Were you told that our world is nonlocal?

Brief description of the event

Gilles Brassard is full professor at Department of Computer Science and Operations Research at University of Montreal. Currently, Gilles Brassard is a visiting professor at ETH. He is worldly known for his fundamental contributions to quantum cryptography. Together with Charles Bennett he invented the BB84 protocol, the first quantum cryptography protocol which enables safe quantum key distribution. Moreover, Prof. Brassard contributed to the study of quantum teleportation in the nineties.

Abstract

One of the most surprising aspects of quantum theory is that it tells us that we live in a nonlocal universe in which random correlations seem to appear instantaneously between arbitrarily distant locations. This idea was completely abhorrent to Einstein, who dismissed it as “spooky action at a distance”, yet the 2022 Nobel Prize in Physics was awarded for experimental demonstrations half a century ago of this phenomenon, exactly 101 years after Einstein's Nobel Prize was awarded for quantum theory. It is even said that so-called loophole-free experiments confirmed nonlocality beyond any reasonable doubt. But have they really? In this talk, I shall argue that no experiment whose purpose is to confirm the predictions of quantum theory can possibly be used as an argument in favour of nonlocality because any theory of physics that does not allow instantaneous signalling to occur and has reversible dynamics (such as unitary quantum theory) can be explained in a purely local and realistic universe. What if Einstein was right after all?... Once again!

This talk is based on the original doctoral work of Paul Raymond-Robichaud while under my supervision, which was published in the journal Entropy and is available open access at this adress.