Following in the path of his father, J. A. “Dee” Deffeyes, a pioneer of petroleum engineering, Ken Deffeyes collaborated with the best minds at Shell Oil. There, he met and befriended geophysicist M. King Hubbert, creator of the Hubbert’s peak theory. Ken’s career has included breakthrough work in geology, sedimentology, early computer programming, topographic mapping, and creation of Deffeyes’ diagram of natural water chemical equilibrium. He holds a BS in petroleum geology from the Colorado School of Mines and a PhD in geology from Princeton University, where he is now professor emeritus. He is author of four books including Hubbert's Peak: The Impending World Oil Shortage (2001), Beyond Oil: The View from Hubbert's Peak (2005), and When Oil Peaked (2010).