Dr. Lise Meitner, Physicist
Theorist Defined Nuclear Fission and Its Unprecedented Power
Aug 17, 2008
Lise Meitner was born in Vienna in 1878 to Philipp and Hedwig Meitner. In 1901 she entered the University of Vienna, becoming the first woman in that institution’s history to study physics. It was a fitting preamble for her professional life.
Meitner learned from the renowned Ludwig Boltzmann. By 1907 she had her doctorate, but traveled to the University of Berlin to study with the physicist she most admired, Max Planck. She could only to audit his classes.
Although skeptical about the idea of female physicists, Max Planck took Meitner under his wing. She spent many hours at the Planck family household, conferring with such scientists as Niels Bohr, Albert Einstein, and chemist Otto Hahn.
Hahn and Meitner shared an interest in radioactivity, and agreed to work together at the Chemistry Institute. Although the Institute director, Emil Fischer, banned all women from the premises, he grudgingly permitted Meitner a basement lab on the outskirts of the campus. The closest bathroom she could use was in a restaurant down the street.
Early Research
Meitner had published more than 20 scientific papers by 1912. Yet despite her hard work—her hands were often blistered from handling radioactive materials—she still had no official position and was unpaid.
In 1913, she was finally made a scientific associate, a rank equal to Hahn’s (though at half the salary). Together they isolated a new element, protactinium, a highly radioactive actinoid. In 1923, Meitner published the first findings on the Auger effect, later named for Pierre Auger, who “discovered” the phenomenon two years later.
The Transuranic Race
In 1933, the newly elected Chancellor Hitler ordered the universities to purge all Jews. Meitner’s family was Jewish, though she had been raised as a Protestant. Although Hahn and Planck pleaded her case, technically she was “non-Aryan.” Meitner was dismissed from her professorship.
Meitner and Hahn soon joined the race to create transuranes, elements larger than uranium, the heaviest known element. In 1938, after numerous experiments bombarding radioactive uranium atoms with free protons, they were poised to conduct their final tests when Germany “annexed” Austria. Meitner’s citizenship could no longer protect her.
Fleeing the Nazis
Meitner resisted leaving, but friends and colleagues grew increasingly concerned, and she finally conceded the danger. Dutch physicists Dirk Coster and Adriaan Fokker hatched a plan, and Coster stole into Berlin to spirit her away. After working late so as not to arouse suspicions, Meitner packed a few things and the two slipped across the border into Holland, barely ahead of the SS.
Meitner was 59, impoverished, all her scientific records were in Germany, and she was heading to Sweden, where she did not speak the language. Yet her main lament was that she could not finish her work with Hahn.
Discovering Nuclear Fission
Hahn and another colleague, Fritz Strassman, completed the experiments but were baffled by results Hahn called “physically absurd.” He wrote to Meitner in 1938, “We know ourselves that [uranium] can’t actually burst apart into [barium].… You will do a good deed if you can find a way out of this”—that is, a way to reconcile the results with the principle of the conservation of energy.
Puzzling over Hahn’s letter with her nephew, physicist Otto Frisch, Meitner intuited that the uranium nucleus grew unstable when bombarded and was in fact bursting apart: they had split an atom. Taking a term from biology, she called this “nuclear fission.” To explain the immense energy needed to drive the positively charged fragments apart, Meitner and Frisch turned to Einstein’s equation, E=mc2, which held that decreasing mass creates energy. Splitting just one 235U atom created 200 MeV—equal to 20 kilotons of dynamite.
“I will have nothing to do with a bomb!”
Meitner and Frisch published their discovery in Nature in 1939, but by then the news had already leaked, and scientists worldwide stepped up fission research. Efforts soon focused on creating a nuclear weapon. Meitner was the only fission expert among the Allies who refused to help develop a bomb.
In 1944, it was Hahn, not Meitner, who received a Nobel Prize; even today, out of 789, there have been only 34 female Nobel laureates. In August 1945 the U.S. dropped nuclear bombs on the Japanese cities of Hiroshima and Nagasaki, killing more than 200,000 people outright. Meitner was horrified by this destructive use of fission.
Final Years
Though nominated many times for a Nobel, Meitner never won. When Hahn accepted his award, he credited her equally for the discovery, but over time he inflated his role until finally he referred to her only as his “assistant.” Meitner received a Max Planck Medal from the German Physics Society (1949), an Enrico Fermi Award (1966), and element 109 was named meitnerium in her honor (1997).
Meitner worked in Sweden for another 20 years before retiring to Cambridge, England, to be near her beloved nephew, Dr. Otto Frisch. She died in a nursing home several days before her ninetieth birthday. Her final honor, Frisch’s inscription on her tombstone, may have been the most important: “Lise Meitner: a physicist who never lost her humanity.”
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