@dpiponi @BartoszMilewski @dougmerritt @johncarlosbaez Quote posting here to continue along this line of discussion without derailing @johncarlosbaez's original thread.
I agree that clearly every interpretation of QM has difficulties, otherwise there would be consensus on the matter. I guess I would hope that none of the views are held with religious fervor. 🙂
I will say that I have never found the criticism of MWI on the basis of Occam's razor convincing. I'll agree that the exact meaning of parsimony is somewhat debatable, but it's generally considered to apply to the simplicity of assumptions, not conclusions. MWI arguably simplifies assumptions, doing away with von Neumann's process 1 (state reduction), at the cost of leading to the conclusion that there should be many parallel branches of the Universe's wavefunction.
I think the more cogent criticisms are about the derivation of the Born rule and meaning of probabilities in this interpretation. Still, I find this to be less dissatisfying than the orthodox interpretation, and I think it fits in a bit more naturally with understanding environmentally-induced decoherence as the mechanism for the emergence of classical dynamics.
QT: https://mathstodon.xyz/@dpiponi/112838797541954778
@internic @johncarlosbaez
You lost the servers on every name mention except the second mention of John; hover your mouse to see that.
You might edit to fix that.
(I happened to look at your timeline soon after you posted else I wouldn't have known about your post, since there was no notification)
@dougmerritt @johncarlosbaez Damn! That was my second try, too (because initially it looked like it was carrying over mentions and didn't). My server doesn't support editing posts yet, so I'll have to settle for mentioning @dpiponi and @BartoszMilewski here to correct my failure to properly mention them in the first post of this thread.
@internic @johncarlosbaez @dpiponi @BartoszMilewski
Indeed Occam's Razor is only supposed to be a heuristic not to *unnecessarily* complicate things; sometimes complication is actually necessary.
I personally feel that the repeated failed attacks on various possible weaknesses in Bell's theorem and EPR and etc. point the way, but of course opinions vary.
I think the main point for this subtopic is that John's suggestion about cosmological inhomogeneity is not outright wrong (or right) simply because of QM interpretations or heuristics. There's a need to cast a wider net.
@internic - that's okay. People here clearly find it more fun to talk about interpretations of quantum mechanics than figure out whether an initially perfectly homogeneous state is compatible with the inhomogeneities we find in our Universe today. And maybe that's no surprise: I'm having a lot of trouble finding any discussion of the latter question. The closest I can get is people talking about the power spectrum of inhomogeneities in the inflationary era, whether it's Gaussian, etc.
@johncarlosbaez Ironically, being the cause of the distraction, I thought it was a quite interesting question. What you said certainly sounds plausible, asymmetry can often arise in an open quantum system via decoherence of a symmetric superposition. It seems to me that I've heard people refer to the inhomogeneities in the CMBR being the signature of pre-inflationary quantum fluctuations, but I don't think I've ever heard any discussion that talked very rigorously about how they arise, as far as the quantum state and decoherence mechanism.
On the latter point, all the decoherence would require is that the stress energy tensor coarse grained over astronomical distance scales be couple to other degrees of freedom.
@internic - thanks. I'm getting fascinated by this question; I will ask some people about it!
Well, it seems like I failed in my attempt not to derail things. Sorry @johncarlosbaez!