Recent content by alemsalem

That's a tough question, you can be thinking about it for years (I have, at least a version of it). Thinking about these things in the abstract is very hard, and very misleading. It's misleading because the high level aspects of a field like theoretical physics may not be highly correlated with...

I'm not sure if Algebra specifically is actually necessary for these fields. However, if the point is to make things easier so that more people pass, then that's not a good educational decision. I think physics and math are valuable to other fields, it could train them to solve problems in ways...

Thank you for the response! Does that mean that you can derive the relations mathematically? without reference to any specific physical theory?

That's probably true. but I'm sure there are reasonable assumptions on the physical theory when this is proved (I haven't looked at proof, if you have a link, I would appreciate it if you shared it). I'm not sure that ergodicity is easy to prove generically.

Yes the question is about this statement from the wikipedia article: On the one hand the probabilities are associated with each atom and does not depend on the presence of other atoms. On the other hand you can derive relationships between these coefficients just by assuming thermal equilibrium...

I agree. But if it did not depend on the details of the microscopic theory, then how can you derive a constraint on the microscopic theory (historically, before QFT was invented) from macroscopic equilibrium?

Einstein predicted constraints on the coefficients of stimulated emission and absorption of radiation by atoms. He did that by assuming that the gas of atoms had to reach thermal equilibrium. For the gas to reach thermal equilibrium the coefficients had to be related in a certain way, otherwise...

What courses or physics topics would you like to see on the internet? I want to make a physics course series. I want to make videos and other resources (like animations, simulations apps, and games). I want it to be on topics that don't have a lot of videos and resources, and there are people...

Yes, |cn|^2 is the probability to find the state Ψn. mathematically they also represent the coordinates of the function Ψ (x,0) in the Ψn basis.

Yes just like any point in space is given by (x,y,z) any point in "Function space" is given by (c1,c2,c3, ..., cn,..)

The electron state in the atom is described by a probability wave, distributed around the nucleus. The wave is changing over time in a way specified by the Schrödinger equation. The point is not every function around the nucleus changing over time is consistent with the Schrödinger equation...

another way to look at E*E: its the amplitude squared of the real wave E = Eo cos(k⋅r−ωt+φ) which is easily seen if E'(r,t)=E'o expi(k⋅r−ωt) then E'E'* = E0^2 for you second equation, where is from? I'm guessing your squaring an electric field which was solved using a green's function. where...

Is physics your passion? does learning things about the physical world excite you? do you have other fields you're thinking of going? the problem with being a pretend physicist is you won't do the things which you absolutely hate, but are necessary to produce good physics understanding and a...

are there examples in non-relativistic scattering off a central potential where the S-matrix can be calculated exactly? Thanks!

Thanks!