World Science Festival 2009 Time Since Einstein event. Albert Einstein shattered previous ideas about time, but left many pivotal questions unanswered: Does time have a beginning? An end? Why does it move in only one direction? Is it real, or something our minds impose on reality?

This video set up the third part of the conversation between John Hockenberry, Fotini Markopoulou, Sean Carroll, George Ellis, David Albert and Roger Penrose, by looking at why time moves in only one direction. See video of live event here: http://vimeo.com/6435742