On Tue, Oct 8, 2019 at 10:25 PM Bruno Marchal <marc...@ulb.ac.be> wrote:
> On 6 Oct 2019, at 10:39, Bruce Kellett <bhkellet...@gmail.com> wrote: > > > On Sun, Oct 6, 2019 at 7:25 PM Bruno Marchal <marc...@ulb.ac.be> wrote: > >> >> > On 6 Oct 2019, at 02:50, Russell Standish <li...@hpcoders.com.au> >> wrote: >> > >> > What I do get is Bruno's point that a single world assumption turns a >> > nonlocal state into FTL "influence", the mechanism of which is quite >> > unimaginable as you point out. An argument by incredulity, as it were, >> > for the MWI. >> >> Exactly. >> > > It is not an indirect argument for MWI because MWI has not provided an > alternative explanation. > > > I don’t believe in MW “I”. MW is just quantum mechanics without collapse. > There is just one unitary evolution, which computable, even linear, and > always local in the Hilbert space. > Local or non-local applies to physical 3-space, or space-time -- using the word for Hilbert space is just a confusion. There are no space-time intervals in Hilbert space -- the metric is all wrong. > The violation of Bell’s inequality shows the inseparability, or > non-locality, but there is no FTL influence. It is up in the believer in > FTL influence to shows them, but as you told me that you don’t believe in > FTL influences, I am not sure what we are discussing. Now, I do believe > that QM-with-collapse does introduce FTL influence, even in the case of > looking to one particle just “diffusing”. If there is a physical collapse > of the position of the particle, it has to be instaneous. > I don't know what you are talking about. All I am asking of you is that if you believe that Aspect's results can be explained by local actions in many worlds, then give me the derivation of the local mechanism. > We might all reject FTL as implausible. But what are you proposing to > replace it? Magic?????? > > > OK. We reject all FTL. You might think that some FTL remains in the MWI, > but just the argument given by Price (although not as general as it could > be) shows why such FTL are just local apparence in the branches where all > resulting Bobs and Alices find themselves into. > The trouble is that Price's argument is just the standard non-local argument from quantum mechanics. He does not make any use of the absence of collapse, or of 'many worlds'. If you do not agree with this, reproduce the argument and show how it differs from the standard quantum argument. We might interpret the wave differently. Of course, from what I have proven > about “digital mechanism”, I expect physics describing only the physical > reality we access to. The wave is epistemic, not ontic. I think that your > problem is that you take the notion of “world” too much seriously. > No, I take the evidence of my experience of the world around me seriously. And physics is the science of trying to understand this. If you dismiss it all as mere appearance, then so be it. But the appearances still need to be explained. > I am ultra-busy, as I teach everyday, (+ a paper to finish), so might be > slow down a little bit. I have just never seen any paper showing that in > the QM-without-collapse, FTL influence exist. Of course, I do not believe > that when Alice makes a measurement, the entire universe is changed. All > interactions are local, and the singlet state only ascribes to Alice and > Bob to the histories were the particle have been correlated, locally at the > start. > But that is the point. Their histories are not correlated *locally* at the start. The correlations do not originate when the singlet state was prepared: the correlations arise only after Alice and Bob have made their measurements. It is their measurement results that are correlated, after all. And these do no exist before they make the measurements. The trouble with your attempted account is that the correlated measurements are made at space-like separations. That is the essential non-locality that you have to explain. And you have never yet managed to do this. You always revert to vague mystical hand-waving. Give me the mathematical derivation of the quantum correlations. 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 everything-list+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/CAFxXSLSXYTwS1URHGPsXgKMZ_H3hxyVMNTZ_zNVWOKyQNM7pXg%40mail.gmail.com.