> On 11 Aug 2018, at 02:49, Bruce Kellett <bhkell...@optusnet.com.au> wrote: > > From: Bruno Marchal <marc...@ulb.ac.be <mailto:marc...@ulb.ac.be>> >> On 9 Aug 2018, at 14:03, Bruce Kellett <bhkell...@optusnet.com.au >> <mailto:bhkell...@optusnet.com.au>> wrote: >>> >>>> Without collapse and FTL potential, or FTL (non-local) hidden variable >>>> theory, how do you interpret the singlet state? >>> >>> That is actually a rather strange question. How do you think I might >>> interpret the singlet state? I think that I have been talking about it here >>> for long enough for you to have worked it out. The singlet state is a >>> non-separable state that is symmetric under rotations about the axis >>> between the particles. However, that symmetry will generally be broken by >>> any interaction with one or other of the constituent particles. >> >> But it is here that I suspect you introduce some collapse. > > The interaction with one particle reduces the symmetry of the non-separable > state so that it becomes separable.
Locally, and from the observer viewpoint, not in the big picture, as nothing is ever reduced. The superposition does not disappear. > You might call this a "collapse" if you wish, but this is an epistemological > collapse, not an ontological one. It is the nature of the state representing > one's knowledge that changes (the old state "collapses" with the advent of > new knowledge). Then I agree. That makes things local, and personal somehow. You get close to “my” version of the many-mind account. > But that is purely epistemological, and does not involve any FTL information > transfer. That’s my point. > It is just as if the probability that your horse will win the race > "collapses" when you find out, after the race has been run, that it came last! > > >>> In particular, the symmetry is broken by the imposition of a directional >>> magnetic field, as in a Stern-Gerlach magnet used to measure the spin >>> component of one of the particles in the direct defined by that external >>> magnetic field. >>> >>> The singlet is strongly non-separable, so this external interaction with >>> one of the constituents is instantaneously felt by the other component >>> particle. >> >> How could this be verified? > > It is verified by the Freedman-Clauser and Aspect experiments (and many other > more recent experiments). This tests only the non separability issue. Not the existence of a physical FTL in our branch. That follows from what you say above. > >> Any verification possible will need further interaction, and we can see only >> the branche of the universe our own result have spread on. > > The verification comes from the results of remote experiments -- and those > results do not change during the time it takes for the experimenters to come > together to compare findings. Those results makes just Alice and Bob knowing which branches they belong too. The non-locality is a global notion on the full wave/multiverse, but the FTL are needed only if we associate the mind on Bob and Alice to the same branche, which has no meaning for me once they are space separated. But we know we disagree on how to interpret the singlet state in the MW frame. > > >>> That non-local influence is the essence of the non-separability of the >>> state -- it is a unit, and any interaction with a part is an interaction >>> with the whole. >> >> That looks magical to me, and as I said, I am not sure this can be verified. >> Aspect-like experiment do not verify this for sure. > > It might look magical to you, but that is because you have not really > accepted the true weirdness of quantum theory. The Aspect-like experiments > certainly do verify this -- why else do you think that these experiments were > performed? To verify QM’s prediction. After Aspect, the choice is between determinacy+locality+many-worlds or one world + 3p indeterminacy, 3p physical FTL. > > There is some interesting history here. When Clauser first encountered the > Bell results (through his interaction with people like Abner Shimony), he > thought that quantum mechanics must be wrong, and that the inequality must be > satisfied. Yes. Bell himself was hoping for that, and was willing to abandon Special relativity. De Broglie also, well before. De Broglie stated once that the “action at a distance” would not work on distance bigger than an atom. It is shocking indeed, but less so with the MW, where the apparent action at a distance is explained by the portioning on the multiverse related to the local choice of spin direction. > His motivation for doing the original Freedman-Clauser experiment was > actually to make his fame and fortune by proving that quantum mechanics was > wrong -- that its predictions for the singlet sate would not be > experimentally verified. History tells a different story…….. Yes. QM’s prediction are very robust. Bruno > > 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 > <mailto:everything-list+unsubscr...@googlegroups.com>. > To post to this group, send email to everything-list@googlegroups.com > <mailto:everything-list@googlegroups.com>. > Visit this group at https://groups.google.com/group/everything-list > <https://groups.google.com/group/everything-list>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- 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.
