Both Robert Oppenheimer and Edward Teller greatly contributed to nuclear weapons development, but their roles were quite different. Oppenheimer, often known as the "father of the atomic bomb," headed the Manhattan Project, which was charged with rapidly developing the first nuclear weapon during World War II. As a physics professor at the University of California, Berkeley, he had significant intellectual input into the bomb's design. He was particularly instrumental in solving the problem of implosion in the plutonium bomb design, which was critical to ensuring the weapon's fearful destructive capability. Edward Teller, on the other hand, worked within the Manhattan Project but is more famous for his later contribution to developing the hydrogen bomb. Throughout the project, he advocated for research into a fusion-based weapon, which would be tremendously more powerful than the fission-based atomic bombs. Though these ideas were not fully realized within the timeline of the Manhattan Project, his efforts paved the way for the development and subsequent detonation of the first hydrogen bomb in 1952. In terms of the first nuclear bomb’s development, Oppenheimer’s role was larger as he led the entire project. However, Teller's ongoing advocacy and research into fusion-based weapons laid the groundwork for the next leap forward in nuclear weaponry. The two scientists' contributions were different and had unique impacts on nuclear weapons development.