I’m taking a writing class at the moment, and one of the assignments was to write a profile about Lise Meitner:
On Christmas Eve, 1938, sitting on a tree trunk in the snow in Sweden, Lise Meitner and her nephew Otto Frisch figured out the mechanism of nuclear fission. They had gone for a walk during a family holiday to discuss a letter Meitner had received from her colleague Otto Hahn. He asked for her opinion on a strange scientific phenomenon he had discovered.
Until a few months earlier, Meitner and Hahn had worked closely together at the Kaiser Wilhelm Institute (KWI) in Berlin, where they studied the effect of bombarding uranium atoms with neutrons.
Meitner had moved to Berlin shortly after completing her doctorate degree in her birth city of Vienna. She was one of the first women to reach this level of academia, and encountered some archaic attitudes and ideas: in Berlin, she worked unsalaried for a few years, and was occasionally expected to entertain the wives of visiting physicists while the men talked about science.
During the three decades she worked in Berlin, Meitner made Germany her home, but when the Second World War edged closer, it was no longer safe for Jewish people in Germany. With her piercing brown eyes, dark frizzy hair and pronounced nose, Meitner’s heritage was unmistakable. She fled to Sweden in July 1938, with help from an international group of friends and colleagues from the physics community.
Now, six months later, Hahn’s curious letter had reached her. He described how, after another round of shooting neutrons at uranium, he discovered barium in the reaction mixture. Where had it come from? Pondering this question with Frisch during their winter walk, Meitner realised that the neutron in Hahn’s experiment must have split the uranium atom in half. This would leave two smaller atoms in its place, which would continue to produce even smaller atoms, and generate large amounts of energy.
The discovery came at a dangerous time: Could the Nazis use this technology to create a weapon? The USA quickly launched the Manhattan Project to ensure they were the first to build an atomic bomb. Meitner was invited to join, but she refused. She didn’t want to be part of such a violent application of her discovery – not even to defeat the enemy who had chased her out of Germany.
After the war, Meitner spent several months in the USA as part of a visiting professorship. She was named Woman of the Year there, in 1946, and was interviewed by Eleanor Roosevelt for NBC radio. Roosevelt told her: “We are proud of your contributions as a woman in science”.
Meitner continued to inspire women in science throughout her retirement years. A photo taken at Bryn Mawr, in 1959, shows her sitting casually on the steps of a university building. Her frizzy hair now grey, but with the same dark piercing eyes, she is surrounded by students in long floral skirts who have come to hear her fascinating stories.
Maybe she told them about the time she went for a walk with her nephew, through the snow in a cold Swedish winter. Or maybe they asked her about that other winter in Sweden, when in December 1945, Hahn – and Hahn alone – received the Nobel Prize in Chemistry at the award ceremony in Stockholm.
It’s an oversight that’s still often mentioned, especially in the context of continuing challenges to retain women at the top level of science. But even without a Nobel Prize, Meitner was well-respected, and happy to sit down for a chat about her work: in the snow with her nephew, on the radio with a former president’s wife, or casually outside on the steps with admiring students.
Image: Meitner and Hahn. Public domain, via Wikimedia. Other image described in the text was not free to use, so click that text for a link.