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qmalzp

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N.b. the article uses d for the dimension, and n for the moment index. I haven't cranked out the details, but I believe that this is already true just assuming the fourth moments of the distance are integers. That is, for n != 1, 2, or 4, the fourth moment is never an integer. Idea of the "brute force" proof:

Take the formula in the article for the 4th moment of the d-dimensional sphere, which is always a rational number. Basically, for n=2^k, the denominator should be divisible by a larger power of two than the numerator (specifically, if I crunched the numbers right, the gap should be k-2). When n is not a power of two, then for any odd prime p dividing n, I believe the denominator should be divisible by a larger power of p than the numerator. This requires calculating exactly how many powers of p divide various factorial expressions, but you get the idea.

If you pass the interview as a generalist, Google absolutely prefers for people to work in their Mountain View office.

1. The cost of relocation is minuscule compared to the total cost of employing someone, so I don't buy that argument.

2. Do you have data to back up that Google engineers in Denver get paid less than their Mountain View counterparts? I believe this is true when comparing US to non-US salaries, but at least where I've worked, engineers get paid the same everywhere within the US (and indeed, you can relocate from the Bay Area to cheaper locales without taking a pay cut).

Known Unknowns 8 years ago

When talking about chess: "But even the most powerful program can be defeated by a skilled human player with access to a computer—even a computer less powerful than the opponent."

Is that true? Can a state-of-the-art chess engine plus a grandmaster really outperform just the state-of-the-art chess engine?

Google doesn't open a 500-engineer research lab in Grand Rapids, MI because there are not 500 Google-caliber engineers already living in Grand Rapids, MI. This is not a statement about the average talent there, but simply that the starting pool is not sufficiently large; hence the need to build offices in high density urban areas.

Google doesn't open an office in Denver so that Bay Area engineers have a slightly cheaper place to work, they do it to tap into the talent of folks who already live there.

Edit: I am basing these claims off of my own experience. I work at a satellite office of one of the big tech co's, and the vast majority of my coworkers are people who are either fresh out of a local university, or already lived here for many years before joining the company.

As a former mathematican, I was at first a little offended and dismissive of his claim. But, perhaps what one can say is that mathematicians don't seem to distinguish "causation" with "implication". After all, if the barometer goes down, that does imply a storm is coming (perhaps with some increased probability), but it still doesn't cause the storm to come (even with increased probability).

In a simplified closed system, where all you have are barometers and storms, maybe there is no difference between implication and causation; all you know is these variables are correlated. Perhaps once you take every atom in the universe into account, the two start to look the same.

I think the first point is only true for symmetric matrices (which includes those that show up in multivariable calc). In general, the eigenvectors need not be orthogonal.

Category theory is basically a language. If one wanted to formulate an explicit conjecture corresponding to the original Langlands program, it could possibly be phrased as some kind of equivalence of a category of automorphic representations and a category of motives. Precisely defining those two categories is the hard part.

So even with this language, one still has to do the work of actually proving these things. It's like having a nice programming language; you still have to write the code to do the thing!

3. There are ways to make money online without ads begging you to click on them, and they involve real-world goods and services that your website can help connect people for?

Yeah, I could even imagine a scenario where you help connect people to real-world goods and services for free; the provider of those goods and services would be more than happy to help keep your bills paid, assuming there was some kind of mechanism that would drive people to their goods and services and not a competitor.

What would such a mechanism look like?

I have never seen a theorem prover applied to even basic 100-year-old results in Algebraic Number Theory. I think you underestimate the difficulty in translating a mathematical idea into a format a computer program can understand.

Tl;Dr

It's slightly more accurate to say if

F(s) = 1^s + 2^s + 3^s + ...

Then

F(1) = -1/12.

This is still a lie, but the truth is that F(s) does make sense for a large domain of s, and there is a unique and canonical way of extending F(s) to a larger domain which contains 1. And then that new function evaluated at 1 is equal to -1/12.

If you're talking about Scholze's lectures about his cutting-edge work, there is not a chance they are accessible to undergraduates; when I attended one as a fourth-year PhD student specializing in algebraic number theory, I would say I only kind of got the gist of it.

Re: your skepticism... The guy is a once-in-a-generation talent; his constructions were able to vastly simplify multiple very long, very complicated proofs that groups of the top people in this field were working on. This is in a field (algebraic number theory) which is considered one of the more saturated and technically difficult within all of mathematics (admittedly, I am likely biased on this point). That being said, all of his work so far has been in the ballpark of Langlands/p-adic/arithmetic geometry, so I would be surprised if he achieved significant results that strayed too far from this stuff.

I'm not sure what you mean about Feynman; Peter's genius is not so much his ability to communicate complex ideas in a simple way, but rather he was able to come up with constructions (or if you like, abstractions) which compartmentalize the complex ideas in the right way so that they are easier to deal with. To make an analogy with computing, think of the concept of a "thread". Without the concept of a thread, you'd have to do so much manual maintenance that you could never dream of building say Google. Scholze's perfectoid spaces are analogous; their definition would have been understood by mathematicians 50 years ago, but no one really got that this was the right thing to consider.