I think it makes more sense to think of MWI as “first many, then even more many,” at which point questions of “when does the split happen?” feel less interesting, because the original state is no longer as special. [...] If time isn’t quantized, then this has to be spread across continuous space, and so thinking of there being a countable number of worlds is right out.
What I called the “nice ontology” isn’t so much about the number of worlds or even countability but about whether the worlds are well-defined. The MWI gives up a unique reality for things. The desirable feature of the “nice ontology” is that the theory tells us what a “version” of a thing is. As we all seem to agree, the MWI doesn’t do this.
If it doesn’t do this, what’s the justification for speaking of different versions in the first place? I think pure MWI makes only sense as “first one, then one”. After all, there’s just the universal wave function evolving and pure MWI doesn’t give us any reason to take a part of this wavefunction and say there are many versions of this.
What I called the “nice ontology” isn’t so much about the number of worlds or even countability but about whether the worlds are well-defined. The MWI gives up a unique reality for things. The desirable feature of the “nice ontology” is that the theory tells us what a “version” of a thing is. As we all seem to agree, the MWI doesn’t do this.
If it doesn’t do this, what’s the justification for speaking of different versions in the first place? I think pure MWI makes only sense as “first one, then one”. After all, there’s just the universal wave function evolving and pure MWI doesn’t give us any reason to take a part of this wavefunction and say there are many versions of this.