This is a rebroadcast of an interview that originally aired on October 26, 2016.  Dark matter. Black holes. Parallel universes. Astrophysics continues to get more intriguing, and more challenging. Astrophysicist Neil deGrasse Tyson, director of the Hayden Planetarium, has teamed up with two of his fellow professors at Princeton University, Michael Strauss and J. Richard Gott, to clear up the confusion in their new book Welcome to the Universe: An Astrophysical Tour, which covers fundamental questions about the birth of the universe and explains the latest discoveries by modern astrophysicists.