5-1-1-1Discovery of Atomic Energy and World War II

Otto Hahn (left) discovered nuclear fission, and Lise Meitner (right) explained it theoretically.
1908 Courtesy of Archives of the Max Planck Society, Berlin

In December 1938, the year before the start of World War II, German scientists discovered a phenomenon called nuclear fission. The countries involved in the war pumped every available resource into all-out warfare. Countless citizens were mobilized for the war effort, and many new weapons were developed. When scientists learned that fission chain reactions in uranium release vast amounts of energy, the search for an atomic bomb began, culminating in its use in combat.