On Monday, April 23, 2018 at 1:50:31 AM UTC, Bruce wrote: > > From: Brent Meeker < <javascript:>meek...@verizon.net <javascript:>> > > > On 4/22/2018 9:19 AM, Bruno Marchal wrote: > >> It follows from both QM and Comp. If Alice and Bob are space-separated, I >> cannot even makes sense of how you can measure correlations, given that >> once they are separated, whatever result they got, will be shared with >> different Alice and Bob in different branch. I am not even sure we can >> define what could be an action at a distance in the quantum formalism. The >> notion does not even makes sense when we assume special relativity. The >> only reason to believe this is the habit to think that there is only one >> bob and one Alice, which makes no sense once separated, unless they are >> correlated with a third observer, but then, again by looking at the wave >> without collapse, there will be no action at a distance. The no locality is >> only an appearance due to the fact that we belong to infinities of >> histories, and cannot known which one we are in. >> >> It depends on what you mean by "action at a distance". The theory you > are depending on for these pronouncements entails that, on a MW picture, > some of the possible worlds have probabilities that go to zero as a result > of an interaction at Alice or at Bob. So an interaction at one of them > changes the probabilities at the other. > > > For Bruno, it seems that "non-locality" means "action at a distance", > where he interprets that to mean that there is some superluminal transfer > of information, by tachyons or some such. And he is quite right to say that > there is no such interaction or dynamics in quantum theory. Because if > "non-locality" meant some superluminal transfer of information, by > particles or something else, then that would be giving a *local* > explanation of non-locality, which is a contradiction. So non-locality can > never mean "action at a distance", it can only mean that the theory is such > that the state is not separable, and changing one end automatically changes > the other, just as pushing one side of a billiard ball moves the other side > as well. (Ignoring the problems of a relativistic explanation of extended > physical objects. This is not a particularly good analogy, but it is the > best I can think of at short notice!) In quantum mechanics, there can be no > "mechanical" explanation of the non-locality inherent in the non-separable > state. That is why we call it "non-locality" rather than "action at a > distance". > > I acknowledge that there are linguistic problems here, but that is just > the nature of quantum mechanics, and we have to live with it. Trying to > "explain" this fact further is bound to fail, because there is no deeper > explanation. > > Bruce >
Let's agree that electrons A and B form a singlet entangled system. Let's further agree that they are non separable. What do you do with the fact that when their spins are measured, they ARE in different spatial locations, not even space separated in Bell experiments. How do we deal with this FACT? AG -- 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.
