Maria Goeppert Mayer
Maria Goeppert-Mayer
1906 — 1972
États-Unis, Allemagne
An American theoretical physicist of German origin, she developed the nuclear shell model of the atomic nucleus. In 1963, she became the second woman in history to receive the Nobel Prize in Physics, after Marie Curie.
Key Facts
- 1906: born in Kattowitz (German Empire, present-day Poland)
- 1930: earns her doctorate in physics from the University of Göttingen
- 1942–1945: contributes to the Manhattan Project (uranium isotope separation)
- 1949: publishes her nuclear shell model and the theory of magic numbers
- 1963: awarded the Nobel Prize in Physics, the second woman to receive it after Marie Curie (1903)
Works & Achievements
The first rigorous theoretical treatment of the simultaneous absorption of two photons by an atom. This work, thirty years ahead of its time, was not experimentally confirmed until the invention of the laser.
Maria contributed to classified research on the separation of uranium isotopes needed for the construction of the atomic bomb. This work deepened her understanding of nuclear physics.
A landmark paper published in Physical Review, presenting evidence for 'magic numbers' (2, 8, 20, 28, 50, 82, 126) corresponding to particularly stable nuclear configurations.
A decisive follow-up paper introducing spin-orbit coupling to mathematically explain the sequence of magic numbers, a cornerstone of the nuclear shell model.
A definitive reference work that synthesizes and develops the nuclear shell model. Co-written with the German physicist who had independently reached the same conclusions, this book became the standard textbook of the field.
Maria's Nobel Prize acceptance lecture, in which she clearly explains the intuition and intellectual journey that led her to the shell model, presented in a way accessible to non-specialists.
Anecdotes
During her years of study at the University of Göttingen, Maria Goeppert was one of the few women admitted into elite scientific circles. She earned her doctorate in 1930 under the supervision of Max Born, and her thesis on two-photon absorption processes was so remarkable that it would not receive experimental confirmation until thirty years later, with the invention of the laser.
After her marriage to chemist Joseph Edward Mayer and their move to the United States, anti-nepotism rules at American universities prevented Maria from obtaining a paid position for years, simply because her husband was already a professor at the same institutions. She therefore worked without pay as an associate at Johns Hopkins and then at Columbia, all while producing first-rate research.
It was a brief question from Enrico Fermi that triggered Maria Goeppert-Mayer's decisive breakthrough. In 1948, as she was presenting her observations on nuclear 'magic numbers,' he asked her: 'Is there any indication of spin-orbit coupling?' Within a matter of hours, she had mathematically formalized this coupling — the cornerstone of her nuclear shell model.
When she received the Nobel Prize in Physics in 1963, the main San Diego newspaper where she lived ran a front-page headline reading: 'San Diego Mother Wins Nobel Physics Prize.' This framing, which reduced a brilliant physicist to her family role, made Maria smile — she had spent decades watching her scientific achievements be downplayed because of her gender.
Maria Goeppert-Mayer was one of the few women to participate in the Manhattan Project during World War II. She worked on the separation of uranium isotopes, highly classified work she was long unable to discuss publicly. This research into nuclear structure directly fed the thinking that would ultimately lead to her shell model.
Primary Sources
The binding energies of nuclei show discontinuities at certain values of N and Z which are suggestive of the existence of nuclear shells. These 'magic numbers' are 2, 8, 20, 28, 50, 82, 126.
The assumption of a strong spin-orbit coupling leads to a splitting of the energy levels which gives the correct magic numbers. The level order obtained accounts for the observed nuclear spins and magnetic moments.
The shell model provides a systematic framework for understanding nuclear properties. The ordering of single-particle levels, determined by the spin-orbit interaction, explains the sequence of magic numbers observed experimentally.
Long ago, when I first started to work in nuclear physics, I noticed that a few numbers kept recurring — 2, 8, 20, 28, 50, 82, 126. These were the magic numbers. I tried to find some simple reason for them.
This doctoral thesis presents the first complete theoretical treatment of the two-photon absorption phenomenon, demonstrating that an atom can simultaneously absorb two photons whose combined energies correspond to an electronic transition.
Key Places
Maria Goeppert's birthplace, then part of the German Empire. Her father was a professor and later rector of the university there, creating an intellectually stimulating environment that profoundly shaped Maria's calling as a scientist.
One of the world's leading centers for theoretical physics in the 1920s and 1930s, where Maria earned her doctorate in 1930 under the supervision of Max Born. There she worked alongside figures such as Werner Heisenberg and Enrico Fermi.
It was here, between 1946 and 1959, that Maria developed her nuclear shell model. She worked alongside Enrico Fermi, whose pivotal question about spin-orbit coupling sparked her theoretical breakthrough.
A federal research laboratory where Maria conducted research alongside her university work. It provided her with experimental resources that complemented her theoretical studies on nuclear structure.
In 1960, Maria finally secured her first full-time paid academic position here, at the age of 54. It was also here that she learned, in 1963, that she would be awarded the Nobel Prize in Physics.