Julius Robert Oppenheimer was an American theoretical physicist who made many important scientific contributions, but he is best known for his work on the Manhattan Project. Like the others that worked on this project, he is known as one of the fathers of the atomic bomb. Oppenheimer was born on April 22nd, 1904 in New York, and died on February 18th, 1967, in New Jersey.
After studying at both Harvard and Cambridge, he earned his PhD from the University of Göttingen in 1927. While in Germany, he met and studied with several prominent physicists, including Niels Bohr and Max Born. In 1929, Oppenheimer received offers to teach at both Cal Tech and the University of California at Berkeley. He accepted both offers, dividing his time between the two. By the time he returned to America, he had published several articles and had established his reputation as a theoretical physicist, making his mark on quantum theory.
In the 1930s, Oppenheimer became involved with left wing politics. He made donations to funds associated with the Communist Party, and, in the security questionnaire he filled out when he joined the Manhattan Project, admitted to being a member of communist organizations. This admission caused many people to view him with suspicion, and eventually played a large role in the loss of his security clearance.
He joined the Manhattan Project in 1941. Eventually the project yielded results, and in July 1945, the first test detonation of an atomic bomb took place, overseen by Oppenheimer and the other scientists working on the project. Upon witnessing the sheer destructive force of the bomb, Oppenheimer was greatly disturbed.
After the war, Oppenheimer became chairman of the influential General Advisory Committee of the newly created United States Atomic Energy Commission. Having come to deeply fear further use of the weapon he had helped creating in future conflicts, he used this position to lobby for international control of nuclear power and against a US led nuclear arms race with the Soviet Union. But because of his outspokenness combined with the widespread Red Scare in the US in the 1950's, he fell out of favor with many powerful politicians and was eventually stripped of his security clearance following a much-publicized hearing in in 1954, and became as such effectively removed from political influence.
After this, Oppenheimer continued to lecture, write and work in physics, and eventually got some redress when President John F. Kennedy awarded (and Lyndon Johnson presented) him with the Enrico Fermi Award in 1963.