The Physicist Who Cracked the Secrets of the Atomic Nucleus

In October 1963, a local California newspaper published an article with the headline "San Diego Mother Wins Nobel Physics Prize." Two paragraphs into the article, readers learned that Maria Goeppert Mayer was a red-haired college professor and mother of two. Her scientific work was pushed aside. 

Goeppert's story is one of struggle, under-recognition, and the difficulties that she faced as a woman in the scientific world of the 20th century. However, these did not deter her from formulating groundbreaking theories and models that earned her a spot as one of the most significant figures in 20th-century physics.

Goeppert was born in 1906 in Kattowitz, Prussia (now Poland), the only daughter of Friedrich Goeppert and his wife, Maria Wolf. She grew up in Göttingen, Germany, and attended a school for girls from middle-class backgrounds aspiring to pursue higher education. During her high school years, she studied in a school run by suffragettes (women's rights activists), which prepared young women for university studies. At the age of 17, she passed the university entrance exams, and in 1924, she began studying mathematics at the University of Göttingen.

After obtaining her degree in mathematics, Goeppert continued her studies and earned a doctorate in physics in 1930. Her three examiners were future Nobel laureates: Max Born, James Franck, and Adolf Windaus. In her dissertation, she introduced the theory of two-photon absorption, which describes how molecules could be excited from a low-energy state to a higher-energy state in the electron shells through the absorption of two photons (light particles). At the time, no technological possibility existed to test the theory, but the development of lasers in the 1960s enabled the verification of the Goeppert Mayer model proposed three decades earlier.

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Upon completing her studies, Goeppert married Joseph Mayer, an American chemist she had met while he was a guest at her parents' home. Together they moved to the United States, where Mayer was appointed a chemistry professor at Johns Hopkins University. Regrettably, strict anti-nepotism policies barred Goeppert from being hired as a faculty member. Instead, she was designated as a research assistant in the physics department, provided with an office, access to research facilities, and a modest salary - a position that didn't fully reflect her extensive education and scientific achievements. She taught some courses, and in 1935, published a significant paper proposing the concept of double-beta decay, a type of radioactive decay that results from the conversion of two protons into two neutrons within the atomic nucleus.

In the early 1930s, Goeppert briefly returned to Göttingen, where she collaborated with local physicists, including Max Born, one of her doctoral examiners, and published several papers during this period. With the rise of the Nazis to power, she fled Germany and returned to the United States.

In 1937, her husband secured a position at Columbia University. Goeppert Mayer was also given a position in the physics department. However, she did not receive a salary, despite her status and reputation in the field. She collaborated with local physicists, including Enrico Fermi, a Nobel laureate in physics and a pioneer of quantum theory. In their joint work, Goeppert studied the highest external energy levels around the nucleus for elements heavier than uranium, which were only theoretically anticipated at the time. She estimated that they would form a new series of elements, a prediction that was later validated. 

In 1941, Goeppert Mayer began teaching at Sarah Lawrence College in New York, finally receiving a salary for her professional work. Shortly thereafter, during World War II, she was invited to join the Manhattan Project, the initiative responsible for the development of the American atomic bomb.

In 1946, when her husband accepted a position at the University of Chicago, Goeppert also joined as a faculty member in the physics department, once again in a voluntary capacity. It was there that she formulated a mathematical model delineating the arrangement of protons and neutrons within an atomic nucleus, demonstrating that they are arranged in pairs, creating overlapping ‘shells’, akin to layers of concentric spheres. 

Maria Goeppert Mayer with her husband, and above, pictured with the king of Sweden at the Nobel Prize ceremony | Photo Credit: Science Photo Library, Wikipedia

Late Recognition

In 1960, Maria Goeppert Mayer was appointed as a full professor at the University of California. In 1963, she was awarded the Nobel Prize in Physics for her work on the nuclear shell model of the atomic nucleus. She shared the prize with J. Hans D. Jensen, who had independently published very similar research, and Eugene Wigner, who studied symmetry in the atomic nucleus. For many decades, she remained one of the only two women, alongside Marie Curie, to have won the Nobel Prize in Physics. It wasn’t until more recently that they were joined by Donna Strickland, who was awarded the 2018 Nobel Prize in Physics for groundbreaking inventions in the field of high-intensity pulsed lasers (alongside Gérard Mourou and Arthur Ashkin), and by Andrea Chez, who was awarded the 2020 Nobel Prize in Physics for the discovery of a supermassive black hole at the center of the Milky Way galaxy (alongside Reinhard Genzel and Roger Penrose).

Sadly, Goeppert Mayer did not have a long tenure to enjoy her new position and status in the physics world. Even prior to receiving the Nobel Prize, she suffered a stroke. She managed to recover and resumed her research and teaching, but in 1971, she suffered a heart attack and remained in a coma until her death in February 1972 at the relatively young age of 66.

After her passing, the American Physical Society established the Maria Goeppert Mayer Award, which recognizes outstanding achievements by young women physicists. Academic institutions where she worked also honor her memory: the Argonne National Laboratory of the University of Chicago presents an annual award in her name to exceptional female scientists or engineers, and the University of California hosts an annual conference named after Geoppert for leading female scientists. Furthermore, the unit of measurement for a nuclear absorption cross-section in nuclear physics and a crater on Venus were named in her honor. 

During much of her long academic career, Goeppert Mayer accompanied her husband, settled for unpaid positions, and did not receive recognition for her achievements. After being awarded the Nobel Prize, she stated that ‘winning the prize wasn’t half as exciting as doing the work itself.’ Her passion for physics and research may explain how she persevered in a world that placed so many obstacles in her path until she finally received the recognition she rightfully deserved.