Einstein said that the wave function does not describe the physical state of a single object, but the possible states of an ensemble. He also said that quantum mechanics is not complete; there must be ...

Quantum mechanics is a weird thing. It says that we can never really know all there is about reality. If we measure a particle, we can't know its exact momentum and position at the same time. If we ...

There’s just enough time left in 2014 to sneak in one more scientific anniversary, and it just might be the most noteworthy of them all. Fifty years ago last month, John Stewart Bell transformed ...

We take for granted that an event in one part of the world cannot instantly affect what happens far away. This principle, which physicists call locality, was long regarded as a bedrock assumption ...