On Wednesday, April 20, 2022 at 5:21:47 PM UTC-6 Alan Grayson wrote:
> > > On Friday, April 15, 2022 at 12:41:03 PM UTC-6 [email protected] wrote: > >> >> >> On 4/14/2022 2:00 PM, George Kahrimanis wrote: >> >> On Wednesday, April 13, 2022 at 8:55:48 PM UTC+3 [email protected] >> (Brent) wrote: >> >> Decoherence has gone part way in solving the when/where/what basis >>> questions, but only part way. >>> >> >> As I wrote at the end of my first reply to your message, I share your >> concern about decoherence but I see the glass as half-full; that is, with a >> little more subtlety I hope that the matter can be formulated in clear >> terms. >> >> Surely collapse is easier to handle as a general concept (except, on the >> other hand, that it requires new dynamics). I forgot to mention that *my >> argument for deriving the Born Rule works with collapse, too* -- so it >> is an alternative to Gleason's theorem. >> >> Here I define colapse as an irreversible process, violating unitarity of >> course, and I keep it separate from randomisation. The latter means that >> each outcome is somehow randomised -- an assumption we can do without. >> >> *Collapse can also be described in a many-world formulation!* It differs >> from the no-collapse MWI only in being irreversible. >> >> >> If you can throw away low probability branches, what's to stop you from >> throwing away all but one? You've already broken unitary evolution. If >> you read Hardy's axiomatization of QM you see that the difference between >> QM and classical mechanics turns on a single word in Axiom 5 Continuity: >> There exists a *continuous *reversible transformation on a system >> between any two pure states of that system. >> >> My argument in outline is >> 1. assessment that MWI-with-collapse is workable; >> 2. therefore, outcomes of small enough measure can be neglected in >> practice; >> >> >> Yes, I've wondered if a smallest non-zero probability could be defined >> consistent with the data. >> >> 3. now Everett's argument can proceed, concluding that the Born Rule is a >> practically safe assumption (to put it briefly). >> >> So I have replaced two assumptions of Gleason's theorem, randomisation >> and non-contextuality, by the assessment of workability only. >> >> If you don't feel comfortable yet with formulating collapse in a >> many-world setting, let us also assume randomisation (God plays dice), for >> the sake of the argument, in a single-world formulation. That is, we ASSUME >> the existence of probability; then the previous argument just guarantees >> that this probability follows the Born Rule. >> >> >> Assume? Randomness is well motivated by evidence. And it's more random >> than just not knowing some inherent variable, because in the EPR experiment >> a randomized hidden variable can on explain the QM result if it's non-local. >> > >> >> >> Of course I favour the first version of the argument, using the >> many-world formulation of collapse, to avoid the "God plays dice" nightmare. >> >> >> Why this fear of true randomness? We have all kinds of classical >> randomness we just attributed to "historical accident". Would it really >> make any difference it were due to inherent quantum randomness? Albrect >> and Phillips have made an argument that there is quantum randomness even >> nominally classical dynamics. https://arxiv.org/abs/1212.0953v3 >> > > The authors regard quantum fluctuations as fundamental. How are they > defined? AG > I think I get it. Whereas before QM we could attribute single, unpredicted outcomes to ignorance of initial conditions, and but with QM our understanding is augmented; now we can attribute it to ... nothing? AG > >> Brent >> >> >> Thanks for the comments so far, because they stirred my thinking and >> motivated fresh ideas, some of which I hope will prove helpful and worth >> discussing, if and when they mature. >> >> George K. >> >> -- >> 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/06930c0c-5537-4fb7-bf70-fd8c7d9859b0n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/everything-list/06930c0c-5537-4fb7-bf70-fd8c7d9859b0n%40googlegroups.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/24897ea1-c490-403d-9a2e-450a4128ba38n%40googlegroups.com.
