Peering Into the Cosmos with Brian Greene

In NOVA's latest four-part series, physicist Brian Greene covers an astonishing swath of material in the world of physics: quantum mechanics, general relativity, lightspeed and gravity and search for elusive subatomic particles. The series is based on his book Fabric of the Cosmos. This week, Hari caught up with Greene to discuss the first installment of the series, "What is Space?"