On Friday, February 7, 2020 at 6:16:45 PM UTC-6, Bruce wrote: > > On Sat, Feb 8, 2020 at 4:33 AM Stathis Papaioannou <[email protected] > <javascript:>> wrote: > >> On Fri, 7 Feb 2020 at 15:59, Bruce Kellett <[email protected] >> <javascript:>> wrote: >> >>> >>> This argument from Kent completely destroys Everett's attempt to derive >>> the Born rule from his many-worlds approach to quantum mechanics. In fact, >>> it totally undermines most attempts to derive the Born rule from any >>> branching theory, and undermines attempts to justify ignoring branches on >>> which the Born rule weights are disconfirmed. In the many-worlds case, >>> recall, all observers are aware that other observers with other data must >>> exist, but each is led to construct a spurious measure of importance that >>> favours their own observations against the others', and this leads to an >>> obvious absurdity. In the one-world case, observers treat what actually >>> happened as important, and ignore what didn't happen: this doesn't lead to >>> the same difficulty. >>> >> Carroll and Sebens worked a paper a year ago illustrating how MWI was consistent with Born rule. They did have to restrict paths or states that were too far removed from being a good Bayeisan prior, so it is a bit loose. However, it was not bad.
The inability to define a clear probability to a particular world path is argued to be one reason that MWI is the best interpretation to work quantum gravitation. This is a sort of nonlocality. I am not sure this clinches MWI as the clearly superior interpretation. Much the same nonlocality can be identified with quantum spacetime if it is built up from quantum entanglements, thus avoiding the use of an interpretation. MWI is sworn by a number of physicists, though Copenhagen still holds it own and Qubism is growing adherents. Qubism actually also has a few things going for it. I frankly see all of these as ancillary postulates that have limited usefulness and mostly useful in expositories. LC > Nevertheless Many Worlds is at least logically possible. What would the >> inhabitants expect to see, if not the world we currently see? >> > > > Many-worlds might be logically possible, but it is also completely > useless. If every possible outcome from any experiment/interaction actually > occurs, then the total data that results is independent of any probability > measure. Consequently, one cannot use data from experiments to infer > anything about any underlying probabilities, even if such exist at all. In > particular, Many-worlds is incompatible with the Born rule, and with the > overwhelming amount of evidence confirming the Born rule in quantum > mechanics. So Many-worlds (and Everett) is a failed theory, disconfirmed by > every experiment ever performed. If Many-worlds is correct, then the > inhabitants have no basis on which to have any expectations about what they > might see. > > 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/c04b5adb-1b18-4d01-97ed-43dda88fc4e5%40googlegroups.com.
