his actions. He was particularly concerned to be open about his sexuality even in the tough and unsympathetic atmosphere of Manchester engineering. He accepted, for a year, injections of oestrogen intended to neutralise his libido rather than go to prison .

His work continued on the morphogenetic theory. Turing developed his theory of pattern formation out of instability into the realm of spherical objects, such as the Radiolaria, and also on the cylinder, as a plant stems model. He set as a particular goal the explanation for the appearance of the Fibonacci numbers in the leaf patterns of plants --- most noticeable in the close-packed spirals of fir cones and sunflower heads.

Turing refreshed his youthful interest in quantum physics, studying the problem of wave-function reduction in quantum mechanics, with a chance that he was considering a non-linear mechanism for it. Alan took a new interest in the representation of elementary particles by spinors, and in relativity theory.

Turing had also continued to work for GCHQ, a factor in his life unknown to most around him, the post-war successor to Bletchley Park, on the basis of a personal connection with Alexander, currently its director. Since 1948, the conditions of the Cold War, and the alliance with the United States, meant that known homosexuals had become ineligible for security clearance. Alan, now therefore excluded, spoke bitterly of this to his onetime wartime colleague, now MI6 engineer Donald Bayley, and to no other personal friends. State security also seems the likely cause of what he described as another intense crisis in March 1953, involving police searching for a Norwegian who had come to see him. Concern over the foreign contacts of one acquainted with state secrets was understandable, and his holiday in Greece in 1953 could not have been calculated to calm the nerves of security officers.

Turing actively sought much greater intimacy of expression with his friends and with a Jungian therapist. Eccentric, solitary, gloomy, vivacious, resigned, angry, eager, dissatisfied. These had always been his characteristics, and despite the strength that he showed the world in coping with outrageous fortune, no one could safely have predicted his future.

Alan Turing was found by his maid when she came in on June 8, 1954. The day before he had died of cyanide poisoning, a half-eaten apple beside the bed. Turing's mother believed he had accidentally ingested cyanide from his fingers after a chemistry experiment, but it is more credible that he had successfully contrived his death to allow her to believe this. The coroner's verdict was suicide.

Alan Turing Timeline

1912: Birth, Paddington, London

1926-31: Sherborne School

1930: Death of a friend Christopher Morcom

1931-34: Undergraduate at King's College, Cambridge University

1932-35: Studies quantum mechanics, probability, logic

1935: Elected fellow of King's College, Cambridge University

1936: The Turing machine: On Computable Numbers...

1936-38: At Princeton University. Ph.D. Papers in logic, algebra, number theory

1939-40 Devises the Bombe, machine for Enigma decryption

1939-42: Breaking of U-boat Enigma cipher, saving battle of the Atlantic

1943-45: Chief Anglo-American consultant. Introduced to electronics

1945: National Physical Laboratory, London

1946: Computer design, leading the world, formally accepted

1947-48: Papers on programming, neural nets, and prospects

1954: Alan Turing found dead by injection of Cyanide Poisoning when maid came to clean.