(August 5, 2020 at 6:02 pm)Grandizer Wrote: Many worlds is very neat and very sufficient and doesn't have to add some extra assumptions that other interpretations have to do. Though it does posit a lot of worlds but so what? When did we ever let counterintuitive be a problem for us?
You say we need to explain collapse, but isn't that sort of begging the question here? Why must there be a collapse at all? Incredulity isn't a good objection here.
ETA: Ok, rereading your post, perhaps charging you with begging the question was premature. Your argument for collapse is that there can't be an infinite regress or our universe would not be realized or something? I'm not sure why this should be the case. Under the MW interpretation, the waveform exists and all possibilities are realized in the form of worlds instead of just one. Not seeing the problem here. Maybe because I'm seeing it in an atemporal sense rather than temporal.
The Many Worlds Interpretation (MWI) has undergone a lot of changes. Many of the originals did have a type of collapse -- the bifurcation of universes. It was explained that such a bifurcation is a gradual process involving decoherence. But, decoherence never fully translates to the classical situation. While the Copenhagen Interpretation would just say "at some time after decoherence, we have collapse", MWI is saying the same thing "at some time after decoherence, we have a split universe".
In the sense that modern MWI tries to not have any form of collapse, I don't see them as fundamentally different than apparent collapse theories like Montevideo. I'm not sure either of them truly work, however.
Both have to "trim down" the alternate histories. MWI does it by postulating that all the other histories exist, just not in your universe (except perhaps with some vestige of correlation to the other universes). Something like Montevideo suggest that the other histories get less and less probable as information is shared among observers, but they always have a vestige of existence that might be seen for some observers.
There is probably no difference. One world with multiple histories, or many worlds with (mostly) one history. It is probably identical. But if either had truly solved the "collapse" problem, we would've declared the problem solved. If you don't have Copenhagen collapse, you still find that all those "vestiges" of correlation between the alternate histories add up, when applied to the entire universe.
