Master Geng: Chinese Alchemist Geng Xiansheng, 'Refining Snow' or Using Mercury to Extract Silver from Snow

Geng Xiansheng, linocut 9.25" x 12.5" by Ele Willoughby, 2025

Mercury is the final prompt for #printerSolstice2425, which again made me think of alchemy. It is an element the alchemists favoured and felt was fundamental in their efforts to transmute base metals into precious metals, both in western and Chinese alchemy (from whence the more familiar western alchemy emerged). Chinese alchemy (煉丹術 liàndānshù), a name which literally means a method for refining cinnabar, or mercury sulphide (HgS) focused on longevity (and alignment with Tao) . It can be divided into the esoteric "inner alchemy" and "external alchemy" focused on making elixirs. 

The earliest recorded woman in Chinese alchemy was Fang (Chinese: 方), who lived roughly the first century BCE and is credited with a method for turning mercury into silver. So little is known about her, and what little that is known is so tragic, that I opted for another woman alchemist associated with "turning" mercury into silver, ten centuries later.  

This is my hand-printed linocut portrait of a woman alchemist known as Master Geng who flourished some time before the year 975 (Chinese: 耿先生; pinyin: Gěng Xiānshēng; Wade–Giles: Kêng Hsien-shêng). According to legend, this daughter of a scholar named Geng Qian (sometimes spelled Keng Chhien),  was known from adolescence for her intelligence, curiosity and skill in alchemy. She appears in the writing of alchemist Wu Shu, in his book Chiang Huai I Jen Lu (or Records of Twenty-five Strange Magician-Technicians between the Yangtze and Huai River) written in 975. An expert in what was called "the art of the yellow and the white" (that is, alchemy), she distilled perfumes and was also known as a talented poet and magician. Her fame grew to the point that the Emperor Xuanzong (circa 846-859) invited her to the palace, where rather than being counted amongst the palace women, she was honoured as a scholar and given the title Master, as in teacher. She was eloquent, spoke with confidence and known for wearing green robes and for her skills in performing alchemical transformations in the Imperial Court. In particular, she was known for using mercury for "creating" silver. One story tells that she could even transform snow into silver. The Emperor wished to test her skills and noted that all her transformations employed fire  and enquired whether she could perform a transformation without it. 

"She answered, 'Let me try. It might be.' So the Emperor took some mercury and enveloped it in several layers of beaten bark-cloth, closing it with the [Imperial] seal; this she placed forthwith in her bosom. After a long time there suddenly came a sound like the tearing of a piece of silk. The Teacher [Geng Xiansheng] smiled and said: 'Your Majesty did not believe in my methods, but now you will see for yourself. Ought you not to trust me ever hereafter?' Then she handed the packet back to the Emperor who saw that the seal was unbroken and upon opening it found that the mercury had all turned to silver."

Song Dynasty scroll painting "Master Geng of the Southern Tang Dynasty refining snow'"

Modern chemists speculate that she might in fact have been using a legitimate chemical process which uses mercury to extract silver from ore. Likewise, her distilling of perfumes could have employed early prohibitive form of the Soxhlet process to continuously extract camphor into alcohol. Thus while alchemy differs from modern chemistry in aims and understanding, she would have been using some methods which we can recognize as scientific and can be seen as part of history of chemistry.

In her personal life she was known for her love of wine and romantic liaisons. 

My portrait is inspired by Song Dynasty paintings including one scroll painting called 'Master Geng of the Southern Tang Dynasty refining snow' and illustrations of alchemists and their tools like the large three-legged ting furnace in which medicines were prepared.

Detail of Song Dynasty scroll painting "Master Geng of the Southern Tang Dynasty refining snow'"

References

Chinese alchemy, Wikipedia, accessed March, 2025

Fitzgerald, C.P. The Horizon History of China, American Publishing Co., Inc., New York, 1969.

Gordon, Robin L. Chinese Women Alchemists, Women Alchemists 2.0 website, accessed March, 2025.

Master Geng, Wikipedia, accessed March, 2025

Maxwell-Stuart, P. G. (2012-03-01). The Chemical Choir: A History of Alchemy. A&C Black. p. 13. ISBN 9781441132970.

Rayner-Canham, Marelene F.; Rayner-Canham, Marelene; Rayner-Canham, Geoffrey (2001). Women in Chemistry: Their Changing Roles from Alchemical Times to the Mid-twentieth Century. Chemical Heritage Foundation. pp. 4–5. ISBN 9780941901277.

Xin, Yang, Barnhart, Richard M., Chongzheng, Nie, Cahill, James, Shaojun, Lang and Hung, Wu. Three Thousand Years of Chinese Painting, Yale University Press, 1997

Florence Bascom geologist

Florence Bascom, linocut print, 9.25" x 12.5" by Ele Willougby, 2025

As an Earth scientist, the #printerSolstice2425 prompt silicon made me think of the Earth's crust, so I took the opportunity to make a portrait of brilliant trailblazing US geologist and professor Florence Bascom (1862-1945) who championed women’s education, and, amongst other things, pioneered the use of microscopy in petrology (the field of geology describing the structure and minearlogic composition of rocks) and used polarizing microscopes for detailed petrographic analysis to show that rocks previously identified as sedimentary were in fact metamorphosed (that is, changed in composition through heat and pressure over time). She called these volcanic rocks she called aporhyolite (implying a change in rhyolite, a silica rich igneous rock, as in her thin sections like the ones in my print). Though she was the second US woman to complete her doctorate in geology, after paleontologist Mary Emilie Holmes (University of Michigan, 1888), Bascom, the most famous US early woman geologist, is often called the first US woman geologist.

A portrait of Florence Bascom (Public Domain). Smithsonian Institution Archives Collection:
Science Service Records, 1902-1965 (Record Unit 7091)

Unusually for the time, she was encouraged to pursue university education. She was born the youngest of five children in Williamstown, Massachusetts. Her father John, Bascom was a teacher, then professor of oratory and rhetoric at Williams College and supporter of women's suffrage and coeducation. He became president of University of Wisconsin in 1874 and by 1875 he had opened the school to women. Her mother was a teacher, firebrand suffragette and women’s rights activist Emma Curtiss Bascom. Florence herself, a quiet, self-possessed, brilliant student, entered the University of Wisconsin in 1877 at age 15. Women still had limited access to the library, gymnasium and classes with full male enrolment. If there were not enough seats for men in attendance, women were asked to leave the classroom. Her interest in science was fostered by trips exploring the outdoors with her father, who maintained an observatory and laboratory at home. She completed both a BA (1882) in literature and a BSc (1884) in natural science, at the University of Wisconsin. She taught at the Hampton Institute (now Hampton University, 1884-1885), created post-Civil War to educate freed Black formerly enslaved students and Indigenous students. Homesickness brought her back to Madison, Wisconsin. During a drive with her father and family friend, Ohio State University geologist Dr. Edward Orton, discussing the formation of the landscape around them, she became fascinated. With some encouragement and cajoling from her father, she re-enrolled and completed her M.Sc in geology at the University of Wisconsin in 1887. She was frustrated that the field did not allow her to participate as fully as her male peers and was barred from taking part in fieldwork, which was (and often still is) considered a fundamental part of the training of geologists. She taught high school at the Rockford Seminary for Women (later Rockford College) for two years but craved a greater challenge. Her professors encouraged her to pursue her doctorate at John Hopkins University, then the premier geology school.

Florence Bascom holding a Brunton compass1. From: Sophia Smith Collection, Smith College

Despite her multiple degrees and glowing letters of recommendation from several geologists and her university president father, she still had to argue her case to be allowed as the first woman enter the doctoral program at John Hopkins University. The university's founder and president Daniel C. Gilman vehemently opposed coeducation. One of the trustees called women "the foreign enemy within the walls." She petitioned for admission, arguing that she could not receive an equivalent education elsewhere, and was successful with support of her professors. But even then, she was not an official student, and was ineligible for scholarships or fellowships. She needed her family's financial support to attend. She was unhelpfully limited in her library and classroom access to protect her from the “rougher influences” of the young men. Many sources claim that Bascom was forced to sit behind a screen during lectures to shield her from the men and avoid distracting them, but other scholars point out there is a lack of primary sources to support this story; whether the story is true or apocryphal, she certainly found herself quite isolated and singled out, the subject of sexism and animosity. In 1891, her father wrote to her that "you better put a stone or two in your pocket to throw at those heads that are thrust out of windows," in response to those who would gawk at the lone woman. She was forbidden as a woman to participate in fieldwork through the university, but her supervisor, renown geologist George Williams, who believed strongly in equal education for women, insisted fieldwork was a necessary part of a geologist's training. He also worked for the United States Geological Survey (USGS) so, he took her on his USGS field excursions, bringing his wife along to avoid unwanted rumours about a male professor alone in the woods with his female student. Bascom fell in love with fieldwork. She did all the physical work of field geology, hiking and hauling tools and samples, as her male peers, in a high necked gown. In her isolation at the university she decided to focus on petrology and became expert in crystallography and mineralogy. She worked in these nascent fields, trained by the leaders and earliest pioneers. Her thesis “A Contribution to the Geology of South Mountain, Pennsylvania” is regarded as a major contribution to Appalachian geology and she published part of it in the first volume of the Journal of Geology in 1893. Though other some faculty denounced the very idea of women PhD candidates, Williams supported her research and publication efforts and cited her research in his own publications. Tragically, Williams, then only 38, contracted typhoid fever while in the field in 1894. Knowing Bascom would face barriers to publication as a woman, as his health worsened, he submitted her work to the USGS and succeeded in having it published as USGS Bulletin 136 before he died. She used the very recent geologic technique of petrographic microscopy to correct misconceptions about the formation of rocks at the northernmost tip of the Blue Ridge Mountains. She furthered understanding of the east coast of the US and redefined the recognized cycles of erosion in Pennsylvania. She published more than 40 papers - still relevant today - about the crystallography and geomorphology of the Appalachian Piedmont, in Maryland and Pennsylvania, including length USGS Bulletins and Folios. After teaching for a couple of years at Ohio State (1893-1895), she was recruited by women's college Bryn Mawr President James Rhoads. She founded the Geology Department at Bryn Mawr in 1895, working out of a small spaced boarded off in the storage area of the biology, chemistry and physics building. After his death, his successor Martha Carey Thomas did not think geology would appeal to women, and discouraged it. Nonetheless, she persisted, working tirelessly to establish their mineral and literature collection for teaching over the course of two years, developing a lab and field-based curriculum. She became a full prof in 1906, and took a year-long sabbatical to the University of Heidelberg to train with renown crystallographer Victor Mordechai Goldschmidt, who had studied alongside Bascom's supervisor Williams. Bascom and Goldschmidt became true friends, and Florence gained a second devoted mentor and confidant with whom she corresponded for many years. She continued to correspond with his wife Leontine after his death.

In her research she was detail-oriented and driven by the data. Her writing was clear and incisive if sometimes terse, forceful and unapologetic. For instance, in correcting a poorly-determined age for certain igneous rocks previously published in the literature she wrote, "this determination was made on the basis of some rather dubious fossils submitted... by Persifor Frazer and cannot, therefore, be considered perfectly trustworthy." She proceeded to make her own case with clear and detailed illustrations, like those I included in my portrait. She also defended her turf fiercely, on occasion feuding with colleagues who published on her area of expertise but neglected to seek her review.

Florence Bascom (second from front, flat rather than pointy hat) on a field trip,
possibly to the Grand Canyon, with students in 1906. Sophia Smith Collection (Smith College)

Having benefited from great mentorship, Bascom followed suit and was an extraordinary mentor. A tough but innovative in teaching and a devoted mentor, she trained the next generation of women in geology, making one of the best geology departments in the country. She invited world-famous geologists to come lecture her students. She emphasized both lab and fieldwork for students. She argued fieldwork should count towards their physical education credit, clashing with university president Thomas who demanded that women wear appropriate apparel. The usual "athletic skirt" was not to be worn off-campus, and students would require walking skirts before being allowed in the field.  In 1932, she wrote, "I have considerable pride in the fact that some of the best work done in geology today by women, ranking with that done by men, has been done by my students... these are all notable young women who will be a credit to the science of geology." In 1937, of the women who had been made Fellows of the Society of America, 8 of 11 had been her students at Bryn Mawr. Hired to do fieldwork by the USGS in the summers, she returned to Bryn Mawr in to teach after her field seasons and write up her research. Working at the USGS gave her access to more books, labs and colleagues. The university president used her passion for fieldwork and her USGS work to argue that the geology program should be dissolved, but Bascom won that battle too. The strain of her double career and teaching load made things difficult and put a strain on her mental health. But she loved her work and wrote, "one finds a joy that is beyond expression in 'sounding the abyss of science' and the secrets of the infinite mind.

Photo of Bascom teaching in the field around 1915. Bryn Mawr College Archives (Public Domain)

She was the first woman: hired by the USGS in 1896; to present a paper at the Geological Society of Washington in 1901; and she was the second women elected to the Geological Society of America in 1924; and elected VP of the GSA in 1930. She was associate editor of the American Geologist, 1896-1905. In 1906 she the only woman added to the list of 100 most influential geologists by the American publication Men in Science; she was recognized by her colleagues as one of the leading figures in the field. Though future editions included many of the women students she trained, it remained "Men" in Science until 1971. A lover of animals as well as the outdoors, she was known for hiding her horse Fantasy around campuses, and bicycling to work when wearing divided skirts to do so was still rather scandalous. She never married, commenting that women were too often lost to science due to marriage and domestic duties - an issue we still see today. She cut her hair short and often did not bother styling it, having other priorities and working from dawn to dusk in the field. She wrote, "This is the life, to plunge into the welcome isolation of the field, to return to the stimulating association of Bryn Mawr, to observe and in part to clear up geologic phenomena, to return to the exposition and interpretation of geologic phenomena." She retired in 1928 from Bryn Mawr to the Berkshires in western Massachusetts but kept working at the USGS until age 74 in 1936. She died June 18, 1945, in Williamstown, where she was born. The USGS Florence Bascom Geoscience Center, and several geological features including a glacial lake, Venusian crater and an asteroid are named in her honour. She left behind a tremendous record of important geological research and excellent mentorship and training of future geologists.

References 

Ball, Jessica. Dr Florence Bascom: Sounding the abyss of science. Finding Ada. April 1, 2021.

Bascom, F. and G. W. Stose. Description of the Coatesville and West Chester Quadrangles. US Geological Survey Atlas of the United States, Folio, 223. 1938.

Bascom, F. and G. W. Stose. Geology and Mineral Resources of the Honeybrook and Phoenixville Quadrangles, Pennsylvania. USGS Bulletin 891, 1938.

Florence Bascom (1862-1945), Geological Digressions, September 26, 2024. 

Florence Bascom Wikipedia, accessed March, 2025.

Florence Bascom, Trailblazer of the U.S. Geological Survey, Communications and Publishing, USGS, March 1, 2023.

Hurler, Kevin. Florence Bascom, a geologic juggernaut. Advanced Science News, January 27, 2022.

Oglivie, Ida H. Florence Bascom 1862-1945. Science. Vol. 102, Issue 2648, pp. 320-321, September 28, 1945, DOI: 10.1126/science.102.2648.320

Schueth, Jon. The Stone Lady: Florence Bascom (Part 1). Bias in the Fossil Record. April 2, 2021.

Schueth, Jon. A "Woman's Sphere" - Florence Bascom (Part 2). Bias in the Fossil Record. April 12, 2021.

Schueth, Jon. On the Shoulders of Giants: Florence Bascom (Part 3). Bias in the Fossil Record. April 20, 2021.

Schueth, Jon. The Bascom-Goldschmidt Letters: Florence Bascom (Part IV). Bias in the Fossil Record. May 6, 2021.

Shillito, Lisa-Marie. Florence Bascom. Trowelblazers. July 14, 2014.

Sneiderman, Jill S. Rock Stars: A Life of Firsts: Florence Bascom. GSA Today, July 1997.

The Stone Lady Florence Bascom, Acadia National Park, National Park Service, last edited February 5, 2021.

Marie Meudrac, where the transition from alchemy to chemistry meets medicine, cooking and cosmetics: chemistry by a woman for women

Marie Meurdrac, linocut, 9.25" x 12.5" by Ele Willoughby, 2025

This is my hand-printed linocut portrait of Marie Meurdrac (c. 1610-1680), one of the first chemistry textbook authors and the first woman to publish a book on early chemistry. Working right at the transition between alchemy and chemistry, in 1666 she published 'La Chymie charitable & facile, en faveur des dames' (Charitable and easy chemistry for ladies). I selected her for the #printerSolstice2425 prompt sodium, as for her, salt, "the father of generation" was the first of the 3 elements, salt, sulphur and mercury, from which all materials were made. 

We do not know a great deal about her life for certain. Born to a land-owning family, in Mandres-les-Roses, now a suburb of Paris, to Vincent Meurdrac or Meurdrat, a notary, and Elisabeth Dove.  Her younger sister Catherine, became the author and memoirist with the nom de plume Madame de la Guette.  She married a military man. Her sister recorded his name as Monsieur de Vibrac, captain du château de Grosbois, where she moved after her marriage. He was commander of Charles de Valois, Duke of Angoulême (illegitimate son of Charles IX of France)'s guard unit. However the Abbot Sanson recorded that she married Guillaume de Brisset; but this discrepancy might be explained if Guillaume de Brisset succeeded his father Monsieur de Vibrac to both the fiefdom of Vibrac and the captaincy.  In any account, living there, she became good friends with Countess de Guiche. She taught herself chemistry following the works and experiments of her contemporaries and reading books on chemistry and alchemy. She had her own lab where she tested all her remedies and recipes. She dared to write a handbook of practical chemistry, which helped popularize the subject throughout Europe, at a time when the very idea of scholarly women was ridiculed in France. The  woman question ("la querelle des femmes")- or rather the question of whether women should be educated at all was widely debated. The book is dedicated to the countess; Meurdrac had access to a high temperature furnace which required permission of the king which she might have got thanks to the countess. 

Chemistry had long been practiced by women in cooking in the kitchen, in making household remedies and cosmetics, but as sciences became formalized it became a man's world. Meurdrac had been keeping notes of all her experiments so as not to forget her results when she realized she had enough for a book as complete or more so than other available chemistry handbooks. The word “chymie” comes from 16th century Swiss doctor Paracelsus, and following in his tradition, she believed that matter is made of various quantities of 3 elements: salt, mercury, and sulphur, but unlike previous alchemist authors (including those she cites like Raymond Lull and Basil Valentine) her writing is clear and unpretentious rather than obscure. She wants to expose what alchemists would keep a secret for the select few. She omits the astrological conditions so come in alchemical recipes. 

The Preface from Marie Meurdrac's  'La Chymie charitable & facile, en faveur des dames' complete with her argument "les Esprits n'ont point de sexe"

She wrote about her uncertainty in daring to publish as a woman, concerned that it might be above her station and knowing that men scorn the products of women's minds but concludes that but minds "have no sex and that if the minds of women were cultivated like those of men, and that if as much time and energy were used to instruct the minds of the former, they would equal those of the latter.” Her words, "les Esprits n'ont point de sexe" appear in my print, as in her book. Knowing that bourgeois or even aristocratic women were denied formal scientific education in universities, she wanted to provide accessible chemistry, botany, pharmacology, medicine, as well as in cosmetics knowledge and hands-on training to women. As women could not legally practice medicine, providing free healing services and lessons was a sort of loophole for her, hence the word "charitable" in her title.  She covered items such as lab techniques, properties of medicines, and cosmetics. She also had a table of weights and 106 alchemical symbols that were used in medicine at the time. The jars behind are marked with these symbols. She presents ingredients as "principles" rather than materials, in the manor of the alchemists and describes methods used both by alchemists and early chemists such as distillation, sublimation, rectification, calcination, cohobation and so forth, with specific vessels and fires to be used. She includes recipes which could be found in contemporary chemistry texts such as for Flowers of Bezoin, or Salt of Saturn. Following Paracelsus she writes about plants in medicine, as they believed them superior to other matter, created prior to animals according to Genesis and having survived the great flood. She was wary of using metals in medicine, viewing such treatment as more aggressive. She brought her knowledge to a wide audience, empowering women to make their own remedies and cosmetics safely, for instance, correctly warning of the dangers of using poisonous mercury sublimate to whiten skin as was done at the time. 

She is surrounded with books, tools, supplies and plants she would have used including scales, glassware, tongs, and a furnace, inspired by the frontispiece in one of the several editions of her book. The plants are rosemary, which she describes as a universal antidote to all sorts of illnesses, and tansy, used to facilitate childbirth. The book was popular for more than 50 years, with five editions in France, six in Germany, and one in Italy. She encouraged her readers to follow her lead and use their skills to freely treat the poor. Recognizing the cost of materials and tools she offers her readers some more accessible alternative suggestions and offers advice on finding the more rare ingredients. She even offers to answer readers' questions or even make demonstrations in person. Writing about chemistry for women, when it was claimed by men for men, was transgressive, and she defends her ability to do so with her strong feminist argument. She made hands-on training in chemistry, botany, pharmacology, and medicine, as well as in cosmetics accessible to generations of women. 

References

Bulletin du bibliophile, Volume 24, Techner, 1859. pp. 252-253

Fiendstein, Sandy. Experience, Authority and Alchemy of Language: Margaret Cavendish and Marie Meurdrac Respond to the Art. Early Modern Women, Volume 15, Number 2, Spring 2021, pp. 133-142 (Article) Published by Arizona Center for Medieval and Renaissance Studies. DOI: https://doi.org/10.1353/emw.2021.0028

Fiendstein, Sandy. La Chymie for Women: Engaging Chemistry's Bodies. Early Modern Women: An Interdisciplinary Journal, vol 4, 2009, pp. 223-234.

Findlay, Sam. 'Mind has no sex': The story of Marie Meurdrac, First Lady of Chemistry, ARC Centre of Excellence for Electromaterials Science, March 10, 2015.

Gordon, Robin L. 2015. Marie Meurdrac. Women Alchemists: Stories and  Reflections on their Place in History, Psyche and Science. accessed, February, 2025

Marie Meudrac - La chymie pour les femmes, YouTube video by Sur les épaules des géantes, February 3, 2021

Marie Meudrac, Wikipedia, accessed February 2025 (both English and French versions)

Meurdrac, Marie.  La chymie charitable & facile, en faveur des dames : 1666, Paris, CNRS, 1999 octobre 1999(réimpr. présentée et annotée par Jean Jacques) (1^re éd. 1666), 249 p. (ISBN 2-271-05726-4).

Rayner-Canham, Marelene F.; Rayner-Canham, Marelene; Rayner-Canham, Geoffrey (2001). Women in Chemistry: Their Changing Roles from Alchemical Times to the Mid-twentieth Century. Chemical Heritage Foundation. pp. 4–5. ISBN 9780941901277.

Neon, as in Nixie tubes and Copper as in blue-blooded horseshoe crabs

 

Nixie Tubes, 8" x 8" linocut by Ele Willoughby, 2025

I wasn't sure what to make for the #PrinterSolstice2425 prompts neon because it's a famously un-reactive noble gas. It does play a role in stellar nucleosynthesis, but that was the subject of my last print. Copper on the other hand has such a long history and huge role in art and science that I didn't know where to begin. I opted for Nixie tubes and horseshoe crabs.

Nixie tubes, also known as or cold cathode display, are electronic devices used for displaying letters or numerals or other information using glow discharge. Introduced in 1955, they are prized today for their vintage aesthetics. Inside a glass tube, there's a wire-mesh honeycomb-shaped anode, and if you look carefully you can make out the multiple cathodes shaped like alphanumeric characters (here printed in silver). When a cathode is powered it becomes surrounded with an orange glow discharge. The tube is filled with a gas at low pressure, usually neon with a small amount of argon.

Horshoe crab, 8" x 8" linocut by Ele Willoughby, 2025

My hand-printed horseshoe crab (Tachypeus gigas) is hand-printed in grey, blue-bronze and dark brown on 8" x 8" cream-coloured Japanese paper with bark inclusions. They get their name from their horseshoe like shape but they are not crabs; they are chelicerates, more closely related to arachnids and they are "living fossils" which have changed very little since they first appeared in the Triassic. The textured sandy paper is meant to look like sand on a beach. They actually swim with their underside up, but prefer to stay on the sea bottom.

There are four species of horseshoe crab which are still living. T. gigas is a species from the Indo-Pacific. The blood of horseshoe crabs (like most mollusks) contains the copper-containing protein hemocyanin rather than hemoglobin (the iron-containing protein), which is the basis of oxygen transport in vertebrates. Colourless when deoxygenated hemocyanin turns dark blue when oxygenated. In circulation, the horseshoe crab's blue is grey-white to pale yellow,  but if exposed to air when they bleed, it turns dark blue. Hemocyanin carries oxygen in extracellular fluid, unlike the oxygen transport in vertebrates by hemoglobin in red blood cells. 

Tachypleus gigas inhabits seagrass meadows, sandy and muddy shores at depths to 40 m (130 ft) and is the only horseshoe crab to have been observed swimming at the surface of the ocean. It lives in both marine and brackish waters in tropical South and Southeast Asia.

Katsuko Saruhashi, marine geochemist who measured CO2 in the oceans and showed how radioactivity spread from nuclear testing

Katsuko Saruhashi, linocut print, 9.25" x 12.5" by Ele Willoughby, 2025

This is my hand-carved and hand printed linocut portrait of Japanese geochemist Katsuko Saruhashi (1920-2007) who created tools that allowed her to make the first measurements of CO2 in seawater, raised the alarm about nuclear fallout, tracing it in the oceans, and researched peaceful uses of nuclear power. A supporter of women in science, she established the Society of Japanese Women Scientists and the Saruhashi Prize for Japanese women researchers for excellence in science and mentoring women scientists. Each print is 9.25” x 12.5” on Japanese kozo, or mulberry paper. I made this print for the #printerSolstice2425 prompt carbon.

Born in 1920, the story goes that her interest was sparked in science watching raindrops in primary school, wondering about the source of rain. Her parents believed in education, but she had to make a case to leave a secure insurance job at 21 to study chemistry. Her family witnessed how women struggled to support themselves without husbands or fathers in wartime. So her mother thought science might be a good way to ensure financial independence. She studied chemistry at the Imperial Women's College of Science (now Toho University). After completing her undergrad degree in 1943 she worked at the Geochemical Laboratory at the Meteorological Research Institute (now the Japan Meteorological Agency) with her mentor, marine chemist and lab director Miyake Yasuo, who had a strict policy against gender discrimination. She developed the first tool to measure CO2 in the oceans using pH and chlorinity, called Saruhashi's Table. She enrolled in the PhD program at the renowned University of Tokyo in 1957, where she was the first woman to earn a science doctorate. Her dissertation was on "The Behaviour of Carbonic Matter in Natural Water". With Miyake, she showed that oxidation of organic material increased CO2 in the ocean; prior to this, oceanic CO2 levels were attributed to dissolved calcium carbonate (for instance from in sea shells) and that global warming could be mitigated by seawater's supposed ability to absorb CO2. She not only showed this was untenable, she found the Pacific Ocean emits more CO2 than it absorbs! This has dire consequences for climate change. 

With Teruko Kanzawa from 1973 to 1978, she recorded the pH of every rainfall, documenting acid rain over the five-year period at the Meteorological Research Institute in Tokyo. 

 

After WW2 the US persisted in testing nuclear weapons at the Bikini Atoll, roughly 4000 km southwest of Japan, and in 1954 several Japanese fishermen became ill after trawling downwind of the testing site. The Japanese government asked the Geochemical Laboratory to investigate. Measuring small concentrations of radioactive elements dispersed in the ocean is quite a difficult technical challenge. Saruhashi and her colleagues used radionuclides to trace ocean circulation about found dispersion was uneven, circulation went clockwise and radiation-contaminated waters went northeast towards Japan, arriving in just 18 months and at much higher concentrations than on the US Pacific coast. Continued testing could contaminate the entire ocean, even if done in such an isolated place. The U.S. Atomic Energy Force was skeptical and sponsored a lab swap, bringing Saruhashi to the Scripps Institute of Oceanography at UCSD so her methods could be compared with those of US oceanographer Theodore Folsom. The two methods gave very similar results and the precision of her methods were undeniable. Her research provided critical evidence to support the end of above ground nuclear testing during the cold war. 

After her positive experience working with Miyake, Saruhashi noticed how differently she was treated as a woman researcher at the University of Tokyo, where she had to prove her abilities, and at Scripps, where her US counterpart Folsom told her not to bother coming in every day and assigned her a wooden hut to work in. Saruhashi believed firmly science and society were linked and that scientists bear social responsibility and should be engaged with the public. She was the first woman elected to the Science Council of Japan, to win Japan’s Miyake Prize for geochemistry. She won the Avon Special Prize for Women for promoting the peaceful use of nuclear power, and the Tanaka Prize from the Society of Sea Water Sciences. She said, “I would like to see the day when women can contribute to science and technology on an equal footing with men.”  She founded the Society of Japanese Women Scientists to recognize women in science and create a venue for discussion of issues faced by women in science as early as 1958. In 1981, she established the yearly Saruhashi Prize, awarded to a woman scientist who serves as a role model for younger women scientists.

She made a lasting impact on our understanding of human impacts on the ocean, climate, and radioactive contamination, blazed a trail for women scientists in Japan and helped foster the next generation of researchers. 

References

Katsuko Saruhashi, Wikipedia, accessed January 2025

Mast, Laura, Meet Katsuko Saruhashi, a resilient geochemist, who detected nuclear fallout in the Pacific, Massive Science, March 22, 2019

Margaret Burbidge, B2FH and stellar nucleosynthesis

Margaret Burbidge, linocut, 11" x 14" by Ele Willoughby, 2025

The #printerSolstice2425 prompt this week is iron, so after talking last week about how certain numbers of nucleons are "magic" as you grow increasingly large nuclei, this week, we're talking about how you do that: how you grow nuclei from a single proton to the largest naturally-occurring transuranic elements. Astrophysicist Margaret Burbidge is one of the people instrumental in building our understanding stellar nucleosynthesis, how nuclei are produced in stars and you and I are all stardust. She was the first author of a monumental scientific paper Synthesis of the Elements in Stars, which became known as B²FH from the initials of its authors: Margaret Burbidge, Geoffrey Burbidge (her husband), William A. Fowler and Fred Hoyle. The landmark paper, one of the most-influential in astronomy and nuclear physics, reviewed everything then known stellar nucleosynthesis, how elements are made, backed up the theory with astronomical and laboratory data and in further explained how elements heavier than iron are made and the abundances of the various elements. Generations of astronomers apparently used to joke that "the early Universe made hydrogen and helium, Burbidge, Burbidge, Fowler and Hoyle made all the rest." Elements up to iron can be built up by nuclear fusion, both slow and rapid neutron-capture, in stars and  B²FH also explained how heavier elements are made. At the base of my print is a stellar absorption spectrum of the sort she gathered and used in arguments presented in B2FH and a cross-section of a supergiant star and how nucleosynthesis leads to a nested series of shells where increasingly heavy elements are burned as fuel producing new elements through fusion. The shells from outermost in are: hydrogen (H), helium (He), carbon (C), neon (Ne), oxygen (O), silicon (Si) and iron (Fe). Behind her is space with stars and galaxies to represent her observations.

Born in Davenport, UK, she was the sort of clever child who deduced that she was born exactly 9 months after the November 11 Armistice which ended the first world war, and concluded she was likely conceived when it was announced. Her father Stanley John Peachey was a lecturer in chemistry at  the Manchester School of Technology (now part of the University of Manchester) and her mother Marjorie Stott Peachey had been one of his students. As a small child her father got a patent related to the vulcanization of rubber, which made him enough money to move to the family to London where he set up his own industrial chemistry lab. She was "star-struck" on a ferry trip over the English Channel at the age of 4, away from the bright lights of London, and by 12, she was reading astronomy textbooks by James Jeans, a distant relative of her mother. She and her younger sister Audrey were expected to pursue education and careers. She gained experience working in her father's lab, before his death when she was 17.  She passed the university entrance exams a year early and thus had an extra year at her high school, taken under the wing of the science teacher, where she was given the run of the physics laboratory to perform her own experiments in electricity, magnetism and optics. This was a unheard of opportunity for a young woman in the mid-30s. She went to University College London (UCL) to study astronomy, where she graduated with her undergraduate with first class honours to little celebration with war looming in 1939. She studied spectroscopy at Imperial College and then she proceeded to pursue graduate school at the University of London Observatory. She split her time between her studies and fabricating optical instruments for the armed forces. Her 1943 thesis was on the spectrum of the star Gamma Cassiopeiae. Many of the men in the department were busy with war work, so she was granted more independence and responsibility than might otherwise have been the case. She made observations at Mill Hill observatory, in the cramped space, in the cold under the open dome while German bombs fell nearby. She never complained, being determined always in her work. “Those nights, standing or sitting on a ladder in the dome of the [J. G.] Wilson reflector [at Mill Hill] . . . fulfilled my early dreams,” she later recalled. Upon seeing a photographic plate of a spiral galaxy for the first time, she said it felt almost sinful to be enjoying astronomy so much and be employed as an astronomer.

Since women were denied access to Mount Wilson Observatory, (on the basis there was no women's bathroom), Margaret's 1945 application to use the telescope was rejected.  She wrote about the experience that a “guiding operational principle in my life was activated: If frustrated in one’s endeavor by a stone wall or any kind of blockage, one must find a way around — another route towards one’s goal. This is advice I have given to many women facing similar situations.” She stayed on in London as Assistant Directory of the observatory.

She met theoretical physicist Geoffrey Burbidge who was in grad school at UCL in 1947 and the two were married in 1948. Their personalities and persons contrasted; Geoff was a large guy who enjoyed arguing pugnaciously whereas Margaret was petite and known for her demure, friendly but quiet demeanour. But he was supportive, loyal and good friends even with colleagues with whom he disagreed and her quietness hid her steely resolve. They were a good match and proved a symbiotic team. Her passion for astronomy was so strong she convinced him to switch to theoretical astrophysics and the two collaborated regularly throughout their subsequent careers. They moved to the US for jobs at observatories at Harvard and the University of Chicago (where Margaret was excited to attend a workshop held by Harold Urey and Maria Goeppert Mayer on the abundance of the elements), before returning to the UK. Seeking two positions and telescope accessed required them to move repeatedly. Willy Fowler recalled a "wonderful Charles Laughton replica," that is Geoff looking and sounding like the famous British-American actor, walked into his office, where he was on sabbatical at Cambridge and said, "why don't you work on problems important for astrophysics?" Hoyle had been working on nuclear reactions in stars since before WWII. When Fowler returned to the US he recommended the Burbidges accompany him; Fred Hoyle was already a frequent visitor. Margaret could work at the Mount Wilson Observatory and Geoff at CalTech. But the Director of Mount Wilson wrote to say the single toilet precluded hiring a woman, still, ten years after her application to do a post-doc there. So, ever-pragmatic, they swapped jobs; Geoff took the Mount Wilson job and Margaret the one at CalTech. She had to pose as Geoffrey's assistant every time he purported went to Mount Wilson and live on a separate cottage on the grounds, as a means to gain access. Geoff worked in the dark room and smoked cigars while Margaret did the observing at night. It took until 1965 for Mount Wilson to officially allow women observers. Once in California they worked on their famous 108-page paper with Fowler and Hoyle, after having first collaborated while at Cambridge. The Burbidges had been looking at spectra of stars with unusual surface conditions; these could be due to upward mixing of nuclear reaction products and proved useful in the paper. They suspected neutron-capture. Fowler's nuclear physics group had been calculating cross-sections of reactions necessary to build heavier elements. Margaret wrote the paper while pregnant. The paper showed how elements were formed at various stages of the lifecycle of stars, explained the existence of of all but the lightest elements (which we now know were in fact formed in the Big Bang) and showed how we, and everything but some of those lightest elements are made of stardust.

They had a daughter, Sarah, in 1956. In 1962 they were both hired by UCSD; to get around anti-nepotism rules, Geoffrey was hired by the physics department and Margaret was hired by the chemistry department, until the rule was changed and she too joined the physics department.

Though her observations helped provide evidence of the Big Bang, Margaret and Geoffrey both followed Fred Hoyle into the "steady state" camp, and were skeptical of the Big Bang theory. Hoyle in fact had derisively coined the term "Big Bang" to poke fun at the idea. His idea was that maker was more or less continuously in a steady state. created and density remained constant. Nonetheless, the name Big Bang stuck and the theory is now become accepted by the field at large. Though Margaret, the observational astronomer, unlike Geoff, rarely commented on theoretical matters, so she is not strongly associated with choosing the wrong side of the Big Bang versus Steady State cosmology debate. She rather worked to keep an open mind.

In the '50s and '60s she measured flat rotational curves for spiral galaxies based on optical observations. Later Vera Rubin got similar results and was able to infer the existence of dark matter galactic haloes. In the '60s and '70s she worked on galaxies and quasars, helping to determine their distance, luminosity and internal processes, finding the most distance object then known (which remained the most distant known object for a decade). With access to the Lick Observatory telescope she was in the right place to join the race to find new and more distant quasars, and known for literally racing to work in the couple's 1961 Jaguar Mark II. Geoff on the other hand never learned to drive, though they both loved that car.  Margaret's work on quasars was very important and lead to advancements like the understanding that galaxies have black holes at their centres. The shear distance to these objects was another blow to Geoff's favoured Steady State model; the expansion of the universe due to the Big Bang was needed to explain objects at the cosmological distances. 

In 1972 she declined the American Astronomical Society's Annie Jump Canon Medal because it is only awarded to women. She wrote, “It is high time that discrimination in favor of, as well as against, women in professional life be removed.” This sparked conversation and forced the AAS to look into discrimination on the basis of sex for the first time and lead eventually to the formation of the AAS Committee on the Status of Women in Astronomy. They also changed the rules of the Annie Jump Canon Medal, awarding it only to early career women who choose to apply for it. 

Burbidge was director of the Royal Greenwich Observatory (1972–1973), She was the first woman in any of these roles. She was notably, the first director of the Royal Greenwich Observatory in 300 years who was not made the Astronomer Royal (and the title was bestowed instead on one of her male peers). At various times she attributed this to sexism or a political desire to reduce the influence of the Royal Greenwich Observatory; either way she resigned after 18 months. She was president of the American Astronomical Society (1976–1978), and following her election, she took US citizenship. As president, she got to introduce the first woman to receive the Russel Lecture Award for lifetime excellence in astronomical research: Cecelia Payne-Gaposchkin. Burbidge herself later received the award in 1984. When the US Equal Rights Amendment (ERA) was introduced, but failed to pass in the required minimum of 38 states, Margaret proposed that AAS meetings be banned in states which had not passed the ERA. The proposal was contentious but she succeeded in having it passed. In the '80s and '90s she worked on the development and use of the Faint Object Spectrograph on the Hubble Space Telescope. She was president of the American Association for the Advancement of Science (1983). In 1983, Fowler received the Nobel Prize for his work on stellar nucleosynthesis and expressed his surprise that Burbidge was not included; she of course was circumspect and did not comment. She was the first female president of the International Astronomical Union's commission on galaxies. She was the first woman to win the Bruce Medal. She was awarded the Medal of Science by President Reagan in 1985, was a fellow of the Royal Society, and the Gold Medal from the Royal Astronomical Society. Burbidge was the first director of the Center for Astronomy and Space Sciences at UCSD and worked there until retirement in 1988. Fowler died in 1995. Hoyle died in 2001. Geoffrey died in 2010. Margaret was the sole surviving author of B²FH, until her death at age 100 in 2020 after a fall. She had been one of the great observational astronomers of the 20th century, a role model and trail blazer for women in the field and a strong voice for eliminating bias against women that she had faced in her career.

References

Alpha process, Wikipedia, accessed January, 2025

B2FH, Wikipedia, accessed January, 2025

Burbidge, E. Margaret, Geoffrey Burbidge, William A. Fowler, and Fred Hoyle, Synthesis of the Elements in Stars, Reviews of Modern Physics, vol 29, 4, October, 1957.

Clark, Stuart. Margaret Burbidge Obituary. The Guardian. April 22, 2020.

Cohen, Adam D. In Memoriam: Margaret Burbidge, Pioneering Astronomer and Advocate for Women in Science. American Association for the Advancement of Science, April 8, 2020.

Dillon, Cynthia. Trailblazing astronomer Margaret Burbidge turns 100 years old. University of California. October 17, 2019.

Margaret Burbidge, Wikipedia, accessed January, 2025

Ostriker, Jeremiah, and Freeman Kenneth ; Eleanor Margaret Burbidge. Physics Today 1 September 2020; 73 (9): 60. https://doi.org/10.1063/PT.3.4575

Rubin, Vera C. E. Margaret Burbidge, President-Elect. Science. Vol. 211, Issue 4485, pp. 915-916, DOI: 10.1126/science.7008193 February 21, 1981.

• Sargent Anneila I. and 
• Longair Malcolm S.
 

2021Eleanor Margaret Burbidge. 12 August 1919—5 April 2020Biogr. Mems Fell. R. Soc.7111–35http://doi.org/10.1098/rsbm.2021.0017

Skuse, Ben. Celebrating Astronomer Margaret Burbidge, 1919-2020. Sky & Telescope. April 6, 2020

Smith, Harrison. Margaret Burbidge: Pioneering astrophysicist who showed we are all made of stardust. The Independent. April 22, 2020.

Stellar nucleosynthesis, Wikipedia, accessed January, 2025

Trimble, Virginia. E. Margaret Burbidge (1919-2020). Nature. April 27, 2020.

Maria Goeppert Mayer: Nuclear Physics, Magic Numbers and the Onion Madonna

Maria Goeppert Mayer, linocut, 11" x 14", by Ele Willoughby, 2025

The first thing that came to mind when I thought about lead for the next #PrinterSolstice2425 prompt is how it is the end of many chains of nuclear transmutations. Lead is particularly stable. The woman who figured out why was the second woman to win the Nobel Prize for physics: German-American theoretical physicist Maria Goeppert Mayer (1906-1972, née Göppert). Another woman would not win the physics prize until Canadian Donna Strickland in 2018.

Maria Göppert was born in Kattowicz, a Silesian city then part of Prussia, now part of Poland, the only child of father, pediatrician and sixth generation professor Frederich Göppert and mother Maria (née Wolfe). Maria would grow up, proud to be a seventh generation academic. The family moved to Göttingen when she was four when her father got a position at the university. She was closer to her father, reasoning, he was more interesting, "He was after all a scientist." He encouraged her to aim for more than a life as a housewife. She went to schools for girls intending to pursue higher eduction. When her suffragette-run private prep school closed before she completed the three year program, she took and passed the university entrance examination at 17, a year early. She entered the University of Göttingen, where Emmy Noether was a professor, to study mathematics, in 1924, spending a term in Cambridge before completing her degree. The prestigious university was known for its world class math and physics departments. Renown mathematician David Hilbert was a neighbour and like famed physicists Max Born and James Franck, a family friend of the Göpperts. There were other female students but the others were studying to become mathematics teachers for girls. Göppert on the other hand became interested in physics and decided to pursue her doctorate with Max Born, himself later a Nobel laureate. In her 1930 thesis, she studied two-photon absorption by atoms - something which was virtually impossible to verify until 1961 with the invention of the laser. Year later, her fellow Nobel laureate Eugene Wigner called her thesis, "a masterpiece of clarity and concreteness" and today the two-photon absorption cross-section is named the Goeppert-Mayer (GM) unit.

She met American physical chemist Joseph Edward Mayer, a Rockefeller Fellow who was working for Göttingen physicist (and later Nobel laureate) James Franck, who boarded with the Göppert family. The two fell in love and married in 1930 after she completed her PhD. They moved to the United States, where he got a faculty job at John Hopkins, at the height of the Depression. They had two children: Maria Ann and Peter Conrad. Like many women scientists married to scientists, she found anti-nepotism rules prevented her from getting a professorship at John Hopkins, but she was hired as an assistant dealing with German correspondence. The job had a small salary, but allowed her access to the facilities and she was able to teach courses. She collaborated with her husband and with Karl Herzfeld, a fellow German theoretical physicist at John Hopkins, on applying quantum mechanics to the chemistry of organic molecules. She also made several visits back to Göttingen to collaborate with Max Born in 1931, 1932 and 1933, before the nazis came to power and Born and Franck lost their jobs. She and Herzfeld became involved with refugee efforts, horrified to see academics of Jewish descent driven out of university jobs. She became an American citizen in 1933. She published a landmark paper on double beta decay in 1935. In 1935 Edward Teller got a position at the nearby George Washington University and they would discuss developing theoretical physics. In 1937, her husband was fired; he believed this was because of Maria's presence in the lab and the dean of science's hatred of women. Herzfeld agreed, but also noted the anti-German sentiment that greeted him, Maria and Franck who were all now at John Hopkins. Mayer got a job at Columbia n 1937, where Maria took an unpaid position. Harold Urey and Enrico Fermi arrived at Columbia in 1939 and the three became good friends. In 1940, Joe and Maria published their textbook Statistical Mechanics. Fermi asked her to work on the valence-shell of transuranic elements, which she correctly predicted would form a new series similar to rare earth elements. In 1941 she was elected a fellow of the American Physical Society; the letter from APS was address, "Dear Sir," as if they had not considered an other possible greeting might be appropriate for fellows. She still had no salary, until later that year when she was hired by Sarah Lawrence College, initially part-time, to teach mathematics, physics, physical chemistry and general science courses. 

In 1942, she was recruited to work for the Manhattan Project. First she worked part-time for Urey at Columbia's Substitute Alloy Materials Laboratories trying to separate the fissile uranium-235 which could be used for weapons from natural uranium. She looked at uranium hexafluoride and investigated whether photochemical reactions could be used; while unfeasible in the 1940s, now lasers can be used to separate isotopes. Joe was working on conventional weapons at the Aberdeen Proving Grounds in Maryland five days a week. It was a challenging time for the family. The children had a nanny while their parents were occupied with war work. She was vehemently anti-nazi but found feared the consequences of producing a weapon which would harm friends and family in German if it were deployed there. She had taught her students at Sarah Lawrence that, "Man's scientific discoveries and inventions might very likely destroy him." She was stretched pretty thin and suffered several illnesses and on top of her full time teaching duties and childcare so negotiated reduced hours working for Urey. Teller recruited her to work on  the Opacity Project on the properties of matter and radiation at extremely high temperature; Teller was working on his "Super" bomb, which would become the basis of the H-bomb. Her husband Joe was sent to fight in the Pacific; Maria decided to leave the children in New York and join Teller's team at Los Alamos. When Joe came back early they returned together to New York in 1945. 

After the war her husband got a job at the University of Chicago; as did she, but it was as a voluntary professor of physics. When Teller joined the university she continued working on the Opacity Project and on the origin of elements. She was offered a part-time senior theoretical physicist job at the nearby Argonne National Laboratory. She responded that she didn't "know anything about nuclear physics" when offered the job. It was a shift in focus which laid the ground for her most impactful discoveries. She programmed the Aberdeen Proving Grounds ENIAC early computer to solve criticality problems of their liquid metal cooled reactor using Monte Carlo methods (that is, with statistical models you might use if trying to calculate gambling odds at the casinos in Monte Carlo). With Jacob Bigeleisen she derived the Bigeleisen-Mayer equation, also known as the Urey model (who independently arrived at the idea), of approximate isotope fractionation in isotope exchange reactions used in quantum chemistry and geochemistry. 

She began working on her mathematical model of the nucleus to explain why nuclei with certain numbers of nucleons (protons and neutrons) are more stable. As you grow nuclei from hydrogen (one proton) to the hundreds in transuranic elements by adding nucleons there are points where the binding energy of the next nucleon is a lot lower than the last and the nuclei are more stable and common in nature. The numbers of nucleons producing very stable nuclei: 2, 8, 20, 28, 50, 82 and 126 were dubbed "magic numbers" by Wigner. For protons these nuclei are helium, oxygen, nickel, tin, lead and the theoretical unbihexium. From her work on the origin of elements she recognized that these were all more common than their periodic table neighbours. You can also get nuclei with magic numbers of neutrons or "doubly magic" nuclei with magic numbers of protons and of neutrons. In 1932 Ivanenko and Gapon were the first to propose that perhaps nucleons were distributed in shells. But in 1937, Niels Bohr and  Kalcar proposed the useful "liquid drop" model of the nucleus. The liquid drop model helped physicist comprehend binding energies, and was for instance, how Lise Meitner and her nephew Otto Frisch explained nuclear fission. But the model did not explain the relative stability of different nuclei or the nature of magic numbers. Because Goeppert Mayer had not come from a nuclear physics background she was less biased in favour of the liquid drop model.

In 1948 she published her first paper summarizing the support for a shell model, but she did not yet have an explanation for the distribution of magic numbers. Fermi suggested she look at spin coupling, and she had a flash of insight. She realized that magic numbers could be explained by a nested sequence of closed nuclear shells where pairs of protons and neutrons would couple together.  In 1949, Maria Goeppert Mayer build her nuclear shell model (green diagram) where the magic of these numbers is explained by a nested sequence energy levels (determined by spin and angular momentum & like with electrons beyond the nuclei, the Pauli exclusion principe) of filled shells. Pauli himself called her “The Onion Madonna” for her model’s onion-like layers. 

In quantum mechanics nucleons have two possible spins: up or down. If you combine spin with their orbital motion you get total angular momentum. She’d found that if orbital and spin motions align to produce a maximum total angular momentum, nucleon energy level shifts down but when they go opposite directions nucleon energy level shifts up. The largest gaps between these shifted energy levels explain the “magic numbers” and these points mark the shells boundaries. Further, her model explained the ground state spins and magnetic moment of nuclei, for which there had been no previous explanation.

Very shortly thereafter, other physicists (Haxel,  Jensen & Suess) independently developed the same idea and & she started collaborating with them & co-authored a book: Elementary Theory of Nuclear Shell Structure with Jensen in ‘50.  In ’63, she & Jensen shared half the Nobel "for their discoveries concerning nuclear shell structure" with Wigner awarded other half.  In a letter, she addressed Jensen as "My Nobel Shell Brother."

She was finally appointed a full professor of physics at a major university in 1960, at UCSD, where her husband was also offered a position. She suffered a stroke but continued teaching and working despite health problems. In 1971 she suffered a heart attack that left her comatose and she died in February 20, 1972. 

The American Physical Society now awards the Maria Goeppert Mayer award to women in physics at the beginning of their careers. In 2018 they named Argonne National labs an APS Historic Site in recognition of her work. A crater on Venus has been named in her honour. In 1996 she was inducted in the National Women's Hall of Fame. The UCSD physics department is named Mayer Hall after her and Joe.

References

August, 1948: Maria Goeppert Mayer and the Nuclear Shell Model, APS News, August 1, 2008

Buntar, Simran, Maria Mayer - The First Woman to Win the Nobel Prize for Nuclear Physics, Secrets of the Universe blog,  accessed January, 2025

Maria Goeppert  Mayer, Wikipedia, accessed January, 2025

Maria Goeppert Mayer: Revisiting Science at Sarah Lawrence College, Sarah Lawrence College Archives Exhibit, accessed January, 2025

Landau, Elizabeth. The Last Woman to Win a Physics Nobel, Scientific American, September 26, 2017.

Magic number (physics), Wikipedia, accessed January, 2025

Nuclear shell model, Wikipedia, accessed January, 2025

Sachs, Robert G. Maria Goeppert Mayer, 1906-1972, National Academy of Sciences, 1979.