Rosen was born in London, England in 1933 and became a U.S. citizen in 1972. He received his doctorate in physics from Oxford University in 1957. He was a professor of physics at Purdue University from 1962-1984. He was the assistant division head of nuclear and particle physics at the Los Alamos National Laboratory from 1983-1990. He was a professor of physics at the University of Texas at Arlington from 1990-1996 serving as the dean of science. Dr. Rosen finished his career as associate director of the Office of High Energy and Nuclear Physics from 1997 to 2003.