Nonlocal classical ‘realism’ and quantum superposition as the nonexistence of definite pre-measurement values of physical quantities

This paper reviews the schemes of experiments in which it was possible to prove, based on measured photon cross-correlation suppression effects in a beam splitter and preparing squeezed states, the nonexistence of a definite value of the photon phase difference in Fock states (otherwise, these two effects cannot exist simultaneously). It is shown that this conclusion emphasizes the internal inconsistency of interpreting the quantum mechanics in the spirit of classical nonlocal ‘realism’ — in the sense that measured physical quantities have no definite values a priori, i.e., before the instant of measurement.