Heroes of: Lise Meitner
An innovative physicist and the mother of nuclear fission
Born in Vienna, Austria, in 1878, Lise Meitner was the third of eight children. During her time at public school Meitner gained a growing interest in physics and maths. By 1901 Meitner had passed her qualifying exams and attended the University of Vienna, where she met professor Franz Exner. As a respected physicist, Exner introduced her into the then growing world of radioactivity.
After completing her doctoral degree in 1906, Meitner spent the next year teaching at an all girls’ school while continuing her research, focusing on alpha and beta radiation absorption. Moving to Berlin in 1907, Meitner joined the Chemistry Institute at the University of Berlin, where she met her future collaborator, chemist Otto Hahn. As an unpaid guest, Meitner was given a small basement room to set up her laboratory. A year later she was made a scientific associate, allowing her and colleague Hahn to combine academic disciplines and expand their lab above ground. It wasn’t until 1912 that Meitner got her first paid position of assistant.
The discovery of the neutron by physicist James Chadwick in 1932 created a buzz in the research of neutron irradiation/bombardment of different elements. Working with radiation, Meitner and Hahn naturally wanted to follow suit and set up a series of experiments irradiating uranium. At the same time, Nazi Germany was on the cusp of starting WWII. As a Jewish woman, Meitner feared for her life and fled from Berlin to Stockholm in 1938. In her absence, Hahn and his assistant Fritz Strassmann continued their work with uranium.
The trio collectively carried on their research, communicating predominately via letter. During Meitner’s absence Hahn was faced with an unexpected result. Writing to Meitner, Hahn informed her he had discovered the presence of the element barium after bombarding uranium with neutrons. Taking a mathematical approach, Meitner concluded the uranium atom had become unstable and ruptured, releasing the unexpected barium and a vast amount of energy. After further repeats Meitner’s hypothesis was
“As meitner had hypothesised, the atom had split, leading her to coin the term ‘nuclear fission’”
proved correct — the atom had split, leading her to coin the term ‘nuclear fission’.
In 1939 Hahn and Strassmann published the trio’s finding and announced they had split the atom by nuclear fission, but Meitner was not listed as an author. As the news broke of nuclear fission, especially the high levels of energy it emits, the potential for a nuclear weapon became clear. Meitner was therefore asked to contribute to the development of the atomic bomb in the Manhattan Project. She refused, stating, “I will have nothing to do with a bomb”.
Hahn went on to win the Nobel Prize for the discovery of nuclear fission in 1944, whereas Meitner wasn’t recognised until 1966, when all three contributors won the prestigious Enrico Fermi Award. Meitner passed away in 1968 in Cambridge, England aged 86.