On Friday, April 20, 2018 at 3:37:48 PM UTC, [email protected] wrote: > > > > On Friday, April 20, 2018 at 2:54:25 PM UTC, [email protected] wrote: >> >> >> >> On Friday, April 20, 2018 at 12:00:25 PM UTC, Bruce wrote: >>> >>> From: <[email protected]> >>> >>> >>> >>> *Does entanglement -- which occurs whenever two systems interact -- >>> imply non-locality? AG* >>> >>> >>> Not necessarily. If there is a common cause explanation of the >>> correlation, as in classical physics where particles always have definite >>> momenta, then there is no need for a non-local explanation. >>> >> > I forget. In classical elastic scattering of two particles, do the > outgoing particles have definite momenta, equal and opposite of the > incoming particles, or what? >
Sorry; that result is just for direct impacts. If not direct, IIRC the equations of motions yield definite results for the outgoing particles. CMIIAW. AG > In the quantum treatment, defined by including uncertainty in momenta, > does non locality arise due to inherent nature of the WF, which is a > superposition where the states of the subsystems (the two particles) are > indeterminate prior to measurement? AG > > >> However, in quantum systems such as the singlet state of entangled >>> spinors, then no common cause or hidden variable explanation is available >>> and we have non-locality. >>> >>> Actually a similar thing happens in any collision between two quantum >>> particles. If we assume an elastic collision, the outgoing particles will >>> be in the form of outgoing spherical waves -- neither the individual >>> momenta or directions are specified by the collision itself. So observing >>> the direction and/or momentum of one particle determines the direction and >>> momentum of the other remote particle. There is no common cause or hidden >>> variable explanation available for this, especially if the observations are >>> at space-like separations. However, as far as I know there are no Bell-like >>> inequalities that are violated by the statistics in this case, >>> >> >> Shouldn't there be such violations? AG >> >> >>> so the non-locality is not always obvious. Interestingly, this forms the >>> basis for an important measurement tool at high energy accelerators. Often >>> the output from experiments will be in the form of a missing mass plot, >>> which is constructed by summing the momenta of the observed particles and >>> determining what is missing. This can then be the basis of a search for >>> undetectable or new particles. >>> >>> 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]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
