Friday, 11 September 2009

A posthumous apology

A letter from Gordon Brown was published in the Daily Telegraph today which comes as close to an apology for the treatment of Alan Turing as it is possible to get, short of a pardon under the Royal Prerogative, which was not (it appears) given.

Turing was a mathematician who prior to the second world war worked in academia, first at King's College, Cambridge as an undergraduate and then in post-graduate mathematical research, and more importantly subsequently at Princeton, where he demonstrated that a programmable computation machine, now called a universal Turing machine (or a "computer" to you and I), could perform any mathematical computation with appropriate algorithms. (Not that it can be proved formally that all mathematical problems involving natural numbers can be solved by applying mathematical axioms, and therefore by a universal Turing machine applying computational algorithms; it is one of life's better jokes that an arithmetical outcome can be true without being provably so). He has given his name to computer science: if a particular set of algorithmic abilities comprised in a computer programming language is capable of solving all solvable mathematical computations, it is said to be "Turing complete".

Returning to the UK shortly before the outbreak of war and joining the Government Code and Cypher School, he was one of the team of brilliant young men who gathered at the then secret Bletchley Park establishment and achieved the remarkable feat of building machines (not initially Turing complete machines) breaking the high quality German cypher codes which they considered to be unbreakable. The fact of the matter is that for at least half of the second world war, the allied powers knew exactly what their enemies were doing on all important matters, giving an enormous advantage that certainly shortened the war considerably even if it did not ultimately change the outcome (I would not want to venture a view on that).

Alan Turing featured prominently with other codebreakers in the somewhat surreal and mostly fictional book Cryptonomicon by Neal Stephenson, a somewhat long but interesting book which is worth a read for those who have not yet tackled it.

Alan Turing was homosexual. He was convicted (as was Oscar Wilde some years earlier) of gross indecency in 1952. As an experimental treatment in place of imprisonment he was offered hormone treatment sometimes referred to as "chemical castration". What was thought to be achieved by such a "cure" is difficult to say, but it was sufficient to cause him to die by cyanide poisoning two years later, apparently by his own hand, having had his security clearance removed in consequence of his conviction which meant he had to give up his government cryptography work (although he was able to carry on his teaching and research).

Some have criticised the apology as political posturing, on the grounds either that it is past history that cannot now be corrected and that all was done in accordance with the norms of the time; or that if one is to apologise for one conviction of this kind, one has to apologise for all of them. However, in my opinion it is an apology that is richly deserved. Sometimes services to one's country require formal steps that may not be capable of being offered to everyone, particularly where those services contrast with the appalling treatment he received. Whatever one thinks of old-boy networks, it is a shame that it was not enough to cause the matter to be quietly forgotten, as it probably would have been at an earlier time (Oscar Wilde would probably have been left unmolested had he not instituted libel proceedings). Maybe the prosecution occurred either 30 years too late or 30 years too early.

Perhaps now a proper posthumous pardon and a statue in a London square? Or perhaps some government support for the Bletchley Park rescue project and museum.

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