Jewish culture and many Jewish scientists had a significant role in the project. The theoretical physicist Robert Oppenheimer, often considered as the ""father of the atomic bomb"", was chosen to direct the Manhattan Project at Los Alamos National Laboratory in 1942. The physicist Leó Szilárd, that conceived the nuclear chain reaction; Edward Teller, ""the father of the hydrogen bomb"" and Stanislaw Ulam; Eugene Wigner contributed to theory of Atomic nucleus and Elementary particle; Hans Bethe whose work included Stellar nucleosynthesis and was head of the Theoretical Division at the secret Los Alamos laboratory; Richard Feynman, Niels Bohr, Victor Weisskopf and Joseph Rotblat.
Soviet atomic bomb project were continuously published as public domain in academic journals. Joseph Stalin, the Soviet leader, had mostly disregarded the atomic knowledge possessed by the Russian scientists and had most of the scientists working in the metallurgy and mining industry or serving in the Soviet Armed Forces technical branches during the World War II's eastern front in 1940–42. In 1940–42, Georgy Flyorov, a Russian physicist serving as an officer in the Soviet Air Force, noted that despite progress in other areas of physics, the German, British, and American scientists had ceased publishing papers on nuclear science; clearly they each had active secret