On Friday, February 7, 2020 at 7:57:24 PM UTC-6, Bruce wrote: > > On Sat, Feb 8, 2020 at 12:28 PM Lawrence Crowell <[email protected] > <javascript:>> wrote: > >> On Friday, February 7, 2020 at 7:10:54 PM UTC-6, Bruce wrote: >>> >>> On Sat, Feb 8, 2020 at 11:51 AM Lawrence Crowell < >>> [email protected]> wrote: >>> >>>> 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]> >>>>> wrote: >>>>> >>>>>> On Fri, 7 Feb 2020 at 15:59, Bruce Kellett <[email protected]> >>>>>> 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. >>>> >>> >>> Not bad!!!! I suppose if you feel justified in just throwing away >>> anything that does not suit your favourite theory, then you can get away >>> with anything. It is the fact that these 'worlds' that are far removed >>> from what one wants to see cannot just be "thrown away" that destroys MWI. >>> Given that the probability of particular outcomes no longer has meaning >>> when all outcomes necessarily occur, one cannot use any observed data to >>> justify any theory about the probabilities. All theories are just as good, >>> or just as bad. Consequently, assuming probabilities for particular >>> outcomes no longer makes any sense. >>> >>> >> The set of amplitudes or paths thrown away is a small measure. The bounds >> are not entirely certain, but they are comparatively small. >> > > > The problem is to justify that the paths thrown away do, in fact, have > small measure. The proof given by Kent shows that, whatever result you > obtain, you can argue that contrary results have "small measure", and can > be thrown away. There is nothing that picks out one particular set of paths > as preferred in the many-worlds situation. One can only get that in a > stochastic one-world model. > > Bruce >
No matter how hard we try statistics always has this element of subjectivity to it. Since entropy is S = -sum p log(p) the summation is a log and these errors tend not to be very large, As a corollary we have various definition of entropy and ways of computing it. This means that no matter how hard we try physics has this subjective aspect to it, and in a lot of ways Qubism has a few points along these lines. LC -- 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/627aff5e-ae1b-4300-bbde-26276d672667%40googlegroups.com.
