Nonlocal realism considered for entangled photons

Experimental measurements of entangled photons have enabled effective probing of foundational principles of physical law, Quantum Mechanics (QM) in particular. When it was noted that QM is non-local and precludes certain real properties, change in the description of basic phenomena was required. Bell's Inequality work clarified this conflict with Local-Realistic descriptions but left open whether locality, realism, or both should be abandoned. More recent investigations consider models that maintain forms of non-local realism as alternatives to QM. Problems with those are illustrated here, and support a non-local QM description of entangled photons having non-determinate properties.