Art spoke with physicist Sean Carroll about the origin and nature of the universe we live in. Carroll discussed the Big Bang, a scientific theory which proposes the universe came about from a tremendously dense and hot state about 14 billion years ago. He provided evidence for this theory, pointing out that the Big Bang model has been "established beyond reasonable doubt."

Carroll covered other cosmological and theoretical physics topics, including the accelerating expansion of the universe, how space and time came into existence, 'quantum gravity,' parallel universes, string theory, and time travel. He also talked about the recent discovery of an Earth-like planet orbiting a red dwarf star 20 light-years away from our solar system. Carroll said it was unlikely there would be the kind of life there that we could find by using radio telescopes.