Leonard Susskind is the Felix Bloch Professor in Theoretical Physics at Stanford University. He is the author of Quantum Mechanics (with Art Friedman) and The Theoretical Minimum (with George Hrabovsky), among other books. 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 Mountain View, California.