On 21 November 2017 at 08:53, Bruce Kellett <bhkell...@optusnet.com.au> wrote:
> On 20/11/2017 11:42 pm, Stathis Papaioannou wrote: > > On Sun, 19 Nov 2017 at 8:35 am, Bruce Kellett <bhkell...@optusnet.com.au> > wrote: > >> On 19/11/2017 12:15 am, Stathis Papaioannou wrote: >> >> On Sat, 18 Nov 2017 at 9:11 am, Bruce Kellett <bhkell...@optusnet.com.au> >> wrote: >> >>> >>> And exactly what is it that you claim has not been proved in MW theory? >>> Bell's theorem applies there too: it has never been proved that it does >>> not. Bell was no fool: he did not like MWI, but if that provided an escape >>> from his theorem, he would have addressed the issue. The fact that he did >>> not suggests strongly that you do not have a case. >>> >> >> Bell’s theory applies in the sense that the experimental results would be >> the same in MWI, but the FTL weirdness is eliminated. This is because in >> MWI the experimenter can’t prepare a random state, >> >> >> What do you mean by this? Are you claiming that there are no free >> variables in MWI? Some form of superdeterminism? >> > > Yes. > > > As far as I know, the only serious advocate of superdeterminism as an > account of QM is Gerard 't Hooft. Tim Maudlin analysed 't Hooft's arguments > in a long exchange with him on Facebook: > > https://www.facebook.com/tim.maudlin/posts/10155670157528398 > > Maudlin's arguments was basically that the type of conspiracies that would > be required in the general case would be such, that if they were > generalized, they would render science and experimental confirmation of > theories meaningless. > > I think Maudlin is quite right here. Apart from the implication that > superdeterminism says that all our scientific theories are necessarily > incomplete, superdeterminism is not really an explanation of anything, > since anything you observe can be explained away in this way. > Maudlin also says this about EPR, Bell and MWI: --quote-- Finally, there is one big idea. Bell showed that measurements made far apart cannot regularly display correlations that violate his inequality if the world is local. But this requires that the measurements have results in order that there be the requisite correlations. What if no “measurement” ever has a unique result at all; what if all the “possible outcomes” occur? What would it even mean to say that in such a situation there is some correlation among the “outcomes of these measurements”? This is, of course, the idea of the Many Worlds interpretation. It does not refute Bell’s analysis, but rather moots it: in this picture, phenomena in the physical world do not, after all, display correlations between distant experiments that violate Bell’s inequality, somehow it just seems that they do. Indeed, the world does not actually conform to the predictions of quantum theory at all (in particular, the prediction that these sorts of experiments have single unique outcomes, which correspond to eigenvalues), it just seems that way. So Bell’s result cannot get a grip on this theory. --endquote-- https://arxiv.org/ftp/arxiv/papers/1408/1408.1826.pdf > But for Bell-type experiments in MWI, or elsewhere, one does not have to >> prepare a random state -- one just prepares a singlet state consisting of >> two entangled particles. Nothing random about it. >> > > Then one makes a measurement, the outcome of which is uncertain until it > is done, but - surprisingly - the distal particle seems to “know” about it > instantaneously. In the MWI there is no uncertainty about the measurement > in the multiverse as a whole, although there is uncertainty from the point > of view of individual observers, because they do not know in which branch > they will end up in. > > Bell actually thought that Bohm's deterministic, though non-local, theory >> was a better bet. But you have not addressed my counterexample to your >> contention that MWI eliminates non-locality. The time-like measurement of >> the two entangled particles clearly requires non-locality in order to >> conserve angular momentum. >> > > There is no question of the distal entangled particle instantaneously > reacting to a measurement of the proximal particle to conserve angular > momentum, because the outcome of the measurement was already fixed. > > > -- > 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 everything-list+unsubscr...@googlegroups.com. > To post to this group, send email to everything-list@googlegroups.com. > Visit this group at https://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/d/optout. > -- Stathis Papaioannou -- You received this message because you are subscribed to the Google Groups "Everything List" group. 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