In this collection of video interviews, top thinkers from the Institute for Advanced Study in Princeton, New Jersey—Einstein's old hangout—grapple with some of the deepest questions in science and other fields. For example, theoretical physicist Edward Witten sounds off about string theory, an attempt to close the gulf between relativity and quantum mechanics; and astrophysicist Sara Seager explains how to divine evidence for extraterrestrial life from measurements of a planet's atmosphere. The discussions are part of Big Ideas, a TV series produced by New York City's public broadcasting station WNET that airs in April and May.