Mathwar/Personlist/Turing Alan
Alan Turing
(* June 23rd 1912, † June 7th 1954)
British mathematician, logician, cryptanalyst and computer scientist.
Turing is often considered to be the father of modern computer science. He provided an influential formalisation of the concept of the algorithm and computation with the Turing machine. For his role in the modern computer, the Time Magazine, in naming Turing one of the 100 most influential people of the 20th century, states: "The fact remains that everyone who taps at a keyboard, opening a spreadsheet or a word-processing program, is working on an incarnation of a Turing machine.
Life
During the Second World War, Turing worked at Bletchley Park, Britain's codebreaking centre, and was for a time head of Hut 8, the section responsible for German naval cryptanalysis. He devised a number of techniques for breaking German ciphers, including the method of the bombe, an electromechanical machine that could find settings for the Enigma machine.
n December 1940, Turing solved the naval Enigma indicator system, which was more mathematically complex than the indicator systems used by the other services. Turing also invented a Bayesian statistical technique termed "Banburismus" to assist in breaking naval Enigma. Banburismus could rule out certain orders of the Enigma rotors, reducing time needed to test settings on the bombes.
In the spring of 1941, Turing proposed marriage to Hut 8 co-worker Joan Clarke, although the engagement was broken off by mutual agreement in the summer.
In July 1942, Turing devised a technique termed Turingismus or Turingery for use against the Lorenz cipher used in the Germans' new Geheimschreiber machine ("secret writer") which was one of those codenamed "Fish". He also introduced the Fish team to Tommy Flowers who, under the guidance of Max Newman, went on to build the Colossus computer, the world's first programmable digital electronic computer, which replaced simpler prior machines (including the "Heath Robinson") and whose superior speed allowed the brute-force decryption techniques to be applied usefully to the daily-changing cyphers.
Turing travelled to the United States in November 1942 and worked with U.S. Navy cryptanalysts on Naval Enigma and bombe construction in Washington, and assisted at Bell Labs with the development of secure speech devices. He returned to Bletchley Park in March 1943. During his absence, Hugh Alexander had officially assumed the position of head of Hut 8, although Alexander had been de facto head for some time—Turing having little interest in the day-to-day running of the section. Turing became a general consultant for cryptanalysis at Bletchley Park.
Turing was arrested for violation of British homosexuality statutes in 1952 when he reported to the police details of a homosexual affair. He had gone to the police because he had been threatened with blackmail. He was tried as a homosexual on 31 March 1952, offering no defence other than that he saw no wrong in his actions. Found guilty he was given the alternatives of prison or oestrogen injections for a year. He accepted the latter. After that the police began to investigate his foreign visitors. Turing died of potassium cyanide poisoning while conducting electrolysis experiments. The cyanide was found on a half eaten apple beside him.