© 2002 David W. Trulock
(an unpublished manuscript from March 2002)
Before Women's History Month ends, there's one woman who
lived during the 20th Century who needs to
receive more attention, especially in these times of war, rumors of war, and an
increased threat of nuclear weapons use.
Ever heard of Lise
Meitner?
That's what I
thought. She was born in Vienna in 1878
and died in Cambridge, England, in 1968.
(Lise was originally Elise, but it's pronounced just like Lisa.) In her 90
years of unmarried life, Meitner earned a doctorate in physics, became a
prominent experimental nuclear physicist in Berlin (and protege of Einstein, Shrodinger,
et al) and then became a refugee from Germany a few months after Hitler's
annexation of Austria in 1938.
It was on Christmas Eve of 1938, after 6 months of living in exile in Sweden, that Meitner made the most important scientific discovery of her life—and one of the most important of the 20th Century. She and her physicist nephew Otto Frisch did some simple calculations and drawings that convinced them a uranium nucleus hit by a neutron could be split in half, a process that they shortly named nuclear fission.
Although Einstein's E = mc2 formula had been around since September 1905, Meitner, on that Christmas Eve morning, was the first to see how it applied to the fissioning of the uranium nucleus. Before being exiled from her work, Meitner had instigated experiments involving neutron bombardment of uranium with her collaborators Otto Hahn and Fritz Strassmann in Berlin. Because she was Jewish, however, Meitner could not continue to lead their experimental team after March 1938, the month of Hitler's annexation and occupation of Austria. The annexation made Meitner a German citizen, and thus subject to the restrictive Nazi anti-Semitic laws. But she and Hahn kept in constant contact by mail after she illegally and with much sadness left Germany for Sweden.
It was only Hahn, however, who later received a Nobel Prize (in chemistry) for his and Strassmann's chemical separations, done in late 1938, showing neutron bombardment of uranium produced barium, an element with about half the mass of uranium. Hahn, like other scientists of the time, could not understand such a result until Meitner received word of it and she and Frisch made their theoretical calculation showing the nucleus could split.
The calcuation, based on Niels Bohr's newly developed liquid-drop model of the nucleus, used E = mc2 and predicted an energy release about a hundred times greater than any known release of energy in a chemical reaction. What was still necessary for the practical use of this energy was that there be a chain reaction, meaning more than one neutron would be released as a result of uranium fission. That more than one neutron was released was soon demonstrated experimentally by Frisch.
When Meitner had a chance to leave her pittance of a research job in Sweden in the early 1940s and work on the Manhattan Project in the United States, she refused, saying "I will have nothing to do with a bomb!" She had been a volunteer X-ray technician during World War I, and unlike many past and present supporters of war, she knew what it truly involved.
Ruth Lewin Sime, in her definitive 1996 biography, Lise Meitner: A Life in Physics, explains: "Meitner wanted no part of deaths anywhere: she could not commit herself and her physics—the two were not distinct—to a weapon of war. She had seen the casualties firsthand in 1915-1916; she had heard the screams. She could not do it. Her decision was instantaneous and absolute: there was no discussion. She would not work on the bomb."
Besides Sime's book, other references on this unusual and overlooked scientist include the 1992 BBC documentary "A Gift From Heaven" (Hahn's phrase for what he regarded as his fission discovery), and Rachel Barron’s book Lise Meitner: Discoverer of Nuclear Fission, published in 2000.
Although Meitner was nominated several times for a Nobel Prize in physics, it was never awarded to her.
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(There's an original b&w photo located outside the
ground floor lecture hall in Robert Lee Moore Hall on the University of Texas at Austin campus that shows Meitner and Irene Curie and about 20
mostly famous male scientists and has their original signatures on it. The photo is from the 1933 Solvay physics conference, held in Brussels. Albert Einstein is not in the photo, and thus it doesn't have his signature on it. He had attended all the earlier conferences, held about every three years starting in 1911, but he permanently moved to
Princeton, New Jersey, in 1933 to escape the Nazi’s, and did not attend the 1933
conference. In fact, even after the war was over, he didn't return to Europe even for a visit.)
