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Cake day: June 27th, 2023

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  • Regarding the last bullet point, there’s always the argument from authority, i.e., appealing to a book with Feynman on the byline.

    Now when mathematicians first addressed these problems, their interest was more general than the practical limits of computation; they were interested in principle with what could be proved. The question spawned a variety of approaches. Alan Turing, a British mathematician, equated the concept of “computability” with the ability of a certain type of machine to perform a computation. Church defined a system of logic and propositions and called it effective calculability. Kleene defined certain so-called “general recursive propositions” and worked in terms of these. Post had yet another approach (see the problem at the end of this chapter), and there were still other ways of examining the problem. All of these workers started off with a mathematical language of sorts and attempted to define a concept of “effective calculability” within that language. Thankfully for us, it can be shown that all of these apparently disparate approaches are equivalent, which means that we will only need to look at one of them.

    From p. 54 of the Feynman Lectures on Computation, by Feynman, Hey and Allen (the latter two being the editors who turned the tape recordings of the lectures into a book several years after Feynman died). There’s a pretty lengthy discussion of Turing machines in chapter 3 that does introduce the halting problem.














  • Since Adam Becker apparently has a new book out that lays into TESCREAL-ism and Silicon Valley ideology, I’m going to give an anti-recommendation regarding his prior book, What Is Real?, which is about quantum mechanics. Unlike the Sequences, it’s not cult shit. Instead, the ambience is more like Becker began with the physicist’s typical indifference to history and philosophy, and he somehow maintained that indifference all the way through writing a book about history and philosophy. The result fairly shimmers with errors. He bungles the description of the Einstein–Podolsky–Rosen thought experiment, one of the foundational publications on quantum entanglement and a major moment in the “what is quantum physics all about?!” conversation. He just fails to report correctly what the Einstein–Podolsky–Rosen paper actually says. He makes a big deal about how “hardly any women or people who aren’t white” appear in the story he’s told, but there were plenty of people he could have included and just didn’t — Jun Ishiwara, Hendrika Johanna van Leeuwen… — so he somehow made physics sound even more sexist and racist than it actually is. He raises a hullaballoo about how Grete Hermann’s criticism of von Neumann was unjustly ignored, while not actually explaining what Grete Hermann’s view of quantum mechanics was, or that she was writing about quantum entanglement before Einstein, Podolsky and Rosen! His treatment of Hermann still pisses me off every time I think about it.