The forgotten women of quantum physics

In the 1960s, a group of physicists and historians began a massive project to catalog and record the history of quantum physics. It was called Sources for the History of Quantum Physics (SHQP). In this context, they conducted interviews with physicists who had contributed to the discovery of this field three or four decades earlier. Of more than 100 people interviewed, only two were women.

This is not necessarily surprising: physics has a reputation for being dominated by men, especially a century ago. But even today, recent surveys show that less than a quarter of physics degrees in the UK and US are earned by women. Follow the trend back in time and you can imagine arriving at a time when women simply didn’t do physiques. However, the history of quantum physics is not so simple, as I discovered in a book I read recently.

Women in the history of quantum physics includes 14 in-depth chapters on women who contributed to the field beginning in the 1920s, many of whom worked at a time when some of the field’s most famous and influential men were active, including Niels Bohr, Wolfgang Pauli, and Paul Dirac. Although I have spent nearly a decade studying or writing about quantum physics, I have to admit that I had only heard of two of these women: mathematician and philosopher Grete Hermann and nuclear physicist Chien-Shiung Wu.

Daniela Monaldi of York University in Canada, who co-edited the book, says she and her collaborators “were united by the conviction that quantum physics, broadly defined, deserves better stories, more complete stories, stories that do not invisibilize women or make them hyper-visible as singulars, anomalies, exceptions, legends, etc.”

Therefore, Women in the history of quantum physics explores the lives of physicists like Williamina Fleming, whose work in stellar spectroscopy – which relies on the analysis of starlight – provided evidence in favor of Bohr’s quantum model of the atomic helium ion. And Hertha Sponer, who experimentally studied the quantum properties of molecules, which also served as a powerful concrete test of Bohr’s theoretical work. He also discusses Lucy Mensing, one of the pioneers in the application of matrix mathematics to problems in quantum physics, a method now common in the study of, for example, quantum spin. Readers also meet Katharine Way, who worked in nuclear physics and collected and edited several publications and databases that have become indispensable in the field, as well as Carolyn Parker, spectroscopist and the first African American woman to receive a graduate degree in physics.

Reading about these physicists, I learned so much about the fine details of how the discipline we now call quantum physics became one of the most amazing branches of science. Even Wu’s story, which I thought I knew largely because she is famous for her work on the weak nuclear force, surprised and amazed me. It contained remarkable details of his pioneering but unrecognized work on quantum entanglement. This strange quantum property now forms the backbone of many rapidly maturing quantum technologies.

But perhaps the most interesting thing I took away was realizing how essential and ordinary many of these women’s jobs were. Their contributions to quantum physics did not necessarily cause paradigm shifts in the field, nor were they all singular, generational talents. They have achieved varying levels of academic achievement, published in journals or contributed to government research programs; some worked on military research projects or trained military technicians as part of the 1940s war effort, as was common for physicists at the time. In other words, they were working physicists – not geniuses or heroes, but each was one of many brilliant minds who, collectively, continue to advance knowledge day in and day out.

Although the book is written in the style of an academic text, Women in the history of quantum physics reveals a human dimension to how science works and how the accumulation of knowledge about our physical reality simply cannot be achieved by just a few people, no matter how exceptional they may be. Even a revolutionary branch of study like quantum physics needed the proverbial village to get off the ground, and we must not forget that some of its citizens were also women.

At the same time, the book goes beyond mere platitudes about science as a team sport. Monaldi hopes that part of its impact will be to make visible the ways in which the division of labor in academia, as well as social hierarchies, place some physicists in positions that may make them invisible. For example, many of the women featured in Women in the history of quantum physics worked as an experimenter or laboratory technician. In their time and in the decades since, this type of work often took a back seat to the big thoughts of theorists—but theorists do not work alone, and they never have. The groundbreaking theoretical work of Bohr – not to mention Albert Einstein or Erwin Schrödinger – had to be validated in one way or another.

In the same way that women’s work was historically less celebrated because they were relegated to “computers” in the sciences—performing complex calculations by hand before the advent of computers—in quantum physics, their work could also keep the field running while being devalued. Most of the women appeared in Women in the history of quantum physics have also spent at least part of their career working as teachers. Sponer and Hendrika Johanna van Leeuwen, who demonstrated that magnetism is an intrinsically quantum phenomenon, both shaped a generation of physicists who followed them.

Women were also, explicitly or by reason of their circumstances, pushed to undertake the kind of reform work that would make academia friendlier to their successors. Wu was responsible for leading a committee investigating the status of women at Columbia University in New York in the 1970s. Her contemporary, Maria Lluïsa Canut of Southern Illinois University, a crystallographer and early developer of computer simulation methods for quantum systems, was a prominent activist for gender equality. Certainly, these tasks reduced the time they could have devoted to their research. In the long run, they improved their field, but part of the price of this common good was their own ability to take advantage of the countless everyday wonders of physics research.

Their lives and careers were also shaped by forces and structures that transcended their particular physics departments. Many of them married other physicists, which in some cases degraded their status as researchers due not only to stereotypes but also to so-called nepotism laws. For example, throughout historical records, Sponer is falsely identified as the student of her quantum physicist husband, even though he never taught her. She appears in an SHQP interview which is only listed under her name.

Another example: Nuclear physicist Freda Friedman Salzman lost a research position because nepotism rules prohibited her and her husband from being employed in the same department – ​​but her position did not end. This particular asymmetry between the pairs of physicists who worked together is repeated throughout the book..

Monaldi says one of the goals of these essays was to show the diversity of physicists, emphasizing that quantum physics was not built only by women in a few European countries and the United States. Accordingly, it explores how intersectional identities have influenced the work of female physicists, for example Wu’s experience as a Chinese immigrant and the obstacles Carolyn Parker faced during the Jim Crow era, when racist laws prevented her from participating fully in the physics community.

The current moment is certainly one where any discussion around a book like Women in the history of quantum physics carries a lot of weight. The United Nations declared 2025 the International Year of Quantum Science and Technology, putting quantum physics in a new light, both its first century of existence and its future evolution. As a quantum journalist, I can also personally vouch that this year has been a big year for quantum technology, and that there is a whole generation of young physicists currently shaping what could be the next great era of quantum physics.

At the same time, here in the United States, it’s been a tumultuous year for science. President Donald Trump and his administration have targeted programs related to diversity, equity and inclusion, and many government-backed research agencies have faced funding cuts. U.S. immigration policies, which have historically allowed the world’s best physicists to work here, have also come under attack by the Trump administration.

Although Monaldi says she and her colleagues didn’t expect their book to be published at such a hot time, they believe it has much to contribute to how we move forward. “Diversity does not mean divergence and dispersion of goals. It means uniting forces from different points of view to solve common problems. And we face many global challenges that must be solved by the union of diverse forces. There is no other way,” she says.

Personally, I was motivated and inspired by reading Women in the history of quantum physics. Having been both a woman and a physicist, it seemed significant to me to find small overlaps between my experience of the world and theirs. And learning that the history of physics is richer than I thought certainly made me love it more.