Aram Harrow

You could likewise say that the US is just 5% of world population so what's the big deal if immigration to the US is restricted? Doesn't affect many people.

The point is that there are big gains to migration, either between or within countries, and the main obstacles are policy choices.

Network effects would cause these places to grow if they could, so stopping their growth hurts the US overall. Chicago grew from 30k to 1.1M over 40 years. We don't do that any more.

Also the issue isn't preferences for cities, it's that jobs are created in places with housing supply constraints.

Life expectancy in 1950s America was lower than in India today. On the other hand, we didn't have social media, so it's kind of a wash.

We're hiring postdocs! Deadline is 15 Nov.

We're also advertising Leinweber postdoctoral fellowships, which also have an earlier nomination deadline of 1 Nov.
academicjobsonline.org/ajo/MIT/CTP-LI

Like Scott, I used chatgpt for a proof. It gave me something convincing but wrong.

Still, it led me to a 1964 theorem about medians of sums of Bernoullis. And to fast algorithms for computing many power sums at once.

Below was my first attempt. See if you can find the bug.

Excited to post my fun collaboration with Angus Lowe and Freek Witteveen on how to truncate better using randomness.

scirate.com/arxiv/2510.0...

The word "macroscopic" always confused me. This is like a W state, not a cat state, right? Do you know of any good discussion of this point?

The money pays for research. If those contracts stop, the research stops. Yes private donations and industrial funding will still exist but the total amount of research will go down.

Apple has to pay college-educated employees more. And colleges give training that's more general and more externally legible than you'd get from a company, thus raising the employees' market value more. So I see your point but it's not at all clear that this is a "subsidy".

Endowments are used more for research than undergrad education.

Thanks Earl! I'm glad you enjoyed it. We really found qDRIFT and your later paper with Berta+Wan inspirational and we think there's a lot of room for more use of those ideas still.

Universal covering of $SO(3,\mathbb{R})$ How do you prove that the universal covering of $SO(3, \mathbb{R})$ is $S^3$ ? Or equivalently, that it is diffeomorphic to $P_3\mathbb{R}$ ? Thank you for your answers.

"why" is always tough because there's no objective answer but the dirac plate etc are meant to illustrate that the fundamental group of SO(3) is Z_2, suggesting its universal cover should map to SO(3) via a 2-1 map. see also
math.stackexchange.com/questions/11...

School closures were hard on kids, not only for test scores. I'm guessing you haven't talked to many parents about this topic?
Maybe a necessary evil, but certainly not a trivial cost.

It's even more impressive without the !.

That's what all physicists hope for more than anything else.

Selling exceptions is lucrative.

Yeah, it is definitely cooler than its symmetric cousin.

I don't find this claim too offensive. Yes they're no better at sending cbits but they're more powerful in other ways. "Richer information" would be better than "more information" but also raises more questions.

craphound.com/category/una...
It's more DRM than AI, but then again "AI" in most of these examples just means "algorithms."

There is of course a Cory Doctorow short story on this theme.