Posted by: Prospector PJ19 JUN 2012
Today (23 June) is the 100th anniversary of the birth of Alan Turing, English mathematician, logician, cryptanalyst and computer scientist. Turing is widely considered to be the father of computer science and artificial intelligence. His Turing machines — formal and simple hypothetical devices that formalised the concepts of algorithm and computation — played an important part in the creation of the modern computer.
Before the 1939–45 war, Turing worked part-time with the Government Code and Cipher School, concentrating on cryptanalysis of the German Enigma code. During the war he worked at Bletchley Park, where he was described as a genius for his work on breaking German ciphers. While at Bletchley, Turing specified an electromechanical machine that could help break Enigma more effectively than the existing Polish method. His “bombe” became the main automated tool used by the British to decipher Enigma coded messages.
In 1942 Turing devised a technique called “Turingery” for use against the Lorenz cipher messages produced by the German’s new Geheimschreiber (secret writer) machine. By the later stages of the war he was working for the Secret Service’s Radio Security Service, where he designed and built a portable secure voice communications machine codenamed Delilah, although this was completed too late to be used in the war. Turing was awarded an OBE for his war-time service, but his work remained secret for many years.
After the war Turing worked on the Automatic Computing Engine (ACE) at the National Physical Laboratory, creating the first detailed design for a stored-program computer in 1946. Although his ACE was never built, subsequent computer designs owe much to its design.
In a paper published in Mind in 1950, Turing considered artificial intelligence, proposing a test to determine whether a computer is “intelligent”. The Turing test was based on the theory that a computer could “think” if a human user could not tell it apart from a human being during a conversation.
Turing was charged with gross indecency in 1952 after a homosexual relationship became public. He was given the choice of imprisonment or chemical castration by oestrogen injections and he chose the latter. His conviction led to the removal of his security clearance, so that he could no longer continue his cryptographic work for the government.
Turing died in June 1954, apparently after eating an apple poisoned with cyanide. An inquest determined that his death was suicide.
In 2009, Prime Minister Gordon Brown issued an apology on behalf of the Government for Turing’s prosecution, describing his treatment at “appalling”.