Irrespective of my below comment where i get more empathetic wiht the motivation for MWI, I do want to point out some of the reasons why I think MWI may be a "bridge too far" to solve any problems.
The universe as we know it has proven to be gigantically "conservative" in the sense of having a bunch of conservation laws that it simply never violates. Conservation of mass-energy being among the deepest and most powerful. In this universe, at this epoch, stuff is neither created nor destroyed: it is converted from one kind of stuff into another with strict conservation. Even particle pairs that arise from random vacuum fluctuations all soon "realize" if they are violating conservation of energy and disappear before you can say within the uncertainty principle that they were ever there.
So now we come along, have a subtle issue with wavefunction collapse and what really causes it and what does it all mean, and the solution is: the universe may be strictly conservative, but the multiverse is growing in total mass and energy about as fast as any growth fuction that you can conceive, and THAT is what makes the direction of time so strong?
Yes, of course this COULD wind up being right and being the simplest. I await proposed experimental verifications, without them I can NEVER pick a non-conservative multiverse.
But thanks for making it clearer what some of the things that are gained are.
but the multiverse is growing in total mass and energy about as fast as any growth fuction that you can conceive, and THAT is what makes the direction of time so strong?
That's not how MWI works. These worlds are not being created. The wavefunction of the universe is being split up between them.
How many universes "branch off" from a "quantum event", and in how many of them is the cat dead vs alive, and what about non-50/50 scenarios, and please answer so that a physics dummy can maybe kind of understand?
(Is it just 1 with the live cat and 1 with the dead one?)