--- TODO: Explain Turing machines and how they work. TODO: Explain how this story ties in with Church and Gödel. TODO: When that's done, end with something like this... --- ## The Martyr 0: Turing finished the proof of the three-way equivalence, thus establishing more clearly than anyone else the plausibility of Church's Thesis, now called Church-Turing. This was the final nail in the coffin. These three giants, the first three developers in the history of computing who together made the first language, the first compiler, and the first hardware design, these same these people now also seemed to have captured the concept of computation itself, in three definitions that none of them expected to be the same. Except maybe Turing. They captured the essence of computation, not within some particular formal system or machine, but any computation that could ever be performed by any physical system past or future. They got it. The final nail was this 1937 paper down below. Almost 100 years later, after all the developments in computing and technology since the late 1930s, our species still hasn;t found a single counterexample to Church and Turing's claim. Computation has a ceiling. That ceiling is universal. And it's damn easy to get there. Everything else is lots and lots of details that take place at or below the ceiling. I can't think of a more important achievement in the foundations of human knowledge in all of human history than that. The story of computation and how our species captured it is as important as the discovery of fire. I think even the discovery of electricity or magnetism or the strong and weak nuclear forces aren't as incredible as the discovery of computation. Despite all the well-deserved books about Gödel and Turing, this story is never told with anything close to the energy it deserves. And I can feel in my bones every way that the version of it I've told here is still an absolute failure compared to what this story deserves. It would take a new curriculum to really tell it properly. Students in our field, and even the profess{or, ional developer}s of our field don't know enough about the beginning or the middle of this story. Sadly most of us know about the end. 1: What was the end? 0: Not the end of the story. But an end to this thread. ![[turing-1937-sex-footnote-1.png]] 0: In any sane universe, Turing's sex life would've been no more than a footnote to his story. No more significant than a randomly chosen footnote in one of his papers. ![[turing-1937-sex-footnote-2.png]] 1: What's that? 0: A footnote in one of his papers that happens to say $S(e(x))$. 1: Is this supposed to be important? 0: No. That's the point. In Turing's story, what should have been an unimportant footnote that happened to say $S(e(x))$ turned out to lead to the premature end of his story. 1: THAT footnote led to--- 0: No not that one. I don't think anyone even noticed that one. Not sure Turing noticed either, though I like to think he did. This next bit is the sad one. The one people noticed. ![[yours-in-distress-alan.png]] %% From: https://turingarchive.kings.cam.ac.uk/correspondence-amtd/amt-d-14a Copyright info: https://turingarchive.kings.cam.ac.uk/copyright-and-terms-use %% 1: What does it say? I can't quite read it. 0: Something like this. > My dear Norman, > > I don’t think I really do know much about jobs, except the one I had during the war, and that certainly did not involve any travelling. I think they do take on conscripts. It certainly involved a good deal of hard thinking, but whether you’d be interested I don’t know. Philip Hall was in the same racket and on the whole, I should say, he didn’t care for it. However I am not at present in a state in which I am able to concentrate well, for reasons explained in the next paragraph. > > I’ve now got myself into the kind of trouble that I have always considered to be quite a possibility for me, though I have usually rated it at about 10:1 against. I shall shortly be pleading guilty to a charge of sexual offences with a young man. The story of how it all came to be found out is a long and fascinating one, which I shall have to make into a short story one day, but haven’t the time to tell you now. No doubt I shall emerge from it all a different man, but quite who I’ve not found out. > > Glad you enjoyed broadcast. Jefferson certainly was rather disappointing though. I’m afraid that the following syllogism may be used by some in the future. > > Turing believes machines think > Turing lies with men > Therefore machines do not think > > Yours in distress, > > Alan --- TODO: Finish this bit off and pop the stack back to Godel, and wrap up that story. --- goto: [[lost+found/fini/Numbers|Numbers]]