Ever had a time in your life when everything seemed to be conspiring against you? Seventy five years ago, the physicist Lise Meitner must surely have felt so.
She fled Nazi Germany in July 1938 with only ten marks in her pocket. After a difficult journey Meitner found refuge in Sweden in November.
Events must have looked incredibly bleak to the 60 year old scientist who had lost her laboratory, life-savings and homeland.
And yet on Christmas day, Meitner had a moment of scientific revelation that would change our view of the physical world forever. The discovery also had dramatic practical consequences.
For in that moment she recognised for the first time that certain heavy atoms could split completely in two by the process of nuclear fission.
Meitner’s revelation completed a five decade old puzzle. In 1896 Henri Becquerel discovered that uranium emitted radiation. Subsequently Marie and Pierre Curie identified the even more radioactive, lighter elements polonium and radium.
Ernest Rutherford then showed that these are intermediates in a chain of disintegration starting with uranium and ending with non-radioactive lead.
Such studies showed that the old alchemist’s dream of transforming one element into another was not so far-fetched after all. And they also led to the realisation that atoms are composed of even smaller particles—electrons, protons and neutrons.
Such discoveries stimulated the imagination of young Meitner who decided to dedicate her life to atomic physics.
Working with Otto Hahn in Berlin, she made several pioneering discoveries. His chemical expertise brilliantly complemented her theoretical genius.
Yet Meitner had to battle constantly against sexist attitudes. When Rutherford visited he said, “Oh, I thought you were a man,” then went off to talk science with Hahn, leaving Meitner to go shopping with his wife.
But even greater challenges faced Meitner, for she was a Jew, and her achievements counted for nothing in Hitler’s Germany. She was lucky to escape alive, but had no money, was homeless and stateless.
Yet Hahn continued to communicate his findings from Berlin. On 22 December he reported that having irradiated uranium with neutrons, he seemed to have produced two much smaller elements—barium and krypton.
This apparent division into two made no sense given the view of atomic structure at the time.
But during a Christmas day walk, Meitner realised the findings could be explained if the uranium atom was like a wobbly, unstable drop of water that could divide at the slightest provocation.
Sitting down with pencil and paper she showed that this “splitting of the atom” was mathematically feasible and, according to Einstein’s equation E=MC2, would release huge amounts of energy.
Meitner’s insight would lead directly to the development of the atomic bomb and the horrors of Hiroshima and Nagasaki.
But while many left wing physicists helped develop the bomb because of fears about the Nazis getting there first, Meitner was adamant from the start that, “I will have nothing to do with a bomb!”
Meitner’s story shows that even the most brilliant scientific discoveries may be used for horrendous ends under capitalism.