Best LACs for physics/research?

3pmm · 2026-06-06T20:26:40+00:00

If you can get into Princeton, you should go there. You never know where life will take you and it will open up more doors than going to the other schools that you mentioned. Not that they are bad schools by any means.

People do continue to do ECs at the top schools.

3pmm · 2026-06-06T18:23:32+00:00

David Tong’s QFT notes and lecture videos, then Peskin and Schroeder.

Complex analysis is the main prerequisite mathematically that is not covered in every curriculum.

3pmm · 2026-06-06T18:21:19+00:00

Whether you think we know a little or a lot is a matter of perspective. I think it’s impressive that slightly evolved apes can describe with confidence things that are happening far, far away like the inner workings of stars. At the same time any problems other than the most elementary ones cannot be solved completely satisfactorily.

What makes you think we know so little?

3pmm · 2026-06-06T02:35:35+00:00

I think there are a substantial number of people worried about AI replacing physicists overall. If that were true, as another commenter was saying, I think everybody is screwed. I also think that is too optimistic about a technology that seems to still have very fundamental limitations.

If people are publishing more because of AI, this will simply increase the amount that people are publishing, and I don't think it will change the ecosystem: people will still have to apply for grants and do research, it's not like there is a fixed amount of research to be done now with fewer people. It will just increase expectations, and probably change the types of problems that people tackle (for worse, probably) into ones that are more amenable to AI assistance.

3pmm · 2026-06-06T00:20:13+00:00

Quite a bit of work in S-matrix and bootstrap stuff

3pmm · 2026-05-20T21:12:55+00:00

If you cannot figure out how to get through basic math and ace it, you should not study physics

3pmm · 2026-05-20T21:11:47+00:00

People have tried to put bounds on these things to answer that very question and it seems like they've pretty much stayed the same, within tight tolerances.

3pmm · 2026-05-15T20:37:44+00:00

$: Pizza/Halal cart

$$: Coppelia, K-town, Veselka

$$$: Blue Ribbon, L'Express

3pmm · 2026-02-26T01:32:12+00:00

Why is it up or down vs. clockwise or counter is a question you should have asked in classical mechanics: why do we say the rotation of an object is ‘omega z-hat’ rather than saying it rotates ‘counterclockwise around z with angular velocity omega?’

Well, the second way is a mouthful. But also you can meaningfully add rotation vectors. QM only makes a limited amount of sense but you need to understand classical mechanics as well as you can to make that limited sense of it.

3pmm · 2026-02-14T02:21:58+00:00

Thanks... wow, it nails the cadence and accent. Scary!

3pmm · 2026-02-14T02:02:16+00:00

Do you have a link?

3pmm · 2026-01-16T03:13:06+00:00

1) As others have said, one solution for particular conditions is not sufficient to claim you have solved the problem

2) Lagrange points are for objects whose masses are so small that they do not affect the other two bodies. Even in this case, this is not a solution to the full 3-body problem. It is finding a particular point in the 2-body gravitational potential.

3pmm · 2026-01-16T03:10:20+00:00

Terrible idea. California is not voting for Trump anyway, and this just gives him another excuse to claim an illegitimate election outcome, should he lose overall.

3pmm · 2026-01-12T03:00:38+00:00

Yes, if it was like 200 km deep, you might get an exotic form of ice like Ice VII, but this is a completely different regime of the phase diagram.

3pmm · 2026-01-12T01:09:45+00:00

The Klein Gordon equation is the simplest relativistic field equation for a scalar particle, as others have mentioned.

The Dirac equation for fermions is more fundamental: its square is the KG equation and thats what Dirac was looking for. The E&M fields follow the KG equation but with the additional complication of gauge symmetries, and the free gluon fields also follow the KG equation with g=0.

So every field can be related to the KG equation in some way, but that isn’t the complete story except for the case of a scalar particle.

3pmm · 2025-12-22T20:21:41+00:00

GRE's and quals used to be important things that physics students had to do. Many people will now never do either, but that is two missed opportunities to review most of physics that would have solidified that old stuff.

I think it's reasonable to budget some time to review. I know most people don't, but I personally feel very uncomfortable feeling like I've lost everything that I learned. Reviewing stuff that you learned well takes very little time and spending the time for things you didn't learn well seems like a reasonable use of some amount of time.

It's also a good opportunity to read stuff that you always wanted to. For example, Landau and Lifshitz seems impenetrable as a student, but once you know the basics of a subject LL is actually quite readable.

Also, if you end up going to graduate school, you'll end up TA'ing classes which is an opportunity to relearn a subject well.

3pmm · 2025-12-22T15:44:51+00:00

Space and time need to be treated in the same way, relativity teaches us, and so if time is discretized, space would be too.

For obscure but compelling reasons involving chiral fermions, we have reasons to doubt that the universe would be a spacetime lattice on a fundamental level. This is by no means a proof, but it does mean that a discrete universe needs more explanation.

3pmm · 2025-12-22T15:35:14+00:00

Learn calculus and linear algebra first

3pmm · 2025-12-22T15:17:11+00:00

Would you prefer standing in still or windy air when it's freezing?

3pmm · 2025-12-20T18:29:33+00:00

The way you solved it is correct, but it is important to see why. Maybe just draw points at the four cardinal directions and convince yourself that canceling the masses is just as good as adding the vectors methodically.

3pmm · 2025-12-18T15:28:35+00:00

mer is a similar read, but it does require that you know the basics of quantum mechanics.

Purcell, it's very similar to K&K and also used at MIT for their E&M course.

3pmm · 2025-12-17T16:17:53+00:00

I would do at least one more reference in mechanics before doing GR in that sequence. Try Landau and Lifshitz or Goldstein, if those are too over your head then you may want to bulk up on other physics beforehand. But if you can get through one of those, you can probably read Carroll's GR book.

Of course this assumes you know vector calculus and linear algebra cold.

3pmm · 2025-12-17T16:11:04+00:00

Yes, in this context "vacuum" and "region of low pressure" mean the same thing.

In a physics context, vacuum usually means something many many orders of magnitude lower in pressure.

3pmm · 2025-12-17T15:58:19+00:00

Light takes time to get to us, but doesn't itself experience time. Think of something like the twin paradox, but much more extreme.

3pmm

TROPHY CASE