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The Cult of St Alan of Bletchley Park

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I realise that to rail against anything published in the Daily Fail is about as effective as pissing against the wind in a force 8 gale but this article on Alan Turing got so up my nose that I have decided to strap on my bother-boots of historical criticism and give the author a good kicking if only to assuage my own frustration. It won’t do any good but it might make me feel better.

Before I start in on a not so subtle demolition job, I should point out that I’m actually a Turing fan who has read and absorbed Andrew Hodges’ excellent Turing biography[1] as well as many books and articles on and by Turing. I have seriously studied his legendary paper on the Entscheidungsproblem[2], I have a copy sitting on my bookshelf, which I understand thoroughly including its significance for Hilbert’s Programme, which the Mail’s journalist almost certainly does not. If I here seem to be seriously challenging Turing’s claims to scientific sainthood it is only in the interests of historical accuracy and not out of any sense of antipathy to the man himself, who would definitely be one of my heroes if I went in for them.

The Mail article opens with a real humdinger of a claim that is so wrong it’s laughable:

Own a laptop, a smartphone or an iPad? If so, you owe it to a man many of us have never heard of – a genius called Alan Turing. ‘He invented the digital world we live in today,’ says Turing’s biographer David Leavitt in a new Channel 4 drama-documentary about the brilliant mathematician.

Sorry folks Alan Turing did not invent the digital world we live in today. In the 1930s Turing was one of several meta-mathematicians who laid the theoretical foundations for computability and although his contributions were, viewed from a technical standpoint, brilliant we would still have had the computer revolution if Alan Turing as an undergraduate had turned his undoubted talents to deciphering ancient Sumerian clay tablets instead of to solving meta-logical problems. The German computer pioneer Konrad Zuse designed and built functioning digital computers in the 1930s and 40s without, as far I know, ever having heard of Turing. Zuse was an engineer and not a mathematician and approached the problem from a purely practical point of view. The American engineer Vannevar Bush built a highly advanced analogue computer, his Differential Analyser, to solve differential equations in 1927 when Turing was still at school. Claude Shannon who laid the foundations of digital circuit design was one of Bush’s graduate students. All three American groups, which developed digital computers in the late 193os and early 1940s, Atanasoff and Berry in Iowa, Aiken in Harvard and Eckert and Mauchly in Pennsylvania all referenced Bush when describing their motivations saying they wished to construct an improved version of his Differential Analyser. As far as I know none of them had read Turing’s paper, which is not surprising as Turing himself claimed that in the 1930’s only two people had responded to his paper. The modern computer industry mainly developed out of the work of these three American groups and not from anything produced by Turing.

Turing did do work on real digital computers at Bletchley Park in the 1940s but this work was kept secret by the British government after the war and so had no influence on the civil development of computing in the 1950s and 60s. Turing like many other of the computer pioneers from Bletchley started again from scratch after the war but due to their delayed start and underfunding they never really successfully competed with the Americans. We now turn to Bletchley Park and Turing’s contribution to the Allied war effort. The Mail writes:

Ironically, the same society that hounded him to his death owed its survival to him. For during the Second World War it was Turing who pioneered the cracking of Nazi military codes at Bletchley Park, allowing the Allies to anticipate every move the Germans made.

The first sentence is a reference to Turing’s suicide caused by his mistreatment as a homosexual, which I’m not going to discuss here other than to say that it’s a very black mark against my country and my countrymen. We now come to a piece of pure hagiography. The cracking of the Germany military codes was actually pioneered by the Poles before Bletchley Park even got in on the act. It should also be pointed out that Turing was one of nine thousand people working in Bletchley by the end of the War. Also he was only in charge of one team working on one of the codes in use, the navel naval Enigma, there were several other teams working on the other German codes. Turing was one cog in a vast machine, an important cog but a long way from being the whole show. The Mail next addresses Turing’s famous paper:

‘While still a student at Cambridge he wrote a paper called Computing Machinery, in which all the developments of modern computer science are foretold. If you take an iPhone to pieces, all the parts in there were anticipated by Turing in the 1930s.’

He wasn’t a student but a postgraduate fellow of his college. The title of the paper is On Computable Numbers, with an Application to the Entscheidungsproblem. It outlines some of the developments of modern computing but not all and no he didn’t anticipate all of the parts of an iPhone. Apart from that the paragraph is correct.

Turing’s outstanding talents were recognised at the outbreak of war, when he was plucked from academic life at Cambridge to head the team at Bletchley Park, codenamed Station X. They were tasked with breaking the German codes, transmitted on complex devices called Enigma machines, which encrypted words into as many as 15 million million possible combinations.

‘Turing took one look at Enigma and said, “I can crack that,”’ says Sen. ‘And he did.’ Part of Turing’s method was to develop prototype computers to decipher the Enigma codes, enabling him to do in minutes what would take a team of scientists months to unravel. It was thanks to him that the movements of German U-boats could be tracked and the battle for control of the Atlantic was won, allowing supplies to reach Britain and saving us from starvation.

Turing was not “plucked from academic life”; interested in the mathematics of cryptology Turing started working for the Government Code and Cypher School already in 1938 and joined the staff of Bletchley Park at the outbreak of war. The department he headed was called Hut 8. With reference to the computers developed in Bletchley, as I have already said in an earlier post Turing was responsible for the design of special single purpose computer, the Bombe, which was actually a development from the earlier Polish computer the Bomba and had nothing to do with the much more advance and better known Bletchley invention, the Colossus. The second paragraph is largely correct.

The life and work of Alan Turing and the role of Bletchley Park in the war effort are both important themes in the histories of science, mathematics and technology and can certainly be used as good examples on which to base popular history but nobody is served by the type of ignorant, ill-informed rubbish propagated by the Daily Fail and obviously by the Channel 4 documentary that they are reporting on, which is obviously being screened tonight. My recommendation don’t watch it!

 


[1] Andrew Hodges, Alan Turing: The Enigma, Simon & Schuster, 1983.

[2] Alan M. Turing, On Computable Numbers, with an Application to the Entscheidungsproblem, Proceedings of the London Mathematical Society, 2 ser. vol. 42, (1936 – 37), pp. 230 – 265.



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