PeterDonis's latest activity
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PeterDonis replied to the thread I Where did the early photons go?.Yes, when @jbriggs444 said "nothing is moving", he was (implicitly) using a comoving coordinate system. That's the most common... -
PeterDonis replied to the thread I Where did the early photons go?.Not really no. The viewpoint that "nothing is moving through space, but space itself is expanding", and the viewpoint that "objects are...
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PeterDonis replied to the thread I Where did the early photons go?.You can't make this statement without specifying a coordinate chart. There is no such thing as "moving" or "not moving" in any absolute...
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PeterDonis replied to the thread I Question about discussions around quantum interpretations.From what I can see, the article (and its first part--what you linked to is the second part) talks about QBism and consistent histories...
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PeterDonis replied to the thread I Question about discussions around quantum interpretations.Note, though, that factorizability is how we would intuitively express the cluster decomposition principle. So this doesn't really help...
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PeterDonis replied to the thread I Question about discussions around quantum interpretations.It's not just that we have no direct experience with the quantum world. It's that we do have tons of direct experience of a world that...
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PeterDonis replied to the thread I Questions about quantum cosmology.Thread closed for moderation.
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PeterDonis replied to the thread I Where did the early photons go?.The set of comoving objects. Comoving objects are objects that see the universe as homogeneous and isotropic (the same everywhere and in...
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PeterDonis replied to the thread A Understanding Barandes' microscopic theory of causality.Unfortunately that's not possible. In classical physics, position and momentum each have their own independent configuration spaces...
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PeterDonis replied to the thread AI user?.As @Nugatory said, we have reports on this user and the moderators are taking appropriate action. For future reference, @sandy stone...
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PeterDonis reacted to Cthugha's post in the thread I Importance of Hanbury Brown and Twiss experiment with
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Michelson interferometers, Mach-Zehnder interferometers (and also the double slit) measure field correlations. The quantity you measure... -
PeterDonis replied to the thread I Importance of Hanbury Brown and Twiss experiment.Correct. Both of them are interferometers, yes. What gets observed at any detector depends on the relative amplitude and phase of the...
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PeterDonis replied to the thread I Importance of Hanbury Brown and Twiss experiment.Both of them have one source, which gets split by a beam splitter into two beams. Just as I described in post #4.
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PeterDonis replied to the thread I Euclidean geometry and gravity.No, but it was part of the specific scenario we were discussing as I understood it. Yes, that's correct. See my discussion with...
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PeterDonis replied to the thread I Euclidean geometry and gravity.In the general sense of "stress", which in relativity means "the components of the stress-energy tensor", yes, I agree. I should have...