On Thu, Apr 28, 2022 at 10:14 AM Brent Meeker <meekerbr...@gmail.com> wrote:

> On 4/27/2022 2:00 PM, smitra wrote: > > If you agree, and are prepared, > with me, to throw out Everett, then we agree, and there is nothing > more to be argued about (at least, until you present some different > complete theory). > > I'm open to the idea that QM itself may only be an approximation to a more > fundamental theory. The arguments in favor of no collapse are strong > arguments but you then do get this issue with probability that you have > discussed here. The disagreement with you about this is that I don't see > it as a fatal inconsistency that would prove the MWI to be wrong. > Probabilities for the different branches do not have to be equal. But that > doesn't mean that this looks to be a rather unnatural feature of the > theory. This suggests that a more fundamental theory exists from which one > could derive quantum mechanics with its formalism involving amplitudes and > the Born rule as an approximation. > > > If there are probabilities attached to the branches, then Gleason's > theorem shows that the probabilities must satisfy the Born rule. So I > don't seen any inconsistency in simply saying they are probabilities of > measurement results, that's Copenhagen. But if they are probabilities of > results that implies that some things happen and others don't...other wise > what does "probability" mean and what use is it as an empirical concept? > That is exactly right. If you try to claim that the probability of 'up' is 90% and the probability of 'down' is 10%, but that both results certainly happen (albeit on different branches), then you are talking nonsensical gibberish. That is why I say that Everett is incompatible with the Born rule. Bruce -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/CAFxXSLQshCCMUUR00%2BXjyGQg3jBpbQWX3SEqmRvh8RnRc069cA%40mail.gmail.com.