> On 22 Feb 2020, at 05:37, Bruce Kellett <[email protected]> wrote: > > On Sat, Feb 22, 2020 at 2:42 PM 'Brent Meeker' via Everything List > <[email protected] <mailto:[email protected]>> > wrote: > On 2/21/2020 5:50 PM, Bruce Kellett wrote: >> I know that they argue in this way. But that is just say "It must be this >> way or else my theory fails." >> >> My argument against this is quite secure. Linear evolution via the SWE and >> Everett means that there is only one "relative state" or branch for each >> term in the original superposition. There is no room for a "weight" in such >> linear evolution. Looking at repeated trials simply highlights this fact -- >> the sequence of bit strings is necessarily independent of the original >> amplitudes -- there are no "weights", and MWI advocates are simply fooling >> themselves. > > I don't think it's so cut and dried as that. In Zurek's envariance based > idea of measurement he says the relative amplitude of the system must > carryover to the apparatus in order to maintain unitary evolution; c.f. III.E > of the attached. It essentially appeals to the ensemble of possible pure > states consistent with the system+apparatus reduced density matrix in > order to avoid your objection. > > I am not sure that I completely understand what Zurek has done here. The > problem of carrying the initial amplitdues through a sequence of repeated > trials is opaque to me.
It seems to me that this is a direct consequence of the linearity of the tensor product. I interpret for example the 1/sqrt(2) in a superposition as describing an infinity of accessible histories, where I can access some particle state (and eigenvalue) with a probability one half. If I make a measurement, that “1/sqrt(2)” is inherited by the state describing me + that particle. I me> (1/sqrt(2) a + 1/sqrt(2) b) = 1/sqrt(2) Ime>Ia> + 1/sqrt(2) Ime>Ib>. The weigth of a has passed on me, by linearity/unitarity. Bruno > Zurek seems to rely on the number of envariant environmental states somehow. > I will have to look into this further: it all needs a little untangling. I > can't quite see how the weights carry through repeated measurements -- the > state is surely a new state in each branched world. > > 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/CAFxXSLQ3xDwGaSg8wUEweT%3Dh%2BncYeD0MJE8jyTmn6CgPN8jhRQ%40mail.gmail.com > > <https://groups.google.com/d/msgid/everything-list/CAFxXSLQ3xDwGaSg8wUEweT%3Dh%2BncYeD0MJE8jyTmn6CgPN8jhRQ%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]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/7FCD6C6F-5881-4034-98A0-C1AF24207D24%40ulb.ac.be.
