**Paul J. Nahin *is emeritus professor of electrical engineering at the University of New Hampshire. He is the author of many popular math books, including most recently In Pursuit of Zeta-3: The World's Most Mysterious Unsolved Math Problem *; Hot Molecules, Cold Electrons: From the Mathematics of ...

**Paul J. Nahin *is emeritus professor of electrical engineering at the University of New Hampshire. He is the author of many popular math books, including most recently In Pursuit of Zeta-3: The World's Most Mysterious Unsolved Math Problem *; Hot Molecules, Cold Electrons: From the Mathematics of Heat to the Development of the Trans-Atlantic Telegraph Cable; and How to Fall Slower Than Gravity: And Other Everyday (and Not So Everyday) Uses of Mathematics and Physical Reasoning (all Princeton).