Theoretical physicist Brian Greene is fascinated by time. Is the time we experience in our day-to-day lives real? Is our interpretation of time actually how the world is structured? Could time be broken up into particles like matter? These questions fuel Greene's curiosity, and their most likely answers indicate that time travel into the future is very much possible. But traveling back in time, well, probably not. Greene explains why.
Brian Greene is the chairman of the World Science Festival
, running May 27-31 in New York City.