It seems likely that however you map the concept of ‘you’ into physical terms, it pretty much has to be based on classical properties rather than quantum coherent ones. So in fact quantum theory and MWI is almost irrelevant here, except as a reason why ‘you’ may be somewhat more plural than you think. Even in a classical multiverse, ‘you’ could be plural so MWI isn’t actually necessary here. Quantum theory just makes it far more likely that such plurality does exist even when we don’t more directly detect it.
No matter how finely you define ‘you’ in terms of pre-flip observations and thought processes, it is very likely that roughly equal parts of ‘you’ post-flip see heads and tails. This would not hold if for some reason a large fraction of ‘you’ flips the coin in a way that is highly correlated with those pre-flip observations and thought processes e.g. knowingly starting with the coin heads-up and just dropping it a short distance.
I’m not convinced that the specifics of “why” someone might consider themselves a plural smeared across a multiverse are irrelevant. MWI and the dynamics of evolving amplitude are a straightforward implication of the foundational math of a highly predictive theory, whereas the different flavors of classical multiverse are a bit harder to justify as “likely to be real”, and also harder to be confident about any implications.
If I do the electron-spin thing I can be fairly confident of the future existence of a thing-which-claims-to-be-me experiencing both outcomes as well as my relative likelihood of “becoming” each one, but if I’m in a classical multiverse doing a coin flip then perhaps my future experiences are contingent on whether the Boltzmann-brain-emulator running on the grand Kolmogorov-brute-forcing hypercomputer is biased against tails (that’s not to say I can make use of any of that to make a better prediction about the coin, but it does mean upon seeing heads that I can conclude approximately nothing about any “me”s running around that saw tails).
Fully agreed, I wasn’t trying to say that there are just as good justifications for a classical multiverse as a quantum multiverse. Just that it’s the “multiverse” part that’s more relevant than the “quantum” part. If you accept multiverses at all, most types include the possibility that there may be indistinguishable pre-flip versions of ‘you’ that experience different post-flip outcomes.
Question 5 is really the most important one here.
It seems likely that however you map the concept of ‘you’ into physical terms, it pretty much has to be based on classical properties rather than quantum coherent ones. So in fact quantum theory and MWI is almost irrelevant here, except as a reason why ‘you’ may be somewhat more plural than you think. Even in a classical multiverse, ‘you’ could be plural so MWI isn’t actually necessary here. Quantum theory just makes it far more likely that such plurality does exist even when we don’t more directly detect it.
No matter how finely you define ‘you’ in terms of pre-flip observations and thought processes, it is very likely that roughly equal parts of ‘you’ post-flip see heads and tails. This would not hold if for some reason a large fraction of ‘you’ flips the coin in a way that is highly correlated with those pre-flip observations and thought processes e.g. knowingly starting with the coin heads-up and just dropping it a short distance.
I’m not convinced that the specifics of “why” someone might consider themselves a plural smeared across a multiverse are irrelevant. MWI and the dynamics of evolving amplitude are a straightforward implication of the foundational math of a highly predictive theory, whereas the different flavors of classical multiverse are a bit harder to justify as “likely to be real”, and also harder to be confident about any implications.
If I do the electron-spin thing I can be fairly confident of the future existence of a thing-which-claims-to-be-me experiencing both outcomes as well as my relative likelihood of “becoming” each one, but if I’m in a classical multiverse doing a coin flip then perhaps my future experiences are contingent on whether the Boltzmann-brain-emulator running on the grand Kolmogorov-brute-forcing hypercomputer is biased against tails (that’s not to say I can make use of any of that to make a better prediction about the coin, but it does mean upon seeing heads that I can conclude approximately nothing about any “me”s running around that saw tails).
Fully agreed, I wasn’t trying to say that there are just as good justifications for a classical multiverse as a quantum multiverse. Just that it’s the “multiverse” part that’s more relevant than the “quantum” part. If you accept multiverses at all, most types include the possibility that there may be indistinguishable pre-flip versions of ‘you’ that experience different post-flip outcomes.
No they are not straightforward, MWI is controversial and subject to ongoing research.