Lise Meitner Explains a Split Nucleus

Lise Meitner built a career in physics when women faced formal and informal barriers in European universities. In Berlin, she collaborated for decades with chemist Otto Hahn on radioactivity and nuclear research. Their skills were different but complementary: chemical experiments identified substances, while physical theory helped explain what happened inside atoms.

In 1938, Nazi persecution forced Meitner, who had Jewish ancestry, to flee Germany. Hahn and Fritz Strassmann continued experiments in Berlin and found barium after bombarding uranium with neutrons. The result was surprising because barium is much lighter than uranium. Hahn wrote to Meitner about the evidence.

While in Sweden, Meitner and her nephew, physicist Otto Frisch, interpreted the result as a uranium nucleus splitting. They used a nuclear model and the relation between mass and energy to explain the large energy release. Frisch soon described the process experimentally and named it nuclear fission.

The discovery did not belong to one isolated moment. It depended on experimental results, theoretical interpretation, correspondence across borders, and earlier shared work. Credit was not distributed equally: Hahn alone received the 1944 Nobel Prize in Chemistry. Meitner's story shows why the history of science must examine both evidence and the conditions governing who can work, escape danger, communicate, and receive recognition.