Recent content by kmm

Great. This has definitely cleared things up for me. Thanks for the help!

OK, so this is probably the source of my confusion. The stress-energy tensor is only defining the fluid itself, which includes the internal interactions and random motions of particles giving rise to pressure within the fluid and so to the fluxes of the fluid particles themselves. I think the...

I had considered the fact that the external forces can be like those of the electric field on charged particles, however, why wouldn't those external forces simply be a part of the flux? Why would only the inter-particle reactions contribute to the flux of momentum and energy on a fluid element...

I've been working through Bernard Schutz's book on GR and have run into some confusion in chapter 4 problem 20 part b. In this chapter, the stress-energy tensor for a general fluid was introduced and was used to derive the general conservation law for energy/momentum, where we found that...

Ah right, of course. Thank you for helping me with this!

Thank you, I think this helps clarify things for me. The way I understand it then is, since the fourth parameter is fixed by the normalization condition, and since the overall scale of ## \psi ## is irrelevant to the continuity conditions and therefore, to the fact that we get quantized energy...

On page 160 in Shankar, he discusses how we get quantized energy levels of bound states - specifically for the particle in a box. We have three regions in space; region I from ## \ - \infty, -L/2 ##, region II from ## \ -L/2, L/2 ##, and region III from ## \ L/2, \infty ##. For the...

Sounds interesting! Putting that on my 'to read' list.

Yes, perhaps I have overly romanticized the "laws of physics" as absolute things, fully capturing the nature of what they describe.

Interesting. Thanks for that, I will take a look at that paper.

I think the source of my confusion was in thinking of conservation of momentum and angular momentum as fundamental principles of reality, that must be exact regardless of any limits of our ability to measure those things; so that in principle, we could find that conservation of momentum and...

This is opening a new door for me to explore! I will be looking further into this. Thanks for the clarification!

I came across this video of Leonard Susskind saying that all symmetries in physics are approximations. Unfortunately, I don't have the links on hand, but I have come across other sources of physicists claiming that all symmetries are approximations. My confusion though is that it was my...

I have spent a bit of time with Special Relativity and am just starting to learn General Relativity, so I still have a lot to learn but this thread was clarifying and made me aware of some false assumptions I was making. Thanks again!

Another question is, does the fact that the formation of a black hole and the collision of two black holes entail a lot of dynamical processes mean that we can't apply standard gravitational time dilation to the process? I imagine that if two black holes are colliding and creating gravitational...