Lise Meitner

Who Did the Arithmetic in the Snow · Physicist · 1878–1968

The refugee physicist who worked out on the back of an envelope, walking in the snow, why uranium bombarded with neutrons produces barium — explained nuclear fission, named it, refused to build the bomb, and was left off the Nobel Prize.

Who was Meitner?

Lise Meitner was born in Vienna in 1878, at a time when Austrian girls could not attend the schools that led to a university. She was educated privately, passed the entrance examination anyway, and became the second woman to take a doctorate in physics at Vienna. In Berlin, Max Planck admitted her to his lectures when women were formally barred; Emil Fischer's institute would let her work only in a converted carpenter's workshop in the basement, with its own entrance, and forbade her the laboratories upstairs. She worked unpaid for years. With the chemist Otto Hahn she collaborated for three decades and discovered the element protactinium. In 1938, being Jewish, she fled Germany with ten marks and a diamond ring Hahn gave her in case she had to bribe a border guard. From exile in Sweden she continued to correspond with Hahn, who wrote that December to report that bombarding uranium with neutrons had produced barium — an element roughly half uranium's size, which his chemistry made certain and which physics said was impossible. Walking in the snow at Kungälv with her nephew Otto Frisch, Meitner treated the nucleus as a liquid drop that could stretch and split, calculated the missing mass, and converted it by Einstein's relation into about two hundred million electron-volts per event. The numbers agreed. She and Frisch published the explanation and named it fission. Hahn published the chemistry without her name and accepted the 1944 Nobel Prize in Chemistry alone. Meitner refused to work on the atomic bomb and detested being called its mother.

Major achievements

• Discovered the element protactinium with Otto Hahn
• Provided the physical explanation of nuclear fission, with Otto Frisch, in 1939
• Calculated the energy released per fission from the mass defect
• Gave the process its name
• Refused an invitation to work on the Manhattan Project

Life in brief

• 1878 — Born in Vienna: When girls could not attend the schools leading to a university.
• 1907 — Arrives in Berlin: Admitted to Planck's lectures; given a basement workshop to work in.
• 1918 — Protactinium: Discovered with Otto Hahn after years of collaboration.
• 1938 — Flight from Germany: Leaves with ten marks and a ring for bribing border guards.
• 1938 — Hahn's letter: Uranium and neutrons have produced barium: certain, and impossible.
• 1938 — The walk at Kungälv: With Frisch: the liquid drop splits, and the mass defect gives the energy.
• 1939 — Fission named: The explanation published with Frisch.
• 1944 — The Nobel Prize: Awarded to Hahn alone, for chemistry.

Explore the life of Meitner — five chapters

1. A Basement With Its Own Entrance — Vienna, Berlin, and the doors that were shut
2. Thirty Years With Hahn — A partnership of physics and chemistry
3. Ten Marks and a Ring — Flight, July 1938
4. The Walk in the Snow — Kungälv, Christmas 1938
5. The Prize She Did Not Get — Hahn alone, 1944, and a refusal

Read the five-chapter life of Lise Meitner →

Where Meitner appears in your course

Lise Meitner has a genuine claim on 2 lessons of the Pearson Edexcel International GCSE science course built into Incandio:

• Nuclear Fission — Physics: Statement 7.18 is Meitner's explanation. In December 1938 Otto Hahn wrote to her in exile reporting that bombarding uranium with neutrons had produced BARIUM — an element about half uranium's size, which his chemistry made certain and which physics said was impossible, since nothing known could take that much off a nucleus. Meitner, with no laboratory, walked in the snow at Kungälv with her nephew Otto Frisch, treated the nucleus as a liquid drop that could stretch and split, calculated the missing mass and converted it to energy. The numbers agreed. She named the process fission; Hahn published without her and took the Nobel Prize alone.
• Nuclear Fusion — Physics: Meitner is the person who first carried out, for fission, exactly the calculation this page describes for fusion: work out the mass of everything before, the mass of everything after, and convert the difference. She is the right figure for statement 7.23 because she can explain what at first looks like a contradiction — that opposite processes both release energy — from the inside of having done the arithmetic. The answer is that both move material towards the most stable nuclei in the middle of the range, and it is the position of the fuel rather than the direction of the process that decides.

Begin

• Start a conversation with Meitner — a dramatised, historically grounded AI portrayal
• Read the Historical Brief
• Explore the life of Meitner — five chapters
• Find your exam topics · Meet all 208 figures