J. Robert Oppenheimer, often referred to as "the father of the atomic bomb," was an American theoretical physicist and professor of physics at the University of California, Berkeley. He is most notably known for his significant contributions to the Manhattan Project, the top-secret program initiated by the U.S. during World War II with the goal of developing the world's first nuclear weapons. Oppenheimer was appointed the Scientific Director of the Manhattan Project in 1942. Not only did he bring together a team of the most proficient physicists of that era, but he also led the effort to design and build the first atomic bombs. His role was central to coordinating and driving the scientific work at the secret laboratory established in Los Alamos, New Mexico. His main contribution was in the development and assembly of the "Fat Man" and "Little Boy" bombs, the two types of atomic bombs created during the project. The "Little Boy" was a gun-type fission bomb, using uranium-235, and it was dropped on Hiroshima, Japan, in August 1945. The "Fat Man" was an implosion-type fission bomb, using plutonium-239, and it was detonated over Nagasaki, Japan, a few days after the Hiroshima bombing. In spite of his essential contribution to achieving this scientific milestone, Oppenheimer later expressed regret about the destructive power that had been unleashed. After seeing the disastrous impact of the atomic bombs on Hiroshima and Nagasaki, he famously quoted from the Bhagavad Gita, "Now I am become Death, the destroyer of worlds." Following the war, Oppenheimer became a leading advocate for controlling nuclear weapons and promoting international cooperation in the field of nuclear energy. His scientific achievements, along with his complex moral and political legacy, make Oppenheimer a significant figure in the history of nuclear physics and global security. For any future reader interested in further exploration of this topic, the biography "American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer" provides an in-depth look at his life and work.