The fact that superposed states do interact significantly on the small scale is important, because its the basis for believing there could be worlds in the first place. The MTM model is completely non interacting, so it misrepresents the physics.
The MTM model is literally computing the same thing as the MWH. Specifically, suppose for a human brain I compute the events observed by the same human brain. Granted, this requires solving both the easy problem of consciousness and the grand unified theory . But I don’t think anyone here is seriously suggesting those are inherently non-computable functions.
I suppose a reasonable objection is that the shortest program is MWH, since I don’t have to determine when an observation happens. But if I ask for the fastest program in terms of time and memory efficiency instead, MWH is a clear loser.
MWI is more than one theory, because everything is more than one thing[*].
If you defined MWI as just the evolution of the SWE (as required by the simplicity theory), then calculating a bunch of non-interacting states is getting it wrong.
If you start with the idea that MWI is a bunch of non-interacting observers observing different things, then the MTM might get it right. The problem is that no-one knows how
to get the second kind of MWI out of the maths. That is where things like the basis problem come in.
[*]
There is an approach based on coherent superposiitions, and and an version based on decoherence. These are incompatible opposites.
Worlds are superpositions, so they in exist at small scales, they can continue to interact with each other, after, “splitting” , and and they can be erased. These coherent superposed states are the kind of “world” we have direct evidence for, although they seem to lack many of the properties requited for a fully fledged many worlds theory, hence the scare quotes. Call these Small worlds.
Worlds are large, in fact universe-like. They are causally and informationally isolated from each other. This approach is often based on quantum decoherence. Call these Big Worlds.
The fact that superposed states do interact significantly on the small scale is important, because its the basis for believing there could be worlds in the first place. The MTM model is completely non interacting, so it misrepresents the physics.
The MTM model is literally computing the same thing as the MWH. Specifically, suppose for a human brain I compute the events observed by the same human brain. Granted, this requires solving both the easy problem of consciousness and the grand unified theory . But I don’t think anyone here is seriously suggesting those are inherently non-computable functions.
I suppose a reasonable objection is that the shortest program is MWH, since I don’t have to determine when an observation happens. But if I ask for the fastest program in terms of time and memory efficiency instead, MWH is a clear loser.
MWI is more than one theory, because everything is more than one thing[*].
If you defined MWI as just the evolution of the SWE (as required by the simplicity theory), then calculating a bunch of non-interacting states is getting it wrong.
If you start with the idea that MWI is a bunch of non-interacting observers observing different things, then the MTM might get it right. The problem is that no-one knows how to get the second kind of MWI out of the maths. That is where things like the basis problem come in.
[*]
There is an approach based on coherent superposiitions, and and an version based on decoherence. These are incompatible opposites.
Worlds are superpositions, so they in exist at small scales, they can continue to interact with each other, after, “splitting” , and and they can be erased. These coherent superposed states are the kind of “world” we have direct evidence for, although they seem to lack many of the properties requited for a fully fledged many worlds theory, hence the scare quotes. Call these Small worlds.
Worlds are large, in fact universe-like. They are causally and informationally isolated from each other. This approach is often based on quantum decoherence. Call these Big Worlds.