John Hersh Seinfeld (born August 3, 1942) is an American chemical engineer and pioneering expert in atmospheric science. His research on air pollution has influenced public policy, and he developed the first mathematical model of air quality, which has influenced air pollution tracking and research across the United States. He has spent his career at the California Institute of Technology, where he is currently the Louis E. Nohl Professor of Chemical Engineering.
Seinfeld grew up in Elmira, New York, and attended the University of Rochester, where he earned a B.S. in chemical engineering in 1964. He then went to Princeton University, where he received a Ph.D. in chemical engineering in 1967. His doctoral dissertation, entitled "Optimal control of distributed-parameter systems," was concerned with the theory of control and optimization of distributed-parameter systems, which are systems governed by partial differential equations.
Seinfeld joined Calt