On Mon, Feb 10, 2025 at 9:25 AM Bruce Kellett <[email protected]> wrote:
> On Mon, Feb 10, 2025 at 8:49 AM Russell Standish <[email protected]> > wrote: > >> On Thu, Feb 06, 2025 at 11:38:52AM +1100, Bruce Kellett wrote: >> > >> > Many worlds theory does not have any comparable way of relating >> probabilities >> > to the properties of the wave function. In fact, if all possibilities >> are >> > realized on every trial, the majority of observers will get results that >> > contradict the Born probabilities. >> > >> >> I'm not sure what you mean by "contradict", but the majority of >> observers will get results that lie within one standard deviation of >> the expected value (ie mean) according to the distribution of Born >> probabilities. If this is what you mean by "contradict", then you are >> trivially correct, but uninteresting. If you mean the above statement >> is false according to the MWI, then I'd like to know why. It sure >> doesn't seem so to me. >> > > It does depend on what value you take for N, the number of trials. In the > limit of very large N, the law of large numbers does give the result you > suggest. But for intermediate values of N, MWI says that there will always > be branches for which the ratio of successes to N falls outside any > reasonable error bound on the expected Born value. > > This problem has been noted by others, and when asked about it, Carroll > simply dismissed the poor suckers that get results that invalidate the Born > Rule as just poor unlucky suckers. Sure, in a single world system, there is > always a small probability that you will get anomalous results. But that is > always a small probability. Whereas, in MWI, there are always such branches > with anomalous results, even for large N. The difference is important. > > The other point is that the set of branches obtained in Everettian many > worlds is independent of the amplitudes, or the Born probabilities for each > outcome, so observations on any one branch cannot be used as evidence, > either for or against the theory. > > See the articles by Adrian Kent and David Albert in "Many Worlds: Everett, > Quantum Theory, and Reality"(OUP, 2010) Edited by Saunders, Barrett, Kent, > and Wallace. > I forgot to add that Kent's paper is also available on arxiv: arxiv.org/abs/0905.0624 > 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 visit https://groups.google.com/d/msgid/everything-list/CAFxXSLR-tDxPJNxtWvQVSBv8-2V7CZQijv04w4YzXjG2CRdhMQ%40mail.gmail.com.
