PeterDonis's latest activity

If I need to spell it out, sure. It's simple: If a quantum system is in an eigenstate of an observable, then observing it does not...

Your post #80 sure looked to me like you were using the consistent histories interpretation to analyze it.

In other words, you're using a different interpretation from Coleman. That means we should be discussing your viewpoint in a separate...

I didn't say it was too weak to explain why we see a single straight line track. I said it (quite strongly) leads to the opposite...

And to take this further: if we assume that states of the observer in which they observe a single straight-line track in a cloud chamber...

Let me expand on this, because there's a seemingly obvious response that Coleman gives a little later in the lecture, using David...

The individual ones do. But the actual quantum state that's prepared is not one of them. It's a linear superposition of all of them...

Maybe it should. Hilbert space is a mathematical tool. It's not reality. Claiming that the entire universe can be modeled with a...

It doesn't change anything in my argument. I can define $$|\Psi_{\Omega}\rangle = |\Omega\rangle \otimes |{\rm apparatus}\; {\rm...

After some thinking, I think the Mott-Coleman argument is simply wrong, because the operator ##L## does not exist. To explain it in...

Yes, it does. I have already given you an explicit reference from Wald. This thread will remain closed.

But "perpendicular to the magnetic field" is not a covariant concept, because "the magnetic field" is not a covariant concept. Only the...

Yes, because you can express both the observer's 4-velocity and the overall EM field as covariant objects (a 4-vector and an...

In the lab frame, yes, this is the case. But it is not the case in the rest frame ##S'## of the object. In that frame there is a nonzero...

Are you familiar with how quantum field theory is developed in textbooks? In a classical field theory, a field has a value at every...