Nuclear fission, splitting heavy atoms like uranium, was discovered in 1938 by Hahn, Strassmann, and Meitner, leading to the U.S. atomic bombs of 1945. Fusion, fusing hydrogen, was understood in the 1930s and weaponized as the H-bomb by 1952. Driven by World War II and the Cold War, these discoveries created powerful weapons, reshaping history with their devastating energy releases. | Historyinmemes