On Thu, Oct 10, 2024 at 10:48 AM John Clark <[email protected]> wrote:
> On Thu, Oct 10, 2024 at 9:47 AM Giulio Prisco <[email protected]> wrote: > > >> >> *> Thank you for sharing John. I'm already persuaded that local realism >> is untenable, but it is always good to see more experimental evidence.* > > > *Actually what they've proven is that local realism is untenable in a > deterministic universe; that's why this experiment doesn't rule out > objective collapse theories, they are local and realistic but not > deterministic. You can't have determinism and localism and realism, you've > got to get rid of at least one of those 3 things. * > In the setup Bell envisioned (and most other setups where Bell inequality is violated), if the two experimenters both choose the same measurement setting, the laws of QM say they should get identical (or opposite, depending on the type of particle) measurement results with probability 1, despite the fact that these choices can be made at a spacelike separation. So in a local realist theory without superdeterminism (i.e. no statistical correlation between experimenter's choices and detailed states of the particles they are going to measure, prior to measurement), isn't the only way to explain this by supposing the particles already have pre-set matching answers to how they will respond to each measurement setting, with this pre-setting having happened in the past, somewhere in the region of spacetime where their past light cones at the time of measurement are overlapping? In that case even though other aspects of the world (including the experimenter's choices) might be non-deterministic, the particle states that determine their response to different possible measurements must be pre-determined prior to measurement--allowing a non-deterministic "collapse on measurement" wouldn't help solve the problem of a local realist account of how you get this perfect match on trials where the measurement settings are the same. Jesse > > *John K Clark* > > -- > 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/CAJPayv0VCEeiDOyDD9-iwRenUiN3yQGizXCDAUWY3jvy%3Dh2psw%40mail.gmail.com > <https://groups.google.com/d/msgid/everything-list/CAJPayv0VCEeiDOyDD9-iwRenUiN3yQGizXCDAUWY3jvy%3Dh2psw%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/CAPCWU3L89jgX60%3D5N007RL9CsCJpo4sOVYR2mh-_q8d2_eo5Ow%40mail.gmail.com.
