On the Nature of Time According to Modern Physics

This is the Annual Sir Thomas Gresham Lecture. What does modern physics have to say about the meaning of time? Is it a fundamental feature of reality or merely an emergent property from something deeper? Does time flow, and is the present moment special when Einstein tells us that all times coexist. Where does the arrow of time come from if all the fundamental laws of physics are symmetric in time? This lecture will examine many of these issues and give our best guess answers as we understand the universe today.