Bernstein studied at Harvard University, receiving his bachelor’s degree in 1951, masters in 1953, and Ph.D. in 1955, on electromagnetic properties of deuterium, under Julian Schwinger. As a theoretical physicist, he worked on elementary particle physics and cosmology. A summer spent at the Los Alamos National Laboratory led to Bernstein taking a position at the Institute for Advanced Study, in Princeton. In 1962, he became a faculty member at New York University. From there he moved to become Professor of Physics at Stevens Institute of Technology in Hoboken, New Jersey, in 1967, a position that he continues to hold as Professor Emeritus. He has held adjunct or visiting positions at the Brookhaven National Laboratory, the European Organization for Nuclear Research (CERN), Oxford University, the University of Islamabad, and the Ecole Polytechnique. Additionally, Bernstein was involved in Project Orion, a study conducted by NASA, the US Air Force, and the Defense Advanced Research Projects Agency (DARPA), which investigated the potential for nuclear pulse propulsion for use in space travel.

Bernstein is also a popular science writer and profiler of scientists. He was a staff writer for The New Yorker from 1961 to 1995, authoring scores of articles. He has also written regularly for The Atlantic Monthly, The New York Review of Books, and Scientific American, among other publications. His books include Physicists on Wall Street and Other Essays on Science and Society (2010), Nuclear Weapons: What You Need to Know (2010), Quantum Leaps (2009), Hitler’s Uranium Club: The Secret Recordings at Farm Hall (2000), In the Himalayas: Journeys through Nepal, Tibet, and Bhutan (1996), and more than two dozen books in all. The Life It Brings, an autobiographical memoir, was published in 1986. Bernstein’s biographical profiles of physicists, including Robert Oppenheimer, Hans Bethe, Albert Einstein, John Stewart Bell and others, draw on his experiences of personal acquaintance. Bernstein’s latest publication is A Bouquet of Dyson: and Other Reflections on Science and Scientists (2018).