Part V — Chapter 16
Nuclear Physics & the Manhattan Project
From atomic nuclei to the most destructive weapon ever built
16.1 The Nucleus
Rutherford's discovery of the proton (1919) and James Chadwick's discovery of the neutron (1932) revealed the composition of the nucleus. The strong nuclear force that binds it together was gradually understood through the work of Yukawa and others.
16.2 Fission and the Chain Reaction
In 1938, Otto Hahn and Fritz Strassmann split uranium, and Meitner explained the physics. Enrico Fermi (1901–1954) built the first self-sustaining nuclear chain reaction in Chicago on December 2, 1942.
16.3 The Manhattan Project
Under J. Robert Oppenheimer, the Manhattan Project built the first atomic bombs, tested at Trinity (July 1945) and dropped on Hiroshima and Nagasaki. The nuclear age had begun, posing profound questions about science, ethics, and power.