|J(ulius) Robert. 1904--67, US nuclear physicist. He was director of the Los Alamos laboratory (1943--45), which produced the first atomic bomb. He opposed the development of the hydrogen bomb (1949) and in 1953 was alleged to be a security risk. He was later exonerated|
|Oppenheimer (ŏp'ən-hī'mər) Pronunciation Key
American physicist who directed the Los Alamos, New Mexico, laboratory during the development of the first atomic bomb (1942-1945). After World War II, he became an advocate for the peaceful use of atomic energy and opposed the development of the hydrogen bomb.