On Sat, Nov 23, 2019 at 1:14 AM John Clark <johnkcl...@gmail.com> wrote:
> On Thu, Nov 21, 2019 at 7:18 PM Bruce Kellett <bhkellet...@gmail.com> > wrote: > > *>>> I can provide many references which claim that Bell did assume >>>> counterfactual definiteness, and this is the reason why his theorem does >>>> not apply in many-worlds theory. One prominent example is a paper by >>>> Baylock (arXiv:0902.3827).* >>>> >>> >>> >> The abstract says "*The view presented in this paper is that the >>> minimal assumptions behind Bell's inequality are locality and >>> counterfactual definiteness*", so if Bell can derive his Inequality >>> from those assumptions but exparament proves that the Inequality is not >>> true then one or both of those assumptions must be false. That was Bell's >>> entire point, he proposed an exparament to determine if the assumptions >>> were true or not. It turned out they were not. >>> >> >> *> But my point was that Bell did not assume counterfactual definiteness.* >> > > That was your point?? You just said "*I can provide many references which > claim that Bell did assume counterfactual definiteness*"! > You are trolling again. My comment was in answer to your comment that "Bell did not assume counterfactual definiteness" was an obviously silly remark. It was a remark that I made, and continue to make. There are many references, like to the Baylock paper, which claim that Bell did assume this, so it is important to get the facts right -- Bell did not assume counterfactual definiteness because he had no need to do so. And also, because counterfactual definiteness is clearly false for quantum mechanics, it would not be among the list of things he had to assume for his theorem. > *All he *[Bell] *assumed was that any possible hidden variables were >> local. So it is locality that is disproven by the experimental results. >> Nothing about counterfactual definiteness or realism, since Bell did not >> assume either of these things*. >> > > You and Maudlin may believe that but it is certainly a minority viewpoint: > > *"The dependability of counterfactually definite values is a basic > assumption, which, together with "time asymmetry" and "local causality" led > to the Bell inequalities. Bell showed that the results of experiments > intended to test the idea of hidden variables would be predicted to fall > within certain limits based on all three of these assumptions"* > That is false. Bell did assume locality, and also ruled out the idea of retrocausality. But he had no need to assume counterfactual definiteness. If you think he did, then it is up to you to show exactly where in his proof use is made of such an assumption. I am quite sure that you cannot do this; no-one has ever been able to do this because Bell did not make any such assumption. The other overwhelming case against the suggestion that this assumption is necessary for Bell's theorem, and the associated implication that if you do not make this assumption, a perfectly local account of the EPR correlations is possible, is the fact that no one has ever been able to provide this magical local account of the correlations. If you think it is possible, produce it! After years of prompting, Bruno has been unable to produce any such local account. And all the other authors who have made this claim have likewise failed in their attempts to produce the required local account. All these many failures tell very much in favour of Maudlin's and my point that Bell did actually prove that any such local account of the correlations was impossible. > Counterfactual definiteness > <https://en.wikipedia.org/wiki/Counterfactual_definiteness#Many_Worlds> > > >> Bell knew exactly what he was assuming, and Baylock's paper came out >>> 10 years ago but it might just as well have fallen into a Black Hole for >>> all the effect it had on the physics community. It wasn't exactly earth >>> shattering. >>> >> >> > *Yes, Baylock's paper has not received much attention -- basically >> because it is obvious nonsense.* >> > > Then why the hell did you reference it?! Why did you have me waste my time > reading the abstract if you think it's "obvious nonsense"? > So that you could see for yourself that it was obvious nonsense. If all you read was the abstract, then you might have failed to get that point. But that is hardly my fault. > *You are entitled to your own opinions. But you are not entitled to your >> own facts. Physicists do not use the term 'realism' to mean >> 'counterfactual definiteness'.* >> > > If by "realistic" physicists don't mean that an object can be in one and > only one physical state both before and after an interaction, if they don't > mean the ability to speak meaningfully of the results of a measurement that > has not been performed, then what in the world do they mean by "realistic? > You show your ignorance of the relevant literature. Scientific realism is a perfectly well-defined concept. And that is what most people mean by realism -- there exists an objective external world that is the subject of scientific study and our best theories relate to this external reality. * > As Maudlin points out, such abuse of Bell's argument has led to endless >> stupidity in these discussions.* >> > > Maudlin says "*If I had my druthers, 'realist' and 'anti-realist' would > be banned from these foundational discussions*", and that strikes me as a > remarkably silly thing to say. > He is not suggesting the the word be banned totally -- just that it has no place in discussion of foundational issues such as the origin of the EPR correlations. > Regardless of what ones philosophy may be the FACT remains that a word is > needed to express the idea that things can be in one and only one physical > state both before and after an interaction, and a short easily spelled word > like "realistic" seems to fit the bill pretty well, although philosophers > like lawyers generally prefer long Latin phrases for simple ideas. > The trouble here is that you have an unreasonably narrow understanding of the word "realistic". I also think it's very strange that Maudlin's book on quantum physics has > the very word "Philosophy" in its title and yet it spends virtually no time > on the measurement problem, perhaps the greatest philosophical mystery of > all in Quantum Mechanics. Why does the act of measurement seem to override > the evolution of Schrödinger's wave function, and what exactly does a > "measurement" even mean? Many Worlds is the only interpretation that can > give a credible answer to that question. Maybe that's why Maudlin never > asked the question. > Have you actually read Maudlin's book? 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/CAFxXSLT%3DGhjoHeJzLF2wpRGtpbm%2B234AisxrOU7_b4LQEVjEVg%40mail.gmail.com.
