Why does the universe exist? And is that even a sensical question to ask? Philosopher Jim Holt has written extensively for publications such as the New Yorker, the New York Times and Harper's, and most recently embarked on this "existential detective story" in his new book, "Why Does the World Exist?: An Existential Detective Story" Jim discusses his book with Massimo and Julia in this live episode of Rationally Speaking, taped at the 2013 Northeast Conference on Science and Skepticism in New York City.