Lorraine Ford Hi Lorraine, this interpretation the qbism is interesting, here is a discussion on facebook with sone thinkers about the different interpretations of our QM, personally I like the copenaghe school and its pure determinism and in adding deeper parameters that we cannot still measure due to limitations,
See this discussion , the professor Hooft explains his viewpoints and Tim Maudlin too,
Cristi Stoica Obviously, to expand from QM to the phenomena of QFT, and then to bring in gravity. Lot's to do.
Gerard 't Hooft
Tim Maudlin If I look at my laptop, I know that the probability of finding another laptop within 1 km is very high, but if you search a light year away from me, the probability of finding a laptop is very small. But I wouldn’t call that non-locality; the laws that control my laptop are entirely local. The fact that we actually have quantum mechanics there doesn’t change a thing. The commutators in a QFT are exactly like this: correlation functions are non-local but the physical laws are local
Gerard 't Hooft Of course you wouldn't call that non-locality. No one would. So I can't understand why you would make that comment. The distribution of laptops does not violate any Bell Inequality. The outcomes of various experiments on photons do. I really have no idea at all what you are trying to convey here, since what your write makes no contact with the issue of violating Bell's Inequality, which cannot be (reliably) done by any local theory.
Peter Warwick Morgan
Gerard 't Hooft My apologies for leaping in here, but to me it seems important to keep in mind that commutators in QFT are trivial at space-like separation, so Vacuum Expectation Values at space-like separation 𝘢𝘳𝘦 exactly like correlation functions, but because commutators in QFT are nontrivial at time-like separation VEVs will in general have an imaginary component, so that VEVs then do not have a direct correlation function interpretation. It seems to me that signal locality is very nearly assured by QFT (up to the issue discussed by Sorkin in arXiv:gr-qc/9302018v2), but any locality that is more demanding than signal locality is more difficult.
The following may be tl;dr, but to construct correlation functions at time-like separation —which we have to do because we can construct auto-correlation functions at time-like separation, which we will want to model— it seems we either (1) use collapse of a quantum state to construct correlation functions at time-like separation; or (2) use the dual construction of projecting subsequent measurements to the eigenspaces of the earlier measurements (the duality is elementary, but my "The collapse of a quantum state as a joint probability construction" in JPhysA 2022 suggests some consequences); or (3) construct a classical random field and an ancillary transformation algebra that derives from the Poisson bracket, which together give us an algebraic structure that is isomorphic to the QFT measurement algebra (which you can see exhibited in a reply to my comment above for the free EM field); or, inevitably, (4) use some other construction.
That third construction seems to me close in spirit to the algebraic probability component of your approach to superdeterminism, however it differs by suggesting that we can stop short of superdeterminism by insisting on the same noise-everywhere-and-at-all-scales as we have become accustomed to in the algebraic probabilities of QFT. [You last looked at my work, that I know of, about five years ago, in a thread in which you also engaged with Tim Maudlin, when you decided that there was nothing to see; I invite you to see whether that is still true.]
Gerard 't Hooft this discussion between you all is very interesting and appears to analyse the complexities of our QM , non locality and QFT . Tim Maudlin emphasizes that QM implies correlations non local wich violate Bells inequality and Gerard Hooft counters in telling that the laptop distributions don t violate this Bell s inequality
but that some experiments do , that implies deeper issues for this QM and the violations when we make experiments . Peter contributions with the commutators in QFT with the space and time separations are interesting for the signals locality in QFT , and so there are challenges to analyse and maybe it is the key with deeper experiments like Gerad Hooft told , that implies various approachs at my humble opinion about the collapses of quantum states and measurements. So it is relelevant when we add the Hooft aapproach and the superdeterminism and the algebraic probability if we treat the noise in the method.
Happy to see this kind of discussions, regards
what kind of experimens can be made to have proofs about the QM and its implications and these different views on locality, Some Bell s tests probably and loophole free bell tests. The quantum entanglement also is a road , that can challenges the notions of locality . There are also roads in analysing the behavior of particles after measurements for the entagled partners and so we analyse the observations and the retrocausality . The fact to test the local realism and the QM seem essential after all . The contextuality of experiments seem important also for the QM and so we can consider the local properties, and the experimental context also . The idea of Peter for the time like separation and its correlations is interesting if in the exoeriments the measure correlations are considered for the locality , there are also roads at high energy collisions to see the comportments of particles and interactions from the QFT and we can in the same time compute the experiments to verify the theoretical predictions with high precisions in the measurements , in all cases the nature of the QM and its relations with this locality seem very important to better understand how to interpret it .