The EPR paradox was proposed by physicists Albert Einstein, Boris Podolsky, and Nathan Rosen (EPR) in a 1935 Physical Review article titled "Can Quantum Mechanical Description of Physical RealityBe Considered Complete?" The EPR paradox was intended to demonstrate the inadequacy of the prevailing interpretation of quantum mechanics, specifically in regard to the relationships between distant particles predicted by quantum nonlocality. The paradox argues for incompleteness or hidden variables in the quantum mechanical description of nature.

One of the foundations of quantum theory is the uncertainty principle that places limits on the accuracy of measurements on the atomic scale. According to the uncertainty principle, it is impossible to measure two complementary variables such as the momentum and the position of a particle with exact precision. Likewise, the components of a particle's spin cannot be all known simultaneously.

If, for example, two particles...