Professor Joe Polchinski presents "Gravity and Quantum Mechanics - The Quest for Unification"
Quantum mechanics and relativity tell us that when we look at the very small, the very fast, or the very massive - then space, time, and matter behave in new and exotic ways. Each of these theories works well in its own regime, but in extreme conditions where both theories reign they conflict, and we still do not have a single theory that unites our basic understanding of the laws of physics. We have made a lot of progress, including string theory and the study of quantum black holes, but there are still many puzzling questions. In this talk I will describe what we have learned and some of the seemingly paradoxical puzzles, including the latest - the black hole 'firewall.'