Article written by John Timmer, via https://arstechnica.com
The experiment wasn’t the first to show that local realism isn’t how the Universe works—it’s not even the first to do so with qubits.
If quantum mechanics were right, then a pair of entangled objects would behave as a single quantum system no matter how far apart the objects were.
Hidden variables preserve what’s called “local realism” but turn out not to actually describe our reality.
Physicist John Bell showed that all local variable frameworks limit the degree to which the behavior of quantum objects can be correlated.
But quantum mechanics predicts that the correlations should be higher than that.