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 ...

Some ideas about the quantum world appear to suggest there are many versions of you spread out across many parallel universes. Now, two scientists have formulated a proof that attempts to show this is ...

For more than 60 years, Bell's theorem has been the gold standard for demonstrating that quantum mechanics defies the rules ...

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 ...