Copenhagen requires a collapse, you can’t get there with fewer assumptions than MWI. At best you have agnosticity between MWI and alternate interpretations.
Maybe some variation of CI involves collapse, but strictly-speaking bare bone CI does not require it. This is typically not discussed by supporters of other interpretations. Even Sean Carroll says according to CI the world follows two distinct rules, one when you are not looking, a different one when you are making a measurement (collapse). However, that is not necessarily CI. For example, as PBR shows, there is only one rule in CI, which describes the behavior of actions. By rejecting “the view from nowhere”, there is no sense in examining how the world behaves when it’s not affecting the perspective center. Here the wavefuntion is epistemic rather than ontic. There is no physical collapse needed.
Can you explain how you end up with fewer assumptions?
Under your terminology, I believe I can formulate MWI epistemically with the same number of assumptions, and if formalized I think MWI comes out slightly simpler.
Because MWI needs perspective-independent objectivity, that it is meaningful to describe reality with “a view from nowhere”, as the universal wave function does. So it needs to accept the postulate in Step 3. CI could (and I argue should) do without. No matter how commonly accepted it is, Step 3 is still an assumption.
Copenhagen as opposed to Objective Reduction doesnt require collapse to be an objective process. Unfortunately, most of the QM material on this site conflates the two.
Can you be explicit about the set of assumptions you’re using for MWI and Copenhagen? I can’t make heads or tails of your comments here. Are you arguing that Copenhagen requires fewer assumptions?
CI, when not confused with OR, is rather minimal. That’s not necessarily a good thing, because, while you don’t have to put a lot of assumptions into it, you don’t get much clarity about what’s actually going on out of it
Minimal CI is rather broad. That explains how it how it became popular—as opposed to the Physics community being a bunch of booby heads who need to be lectured about Bayes.
I think no matter how board CI is can MWI be regarded as a special case of it. The two are very distinct. The MWI is top-down. It describes the world with the universal wavefuntion as objective reality from a view from nowhere. So its problem is explaining our individual experience and experiment results, e.g. the Born rule. The CI is bottom-up, it describes our experiments and measurements. So its problem is to provide a comprehensible explanation of reality. The unresolvable conflict between the two is the special role of the observer. CI recognizes it, MWI rejects it.
I think it’s also important not to confiate CI with consciousness-causes-collapse theories. CI doesn’t need to regard observers as ontologically special, it just asserts that macroscopic observers will make classical style , real valued observations
And that QM, nonetheless, isn’t a classical theory. At the time if it’s formulation, the main rivals were theories that tried to explain away the probablistic nature of QM as statistics applying to ensembles.
Yes. The special role of observers does not mean Wigner style consciousness-induces-collapse theories, which I am firmly against. That could potentially lead to some bizarre conclusions such as a dog could collapse the wavefuntion but a cat can’t. CI doesn’t say that (it didn’t say much at all). For example, PBR suggests the perspective center (the observer) can be a person just like it can be a Geiger counter.
That being said, PBR can be regarded as a consciousness-related theory if one pushes it. Our natural first-person perspective can be simple treated as primitively given or fundamental. But if there has to be an explanation to this perspective, “why is it apparent that I am the perspective center?”, then the answer ought to be because the only subjectivity available is of this particular human/physical system. By postulation, we can choose to reason from other perspectives (e.g. a Geiger counter’s). Now asking why the Geiger counter is the perspective center would potentially point to a subjectivity of its own. Granted, it does not suggest its subjective experience has got anything in common with humans’. Yet that in essence would lead to panpsychism.
Of course, all this has got nothing to do with actions upon the perspective center or anything physically detectable. So I don’t think they are related to the discussion of QM. Just some random thoughts.
Copenhagen requires a collapse, you can’t get there with fewer assumptions than MWI. At best you have agnosticity between MWI and alternate interpretations.
Maybe some variation of CI involves collapse, but strictly-speaking bare bone CI does not require it. This is typically not discussed by supporters of other interpretations. Even Sean Carroll says according to CI the world follows two distinct rules, one when you are not looking, a different one when you are making a measurement (collapse). However, that is not necessarily CI. For example, as PBR shows, there is only one rule in CI, which describes the behavior of actions. By rejecting “the view from nowhere”, there is no sense in examining how the world behaves when it’s not affecting the perspective center. Here the wavefuntion is epistemic rather than ontic. There is no physical collapse needed.
Can you explain how you end up with fewer assumptions?
Under your terminology, I believe I can formulate MWI epistemically with the same number of assumptions, and if formalized I think MWI comes out slightly simpler.
Because MWI needs perspective-independent objectivity, that it is meaningful to describe reality with “a view from nowhere”, as the universal wave function does. So it needs to accept the postulate in Step 3. CI could (and I argue should) do without. No matter how commonly accepted it is, Step 3 is still an assumption.
I deny that MWI requires that. In fact, all three of your postulates are incoherent, and I believe in a form of MWI that doesn’t require any of them.
Fair enough.
Copenhagen as opposed to Objective Reduction doesnt require collapse to be an objective process. Unfortunately, most of the QM material on this site conflates the two.
If collapse is not objective then in what sense is that theory different than MWI?
It is not denied that collapse occurs. But it is not confirmed either.
So not at all different than MWI, using the exact same assumptions.
MWI has to deny collapse, because otherwise branching would not occur. (And it has to be realistic about wave functions).
Can you be explicit about the set of assumptions you’re using for MWI and Copenhagen? I can’t make heads or tails of your comments here. Are you arguing that Copenhagen requires fewer assumptions?
CI, when not confused with OR, is rather minimal. That’s not necessarily a good thing, because, while you don’t have to put a lot of assumptions into it, you don’t get much clarity about what’s actually going on out of it
It sounds like your version of CI is broad enough that MWI is a special case of it, or vice verse, or something.
Minimal CI is rather broad. That explains how it how it became popular—as opposed to the Physics community being a bunch of booby heads who need to be lectured about Bayes.
Do you have any sources explaining the assumptions that go into this minimal version?
I think no matter how board CI is can MWI be regarded as a special case of it. The two are very distinct. The MWI is top-down. It describes the world with the universal wavefuntion as objective reality from a view from nowhere. So its problem is explaining our individual experience and experiment results, e.g. the Born rule. The CI is bottom-up, it describes our experiments and measurements. So its problem is to provide a comprehensible explanation of reality. The unresolvable conflict between the two is the special role of the observer. CI recognizes it, MWI rejects it.
I think it’s also important not to confiate CI with consciousness-causes-collapse theories. CI doesn’t need to regard observers as ontologically special, it just asserts that macroscopic observers will make classical style , real valued observations
And that QM, nonetheless, isn’t a classical theory. At the time if it’s formulation, the main rivals were theories that tried to explain away the probablistic nature of QM as statistics applying to ensembles.
Yes. The special role of observers does not mean Wigner style consciousness-induces-collapse theories, which I am firmly against. That could potentially lead to some bizarre conclusions such as a dog could collapse the wavefuntion but a cat can’t. CI doesn’t say that (it didn’t say much at all). For example, PBR suggests the perspective center (the observer) can be a person just like it can be a Geiger counter.
That being said, PBR can be regarded as a consciousness-related theory if one pushes it. Our natural first-person perspective can be simple treated as primitively given or fundamental. But if there has to be an explanation to this perspective, “why is it apparent that I am the perspective center?”, then the answer ought to be because the only subjectivity available is of this particular human/physical system. By postulation, we can choose to reason from other perspectives (e.g. a Geiger counter’s). Now asking why the Geiger counter is the perspective center would potentially point to a subjectivity of its own. Granted, it does not suggest its subjective experience has got anything in common with humans’. Yet that in essence would lead to panpsychism.
Of course, all this has got nothing to do with actions upon the perspective center or anything physically detectable. So I don’t think they are related to the discussion of QM. Just some random thoughts.
Every calculation requires a projection postulate, there is no way around it.
Projection:map :: Collapse: territory.