I once read a proof of Gödel's first incompleteness theorem that used a version of Turing's undecidability proof, which have had great impact on me. That being said, I find the point of this article, if not nitpicking, then asking too much of a Hollywood movie. I may be a bit cynical in suspecting Petzold sees an oppurtunity here to Google rank his book.<p>With his famous paper, Turing (1) formalized the concept of the computation and (2) showed, analogously to Gödel, that there are some facts about computing that aren't reachable by computational means. He also did things like <i>saving the world by decrypting the German Enigma machine</i>. Yet he was a socially marginalized individual who died tragically because of it. I haven't seen the movie, don't know what it's about. But I know it's not made for computer scientists, and we should be glad that Turing is finally getting the recognition he desereves.
This is why I think non-documentary movie making of the lives of historical people is a fool's errand. Of course Hollywood had to sex up Turing. He's a pretty boring guy by Hollywood hero standards. There was no big breakthrough with the Enigma. Well, there was, but it was a Polish team that figured it out. Obviously, his sexuality is a dramatic point in his life, but that's not much to build a movie on. I really wonder if a decent documentary team was granted 1/10th the budget of this movie, what would their output be? Probably a decent and educational flick.<p>Its also a weird production. I'm not even sure who made this movie. It seems that it was produced by a near non-entity called Black Bear Pictures out of NYC, which shows only this movie and three others on their webpage. It was directed by a nobody with 3 other mediocre films under his belt and written by a novice writer. It really has "pet indie project of a wealthy person or two" written all over it. Shame really, a more mature and historically serious team probably would have punched out a better film.<p>There's a great Turing/Enigma/WWII film to be made, and this just isn't it. Considering its poor box office response (only 1m so far), I imagine this will be the only one, ever for Turing. I really feel his story is Spielberg or Scorsese worthy, but now alas, Turing is established as box office poison.
To me,<p>> any conceivable mathematical calculation can be done by a single device shuffling 1’s and 0’s back and forth<p>seems right. It does not say that Turing's machine solves every problem. It says it does every conceivable calculation.<p>That was Turing's contribution (anyway, one of them). The controversy at the time (1930's) was that there were a number of proposed definitions for what are conceivable mathematical computations (Kleene, Post, Herbrand ..). All of them gave schemes that the authors claimed were exhaustive. Turing's paper convinces a reader, as it convinced Godel, that his definition does indeed do everything mechanically possible (and everyone else's definitions, since they all prove to be equi-powerfull).<p>Of course Godel knew there were unsolvable problems. The question was whether there was a single maximally-powerful device.
“On Computable Numbers, with an Application to the Entscheidungsproblem” is a hugely important work, and Petzold's book "The Annotated Turing" makes it very accessible. I highly recommend anyone who is interested pick up a copy. High school education is all that's really needed.<p>Turing was decades ahead of the rest of us. It's a shame that we're portraying him so inaccurately (though really, not nearly as shameful as how we treated him when he lived).
This is true, but there are so many other things horribly wrong with that film that it hardly seems worth mentioning that they screwed up the description of the Turing Machine's capabilities.
This is a good essay, and I am hesitant to see the film because I am worried that I will cringe every few minutes. But, I disagree with this sentence:<p>"Everyone agrees that Alan Turing is a seminal figure in the computer revolution, so it's puzzling why these movies deliberately misrepresent his work."<p>I sincerely doubt the movies <i>deliberately</i> misrepresent his work. Rather, I assume they <i>honestly</i> misrepresent his work, meaning that they tried to get it right, but they don't understand it well enough to do so.
Odd that an article so nit-pickily concerned with the accuracy of the mathematics of Turing's work would over-generalize the actual computation he proved to be impossible, which was deciding if an arbitrary algorithm terminates on all possible inputs (i.e. there are no infinite loops), to "there are no bugs".<p>The Annotated Turing is a great book though, I highly reccomend it (Turing's original paper is _very_ dense).
Considering the budget for these kinds of things, I'm shocked they don't just pay some theoretical computer scientists to read the script and provide feedback on the mathematical correctness of the lines. You don't even need to find <i>great</i> computer scientists; you'd root out this bug with graduate students.
The New Yorker had a pretty good review of this movie: <a href="http://www.newyorker.com/magazine/2014/12/01/keeping-secrets-2" rel="nofollow">http://www.newyorker.com/magazine/2014/12/01/keeping-secrets...</a>