Leonard Susskind is the Felix Bloch professor of Theoretical Physics at Stanford University. He is a member of the National Academy of Sciences and a recipient of the Dirac Medal, the Galileo Medal, and the Carl Sagan Prize for Science Popularization, among numerous other honors. He is the author of the New York Times-bestselling The Theoretical Minimum series. He lives in Palo Alto, California. 
   
Art Friedman is a data consultant who previously spent fifteen years at Hewlett-Packard as a software engineer. A lifelong student of physics, he lives in Murphys, California.