Correlations and Physical Locality

Abstract

Correlations between the behavior of pairs of particles are generated in the following experimental situation. An on-line source emits a stream of two-particle systems, where each system is in one and the same quantum state. After emission, the particles – call then (I) and (II) – move off in opposite directions. Each particle then encounters one of several possible barriers that either it passes or doesn't. A short distance behind each barrier is a detector set to register the presence of the particle, should it get that far. Finally, the detectors are connected by a timed relay and counter that registers a “coincidence count” should the two detectors fire within a set, brief time interval. When the experiment is run with various different barriers, detection rates accumulate for each barrier singly, and coincidence rates (the correlations) for the various pairs of barriers.