> On 10 Jun 2019, at 08:54, Bruce Kellett <[email protected]> wrote: > > On Mon, Jun 10, 2019 at 4:34 PM Philip Thrift <[email protected] > <mailto:[email protected]>> wrote: > On Sunday, June 9, 2019 at 11:52:02 PM UTC-5, Bruce wrote: > On Wed, Jun 5, 2019 at 11:25 PM Philip Thrift <[email protected] <>> wrote: > On Wednesday, June 5, 2019 at 7:56:41 AM UTC-5, Philip Thrift wrote: > On Wednesday, June 5, 2019 at 6:45:32 AM UTC-5, Lawrence Crowell wrote: > On Tuesday, June 4, 2019 at 10:22:51 PM UTC-5, Bruce wrote: > On Wed, Jun 5, 2019 at 1:15 PM Philip Thrift <[email protected] <>> wrote: > > As for quantum stochastic retrodependency (which physicists avoid like > vampires avoid sunlight), it simplifies the "puzzles" of QM, meaning that, > for the most part, the articles you see talking about the "spooky action at a > distance" or "many wolds" of QM you can dump in the trashcan and save a lot > of time! > > The trouble is that these retrocausal "explanations" do not actually explain > anything! They sound like they should: "The formation of the EPR pair depends > on the future setting of the polarises as well as on the state preparation." > (Or something similar). But no detailed dynamics are ever given, and the > supposed explanation is even more mystical than "spooky action at a > distance...." > > Bruce > > Bingo --- ting ding ting ding ... . Thanks Bruce. Since QM is time symmetric > or invariant in its form with respect to time direction whether you define > time forwards or backwards, or do so for some partition of a density matrix > or wave, makes no difference. Retrocausality in effect solves nothing. > Nonlocality and the contextual nature of QM, eg the Mermin-Peres square that > gives Kochen-Specker, have no definition with respect to any time direction. > If you have locality in QM then it is still not possible to think > meaningfully of counterfactual definiteness (CFD), or if QM is regarded as > nonlocal only then can you have CFD, such as with Many Worlds Interpretation. > It makes no difference whether the observables measured are considered > forwards or backwards evolving. > > LC > > > Retrocausality in effect solves nothing. > > It solves wasting any time reading papers about QM many worlds, non-locality, > all the nonsense you read today. > > [If one views QM as a generalized measure on a space of histories, then one > sees not only how quantal processes differ from classical stochastic > processes (the main difference, they satisfy different sum rules), but also > how closely the two resemble each other.] > via Rafael Sorkin > > @philipthrift > > > Anyway, as you know well, I "adopted" the retrocausal view 20 years ago via > Victor J. Stenger, who pointed of course to Huw Price. > > > Apart from not solving anything, and the problem of the absence of any > dynamical explanation as to how retrocausality might work to eliminate > non-locality, the real problem is that retrocausal explanations have been > ruled out experimentally. > > The seminal experiment by Aspect, et al., published in 1982 really put the > last nail in the coffin of retrocausal explanations. The point is that in > Aspect's experiment, the polariser settings were chosen while the photons > were in flight -- in other words, at some time after the singlet pair was > created. So there is no way the photons, travelling back in time at the speed > of light, could ever reach the original singlet state after they had detected > the polariser setting. The best they could do would be to carry the polariser > setting back half way, but no way could they reach back to the interaction > that created the original singlet state. > > So all these years, Huw Price and his cronies have been talking absolute > rubbish -- their theory has already been falsified by experiment. > > Bruce > > > Rubbish. A complete misunderstanding of quantum mechanics. > > Retrocausal hidden variable models are completely compatible with > experiments, unless QM itself is wrong. > > If retrocausality is right, then QM itself is certainly wrong. In the EPR > situation, the singlet state is rotationally symmetric in standard QM, and > this cannot be the case if that state is dependent on the future polariser > settings. Conversely, if QM is right, retrocausality is impossible.
If QM with collapse is right, I would understand and agree. That is why Deutsch see the “retrocausality” has a semantic variant of the many-worlds interpretations, but I have not entirely figure out if this makes sense in the Omnes-Griffith-Gelman-Hartle view of the many-worlds. That would be nice and eliminate t’hooft’s need of “super-determinism” (mechanism is trivially "super-deterministic" in the third person view, but not at all in the first person views—that plays a role for free-will/self-determination). 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 [email protected] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/CAFxXSLQDF3yRJo48%3DS613zjst1Sh1-Wu7qTjjdWBQvCOW_SFWA%40mail.gmail.com > > <https://groups.google.com/d/msgid/everything-list/CAFxXSLQDF3yRJo48%3DS613zjst1Sh1-Wu7qTjjdWBQvCOW_SFWA%40mail.gmail.com?utm_medium=email&utm_source=footer>. -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/775C9AA5-20C3-4067-859D-6A86D3291077%40ulb.ac.be.
