Klein was born in the
Bronx,
New York City. He was an only child and both his parents were schoolteachers. After graduating from
James Monroe High School at the age of 14, he attended
Columbia University, where he received a bachelor's degree in
mathematics in 1942 and a master's degree in physics in 1944. In 1948, he received a Ph.D. in physics under
László Tisza at the
Massachusetts Institute of Technology (MIT). From 1949 to 1966, Klein was a member of the staff of the physics department of Cleveland's
Case Institute of Technology, starting as an instructor and becoming a full professor in 1960. Throughout the 1950s, he became more interested in the history of physics. During this time, Klein contributed to the Theoretical Physics Department at the
Dublin Institute for Advanced Studies. During the academic year 1958–1959 he was a
Guggenheim Fellow at the
Lorentz Institute of the
University of Leiden. He joined
Yale University's Department of the History of Science and Medicine in 1967 and in 1971 became the chair of the department. In 1977, due to fiscal concerns, Yale University eliminated the department and Klein became a professor in the physics department, where he remained until his retirement. From 1963 to 1979, Klein wrote 20 articles devoted exclusively to Einstein's work. From 1988 to 1998, he was the editor-in-chief of
The Collected Papers of Albert Einstein under the aegis of
Princeton University Press. The
Einstein Papers Project started in the mid-1970s and published 2 volumes before Klein took over. He led the team that produced volumes 3 through 6, covering Einstein's papers from 1909 through 1917. At Yale University, he was the Eugene Higgins
emeritus professor of the
history of physics and of physics. He was elected to the
Académie Internationale d'Histoire des Sciences (1971), the
National Academy of Sciences (1977) and the
American Academy of Arts and Sciences (1979). In 2005 Klein was the first recipient of the
Abraham Pais Prize for the history of physics, a joint award of the
American Physical Society and the
American Institute of Physics. His doctoral students include
Russell McCormmach. He died in
Chapel Hill, North Carolina. ==Publications==