Fritz Strassmann

Fritz Strassmann was the analytical chemist whose measurements established that uranium nuclei split, and who refused to work for the Nazi state at severe personal cost. Born in Boppard in the Rhineland in 1902, he studied chemistry at Hannover and took a doctorate there, specialising in the analytical chemistry of very small quantities — an unglamorous skill that turned out to be the decisive one. He joined the Kaiser Wilhelm Institute for Chemistry in Berlin in 1929 as a fellow, working with Otto Hahn and Lise Meitner. When his stipend ended in the Depression he was kept on at half pay. In 1933 he resigned from the Society of German Chemists because it had been brought under Nazi control, which made him effectively unemployable in industry and blocked any academic appointment. He worked on at the institute for a fraction of a normal salary. He and his wife later hid a Jewish acquaintance in their flat for months, for which they were recognised as Righteous Among the Nations in 1985. After Meitner fled Germany in July 1938, Strassmann and Hahn continued bombarding uranium with neutrons. In December 1938 Strassmann's meticulous fractionation showed that the product behaved chemically as barium — element 56, roughly half uranium's mass — and could not be radium. His analysis was so careful that the result could not be dismissed as contamination, which is what made it credible. Hahn wrote to Meitner, who with Otto Frisch supplied the physical explanation. The 1944 Nobel Prize went to Hahn alone, omitting both Strassmann and Meitner. He refused to join the German nuclear project. He led the institute after the war and taught at Mainz until 1970, dying in 1980.

• Lived: 1902 CE – 1980 CE
• Nationality: German
• Roles: chemist, scientist