|SocialismToday Socialist Party magazine|
Lise Meitner: a physicist in the eye of 20th century storms
Socialism Today No.136 carried a review of a book on the physicist Paul Dirac. Here GEOFF JONES and KATE JONES look at the equally turbulent life and times of Dirac’s near contemporary, Lise Meitner.
ASKED TO name a famous woman physicist, most people could probably come up with Marie Curie. Very few would be able to name Lise Meitner, yet she was a woman who battled sexism and racism throughout her life to become arguably the greatest woman physicist of the 20th century. Her work on nuclear physics led her to discover nuclear fission and hence to atomic energy and the atomic bomb.
Like other great women scientists, Meitner has been airbrushed from history. But as an Austrian Jewish woman she was also caught up by the madness of Nazism and was cheated out of the Nobel prize that her work merited. Her life makes an interesting comparison with that of her near contemporary, Paul Dirac.
Lise Meitner was born in Vienna in 1878 in an intellectual, non-religious Jewish family. Although her formal schooling ended at 14, she continued to study informally and entered the University of Vienna in 1901. There she gained her lifelong vision of physics as a battle for ultimate truth.
At that time, the hot topic in physics was the study of radioactive elements (the first of which, radium, had been discovered by Marie Curie a few years earlier). Meitner started her research measuring radioactive lifetimes. In those days, physicists had to invent and build their own apparatus before they could take any measurement or make any theoretical predictions. Meitner proved brilliant at both. She moved to Berlin University in 1907, where she met Otto Hahn, a chemist, who was to be her friend and close collaborator for most of her career.
Although she was eminently qualified to work at the university’s chemistry institute, there was a problem: women were not allowed into the building! Finally, she was allocated a room in an ex-carpenter’s shop in the basement with its own entrance. For toilet facilities she had to go to the café down the street. She was not given an academic post or a decent salary but saw this as a small price to pay for her own laboratory, where she carried out meticulous studies on the decay of radioactive elements prepared upstairs in the chemistry laboratory by Hahn. She played a major part in the first estimation of the radioactive decay series of elements such as radium and uranium, identifying and measuring the lifetimes of the short-lived products of these decays.
Her research was cut across by the first world war. In 1915, Meitner volunteered as an x-ray nurse-technician in the Austrian army. Ironically, Curie was doing the same thing in France on the other side of the lines. Meitner’s two years of battlefield nursing gave her a lifelong hatred of war. She returned to the institute in 1916 and was soon appointed head of her own physics department, a post which, at last, carried a decent salary.
In the years after the war, nuclear physics was a key area of experimental research. Only a few years earlier, in Manchester, Ernest Rutherford had shown that the atom, previously thought of as an indivisible sphere, actually consisted of a tiny, positively charged nucleus surrounded by a cloud of even tinier, negatively charged electrons. But what was the nucleus made of? One clue was the existence of the very few radioactive elements, among the heaviest existing, which seemed to decay spontaneously, giving out several types of radiation and decaying into other heavy elements.
During the 1920s and 1930s, Meitner and Hahn were at the forefront of research, Hahn carrying out the chemical isolation of the elements, and Meitner analysing the physical processes involved. She began to study the construction of the nucleus itself, collaborating (and sometimes competing) with the Curies in Paris, Rutherford’s group in Cambridge, and others around the world. She took part in the famous Solvay Conferences where the form of modern physics was hammered out by the leading experimentalists and theoreticians of the day. By the mid-1930s, the different radioactive ‘families’ were becoming clear and models of nuclear structure were being agreed.
But life got harder. After the Nazis came to power in Germany in 1933, attacks on Jews became a regular occurrence and some scientists in the university clamoured for the ‘Aryanisation’ of science: the expulsion of Jews from academic posts (and, of course, promotion for themselves). Germany’s premier scientific journal, Naturwissenschaften, was boycotted for publishing ‘Jewish science’ and its editor finally driven to suicide. Many eminent scientists, not only Jewish ones, fled the country, but the Nazis made this increasingly difficult. Meitner and Hahn, utterly dedicated to pursuing the structure of the nucleus, tried their best to stand aside, especially since their work on uranium U235 was at a crucial stage. Meitner believed that, as an Austrian citizen, she had some immunity. But in 1938, when the Nazis incorporated Austria into the Third Reich, her position became even more perilous, and she just managed to escape from Germany, without even a passport or luggage.
Once safely in Copenhagen, she had an inspiration. She worked out that the U235 nucleus was not merely decaying to form another heavy element, but was splitting apart into two much lighter elements, with the emission of energy given by Albert Einstein’s famous formula E=Mc2. She wrote to Hahn explaining this and he was able to check for the presence of the two ‘fission products’. The age of nuclear energy was born.
Meitner settled in Sweden, and although invited to join the atomic bomb project in the USA she refused. She saw nuclear fission as having a peaceful purpose, the provision of abundant energy, not as a weapon of war. She spent the rest of her working life in Sweden but was given few research facilities. She finally retired to England where she died in 1968.
Hahn, although not a Nazi, stayed in Germany and in 1944 received the chemistry Nobel prize for ‘the discovery of nuclear fission’. He continually refused to acknowledge that it was Meitner who had made the discovery, and this fiction was perpetrated in Germany. Even very recently, apparatus designed and used by Meitner in her laboratory was displayed in the Deutsches Museum, Munich, as ‘The worktable of Otto Hahn’.
Throughout her life, Meitner’s only inspiration was to work at physics – not in the rarefied atmosphere of theory, but in the difficult and dangerous world of experimental nuclear physics. It is significant that, while many of her fellow experimenters died of cancer and their laboratories had to be completely stripped or condemned as radiological hazards, Meitner lived into her 90s, and her techniques were so precise that her labs can still be used.
Meitner was undoubtedly one of the great 20th century physicists. Why is she unknown? In the main, because she was a woman in a masculine field. She was lucky because her family had the means and the willingness to allow her to pursue the subject, opportunities open to very few women of her generation. And today? In theory, all the doors she had to push through are now open. In practice, in Britain only 20% or so of students studying A-level physics are young women. At university level, the number of women is lower still. Although a woman, Jocelyn Bell Burnell, is currently president of the Institute of Physics (IoP), only 5% of professors in the subject are women.
Organisations like the IoP do what they can to enthuse young people of both sexes, and to give extra encouragement to girls, but young women face all the pressures of modern capitalism. Despite equal pay and anti-discrimination laws, and despite all the claims that women today can ‘have it all’, working-class women are still largely channelled into low-paid, low-status jobs in the caring or service sectors, even though these days they may need a degree to undertake them. Women are targeted as prime consumers of fashion, not as the future of science and technology. The very idea of a woman with a single-minded dedication to a cause, whether exploring the atomic nucleus or changing society, is discouraged from the cradle on. So, in the year of the 100th anniversary of International Women’s Day, the example of women like Lise Meitner, who had to battle prejudice at every stage of her career, is one to celebrate. She deserves to be better known.
Ruth Sime Lewin wrote an excellent biography, Lise Meitner: A Life in Physics (University of California Press, 1996). It has never been issued in Britain.