Mario Livio is a senior astrophysicist at the Hubble Space Telescope Science Institute. His books include: "Is God a Mathematician?" and "Brilliant Blunders: From Darwin to Einstein — Colossal Mistakes by Great Scientists That Changed Our Understanding of Life and the Universe." This interview is edited and produced with music and other features in the On Being episode "Mario Livio — Mysteries of an Expanding Universe." Find more at onbeing.org.