THE INTERFERENCE OF LIGHT AND THE BELL THEOREM

The intensity interference of light waves observed with photon counters and coincidence circuits gives a clear demonstration of the Bell's theorem, which states that in general it is impossible to ascribe a priori definite properties to quantum objects - the light waves, in the present example. Several possible experimental procedures with 2,3 or N observers are described in detail, as well as their tentative interpretations by various classical models and quantum theory. Alternative formulations of the Bell's theorem such as the N-particle Bell inequalities, the Bell theorem without inequalities, the Kochen-Specker theorem are also considered.