Manhattan Project J. Robert Oppenheimer was the scientific director of the Manhattan Project, the top-secret World War II program which developed the world ' s first atomic bomb. Oppenheimer was an unusual personality: intensely brainy and ambitious and yet distinctly philosophical, with a facility for languages and an interest in Eastern religions and philosophy. In the 1930s he taught physics at both Caltech and the University of California at Berkeley, before being chosen to lead the Manhattan Project ' s team of scientists. The first atomic bomb was exploded on 16 July 1945, and less than a month later President Harry S. Truman ordered two bombs dropped on Japan, ending World War II. After the war, Oppenheimer became head of the General Advisory Committee of the U. S. Atomic Energy Commission. As such, in 1949 he recommended against the development of the super-powerful hydrogen bomb, pitting him against fellow physicist and H-bomb proponent Edward Teller. n 1953, during the era of intense anti-communism fomented by Senator Joseph McCarthy, Oppenheimer was accused of being a communist sympathizer, based on his support of various pro-communist and left-wing groups during the years before and during WWII. ncreasingly concerned about the potential danger to humanity arising from scientific discoveries, Oppenheimer joined with Albert Einstein, Bertrand Russell, Joseph Rotblat and other eminent scientists and academics to establish what would eventually become the World Academy of Art and Science in 1960. Significantly, after his public humiliation, he did not sign the major open protests against nuclear weapons of the 1950s, including the Russell – Einstein Manifesto of 1955.