Daniel Sheehan is a professor of physics at the University of San Diego. He has explored experimentally testable challenges to the second law of thermodynamics for more than 25 years. In 2002 he organized the first international conference on the limits to the second law, and in 2005 coauthored the first mainstream treatise on the subject. Financial disclosure statement: In 2015, the author received a U.S. patent on the Epicatalytic Thermal Diode (No. 9,212,828) and collaborates with Pacific Integrated Energy to develop the technology.