More at philosophytalk.org/shows/reality-time.

St. Augustine suggested that when we try to grasp the idea of time, it seems to evade us: "What then is time? If no one asks me, I know what it is. If I wish to explain it to him who asks, I do not know." So is time real or merely an artificial construct? Is time a fundamental or emergent property of our universe or a part of our cognitive apparatus? Do we live in a continuum with a definite past and present, or do we live in a succession of ‘Nows’, and if the latter is the case, how does it affect our perception of memory or recollection? John and Ken take their time with Julian Barbour from the University of Oxford, author of "The End of Time: The Next Revolution in Physics."