In the 1930s, Otto Hahn (1879-1968), Lise Meitner (1878-1968), and Enrico Fermi (1901-1954) conducted experiments bombarding uranium with neutrons in search of “transuraniums,” elements heavier than uranium. They were successful, and Fermi (1938) and Hahn (1944) were later rewarded with Nobel prizes as a result. During a neutron bombardment in 1938, Hahn observed the creation of two elements that were, together, lighter than uranium. Meitner declared this loss of mass, along with the release of large amounts of energy, nuclear fission. Following this discovery, in 1942 Fermi started the first controlled nuclear chain reaction while working to build atomic bombs as part of the American Manhattan Project at the University of Chicago. The Fermi Reactor, built for this purpose, became the model for all atomic energy plants worldwide after the Second World War.
- Brandt, Siegmund. The Harvest of a Century: Discoveries of Modern Physics in 100 Episodes. Oxford: Oxford University Press, 2009.