In this Sean Carroll speech, the cosmologist engages in an entertaining discussion that questions the earth's existence, specifically honing in on the notion of time.
Discussing a topic that could be perceived as exceedingly confusing and difficult to grasp by those without a science background, Sean Carroll is effective in clearly expressing himself and the points he makes about the universe and the existence of time. He explains how it was recently discovered that our world is accelerating; each universe moving away from one another as time goes on.
He then introduces the concept of dark energy. The idea here is that empty space itself has energy, regardless of whether or not anything exists in that space.
Carroll concludes with the most important point of the speech; the big bang theory may in fact not be the beginning of the universe.