In the 1970s he founded and became President of Digital Pathways. In 1972 he published a textbook on classical electrodynamics that has become a standard reference for intermediate and advanced students for its particularly clear exposition of the basic physical principles of the theory. In 1991, he became Associate Director of High Energy and Nuclear Physics at Brookhaven National Laboratory. At the same time, he rejoined the Columbia faculty as Professor of Physics. He became I. I. Rabi Professor of Physics in 1994 and retired as Rabi Professor Emeritus in 2000. He spent his retirement years in Ketchum, Idaho, and died August 28, 2006 at a Twin Falls, Idaho, nursing home after struggling with Parkinson's disease and hepatitis C.