Otto Hahn

Otto Hahn was a German chemist who, together with Fritz Strassmann in his Berlin laboratory in December 1938, carried out the experiments that first split the uranium nucleus, the discovery of nuclear fission that made both nuclear power and nuclear weapons possible. Hahn and Strassmann found that bombarding uranium with neutrons produced barium, a much lighter element, a result Hahn could not explain but reported to his longtime collaborator Lise Meitner, who worked out with her nephew Otto Robert Frisch the physical interpretation that the uranium nucleus had actually split. Hahn was awarded the Nobel Prize in Chemistry in 1944 for the discovery, though the prize committees omission of Meitner from that recognition is now widely regarded as an injustice. After the war Hahn became an outspoken opponent of nuclear weapons even as the fission reaction he had discovered became the basis of the civilian nuclear power industry.