PHYSICS COLLOQUIUM: Philosophy of quantum theory: Why all the options are puzzling - Associate Professor Simon Friederich (Groningen)

PHYSICS COLLOQUIUM: Jointly advertised by the HPI SCHOOL 

In this talk, I present three different puzzles, one for each of the three major avenues of interpreting quantum theory: Everettian ("many worlds"), anti-realist ("Copenhagenian"), and "hidden variables." I also explore the prospects for solving these puzzles.

For the Everett interpretation, the puzzle I consider is why the modulus squared of the wave function should play the role of probability. As a candidate response, I consider a proposal by Charles Sebens and Sean Carroll based on "self-locating belief" theory, but I argue that it fails. For the anti-realist avenue, the puzzle I consider is whether it really makes sense to assume, as many anti-realists do, that some function of position and momentum has a value whereas position and momentum themselves don't. In response, I consider whether the idea that we live in a computer simulation might help us by providing a model for how such talk may make sense. For the hidden variables avenue, the puzzle I consider is how any interpretation that assigns simultaneous sharp values to position and momentum can possibly be empirically adequate. I sketch how Bohmian mechanics avoids this problem and how the Bohmian solution is mirrored in a new approach through phase space that has recently been proposed by two Melbourne physicists, which has better prospects for being compatible with relativity theory.