Knowra Manhattan Project Manhattan Project The Manhattan Project was a secret U.S.-led wartime program that developed the first nuclear weapons, culminating in the Trinity test and the atomic bombings of Hiroshima and Nagasaki.
Nuclear fission : The splitting of an atomic nucleus into lighter nuclei, releasing energy and often additional neutrons. Fission supplied the energy release that made the project’s weapons possible.
Albert Einstein–Leo Szilard letter : A 1939 letter to President Franklin D. Roosevelt warning that uranium research might lead to powerful bombs. The letter helped prompt U.S. government attention to nuclear fission as a wartime danger.
J. Robert Oppenheimer : An American theoretical physicist who directed the Los Alamos laboratory during the Manhattan Project. He led the scientists designing and assembling the first bombs.
Chicago Pile-1 : The first artificial reactor to achieve a controlled, self-sustaining nuclear chain reaction, on December 2, 1942. Its success showed that a controlled chain reaction could be sustained.
Nuclear arms race : The competition among states to develop and expand nuclear arsenals, especially during the Cold War. The project’s weapons helped initiate a sustained competition to build nuclear forces.
Little Boy : The uranium gun-type atomic bomb dropped on Hiroshima on August 6, 1945. It used a comparatively direct design that joined two pieces of highly enriched uranium.
MAUD Committee : A British wartime scientific committee that concluded an atomic bomb was feasible and could be built during the war. Its 1941 findings strengthened the case for a full-scale American program.
Leslie Groves : A U.S. Army general who directed the Manhattan Project from 1942 until its wartime completion. He managed the project’s vast construction, security, and production effort.
Trinity test : The first detonation of a nuclear weapon, conducted in New Mexico on July 16, 1945. It tested the plutonium implosion design before its use in war.
Nuclear deterrence : A strategy that seeks to prevent attack by threatening a devastating nuclear response. The bombs’ demonstrated destructive power shaped later theories of preventing war.
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