Alan Mathison Turing 1912 1954 British mathematician logician

Alan Mathison Turing (1912 – 1954) • British mathematician, logician, and cryptographer, • One of the fathers of modern computer science. Fundamentals of Software Development 1 1

Some Contributions • Provided an influential formalization of the concept of algorithm and computation: the Turing machine. Also formulated the Church-Turing thesis stating that any practical computing model has either the equivalent or a subset of the capabilities of a Turing machine. • During World War II he worked on breaking German ciphers, particularly the Enigma machine. • He designed one of the earliest electronic programmable digital computers at the National Physical Laboratory. Fundamentals of Software Development 1 2

Death • Prosecution for his homosexuality crippled his career. He was charged with “gross indecency and sexual perversion”. • He unapologetically offered no defense, and was convicted. • He was given a choice between incarceration and estrogen hormonal treatment. He chose the latter. • In 1954, he died of cyanide poisoning. His death was ruled a suicide. Fundamentals of Software Development 1 3

Recognition • A statue of Turing was unveiled in Manchester on June 23, 2001. • To mark the 50 th anniversary of his untimely death, a memorial plaque was unveiled at his former residence 'Hollymeade' in Wilmslow on June 7, 2004. • The Turing Award is given by the Association for Computing Machinery to a person for technical contributions to the computing community. It is widely considered to be the equivalent of the Nobel Prize in the computing world. Fundamentals of Software Development 1 4