549 karma · joined May 13, 2018
The dog whistle in your earlier post is that the mean old liberals wouldn't let you talk about violence committed by Muslims, but fortunately Donald's fans were there to give you a space; how generous of them.
But, uh, any evidence that that's real? We should be careful with Gödel's results here; the Gödelian incompleteness of the human mind is that a human cannot consistently believe that everything they believe is true. It has nothing to do with sanity and perception: https://en.wikipedia.org/wiki/Doxastic_logic
(Also, like, stop blowing your dogwhistle so damn loud.)
* Size issues. All the problems in set theory are back with a vengeance. Exploring size issues makes it clear that Russell's Paradox is not a fluke.
* Topoi. A topos is a generalization of the past few millennia of maths, and their existence shows that maths is a multiverse rather than a single collection of rules. Some topoi witness refutations of LEM, making them valuable counterexamples.
* Yoneda's lemma. The core of pragmatic philosophy is that objects are not separable from their effects in the world. Yoneda's result takes that to its logical conclusion: An object is equivalent to all of its effects under transformation.
* Equivalence of categories. Rel is equivalent to its dual (Rel is daggered) and so is Hilb; the category Set* of sets with an extra point is equivalent to the category Pfn of sets and partial functions. These show us that parts of maths are self-symmetric beyond group theory.
In addition, why shouldn't adjunctions be covered at some point? Adjunctions can't be studied without category theory (look up "Galois connections" for a history) and they're hard to avoid once we're talking about enough categories of note. I bet that the adjointness of syntax and semantics is very relevant to philosophy of language.
Although, doesn't this suggest a meeting of the minds? Free Software is usually proffered and consumed without such a meeting. So was a contract actually formed? I'm skeptical.
Remember: Sets are 0-categories, so set theory is 0-category theory.
It shouldn't be surprising that two sheep plus two sheep is four sheep. We can go further. Suppose that we have lots of longhair sheep and shorthair sheep. If we choose some sheep, how many ways can we have some shorthair and some longhair? This gives exponentiation intuitively, so that we could ask how many ways we could choose zero sheep from a collection of zero sheep, or in other words, why zero to the zeroth power is one.
The parts of category theory that you're imagining, with the morphisms and natural transformations, doesn't have to be taught before arithmetic. It can be taught when lambdas are first introduced, when we write "f(x)" on the board for the first time.
(I've been attacked by dogs multiple times, and indeed, they warn before attacking.)
> In mathematical logic, Goodstein's theorem is a statement about the natural numbers, proved by Reuben Goodstein in 1944, which states that every Goodstein sequence eventually terminates at 0. Kirby and Paris[1] showed that it is unprovable in Peano arithmetic (but it can be proven in stronger systems, such as second-order arithmetic).
Despite PA having such a big proof-theoretic ordinal, PA cannot prove Goodstein's theorem. We need SOL.
Also, as one constructivist to another: Nobody cares la~ Hopefully you know the difference between PA, which describes NNOs, and HOL, which is ambient in each topos. Just because some topoi have NNO (just because HOL can host PA) and topoi recognize Goodstein's theorem (because Goodstein's provable in HOL) doesn't imply that all NNOs can witness Goodstein.
Indeed, double-check your understanding with the following quirk: In the topos Diff for synthetic differential geometry, the natural numbers are decideable and countable, but the real numbers are not decidable (and in fact prove LEM false!) and uncountable. Due to smoothness requirements, the real numbers are fundamentally different from the natural numbers in Diff. These are two different objects, two different infinities, with two different topologies.
The better point to make in the context of the parent comment is that ω is the first of many transfinite numbers; our ability to talk about multiple numbers "above infinity" is intimately related to the set theory which underlies Cantor's theorems. Infinities aren't just about some sort of mathematical game, but directly influence what we can define and describe.
Nike is a poor choice for making this point, because their original business was making waffle-iron shoes in a garage. They could have stuck to being a specialty cobbler who only caters to the top stars of track-and-field sports. None of the abuses had to happen. The only sad thing that was obligatory in Nike's story was the death of Steve Prefontaine.
As somebody who grew up in Oregon, this is precisely it. I don't just want Nike to change its outward branding; I want Nike to stop advertising. I don't just want friendlier campus life for women; I want Nike to stop employing. I don't just want Nike to move its sweatshops from one country to another; I want Nike to stop enslaving.
Nike should stop existing. Anything less is neoliberal simpering.
Edit: Downvoters, try a little harder. Engage your emotional core. Really work those empathy centers. Think about it: If nobody had to justify their existence, and people just allowed each other to exist, then we wouldn't have to weigh whether sex workers are more deserving of rights than computer scientists. We could allow both; we could allow everybody.
Could we get a (2010) in the title?