> On 23 Apr 2018, at 05:43, Brent Meeker <[email protected]> wrote: > > > > On 4/22/2018 6:50 PM, Bruce Kellett wrote: >> From: Brent Meeker <[email protected] <mailto:[email protected]>> >>> >>> 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,
I prefer to distinguish non-locality (inseparability), action at a distance, and transfer of information at a distance. Even in a mono-universe theory, the action at a distance exists (by EPR-BELL) but cannot be used to transfer information. But in the multiverse, we have the inseparability, but we don’t have any action-at-a-distance. At least that is what I am arguing for. >> 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. Of course, I do believe that there is a deeper and simpler explanation. QM seems very plausibly be only how the numbers can structured arithmetic from their indexical internal points of view. It is the canonical logic, imposed by incompleteness, on what is observable ([]p & <>t (& p)) for them. > > I think one way to look at it is, if a hidden variable explanation requires > that the hidden variable be FTL, then the phenomenon is non-local. > > If find it hard to see how Bruno can say whether or not his theory is > non-local since he has not derived any concept of space, time, and a Lorentz > metric. I would think that would be a minimum before you could claim a > theory had not FTL signaling. I was not reasoning in any theory. I was just saying that EPR-BELL entails non-locality only in hidden variable theories in a mono-universe theory, but that deriving action-at-a-distance, from EPR-BELL in one branch of the multiverse is not valid (without assuming Mechanism). It is pure applied logic. Of course, all physical theories which assumes any number of universe different from zero are wrong, so even Everett is wrong, but that is another chapter of metaphysics, and I am not there in this discussion in physics (not to confuse with metaphysics unless we put the Aristotelian metaphysics in the hypothesis, which many do that implicitly. Bruno > > Brent > > -- > 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] > <mailto:[email protected]>. > To post to this group, send email to [email protected] > <mailto:[email protected]>. > 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
