Alan Mathison Turing, OBE, FRS ,was an English mathematician, logician, cryptanalyst, and computer scientist. He was influential in the development of computer science and provided an influential formalisation of the concept of the algorithm and computation with the Turing machine. In 1999 Time Magazine named Turing as one of the 100 Most Important People of the 20th Century for his role in the creation of the modern computer. His Turing test was a significant and characteristically provocative contribution to the debate regarding artificial intelligence. During the Second World War, Turing worked for the Government Code and Cypher School at Bletchley Park, Britain`s codebreaking centre. For a time he was 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. After the war he worked at the National Physical Laboratory, where he created one of the first designs for a stored-program computer, the ACE.
Towards the end of his life Turing became interested in chemistry. He wrote a paper on the chemical basis of morphogenesis, and he predicted oscillating chemical reactions such as the Belousov–Zhabotinsky reaction, which were first observed in the 1960s.
Turing`s homosexuality, which was illegal and considered to be a mental illness during his lifetime, resulted in a criminal prosecution in 1952. He accepted treatment with female hormones as an alternative to going to prison. He died in 1954, several weeks before his 42nd birthday, from an apparently self-administered cyanide poisoning, although his mother (and some others) considered the circumstances of his death to be suspicious. On 10 September 2009, following an Internet campaign, British Prime Minister Gordon Brown made an official public apology on behalf of the British government for the way in which Turing was treated after the war.