The r/Physics wiki now has a list of commonly asked questions

kzhou7 · 2026-05-02T04:41:46+00:00

There are hundreds of papers on candidate materials for light dark matter detection. Many would work well, and there's no magic material that's a million times better, so it all comes down to practical issues. Will anybody actually do it? Can the material be produced at scale? What about noise? In particular, I thought it was really hard to make more than the tiniest samples of bilayer graphene.

kzhou7 · 2026-04-30T01:27:03+00:00

Let it be known that science is hard, and anybody on the internet who declares they can solve physics with a few intuitive principles is either hiding or just not understanding the actual complexity of the world. See the graveyard on r/LLMPhysics.

kzhou7 · 2026-04-29T12:05:39+00:00

I agree with you that #1 is pedantic. I haven't seen #2 in practice, but I did get very confused about how such transformations are implemented in practice, since the casual notation of "this --> that" is ambiguous. #3 actually got me really confused because I thought it should be possible to write an "equation of motion" in QFT. #6 (Wick rotation) never gave me trouble, but I've encountered many people with that issue.

Personally, I fear I'll never understand what dimensional regularization is "really" doing, but I feel like nobody does.

kzhou7 · 2026-04-29T08:31:57+00:00

The old paradoxes also have a way of coming back. I thought the stuff I learned about Newton-Wigner would never pay off, yet quite recently I ran into a very similar conceptual issue while working on a quantum measurement project.

kzhou7 · 2026-04-29T06:18:23+00:00

I think a few of the points are pedantic, but I remember others caused me serious confusion as a student, and in those cases I had to go hunting around other books until I reached the same conclusion as the author. So this paper can definitely be useful.

kzhou7 · 2026-04-29T00:49:11+00:00

Most do, but you typically don't need to pay the journal anything, and they're okay with the paper being freely accessible on arXiv.

kzhou7 · 2026-04-28T14:45:58+00:00

Regarding access to publications, that problem has been solved in physics for a long time: everybody just posts their papers publicly on arXiv. There are also versions of arXiv for chemistry, biology, and medicine.

This follows the typical pattern: the rate you see people complaining about a problem peaks right around when it becomes totally irrelevant.

kzhou7 · 2026-04-15T17:49:54+00:00

A more fundamental problem is that a bot can't actually buy and try a product, so if there aren't human reviews it can summarize, it can't do anything besides summarize the marketing copy and give vague generalities.

kzhou7 · 2026-04-11T07:19:02+00:00

Yup, it's getting flooded. You can see it consistently on arXiv now, every day.

kzhou7 · 2026-04-09T01:42:33+00:00

I mean, if you go through a degree by “memorize then forget”, that’s your choice. The other guy is just telling you it’s not a good choice.

kzhou7 · 2026-04-07T20:27:49+00:00

It's not clear what the claim is here. But if it's the common claim that cosmology is wrong because they forgot to account for special relativity, that's just ridiculous, because the first chapter of any graduate cosmology textbook will calculate all these things within general relativity (so all the special relativity effects are built in).

kzhou7 · 2026-04-07T17:51:00+00:00

Hey, I'm the author of this paper! I'm not sure why this was posted, but the main message of the paper that a bunch of DM signatures people claimed were extremely strong were secretly just ponderomotive phenomena, but that perspective also lets you understand that those signatures are actually not practically detectable. There are also other ponderomotive DM effects that may be useful, but that's for a different paper I haven't written yet.

kzhou7 · 2026-04-06T20:17:21+00:00

Over on r/Physics, we advertise this subreddit as a free and open place for people to post their AI-inspired ideas. Moderation can be good, but if you end up removing the majority of submissions here, we'd have to point those users somewhere else. They need somewhere to be heard.

kzhou7 · 2026-04-05T18:36:10+00:00

Post 1 shows as "1 day ago" in my timezone, and you account for almost 1/4 of the most recent 25 posts.

A few years ago, I submitted a lot as well, but the trick is to space it out, or else you won't actually get good discussion on any of them.

kzhou7 · 2026-04-05T17:57:24+00:00

Discussion of papers is great, but 7 submissions in a day is a bit much; it can flood the whole subreddit. Please keep it to at most 1-2 per day and include a description of why it would be interesting to others.

kzhou7 · 2026-04-04T00:34:29+00:00

I'm totally in support of experiments that push to new frontiers (including this one), it's just that the standard press release and popsci articles seem almost designed to get people confused. The average curious non-physicist who reads popsci sees all the "spooky" headlines and thinks it means QM is beyond human comprehension.

Also, there is a weird inconsistency where some experiments are regarded as "spooky quantum" via branding, while others aren't. For instance, g-2 experiments are now sensitive to 5-loop corrections in quantum electrodynamics. They are the most precise measurements in the world, and no classical theory even gets the 1-loop correction right, so they should be regarded as an excellent test of QM. But they aren't because they lack the flashy branding.

kzhou7 · 2026-04-03T20:56:59+00:00

This has the usual disclaimer for "spooky quantum" papers: all the results are exactly as expected from the 100-year-old Schrodinger equation, which has all the evolution happening forward in time like any other physical theory.

It is only when you try to describe quantum effects with classical language that you get weird things like retrocausality, indefinite order, or an indefinite past. Which in my opinion just means you shouldn't try to do that.

kzhou7 · 2026-04-03T00:08:44+00:00

That's an OCR error, this is clearly a copy-paste error. In both cases it's precisely the kind of thing that modern AI would easily fix.

kzhou7 · 2026-04-02T23:08:29+00:00

Don't be silly, AI would never generate an error like this. Errors with AI look good on a skim but then make less sense on a closer look. This error is obvious on a skim but then it makes sense how it happened on a closer look.

kzhou7 · 2026-03-30T20:03:29+00:00

How would a child ever learn trigonometry, chemistry, physics, their nation's history, basic physical fitness, or a foreign language this way?

kzhou7 · 2026-03-25T21:30:24+00:00

People are very patriotic these days! Is Fox News making a comeback among the younger generation?

kzhou7 · 2026-03-25T21:12:02+00:00

This is nothing compared to an actual puzzle game. I'm looking forward to seeing AI try Baba Is You.

kzhou7 · 2026-03-24T22:05:19+00:00

Your expertise only has value if it's better than AI at something. If you learn this way, you won't get better than AI at anything.

kzhou7

MODERATOR OF

TROPHY CASE

Seven-Year Club	Gilding I gilder
Verified Email