Science and politics: The discovery of nuclear fission 75 years ago

Abstract

The discovery of nuclear fission came as a sensational surprise to scientists everywhere, not least to the discoverers themselves. That much is undisputed, but almost everything else about the history of this discovery has been controversial, at the time and ever since. Most often the discovery is portrayed as a purely chemical achievement: Fission is discovered in Berlin in December 1938 at the Kaiser Wilhelm Institute for Chemistry, when the chemists Otto Hahn and Fritz Strassmann identify barium as a product of the neutron irradiation of uranium. This corresponds to Hahn’s own account of the discovery, for which he was awarded the 1944 Nobel Prize for Chemistry. Over the years, however, the chemistry narrative has been criticized for omitting physics and the contributions of Hahn’s closest colleague, the physicist Lise Meitner (Fig. 1). In a more comprehensive narrative, the team of Hahn, Meitner, and Strassmann (Fig. 2) conducts a four-year investigation that involves physics and chemistry at every stage, and even after Meitner is forced to emigrate from Germany in July 1938 she and physics play an essential role in the discovery. In this narrative Meitner is a co-discoverer of nuclear fission who is unjustly denied the recognition she is due. Which of these narratives more truly represents how the science was done and who was responsible for it? In this article I will focus on the science, keeping in mind that this discovery cannot be fully understood without also considering its historical context. For it took place at a time of racial persecution, forced emigration, political pressure, and fear – conditions that affected the