The 'proof' you refer to is likely Bell's theorem and friends: "Bell's Theorem states that the predictions of quantum mechanics cannot be reproduced by any loc

The 'proof' you refer to is likely Bell's theorem and friends: "Bell's Theorem states that the predictions of quantum mechanics cannot be reproduced by any local hidden variable theory.": https://en.wikipedia.org/wiki/Bell_test_experiments https://en.wikipedia.org/wiki/Bell_test_experiments https://en.wikipedia.org/wiki/Bell's_theorem https://en.wikipedia.org/wiki/Bell's_theorem edit: the theorem has been fairly thoroughly experimentally tested and still holds.