On Thu, Jun 13, 2019 at 10:18 PM Bruce Kellett <[email protected]> wrote:
On Fri, Jun 14, 2019 at 11:32 AM Lawrence Crowell < >> [email protected]> wrote: > > >> >> The dependency of the initial and final states means the >> probabilities are classical and will obey the Bell inequality. This is a >> pretty iron clad result and I am not sure why some people persist in >> thinking they can get around it. >> > > *> That would be a useful result because it would put these retrocausal > models to rest permanently. But how do you prove this?* > You prove it the same way physicists prove anything, by performing an experiment. It makes no difference if Quantum Mechanics is someday superseded by a better theory, if probabilities are classical it would be logically impossible to ever violate Bell's inequality even in theory, but in actuality it is quite easy to do so, you do it every time you put on polarizing sunglasses. > *> The retrocausal argument takes the form given by Price in 1996 ('Time's > Arrow and Archimedes' Point, p.246-7). Price notes that all that you need > is that the production of the particle pairs is governed by the following > constraint: "In those directions G and H (if any) in which the spins are > going to be measured, the probability that the particles have opposite spin > is cos^2(alpha/2), where alpha is the angle between G and H." Price notes > that such a condition explicitly violates Bell's independence assumption.My > problem with this has been that such a condition does not specify any > plausible dynamics that could operate in this way.* Since 1809 we've know from experiment that Malus's law always works, that is to say the amount of light polarized at 0 degrees that will make it through a polarizing filter set at X degrees is [COS (x)]^2. For example if x = 30 DEGREES then the value is .75; if light is made of photons that translates to the probability any individual photon will make it through the filter is 75%. However if *ANY* local hidden variable theory is true Bell proved that the probability must be less than or equal to 66.666%. But 3/4 is greater than 2/3, so Bell's inequality is violated. So local hidden variables are as dead as a doornail. 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/CAJPayv3knYG61NWhQVDDjDu3mW2OB2wvF-8yZ4NFrFXaKmbr5Q%40mail.gmail.com.
