The answer is: it all depends on what you mean by “world”.
There is an approach to MWI based on coherent superpositions, and a version based on decoherence. Following Yudkowsky, you are assuming the coherence based approach.
The issue is not whether superpositions exist, but whether they qualify as worlds.. it’s a conceptual issue.
Superposed states lack a number of features that one would typically assiciate with a world: objectivity, size, causal isolation, and permanence.
I’m not sure what you mean by objectivity or why superimposed states don’t have it.
If a pair of superimposed state differ by a couple of atom positions, they can interact and merge. If they differ by “cat alive” to “cat dead” then there is practically no interaction. The world stays superimposed forever. So that gives causal isolation and permanence.
I mean maybe some of the connotations of “worlds” aren’t quite accurate. Its a reasonably good word to use.
No objectivity means that superpositions can be made to disappear by a suitable choice of basis
If there is no inteerction, they are decoherent states. If you could show that decoherence smoothly follows from coherent superposition, without any additional postulates, you would be on to something .
The answer is: it all depends on what you mean by “world”.
There is an approach to MWI based on coherent superpositions, and a version based on decoherence. Following Yudkowsky, you are assuming the coherence based approach.
The issue is not whether superpositions exist, but whether they qualify as worlds.. it’s a conceptual issue.
Superposed states lack a number of features that one would typically assiciate with a world: objectivity, size, causal isolation, and permanence.
I’m not sure what you mean by objectivity or why superimposed states don’t have it.
If a pair of superimposed state differ by a couple of atom positions, they can interact and merge. If they differ by “cat alive” to “cat dead” then there is practically no interaction. The world stays superimposed forever. So that gives causal isolation and permanence.
I mean maybe some of the connotations of “worlds” aren’t quite accurate. Its a reasonably good word to use.
No objectivity means that superpositions can be made to disappear by a suitable choice of basis
If there is no inteerction, they are decoherent states. If you could show that decoherence smoothly follows from coherent superposition, without any additional postulates, you would be on to something .