Question: What was Alan Turing's contribution to the field of computer science?
About the article "Computer science", section "The great insights of computer science".

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There was a three-day conference in Manchester, UK in June, a two-day conference in San Francisco, organised by the ACM, and a birthday party and Turing Centenary Conference in Cambridge organised at King's College, Cambridge and the University of Cambridge, the latter organised by the association Computability in Europe.
The Science Museum in London launched a free exhibition devoted to Turing's life and achievements in June 2012, to run until July 2013.
In February 2012, the Royal Mail issued a stamp featuring Turing as part of its "Britons of Distinction" series.
The London 2012 Olympic Torch flame was passed on in front of Turing's statue in Sackville Gardens, Manchester, on the evening of 23 June 2012, the 100th anniversary of his birth.
On 22 June 2012 Manchester City Council, in partnership with the Lesbian and Gay Foundation, launched the Alan Turing Memorial Award which will recognise individuals or groups who have made a significant contribution to the fight against homophobia in Manchester.
At the University of Oxford, a new course in Computer Science and Philosophy was established to coincide with the centenary of Turing's birth.
Previous events have included a celebration of Turing's life and achievements, at the University of Manchester, arranged by the British Logic Colloquium and the British Society for the History of Mathematics on 5 June 2004. 
His 1987 drama "Alan Turing" featured one of the fathers of modern computer science, who had made significant contributions to breaking German ciphers during World War II.
The play also covered Turing's homosexuality, discovery of which resulted in his loss of career, court-ordered chemical castration, depression, and suicide. 
In 1959, Arthur Samuel defined machine learning as a "Field of study that gives computers the ability to learn without being explicitly programmed".
Tom M. Mitchell provided a widely quoted, more formal definition: "A computer program is said to learn from experience E with respect to some class of tasks T and performance measure P, if its performance at tasks in T, as measured by P, improves with experience E".
This definition is notable for its defining machine learning in fundamentally operational rather than cognitive terms, thus following Alan Turing's proposal in Turing's paper "Computing Machinery and Intelligence" that the question "Can machines think?"
be replaced with the question "Can machines do what we (as thinking entities) can do?"
Breaking the Code is a 1986 play by Hugh Whitemore about British mathematician Alan Turing, who was a key player in the breaking of the German Enigma code at Bletchley Park during World War II and founder of computer science.
The play thematically links Turing's cryptographic activities with his attempts to grapple with his homosexuality. 
Before stored-program digital computers.
Origins of computer science.
The first piece of software was arguably created by Ada Lovelace in the 19th century, for the planned analytical engine.
However, it was never executed.
The first theory about software - prior to the creation of computers as we know them today - was proposed by Alan Turing in his 1935 essay "Computable numbers with an application to the Entscheidungsproblem (decision problem)".
This eventually led to the creation of the twin academic fields of computer science and software engineering, which both study software and its creation.
Computer science is more theoretical (Turing's essay is an example of computer science), whereas software engineering is focused on more practical concerns.
However, prior to 1946, software as we now understand it - programs stored in the memory of stored-program digital computers - did not yet exist.
The very first electronic computing devices were instead rewired in order to "reprogram" them - see History of computing hardware.