> On 17 Feb 2020, at 23:46, 'Brent Meeker' via Everything List > <[email protected]> wrote: > > > > On 2/17/2020 2:11 AM, Bruce Kellett wrote: >> On Mon, Feb 17, 2020 at 6:04 PM 'Brent Meeker' via Everything List >> <[email protected] <mailto:[email protected]>> >> wrote: >> On 2/16/2020 9:48 PM, Bruce Kellett wrote: >>> On Mon, Feb 17, 2020 at 4:13 PM 'Brent Meeker' via Everything List >>> <[email protected] >>> <mailto:[email protected]>> wrote: >>> >>> But exactly the same reasoning applies for any given true value of p. >>> There will be different estimates by different experimenters and they can't >>> all be right. Each will infer that any proportion other than the one he >>> observed will have zero measure in the limit N->oo. >>> >>> Exactly right. That is what my example of spin measurements on an ensemble >>> of equally prepared spin states comes into play. If all 2^N bit strings are >>> realized for one orientation of the S-G magnet, then exactly the same 2^N >>> bit strings are realized for every other orientation. >> >> ?? Suppose the ensemble is equally prepared in spin-up. What does it mean >> to say all 2^N bit strings are realized for the S-G oriented left/right? We >> may expect they will be for any number of trials >>N. But certainly not >> for the S-G oriented up/down. >> >> I think we are beginning to argue at cross-purposes, and I may not have >> understood you correctly. Let me try to restate the position clearly, and >> see if you can agree. >> >> Take a spin-half state, and prepare a linear combination in the x-basis: >> >> |psi> = (alpha*|x-spin up> + beta*|x-spin down>), >> >> where we assume that neither alpha nor beta is equal to zero. We can now >> measure this state in the x-direction and assume Everett, so that every >> result is obtained in a separate branch on every trial. Coding these results >> as zero and one, a run of N experiments will give 2^N binary strings of >> results, consisting of the set of all 2^N binary strings of length N. Now >> rotate the S-G magnet from the x-direction by, say, 10 degrees. Your results >> are again the set of all binary strings of length N. Similarly for any other >> angle (except those for which alpha or beta rotates to zero). Since the set >> of results is the same in all cases, even though rotation of the S-G magnet >> is equivalent to changing alpha and beta in the superposition, the >> individual sets of results must be independent of alpha and beta. However, >> the Born rule states that the probabilities depend on |alpha|^2 and |beta|^. >> But we have seen that the many-worlds data are actually independent of alpha >> and beta. The Born rule for probabilities is thus disconfirmed in this >> Everettian case. >> >> That is the crux of what I am trying to get across -- Everettian QM is >> disconfirmed by experiment, since experiments show results that depend on >> the coefficients alpha and beta, in accordance with the Born Rule. There are >> other points that I have been making, but let's get this straight first. > > Yes, I agree with that. It's another way of expressing my objection that > while alpha=0.5 produces a split into two worlds, alpha= 0.499 produces a > split into a thousand worlds. > > But proponents of MWI like Sean Carroll and Bruno, essentially assume there > are already (infinitely?)
Yes, infinitely, as your own example of 0.499 already suggest. Recently I have found reason that it could even be a *very* large cardinal (I really don’t know, but some axioms in set theory do provide light on the measure problem, It is very technical alas. Bruno > many branches which, prior to the measurement, are identical at the > macroscopic level, but which get projected (split) onto orthogonal subspaces > by a measurement. > > Brent > >> >> 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] >> <mailto:[email protected]>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/everything-list/CAFxXSLQM-O%3DjP9MOjKuny5%3DWJ2h%3D9fPKqZsaqDibgss0ugRziw%40mail.gmail.com >> >> <https://groups.google.com/d/msgid/everything-list/CAFxXSLQM-O%3DjP9MOjKuny5%3DWJ2h%3D9fPKqZsaqDibgss0ugRziw%40mail.gmail.com?utm_medium=email&utm_source=footer>. > > > -- > 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] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/fcab7173-3419-1018-6efe-813d2ec5a2d7%40verizon.net > > <https://groups.google.com/d/msgid/everything-list/fcab7173-3419-1018-6efe-813d2ec5a2d7%40verizon.net?utm_medium=email&utm_source=footer>. -- 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/8286A98B-9E0B-4AE6-9503-705765C0A7D6%40ulb.ac.be.
