As a rule, how it works is that non-physicist MWI believers just assume that configurations are the preferred basis, because spatial configurations are the everyday reality they’re already familiar with, and physicist MWI believers import whatever they need from Copenhagen QM in order to avoid having an ontologically preferred basis, even though a self-sufficient objective theory should have no logical room for such “imported” extra components.
How, do you think, does EY think about it? I could not find it stated clearly anywhere in the sequence, beyond “MWI is decoherence, decoherence is MWI”, which is not overly helpful.
Along with the emphasis on decoherence, he has expressed a liking for Robin Hanson’s “mangled worlds” approach, for the position basis because of the importance of relativistic locality, and for the “time capsules” of Julian Barbour. These ideas are at odds with each other in various ways. The last two utilize the position basis, the first two do not; and Barbour’s time-capsules are universe-wide configurations, so the spirit of relativity is lacking in his theory, putting it at odds with the other motivation for preferring the position basis. But I think you should regard this as a dynamic tension in Eliezer’s thought, rather than as a complacent contradiction. He knows his preferred hypothesis, but he doesn’t know the details, so various mutually contradictory refinements of the idea are playing a role in his thinking at the same time.
How, do you think, does EY think about it? I could not find it stated clearly anywhere in the sequence, beyond “MWI is decoherence, decoherence is MWI”, which is not overly helpful.
Along with the emphasis on decoherence, he has expressed a liking for Robin Hanson’s “mangled worlds” approach, for the position basis because of the importance of relativistic locality, and for the “time capsules” of Julian Barbour. These ideas are at odds with each other in various ways. The last two utilize the position basis, the first two do not; and Barbour’s time-capsules are universe-wide configurations, so the spirit of relativity is lacking in his theory, putting it at odds with the other motivation for preferring the position basis. But I think you should regard this as a dynamic tension in Eliezer’s thought, rather than as a complacent contradiction. He knows his preferred hypothesis, but he doesn’t know the details, so various mutually contradictory refinements of the idea are playing a role in his thinking at the same time.