On 7/4/2021 7:38 PM, Jason Resch wrote:
All QM interpretations are "many-component" theories. It's just that some posit that, at certain (often not well-defined) times, all but one of those many-components stop existing. So as to "Why keep those components?" I think it leads to a simpler theory, and one is more in the spirit of all other physical theories: it's reversible, linear, local, deterministic, and avoids the fuzzy definitions around measurement, observation, consciousness, etc. MW doesn't add the many-components, rather it subtracts the step of "deleting all but one of them."
I don't think it avoids those fuzzy definitions. There's just some hand waving that decoherence will make cross terms in the density matrix small so we can ignore them and set them to zero and not the world has split and we can renormalize the probabilities relative to what we've measured. But the cross terms being small in one basis doesn't mean they are small in other bases. So setting them to zero is just as arbitrary or non-arbitrary as Bohr's "collapse". It's only keeping them that makes the theory reversible.
And as in the multiverse case, if you let the number be infinite you have the same measure problems over an infinite set. If you just assume it's very big but not infinite then that's the same as assuming there is some smallest non-zero probability and when the Born predicted probability is less than that it must be zero. Of course you could avoid that that letting the number grow, but then you're back to the splitting problem...when exactly does it split and can we really zero those cross terms.
So I don't think it's a simpler theory. I think it's just distaste for randomness.
Brent -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/4453213f-96dc-9fdd-535b-959362ffde77%40verizon.net.
