Hans.Moravec@ROVER.RI.CMU.EDU (12/06/85)
The observation that two polarization-correlated photons travelling away in opposite directions from an event are effectively co-incident in either's rest frame (no elapsed time, distance between them Lorentz contracted to zero) is interesting, but irrelevant. Two identical fermions with rest mass (electrons or protons, say) brought very close together acquire opposite spins (because of the Pauli exclusion principle, to be old fashioned) whose measurement later, when they're separated has the same strange correlation properties as the photon pair polarization. But since they have mass, the separation happens at less than the speed of light, and they experience elapsed time and distance.