Recent content by PeterDonis

In which case, as I have already said (I think before you even entered this thread), you can't say anything about energy conservation, because you don't have a well-defined energy for the total system at all.

It's very simple: You have a system consisting of an electron plus a photon. During Compton scattering, that system is closed; the electron and photon interact with each other, but they don't interact with anything else. During scattering, therefore, if the electron and photon are in energy...

Where do these notes talk about a Bose-Einstein distribution? What makes you think the "Bose-Einstein distribution" is a mixed quantum state?

What quantum state are you talking about? Do you have a reference?

I don't see the point since what we are discussing is part of determining how an answer to the OP question in this thread can be obtained.

Yes. No. You are still misstating it. You keep talking as if a given system can only be open or closed. That's not true. A system can be closed at one time and open at another. When you say "energy is conserved locally", what you mean is that the system you are looking at is closed during the...

After some cleanup, thread is reopened.

Thread closed.

We won't know the answer to this unless and until we discover a TOE.

Moderator's note: Thread moved to the relativity forum.

You keep misstating it. Yes, "locally" means in a small region of space and time, and a system can be closed within that small region of space and time and open in other regions of space and time. That doesn't mean "locally" means the same thing as "closed". It means, as I have said multiple...

That is indeed what one would need in order to address the actual OP question in this thread, which is about how to assess conservation of energy is affected by "wave function collapse" (which really means "measurement"). But you cannot limit such consideration to energy eigenstates, which is...

No, because the discussion in this thread is not limited to cases where the system is in an energy eigenstate. So your (2) does not cover all the cases that need to be covered.

In certain cases, yes. But this thread is about all cases, not just the particular ones where you can get away with this.

I quoted you explicitly, before responding "thank you for agreeing with my point". You are misstating things. What you mean by "energy conservation locally" is treating the system of interest (in this case the electron plus photon during Compton scattering) as a closed system during the time...