Saul Perlmutter is a professor in Berkeley’s Department of Physics and a senior scientist at the Lawrence Berkeley National Laboratory. He is the leader of the Supernova Cosmology Project, an international collaboration of research teams from seven countries measuring the expansion history of the universe.

Brian Greene is a professor of physics and mathematics at Columbia University, and is recognized for a number of groundbreaking discoveries in his field of superstring theory. His books, The Elegant Universe, The Fabric of the Cosmos, and The Hidden Reality, have collectively spent 65 weeks on The New York Times bestseller list.