On Tue, Jun 11, 2019 at 3:53 PM Bruno Marchal <[email protected]> wrote:
> 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]> > wrote: > > 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 > It makes no sense at all! Deutsch has gone completely off the rails over quantum mechanics. He is essentially abandoning the theory as it currently stands. The argument from symmetry is, to my mind, a total killer of any retrocausal explanation -- retrocausality must destroy the very symmetry that is at the heart of the QM predictions for the singlet state, Collapse and many worlds are all irrelevant to this argument. The non-locality of the quantum singlet state is irreducible, and neither retrocausality nor many worlds has any impact on this central conclusion. Bruce > 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 > -- 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/CAFxXSLSNfoujP2NxUMLk4LZ8hJW1_N0F0PXNVmN4MM47pryj4A%40mail.gmail.com.
