Jagdish Mehra has been, for a long time, University Distinguished Professor of Sciences and Humanities at the University of Houston, Texas, and also served as UNESCO-Sir Julian Huxley Distinguished Professor of Physics and The History of Science, at Trieste and Paris. He has published extensively on the historical and conceptual development of modern physics, and is the author of The Beat of a Different Drum: The Life and Science of Richard Feynman. From Spring 1959 until Schwinger's death Mehra remained his close friend.
Kimball A. Milton is Professor of Physics at the University of Oklahoma, where he leads the theoretical high-energy physics group. He has numerous publications in the area of nonperturbative quantum field theory. He was a student of Julian Schwinger at Harvard, and was his postdoctoral associate at UCLA for nearly a decade.