PeterDonis's latest activity
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PeterDonis replied to the thread Graduate Sidney Coleman's opinion on interpretation in his Dirac lecture.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... -
PeterDonis replied to the thread Graduate Sidney Coleman's opinion on interpretation in his Dirac lecture.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... -
PeterDonis replied to the thread Graduate Sidney Coleman's opinion on interpretation in his Dirac lecture.Let me expand on this, because there's a seemingly obvious response that Coleman gives a little later in the lecture, using David... -
PeterDonis replied to the thread Graduate Sidney Coleman's opinion on interpretation in his Dirac lecture.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... -
PeterDonis replied to the thread Graduate Sidney Coleman's opinion on interpretation in his Dirac lecture.Maybe it should. Hilbert space is a mathematical tool. It's not reality. Claiming that the entire universe can be modeled with a... -
PeterDonis reacted to Demystifier's post in the thread Graduate Sidney Coleman's opinion on interpretation in his Dirac lecture with
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It doesn't change anything in my argument. I can define $$|\Psi_{\Omega}\rangle = |\Omega\rangle \otimes |{\rm apparatus}\; {\rm... -
PeterDonis reacted to Demystifier's post in the thread Graduate Sidney Coleman's opinion on interpretation in his Dirac lecture with
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After some thinking, I think the Mott-Coleman argument is simply wrong, because the operator ##L## does not exist. To explain it in... -
PeterDonis replied to the thread Graduate Gravitational wave propagation in GR - follow up.Yes, it does. I have already given you an explicit reference from Wald. This thread will remain closed. -
PeterDonis replied to the thread Undergrad Why is the Lorentz Force always perpendicular to velocity?.But "perpendicular to the magnetic field" is not a covariant concept, because "the magnetic field" is not a covariant concept. Only the... -
PeterDonis replied to the thread Undergrad Why is the Lorentz Force always perpendicular to velocity?.Yes, because you can express both the observer's 4-velocity and the overall EM field as covariant objects (a 4-vector and an... -
PeterDonis replied to the thread Undergrad Why is the Lorentz Force always perpendicular to velocity?.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... -
PeterDonis reacted to mitchell porter's post in the thread Graduate Quaternionic Rays instead of Complex with
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Are you familiar with how quantum field theory is developed in textbooks? In a classical field theory, a field has a value at every... -
PeterDonis replied to the thread Graduate Quaternionic Rays instead of Complex.Enough to follow your post, yes. I see, yes. -
PeterDonis reacted to Paul Colby's post in the thread Graduate Quaternionic Rays instead of Complex with
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Yes, I purchased this text quite some time ago and put it down when it became apparent the concept was a wash. As to Adler referencing... -
PeterDonis replied to the thread Undergrad Why is the Lorentz Force always perpendicular to velocity?.Which is equivalent to what I wrote in post #4, i.e., it is not just the magnetic force. So what I said in post #4 would apply if one...