In 1935 Einstein, Podolsky, and Rosen publish "Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?": since measuring one entangled particle instantaneously determines the outcome for the other regardless of distance, and no influence can propagate faster than light, they argue quantum mechanics must be incomplete, requiring hidden variables. In 1964 Bell shows local hidden-variable theories make experimentally distinguishable predictions; later experiments (Aspect, 1982) confirm nature violates Bell's inequalities. The EPR paradox, designed to refute quantum mechanics, becomes the starting point of quantum information, cryptography, and computing.