Abstract

The Freedman-Clauser experiment in Berkeley and the Aspect experiment in Orsay were the defining physical experiments demonstrating nonlocal causality in quantum mechanics. They each counted coincidence meaurements on entangled polarized photons from a common source. This article begins with a brief discussion of the quantum mechanics of polarized photons. We show an example of the changes in the count rates when the polarizers are changed under assumptions of local causality. This causes a contradiction with quantum mechanical predictions. The example uses a logical flow and the algebra of inequalities. It constitutes a conditional proof of the Bell inequality. Next we discuss the experimental background and the events leading up to it. We discuss several hypotheses in explanation, of which our favored is the time reversal of cause and effect.