On Thursday, November 30, 2017 at 9:47:37 PM UTC, Bruce wrote: > > On 30/11/2017 10:59 pm, [email protected] <javascript:> wrote: > > On Thursday, November 30, 2017 at 11:42:51 AM UTC, Bruce wrote: >> >> On 30/11/2017 10:32 pm, [email protected] wrote: >> >> On Thursday, November 30, 2017 at 4:08:20 AM UTC-7, Bruce wrote: >>> >>> On 30/11/2017 9:53 pm, [email protected] wrote: >>> >>> On Wednesday, November 29, 2017 at 10:40:36 PM UTC, Bruce wrote: >>> >>> On 30/11/2017 5:31 am, John Clark wrote: >>> >>> On Tue, Nov 28, 2017 at 10:59 PM, Bruce Kellett <[email protected] >>> > wrote: >>> >>> >>> > >>> I see no reason all the Everett worlds have the same physics, >>> >>> >>> > >>> Everettian worlds follow from assuming that the Schrödinger equation >>> applies everywhere without exception, so that all physical evolution is >>> unitary. A change in the underlying physics -- such as a change in the >>> value of fundamental constants, Planck's constant or Newton's constant for >>> example -- would not be unitary, so cannot occur in MWI. >>> >>> >>> >>> Why can't it be unitary?? Show me why if >>> >>> Newton's constant had any value other than >>> >>> 6.754* 10^-11 m3 kg^−1 s^−2 >>> >>> the sum of all quantum probabilities would no longer add up to exactly >>> 1. If you can really do that then you've just derived Newton's constant >>> directly from first principles and you should but a ticket to Stockholm >>> right now because you're absolutely certain to win the next nobel Prize. >>> >>> Although unitarity does mean that probabilities always sum to unity, >>>> that is a consequence of unitary evolution, not a definition of it. A >>>> unitary transformation is one that can be reversed: so the unitary >>>> operator >>>> U can be written as exp(-iH), for example, and the complex conjugate (or >>>> the adjoint for hermitian operators) is the inverse transformation. >>>> >>> *Considering the evolution of the wf, if there exists a DE that >>>> describes the collapse process, would it necessarily be nonlinear? Is >>>> nonlinear a problem; that is, what is the downside to nonlinear? How would >>>> it effect the issue of hidden variables? TIA, AG * >>>> >>> >> Collapse would be non-linear and non-unitary -- >> intrinsically non-reversible. This is not necessarily a problem since there >> are plenty of non-linearities in physics. It has nothing to do with hidden >> variables. >> >> *Why would it be non linear? Brent claimed (on page 1)* >> >> >> Page 1 of what? >> > > > *On Google it's organized as pages, now up to page 15. Go to top of thread > and read second message by Brent. AG * > >> >> * that if the QM could be made deterministic, say by a DE that described >> collapse, it would imply awful consequences, such as the future determining >> the past.* >> >> >> No, it wouldn't imply that. >> >> * Would making QM into a deterministic theory imply an inconsistency in >> the postulates of QM? TIA, AG* >> >> >> QM in MWI is deterministic. Bohm's theory is deterministic, though >> expressly non-local. Determinism is not really an issue. One world theories >> are intrinsically random, not deterministic. >> > > *How can MWI be deterministic if it can't tell us what outcome we will > observe in this world, or any other? AG* > > > Because MWI says that all outcomes are realized, each in a separate world. > Apparent randomness comes about because we don't know which world we will > end up in (though we actually end up in all the worlds, so we, or our > duplicates, observe all possible outcomes). > > 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 post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
