Lise Meitner helped to discover nuclear fission in late 1938. At the end of World War II, Meitner became known as “the mother of the atomic bomb,” though she never worked on the bomb and when invited to do so, responded, “I will have nothing to do with a bomb.”
Meitner, one of the greatest nuclear physicists of the twentieth century, was a pioneer in the study of radioactivity. Albert Einstein dubbed her “The German Madame Curie.”
Though most of her work was done in Berlin, Meitner was born in Vienna, Austria, in 1878, to Jewish parents. Her father, a lawyer, was a freethinker and raised the eight Meitner children in a non-religious Jewish home. Lise loved music, mathematics and science, and at age eight slept with a math book under her pillow. Her spirit of scientific inquiry showed itself early on:
Once, when Lise was still very young, her grandmother warned her never to sew on the Sabbath, or the heavens would come tumbling down. Lise was doing some embroidery at the time and decided to make a test. Placing her needle on the embroidery, she stuck just the tip of it in and glanced anxiously at the sky, took a stitch, waited again, and then, satisfied that there would be no objections from above, contentedly went on with her work.
In Austria at that time, girls could not attend public school after age fourteen. But Lise’s father insisted that his daughters receive the same education as his sons, and Lise was privately tutored. She passed the difficult entrance exam to the University of Vienna and was the first woman admitted to the university’s physics lecture and laboratories.
In 1905 Meitner became the second woman to receive a Ph.D. in physics from the university. She had been introduced to Max Planck, the founder of quantum mechanics, when he visited Vienna. In 1907 Planck invited Meitner to Berlin for post-doctoral study and research. Meitner greatly admired Planck, noting, “He had an unusually pure disposition and inner rectitude, which corresponded to his outer simplicity and lack of pretension.”
Meitner’s biographer, Ruth Sime, speculates that Meitner’s great respect for Planck, the son of a Protestant minister, may have influenced a major decision: in 1908 she became a member of the Evangelical (Protestant) denomination. Sime notes, “Although she never explicitly stated why she chose to be Protestant, she maintained a genuine interest in the ethical teachings of the religion all her life.”
In 1907 Meitner had met chemist Otto Hahn, who became her research partner for the next thirty years in discovering new radioactive elements and explaining their complex physical properties. When Hitler came to power in 1933, many “non-Aryan” scientists lost their positions and went abroad. Meitner’s Austrian citizenship protected her, and she kept on with her work in Berlin.
But when Germany occupied Austria in March 1938, that protection ended. As her nephew and fellow physicist Otto Frisch points out, “Her honesty did not allow her to conceal her Jewish descent (as some people did), and her dismissal could only be a question of time.”
That day came on the evening of July 12, 1938, and Meitner had only an hour and a half to pack her things. The next morning she escaped by train to Holland. In the fall she took a position at the Nobel Institute for Physics in Stockholm, Sweden.
While Frisch was visiting his aunt in Sweden in late December 1938, she received a letter from her old lab partner Hahn. He had been bombarding uranium with neutrons and produced barium, a result he was unable to explain. Could Meitner help him understand what had happened?
Meitner and Frisch went for a walk in the snow to discuss it and sat down on a tree trunk to do calculations on scraps of paper. They came to the stunning conclusion that Hahn had produced nuclear fission, with the resultant release in energy explained by Einsteins’s famous formula, E=mc2. Frisch was working in Denmark with Niels Bohr, who had developed the model of the atom and won the Nobel Prize in Physics in 1922. When Frisch shared the news, Bohr exclaimed, “Oh, what idiots we all have been! This is just as it must be!”
News of the discovery spread to American scientists, including Enrico Fermi, who recognized the enormous power that could be unleashed through fission. Fearing that Nazi Germany would develop an atomic bomb, the United States enlisted Fermi and others to make one first.
When the U.S. bombed Hiroshima on August 6, 1945, Meitner was as shocked as the rest of the world. Although she had realized the devastating potential of her own discovery, she said, “It was, just the same, a terrible surprise, like a bolt of lightning out of the blue, when I learned that the atomic bomb had become a fact.” She added, “I must stress that I myself have not in any way worked on the smashing of the atom with the idea of producing death-dealing weapons. You must not blame us scientists for the use to which war technicians have put our discoveries.”
Many felt Meitner should have received the Nobel Prize for her work on fission, but she never complained. She loved her work and said that she had decided at an early age “that life need not be easy provided only it was not empty.”
Always aware of the ethical issues of scientific research, in 1962 Meitner confided with a friend, “Spiritually and morally, we are in no way keeping pace with technical advances.” When she died in October 1968, a few days before her 90th birthday, her devoted nephew Otto selected the headstone and inscription: “Lise Meitner: a physicist who never lost her humanity.”