Wednesday, February 25, 2015

Some stories about Alan Turing

So, here are a few Turing stories of my own. The first from Robin Gandy, who supervised by DPhil, and who, in turn, was Turing's PhD student. Robin had a wealth of stories about Turing, many of which made their way into Andrew Hodges' book – Hodges was a postgrad in Oxford with Penrose around the beginning of the 80s. Perhaps most poignant [quoting from Mike Yates' obituary of Robin]  was when asked about Turing's motives if he really did commit suicide, Gandy would become quite heated: “Some things are too deep and private and should not be pried into.” Sara Turing, Alan's mother, certainly always maintained that his death was an accident.

Her biography of Alan was republished in the centenary year by Cambridge University Press, and that also has only remembered stories of his youth and adulthood. The most striking thing for me was the postscript written by his brother John, on their upbringing, which was not untypical for the English upper middle classes in the early years of the century. Two quotes
  • When Alan was two “rightly or wrongly, [my father] decided that he and my mother should return alone to India, leaving both children with foster parents in England” … “it was certainly a shock for me, even at the age of five” but “it was accepted procedure” (and he goes on to compare it with Kipling's horrendous experience, noting that at least they “escaped” that).
  • The real bombshell, though, is schooling. John says, without an ounce of irony or indeed anger “I take credit for persuading my parents to send [Alan] to Sherborne instead of Marlborough, which all but crushed me and would certainly have crushed him”.
A final anecdote. In our previous house, a near neighbour was a retired canon from Canterbury Cathedral, Donald Eperson, who wrote puzzles for the Mathematical Gazette, and who had been a schoolteacher before being ordained. Not any teacher, though, he's taught Alan at Sherborne, and indeed is mentioned in the Hodges biography. He remembered Alan, and I lent him the book – unfortunately, references to his naiveté rather upset him, and I was sorry for unsettling him. 

It's certainly a great thing that Turing has become almost a household name, and that his memory has been rescued for generations to come as one of the greatest scientists of the twentieth century. It's also a great thing that he was pardoned for his conviction for being gay … but surely something that should apply to everyone who was treated so shamefully?


Gandy obituary

Sara Turing bio of Alan

Memoir of Donald Eperson (look for "Music and Mathematics")

The Imitation Game – telling a good story about Alan Turing

So, what to make of The Imitation Game, the film based on the life of Alan Turing?

Well, first of all it tells a good story. Some of the key messages about codebreaking are there:

  • Knowing something about the content – particularly stylised beginnings or endings – make it easier to break the code.  
  • The paradox of the codebreaker: you can't betray that by changing your behaviour too much, or the coders will change their setup … something card players surely recognise.
  • The Bletchley crowd were a mixed bunch: classicists rubbed shoulders with mathematicians and debs.
But it's clearly telling a story in the sense of lying too, and that's a frustration. Maybe it must to move the plot along, but some of the changes seem wilful and so out of character:
  • Part of the extraordinary nature of Bletchley was its scale: in the film it's shrunk to something like a "Famous Five" adventure: Turing and his small crew have the idea for the machine, build it (no Tommy Flowers), and then take the decision about not being able to reveal that the code has been cracked; that just doesn't make historical sense, but I guess keeps the plot moving;
  • An anecdote about the scale of the place: a couple who were in the forces during WW2 were recently visiting Bletchley, and half way round the husband confesses to his wife that he'd worked there during the war – because of the secrecy surrounding the whole operation, he'd been sworn to secrecy – only for her to admit to working there too; perfectly possible
  • More egregious is the sub-plot about Cairncross, and suggesting that Turing had in some way colluded with him – no historical evidence for this at all.
  • Worst of all, I think, was the conceit of Turing's "home computer" Christopher. No evidence for  that at all.
So, it's a good story, well acted and put together, but it tells too many stories to be completely satisfactory. Check out the biography by Andrew Hodges for a comprehensive and erudite view of Turing's life.