Prominent physicist and Nobel Prize winner Owen Chamberlain, who worked on the Manhattan Project and completed his doctorate in physics at the University of Chicago, died on February 28 from complications of Parkinson’s Disease.

Near the end of World War II, Chamberlain worked under Emilio Segré, a longtime collaborator, the Manhattan Project at Los Alamos. Segré and Chamberlain’s research on plutonium contributed to the creation of Fat Man, the bomb eventually dropped on Nagasaki.

After the Manhattan Project, Chamberlain returned to his graduate work, enrolling at the University of Chicago in 1946. He received his doctorate in 1949.

In 1948, Chamberlain joined the University of California at Berkeley, where he would spend the rest of his career. Alongside Professor Segré, also at UC Berkeley, Chamberlain discovered the antiproton, a negatively charged antimatter equivalent of the proton, a phenomenon that many assumed did not exist. In 1958, Chamberlain was promoted to full professor, and in 1959, he and Segré won the Nobel Prize in Physics for their discovery.

Chamberlain was renowned not only for his Nobel Prize, but also for his teaching skills. A professor at UC Berkeley since 1948 and full professor since 1958, he stressed an informal class atmosphere and always had insightful explanations for difficult concepts. In contrast to his Manhattan Project work, Chamberlain became politically active, involving himself in the Free Speech Movement and anti-Vietnam War rallies of the 1960s.

Chamberlain was born on July 10, 1920 in San Francisco to W. Edward Chamberlain and Genevieve Lucinda Owen. He attended Dartmouth College, graduating in 1941, and began graduate study in physics at the University of California. In addition to being a Nobel laureate, Chamberlain was a member of the National Academy of Sciences, a fellow of the American Academy of Arts and Sciences, and a former Guggenheim fellow.

Chamberlain was diagnosed with Parkinson’s Disease in 1985 and retired from teaching in 1989.