Published on 09/27/2025 at 1:43 PM by Verguet-Bailly Matias
Lise Meitner's Theory
How a physicist discovered the secret hidden at the heart of the atom.
CONTEXT
In the late 1930s, Lise Meitner studied an element called uranium.
Conducting physics experiments in the laboratory, she discovered that when a neutron is sent at a uranium nucleus, it breaks into two smaller nuclei.
This phenomenon, no one had yet understood: an atom had just been split, a revolutionary idea.
THE BIRTH OF NUCLEAR FISSION
Lise Meitner, in exile because of the Nazi regime, reflected on what they had just observed.
She calculated that the "loss" of matter during this split actually corresponds to released energy, according to Einstein's equation E = mc².
In simple terms: a tiny bit of matter can produce an enormous amount of energy.
THIS THEORY OPENS TWO PATHS
- the creation of nuclear power plants, which produce electricity.
- but also, sadly, the atomic bomb during World War II.
Lise Meitner, horrified by this military use, always refused to participate in the development of the weapon.
In 1944, the Nobel Prize in Chemistry was awarded solely to Otto Hahn.
Lise Meitner, yet the source of the scientific explanation, is not even mentioned.
This is one of the symbols of the Matilda Effect, when the contributions of women scientists are erased or minimized.