Agnes Pockels Find Wonder While Washing Dishes and Invents Surface Science

Agnes Pockels, linocut, 11" x 14" on Japanese paper, by Ele Willoughby, 2026

The seventh prompt for #PrinterSolstice2026 is division, and I have decided to focus on the dividing line or interface, and the self-taught scientist who pioneered surface science. 

When Agnes Pockels (1862-1935) was 18, she did not get the chance to go to university and study physics like her brother Friedrich, who became a professor of theoretical physics and discovered the Pockels effect studying optics and electromagnetism. She took her "passionate interest for natural science" to those household chores she was allowed to pursue, and applied her analytic mind and careful observation to what she saw even in greasy dishwater. She became fascinated with how soap behaves on the surface of the water, and especially in the effect of impurities. She began performing experiments as an amateur chemist. In so doing, she pioneered the entire field of surface science describing physical properties of liquids and solids at interfaces, gained international recognition, published a series of peer-reviewed papers and earned an honorary doctoral degree from Braunschweig University, Germany. Performing kitchen-table research, she developed a surface film balance technique to study soap and surfactants at the air-liquid interfaces and defined the Pockels point, the minimum area a single molecule can occupy in a monomolecular film.

Agnes Pockels' first paper 'Surface Tension'
published in Nature in 1891, complete
with Lord Rayleigh's introduction.

Born in Venice in 1862, when it was part of the Kingdom of Lombardy-Venetia, Agnes' father Theodor served in the Austrian army. Malaria was an ever-present risk in the region and struck the family. When Theodor fell ill in 1871, he retired and moved the family, his wife Alwine, daughter Agnes and son Friedrich, to Brunswick, in the newly formed German Empire. Agnes was interested in science, and attended the Municipal High School for Girls. Though she would have loved to pursue higher education in science, and especially in physics, women were not admitted to German universities (with a very few notable exceptions). So, she studied science at home, while caring for her parents for three decades, as expected for an unmarried daughter. When her younger brother Friedrich went to study physics at the University of Göttingen, he would share his textbooks with her. Later, he would supply her with research in the academic literature to help her pursue her own self-taught studies. When the universities finally began admitting women, Agnes followed her father's wishes and refrained from attending so she could continue keep house and to care for her sick parents.

She began experiments when she was 18, and by age 20 in 1882, she had devised a slide through for making quantitative measurements of soapy water and other materials. Her water-filled through was 70 cm long, 5 cm wide and 2 cm deep and she laid a metal strip (about 1.5 cm wide) on the water, across the width of the through, so she could divide the surface into two parts. A lengthwise ruler along the through allowed her to precisely measure the surface area of both sides as the strip was moved along the length of the through. Building on the plate method of Ludwig Wilhelmy, she devised a simple but clever means of measuring surface tension in either area with a ceramic button (6 mm in diameter) placed on the surface. She would raise the button with an apothecary's balance or weighing scale to measure the force required to lift it from the water. She could then compare the force required to lift her button from pure water, or water with various added substances and impurities. Using her through, she investigated surface forces of monomolecular films, emulsions, solutions and the effect of impurities on physical properties and she came to understand surfactancy, the property of a chemical compound to decrease surface tension at an interface between different materials (at least one of which is a fluid).  She found that small amounts of impurities could have a large impact on surface tension. 

Agnes Pockels in 1885

Her through influenced future experimentalists in colloidal and surface science who employ the modern Langmuir-Blodgett through, an improved apparatus based on her work, still in use today. When Irving Langmuir won the 1932 Nobel Prize in Chemistry for his work in the surface chemistry of oil films, he was building on the 18 year old autodidact Agnes Pockels' experiments with a button and thin tray, performed in her kitchen (not that he bothered to mention this in his Nobel lecture). Her sister-in law, Elisabeth Pockels wrote, "every day, millions of housewives were unhappy to see greasy dish water and just wanted to get rid of it, but it inspired this very person to make observations and finally also work on scientific treatises." She made her meticulous investigations for a full decade without any communication or collaboration with the world of academic science. She had tried writing to physicists at the University of Göttingen about her work but received no reply. Then in 1890, her brother sent her a paper on surface phenomena by renown physicist Lord Rayleigh.  With her brother's encouragement, she wrote Rayleigh a modest, 12 page letter, including all her results. She explained that she had been unable to publish her results in any scientific journal and she gave him her permission to use her results if they were at all useful. Rayleigh did not speak German, but luckily, his wife Evelyn could translate the letter for him. He instantly recognized the importance of Agnes' work and to his credit he sent them to Nature, putting the weight of his reputation behind supporting the work of an unknown amateur, writing, "I shall be obliged if you can find space for the accompanying translation of an interesting letter which I have received from a German lady, who with very homely appliances has arrived at valuable results regarding the behaviour of contaminated water surfaces. The earlier part of Miss Pickles' letter covers nearly the same ground as some of my own recent work, and the main harmonises with it. The later sections seem to me very suggestive, raising if they do not fully answer, many important questions. I hope soon to find opportunity for repeating some of Miss Pockels' experiments." Nature published Ages' letter with Rayleigh's cover letter. This paper, 'Surface Tension' is considered a landmark in the history of surface chemistry.

Seeing her research published encouraged her to continue her experiments, and her correspondence with Rayleigh. She wrote to him about the paramount importance of cleanliness in these experiments and her recognition of how contamination had hampered her previous efforts. Even dust could hinder reproducibility. To study monolayer films, she developed a procedure for the deposition of the compound of interest as a solution in benzene on the surface of the water in her trough and she was able to measure layer thickness at 13Å (an Angstrom is a billionth of a metre, roughly the size of a single atom). She published her second paper, with Rayleigh's help, in Nature in 1892. She went on to study forces on monomolecular films, the calming effect various oils can have on water, various liquids and their adhesion on glass and the surface tension of emulsions and solutions, other surface phenomena like capillary and contact angles, publishing her results in scientific journals including Nature, Wissenschaftliche Rundschau, Annalen der Physik, and Science.  She was invited to give public lectures by German universities.  She published subjects beyond surface science, including her translation of Georg Howard Darwin's 'The Tides and Kindred Phenomena in the Solar System' and a philosophy paper in Annalen der Naturaphilosophie. 

German scientists finally took notice. At the Physikalische Institut of Techniche Hochschile Brauschweig (the Physical Institute of the Technical University Brauschweig), crystal physicist Woldemar Voigt (1850-1919) offered her lab facilities, so over the next decade, she squeezed in further research there around her responsibilities at home. 

Soaps are surfactants made of molecules which have a "water loving" hydrophilic head and a water-repelling hydrophobic tail which is insoluble in water and tends to sit on its surface. Using her sliding through, Agnes found the tiny addition of surfactants had a small impact on surface tension until the slider passed a certain point, where tension would suddenly increase. She plotted surface tension versus slider position, showing the compression isotherm. She realized that the point the compression isotherm abruptly changed was when the continuous film of surfactant was a single molecule thick. With further experimentation she found that the threshold point is the same for a variety of surfactants. Knowing the volume of surfactant soap and the surface area covered by the film, she was able to calculate the surface area of the water occupied by a single molecule to be 20 square Angstroms, now known as the Pockels Point.

Early in the new century, in 1902, her parents' worsening health interrupted her work at the university and she became their full-time carer. Her father died in 1906, her brother died in 1913 and her mother died in 1914. She herself was in quite poor health and she needed to have a stay in a sanitarium. Then during the first world war, she lost contact with the scientific community. Germany was isolated and she was unable to access the foreign scientific literature. Her health and eyesight deteriorated. She had invested wisely and was more financially insulated than other Germans from the post-war financial chaos. She felt the responsibility to protect those around her from the threat of hunger and homelessness and she stopped carrying out her experiments. She published the last of her 14 papers, reviewing her classic work, in 1926. She spent her later years travelling in Europe and as the devoted Auntie Agnes to her brother's children. She finally received public recognition for her work, winning the Laura R. Leonard Prize of the Colloid Society in 1931. In 1932, Techniche Hochschile Brauschweig granted her an honorary doctorate in engineering. She was the first woman to receive such an award. Legendary German colloid chemist Wolfgang Ostwald published her biography on her 70th birthday in 1832. Her sister-in-law Elisabeth Pockels also wrote a biography of Agnes, focusing on her personal life. Since 1993 the university has granted the Agnes Pockels Medal to people who have made outstanding contributions to the development of the university, promoting research and teaching, particularly by women. In 2002 Techniche Hochschile Brauschweig established the Agnes Pockels Laboratory to foster chemical education and aid chemistry teachers, focusing on children under 10, especially girls.

Despite her limited access to education Agnes Pockels found wonder in a mundane tub of dishwater, and launched an entirely new field of science.

References

Agnes Pockels, Wikipedia, accessed January, 2026

DeBakcsy, Dale. How a Kitchen Experiment Spawned a New Science: The Surface Physics of Agnes Pockels. The Women in Science Archive. October 16, 2023.

Derrick, M. Elizabeth. Agnes Pockels, 1862-1935, Journal of Chemical Education, vol. 59, no, 12, pp. 1030-1031, December 1982

Gratzer, Walter (ed.). A Beside Nature - Genius and Eccentricity in Science 1869-1953. W.H. Freeman and Company, New York. pp. 88. 1999.

Kruse, Andrea and Sonja M. Schwarzl. "Zum Beispiel Agnes Pockels," Nachrichten aus der Chemie, 06, 2002, translated as "Who was Agnes Pockels - Agnes Pockels - Housewife and Chemist", Braunschweig Technical University, accessed January, 2026.

RAYLEIGH Surface Tension. Nature 43, 437–439 (1891). https://doi.org/10.1038/043437c0

Mathematician Olga Ladyzhenskaya, Turbulent History, Fluid Dynamics and Partial Differential Equations

Olga Ladyzhenskaya, linocut print, 11" x 14" by Ele Willoughby, 2026

For the 6th #PrinterSolstice prompt 'expression' I chose Olga Ladyzhenskaya, a mathematician who overcame personal tragedy, faced Soviet totalitarianism and the catastrophic political upheaval of the 20th century to make a huge impact on the math, making important contributions to study of partial differential equations and left a legacy of influence on a school of students and collaborators in this field. She changed the very way partial differential equations are examined and was one of the leading figures to popularize the notion of weak solutions (which satisfy the equations but may not be differentiable) for partial differential equations. Expressions included in my portrait are for the Navier-Stokes equation, quoted directly from her 1958 paper on the subject*. She was known for her courage, kindness and integrity as well as her indelible mark on mathematics.

Born in the wild woods in Kologriv, a small, remote town on northwest of Moscow, Olga Ladyzhenskaya (1922-2004) and her older sisters were taught mathematics by their math teacher father Aleksandr Ivanovich Ladýzhenski. He would formulate a theorem and ask his daughters to prove it, a technique which fostered Olga's mathematical intuition. Olga showed the most promise amongst her sisters and soon she and her father were working on calculus together. His family had descended from nobility, and it was not a good time to be either an intellectual, or descendent from nobility, in the USSR. His uncle, who also lived with the family in Kologriv, was a famous watercolour painter, Gennardy Ladýzhenski. Olga was close with her great-uncle, whom she called "Dedushka" or grandfather, and she carefully preserved his landscape paintings of the River Ounja. Her mother Anna Mikhailovna was originally from a small town in Estonia and was the homemaker. Their home was full of books and the girls were exposed to culture, though they grew up in what felt like the hinterland. Olga had a lifelong love of art and literature. Aleksandr stood up for his students after their parents were arrested by the NKVD (the predecessor of the KGB secret police). In his epic The Gulag Archipelago Solzhenitsyn recounted that a peasant warned Aleksandr Ladýzhenski that he was on a list of enemies of the state, but he refused to hide. Shortly thereafter in 1937 he was arrested and executed, likely in a NKVD torture chamber like many other great teachers, declared an "enemy of the people." It was a great shock to his family. Olga's mother and eldest sister managed to support the family through this terrible time. Her mother made dresses, soap and other craft work to earn an income and survive. Olga's older sisters were expelled from school as daughters of Aleksandr. Her father's status, and the resulting impacts on his family, was not rehabilitated until 1956, when Khrushchev delivered the "Secret Speech" at the 20th Party Congress of the Communist Party which denounced the Stalin's purges and exonerated the teachers who had been killed. This was a speech which also finally allowed a resumption of communication between mathematicians, across the Iron Curtain. Prior to the speech the two groups were working in isolation of each other. Olga had been tackling the some of the most difficult equations of mathematical physics without the benefit of knowing about progress made in the West.

Despite her excellent grades, when Olga graduated from high school two years later, she was not admitted to Leningrad State University, as the daughter of an "enemy of the people." She was allowed to attend Pokrovski Teachers' Training College in Leningrad. Then during the war years, she was forced to leave Leningrad and she taught at an orphanage at Godorets before returning home to teach at the high school in Kologriv, like her father, as well as in her home. She welcomed all students, regardless of their ability to pay. In thanks for her kindness, a student's mother interceded on her behalf and Olga got an opportunity to study mathematics at Moscow State University. She was awarded a Stalin stipend (despite her family history) and ration card so she could survive as a student, but she was often hungry. Sometimes she had to sleep on the auditorium benches, joking that she was learning through osmosis by using her books as a pillow. 

She wrote a thesis supervised by renown mathematician Ivan Georgievich Petrovskiǐ.  She started studying algebra and number theory and her interest in partial differential equations (PDEs) grew. This is the calculus of multivariable functions, a way to determine the rate of change of a function with respect to one of its variables. This is a branch of mathematics which is invaluable to physics, engineering and other fields which use applied mathematics. It is often impossible to find explicit formulas for solutions for partial differential equations so a lot of modern math and science research goes into finding approximate numerical solutions for PDEs. In pure mathematics, there is research into what we can know qualitatively about the nature of solutions of certain important, but impossible to explicitly solve, PDEs: things like whether solutions exist at all, if so, whether are they unique, whether they are differentiable or smooth, whether solutions are regular or stable. 

After she graduated in 1947, she got married to Alekseevich Kiselev, a specialist in number theory and the history of mathematics who lived in Leningrad. Thus she moved to Leningrad for graduate school, where she taught in the physics department. Though they had a loving marriage, it was brief. She and her husband separated because he wanted children whereas she wanted to devote her life to mathematics and felt that children would be an obstacle. She remained single thereafter. 

Her official supervisor for her thesis on linear and quasilinear hyperbolic systems of partial differential equations was Sergei Sobolev, but unofficially she was guided by Vladimir Smirnov and they became friends. Smirnov was in charge of several branches of mathematics, seismology, hydrodynamics and aerodynamics and she was strongly influenced to study mathematical physics. She defended her PhD in 1951. Two years later, 1953 was an important year for Ladyzhenskya; She published her first book, she also defended her "habilitation" dissertation (the highest university degree awarded in some European nations typically 5 to 15 years after a PhD) and Stalin died, thus things slowly began to change in Russia. She went on to publish six monographs (some as long as 700 pages) and more than 250 papers! 

Ladyzhenskaya and Smirnov started the weekly mathematical physics "Smirnov Seminar," in 1947 and she took over the seminar after his death in 1974. She is remembered for asking just the right questions in seminars, which were revealing for teaching. She organized sporadic very popular conferences of differential equations and their applications.  She was known for her work on partial differential equations and especially her work on whether the solutions to regular problems in the calculus of variations are analytic, which is the 19th of famed mathematician David Hilbert's list of 23 (at the time) unsolved problems. In 1954 she joined the Stekov Institute mathematical physics laboratory and would go on to become its head in 1961. 

By the mid-50s she was working on problems in fluid dynamics, a particularly mathematically-challenging field of physics, and the Navier-Stokes equations for the motion of viscous fluids, in particular. These equations would interest her for the rest of her career. These partial differential equations are vital to modelling everything from the weather, to turbulence, to ocean currents, to flow in a pipe, or in blood vessels or around an airplane wing. Despite having been developed in the 19th century and their importance to such a wide array of science and engineering, to this day, there is much we still do not know about these equations. Turbulence may be common in everyday life but the physics and underlying mathematics remain some of the least understood. Physicists are interested in how the smooth laminar flow say in a river, breaks down when it hits an obstacle causing eddies upon eddies in the flow until we are left with turbulence - and whether we can correctly model that turbulence thereafter. In my portrait I show precisely this: laminar flow lines hitting an obstacle, the ensuing eddies and devolution into turbulence. Mathematicians however still have not even been able to show whether smooth solutions even always exist in three dimensions. We do not even know if the equations will allow us to model fluids with any given initial conditions, indefinitely into the future. This is called the Navier-Stokes existence and smoothness problem, deemed one of the seven most important unsolved math problems. The Clay Mathematics Institute is offering a 1 million US dollar Millennium Prize award for a proof or counter-example to the problem. 

In the 1930s, Jean Leray had demonstrated the existence of weak solutions of the Navier-Stokes equations, but it had proved more difficult to show whether solutions were unique, until Olga was able to show both existence and uniqueness. She did this at a time when, as a Soviet mathematician, she was not able to read Leray's work. She was the first to prove the convergence of finite difference methods to solve the Navier-Stokes equations. That means she showed that we can reliably find a solution to the equations of how viscous fluids move by using the very useful trick of approximating derivatives with finite differences. She also analyzed the regularity of solutions under certain conditions for two-dimensional flows. Her resulting monograph of the Navier-Stokes equations ranks amongst the most influential mathematical books ever published. She believed that when flow becomes highly turbulent in 3D systems that the Navier-Stokes equations are insufficient so she present her own modification to the equations at the International Congress of Mathematicians in Moscow in 1966. 

She also analyzed the regularity of other types of partial differential equations, including parabolic equations (Vsevolod A. Solonnikov and her student Nina Ural'tseva) and quasilinear elliptical equations. These two types of equations are invaluable to the physics and engineering of time-dependent and steady-state phenomena, respectively. In the 1960s, these three published a veritable encyclopedia on the subject of the regularity of the solutions of PDEs that remains authoritative today. She published her influential text The Mathematical Theory of Viscous Incompressible Flow in 1961. She dedicated the book to the three people she most respected: her father, Vladimir Ivanovich Smirnov and Jean Leray.  At a time when exchanges between Western and Soviet scientists and mathematicians were virtually non-existent, she extended the results of Ennio De Giorgi, Jurgen Moser and John Nash ( the 1994 Nobel Laureate in Economics). 

Olga Ladyzhenskaya

She taught mathematics throughout her career and was recognized as one of the most significant and influential 20th century mathematicians. She nominated for the 1958 Fields Medal. She was president of the St Petersburg Mathematical Society. She was awarded the 1969 State Prize of the USSR and the Chebyshev Prize of the USSR Academy of Science. She was elected a corresponding member of the USSR Academy of Science in 1981, a foreign member of The German Academy of Scientists Leopoldina in 1985, a foreign member of the Academia die Lincei in 1989, a full member of the Russian Academy of Sciences in 1990 and a foreign member of the American Academy of Arts and Science in 2001. In 1989 Communist rule in the USSR ended, and Olga could travel more freely. She won the Great Gold Lomonosov Medal in 2002. Her name is inscribed in marble on a table at the Science Museum of Boston alongside the other most influential 20th century mathematicians. 

She counted amongst her friends dissent writer Aleksandr Solzhenitsyn, famous for raising awareness of repression and the Gulag prison system in Soviet Russia, and poet Anna Akhmatova, who wrote about the Stalinist terror, was twice nominated for the Nobel Prize for literature and dedicated a poem to her. She loved nature and travelling and was a skilled storyteller. She was once on the city council, and was engaged in her community, often risking her own safety and career to aid people opposed to the Soviet regime. She helped many mathematicians in Leningrad obtain apartments, free of charge, for themselves and their families. She cared deeply, was beloved and known to be full of energy and as a person of integrity, courage, faith, and unafraid to express her viewpoint despite a dangerous political climate. Nonetheless she remained a patriotic Russian and encouraged fellow Russian mathematicians to remain in Russia. She was plagued by eye problems and relied on special pencils to work in later years. She loved the sun and with her vision loss found the dark St Petersburg winters a challenge in later life. She was about to make a trip to Florida, and complete a paper on computational hydrodynamics when she died in her sleep in 2004 at the age of 81.

*The text reads "систему уравнений Навье — Стокса" which means 'a system of Navier-Stokes equations' and also "для функций" which means 'for functions' and "при граничных и начальных

условиях" which means 'under boundary and initial conditions'.

References

Dumbaugh, Della, Panagiota Daskalopoulos, Anatoly Vershik, Lev Kapitanski, Nicolai Reshetikhin, Darya Apushkinskaya, and Alecander Nazarov, The Ties That Bind - Olga Ladyzhenskaya and the 2022 ICM in St. Petersburgh. Notices of the American Mathematical Society. DOI: https://dx.doi.org/10.1090/noti2047. March, 20220.

Friedlander, Susan, Peter Lax, Cathleen Morawetz, Louis Nirenberg, Gregory Seregin, Nina Ural'tseva, and Mark Vishik. Olga Alexandrovna Ladyzhenskaya (1922-2004). Notices of the AMS, Volume 51, Number 11, pp. 1321-1331, December, 2004. 

Goudon, Thierry and Irina Sophia Antipolis. Olga Alexandrovna Ladyzhenskaya. Brèves de Maths - Mathématiques de la planète Terre. April 23, 2013.

O'Connor, J.J. and E.F. Robertson, Olga Alexandrovna Ladyzhenskaya. MacTutor. University of St. Andrews, August, 2005.

Olga Ladyzhenskaya. Wikipedia, accessed January, 2026.

Insect Break: Seven-spotted Ladybettle and the Alfalfa Leafcutting Bee

 Ladybeetle on Blossom, 8" x 8" linocut by Ele Willoughby, 2026

The 5th prompt for #PrintmakerSolstice2526 was odd. I decided to veer from my series of women in STEM prints. This was partially because I couldn't think of a good mathematician or scientist choice for the theme that I had not already portrayed, and partially because describing someone as "odd" is not necessarily flattering. Also, one portrait a week is also a fast pace, what with the amount of labour involved carving and printing lino blocks.

So, I thought I would use some of the blocks I made for the Invertefest Anthology. For odd, I chose the seven-spotted ladybeetle (or ladybird or lady bug) on an apple blossom. Both the 7 spots and the 5 petals match are odd numbers of course.

Alfalfa Leafcutting Bee, 9" x 11" linocut by Ele Willoughby, 2026

A second print from blocks I made for the Invertefest Anthology is my alfalfa leafcutting bee, cutting a leaf. The alfalfa leafcutting bee (Megachile rotundata) is a solitary bee originally from Europe which has been spread to all continents but Antartica for agriculture. In North America it has become feral and widespread. A prolific pollinator (but not a honey-maker) of alfalfa, amongst other food crops, this little bee cuts telltale half-moon shaped pieces out of leaves with which to line her nest. This hand-printed linocut print is made on 9" x 11" Japanese paper.

Both prints can now be found in my shop.

Marine Biologist, Conservationist and Writer Rachel Carson and The Silent Spring

Rachel Carson, linocut print, 9.25" x 12.5" by Ele Willoughby, 2026

The 4th prompt for #PrinterSolstice2526 is "subtraction" so I thought of a scientist and talented writer who brought the world's attention to what was missing. After publishing the sea trilogy in the 40s and 50s, when marine biologist and conservationist Rachel Carson (1907-1964) published Silent Spring in 1962 she captured the world's attention to the risks to health and environment posed by pesticides and DDT in particular. What was missing after indiscriminate spraying of DDT, to eliminate agricultural insect pests and for disease prevention, was birdsong. Pesticide overuse was "silencing the birds" and rapidly decreasing their populations. She inspired the creation of grassroots environmental groups which culminated in the creation of the US Environmental Protection Agency and ultimately to the US banning DDT for agricultural use in 1972 and a worldwide ban on agricultural use under the Stockholm Convention on Persistent Organic Pollutants since 2004. 

Rachel Carson

A bookish child fond of animals, marine biologist Rachel Carson was born in 1907, and grew up roaming her family's 65-acre farm near Springdale, Pennsylvania. She was the youngest of Robert and Maria Maclean Carson's three children. Her mother taught her "as a tiny child joy in the out-of-doors and the lore of birds, insects, and residents of streams and ponds." Her favourite stories involved the ocean and she began writing her own by age 8. She published her first story in a children's literary magazine by the age of 10. She attended the small local school till grade ten when she transferred to the high school in Parnassus, where she graduated the top of class. She went to the Pennsylvania College for Women in Pittsburgh (now Chatham University) where she majored in English but transferred to biology and wrote for the school newspaper and literary supplement. She was admitted to grad school at Johns Hopkins in 1928 but remained at the Pennsylvania College for Women for financial reasons, where she graduated magna cum laude in 1929. She then went to a summer course at the Marine Biological Laboratory in Woods Hole, Massachusetts. It was her first sight of the ocean. She then proceeded to Johns Hopkins in Baltimore to study zoology and genetics in the fall. Money was tight and after her first year, she switched to part time studies so she could earn money working with rats and Drosophila as an assistant in Robert Pearl's lab. She tried research projects working with pit vipers, then squirrels but finally settled on the embryonic development of the urinary organ in fish, earning her master's in 1932. She planned to continue and complete her doctorate but was forced to leave Johns Hopkins in 1934 and earn an income as a teacher to help support her family during the Depression. Then in 1935 her father died suddenly, compounding their financial straights. Rachel had to care for her mother. 

Her undergraduate mentor Mary Scott Skinner encouraged Rachel to take a temporary position with the US Bureau of Fisheries, writing weekly radio copy for educational broadcasts called Romance Under the Waters. The Bureau had been trying, and failing, to generate interest in fish biology and their role, but Rachel proved more successful. Rachel submitted work on marine life in Chesapeake Bay based on her own research to both the show and to local newspapers and magazines. She further supplemented her income lecturing at the University of Maryland's Dental and Pharmacy schools as well as at Johns Hopkins. Her boss at the Bureau invited her to write a public brochure about their work and tried to find her a full-time position. She aced the civil service exam, outscoring all other applicants, and became the second woman to get a full position with the Bureau of Fisheries, as junior aquatic biologist. 

Detail of colour print magazine ad
for Pennsalt DDT products.
This ad appeared in Time Magazine,
 June 30, 1947.

Using her own research and by interviewing colleagues she published a string of articles for the public in the Baltimore Sun and other newspapers. Then in 1937, her older sister died, leaving her the sole bread earner for her mother and two nieces, and she had to take on more family duties. Her supervisor deemed her draft of a brochure too good and too poetic for that purpose and with his encouragement she revised it and published it as Undersea, a vivid tale of a journey to the seafloor, in the Atlantic Monthly. Her lyrical writing drew the reader in. She wrote, "Who has known the ocean? Neither you nor I, with our earth-bound senses, know the foam and surge of the tide that beats over the crab hiding under the seaweed of his tide-pool home; or the lilt of the long, slow swells of mid-ocean, where shoals of wandering fish prey and are preyed upon, and the dolphin breaks the waves to breathe the upper atmosphere." It caught the attention of Simon & Schuster who suggested she expand the essay into a book. She published the result, Under the Sea Wind in 1941 to critical acclaim but poor sales. Meanwhile she published many articles with Sun Magazine, Nature and Collier's. 

By 1945, she wanted to leave the Bureau, by then known as the US Fish and Wildlife Service, but there were few science jobs for naturalists. She had risen through the ranks and was supervising a small writing staff. That year she learned of Dichlorodiphenyltrichloroethane (DDT), grandly described as the "insect bomb" after the atomic bombing of Hiroshima and Nagasaki, initially intended to protect soldiers from insect-borne malaria. It was beginning tests for safety and ecological effects. DDT was lauded as a miracle for warding off disease and maximizing crop yields, though some were concerned about unintended potential impacts. Swiss chemist Paul Herman Müller, who discovered its insecticidal action in 1939 was rewarded with the 1948 Nobel Prize in Physiology or Medicine. Rachel was interested in writing about it but editors found pesticides an unappealing subject. She gathered a large file but did not manage to publish on the subject until 1962. By 1948 she was working on a second book and hoping to become a full-time writer; she took on literary agent Marie Rodell with whom she shared a close working relationship for the rest of her career. Studies in 1949 found DDT had made its way into the milk supply and newspapers noted that the "slow insidious poison" was built up in the body. That year she was promoted to chief editor of publications which allowed her more freedom to choose projects and do fieldwork but also required much more administration. 

Oxford University Press was interested in her proposed life history of the ocean and she submitted her manuscript of The Sea Around Us in 1950. She published chapters in Science Digest, and The Yale Review, where "The Birth of an Island" won the American Association for the Advancement of Science's George Westinghouse Science Writing Prize. In 1951 she serialized 9 chapters in The New Yorker and published the full book with OUP. It remained on the New York Times Bestseller List for 86 weeks, 39 of those weeks in first place, was abridged in Reader's Digest, won the 1952 National Book Award for Nonfiction, the Gold Medal for the New York Zoological Society and the John Burrows Medal for natural history writing. She was awarded two honorary doctorates, and a Guggenheim science writing grant and was finally able to leave her government job to write full time. She indulged herself by purchasing a very fine binocular microscope, like she had always wanted and moved to Southport Island, Maine.

Irvin Allen wrote a script for a documentary called The Sea based on and licensed from The Sea Around Us. Carson's right to review the script did not actually allow her to request revisions and she found it inconsistent, scientifically embarrassing, untrue to the tone of her book and "a cross between a believe-it-or-not and a breezy travelogue." Allen did not take her advice and nonetheless produced a very successful film which won the 1953 Academy Award for Best Documentary. Carson was so frustrated by errors in the film she never again sold the film rights to her writing.  Nonetheless, the film's success resulted in the reissue of Under the Sea Wind, and it too became a bestseller. 

That summer she began the defining relationship of her life when she met a soul mate, in kindred spirit and nature lover Dorothy M. Freeman, a summer resident of Maine. They spent their summers together when in Maine and exchanged about 900 letters when apart. The surviving letters were published posthumously in Always, Rachel: The Letters of Rachel Carson and Dorothy Freeman, 1952-1964: An Intimate Portrait of a Remarkable Friendship (1995) by Freeman's granddaughter Martha Freeman. Dorothy shared parts of their letters with her husband to explain their relationship, but carefully guarded others. It seems likely this was a chaste but romantic relationship. Carson wrote Freeman, "But, oh darling, I want to be with you so terribly that it hurts!" and Freeman wrote to Carson, "I love you beyond expression... My love is as boundless as the Sea." Freeman was devoted, accepted Carson wholly and was a much needed listener. They destroyed hundreds of their letters shortly before Carson's death. 

She completed her third book in the sea trilogy, The Edge of the Sea, about coastal ecosystems, especially those she studied on the Eastern seaboard, in 1955. She documented the well recognized fact of climate change and its impact on the ocean but mainly she celebrated ocean life. She published it in two instalments in The New Yorker and as a book with Houghton Mifflin, to good reviews. She wrote an episode of an educational variety television show called Omnibus called "Something About the Sky" and several magazine articles. She planned a book on evolution but opted to veer instead towards writing about conservation. She became involved with The Nature Conservancy, and bought property in Maine to save it from development. She and Dorothy called it the "Lost Woods." Then, in 1957 tragically, one of the nieces she had cared for since the 40s died at age 31, leaving her 5 year old son Roger Christie an orphan. Rachel adopted Roger, and moved to Silver Spring Maryland to care for her grandnephew along with her aging mother. 

Her research for writing became focused on environmental issues and she closely followed federal plans for widespread pesticide spraying by the US Department of Agriculture (USDA) to eradicate fire ants and spongy moths (also known as gypsy moths).  DDT mixed with fuel oils was sprayed to kill the spongy moths, including on private land. Landowners on Long Island sued, unsuccessfully, to have the spraying stopped, but the Supreme Court did grant petitioners the right to gain injections against potential environmental damage in the future, a right which has since been used successfully.  The Audubon Naturalist Society also objected and commissioned Carson to help them publicize the government's actions and the related research on the effects of DDT. This became a four year project. First she tried to enlist other writers or co-write with Newsweek science journalist Edwin Diamond, planning only to write the introduction and conclusion. But when The New Yorker commissioned a long, well-paid article she decided to adapt this to a solo writing project. The resulting book, warning of the dangers of indiscriminate pesticide use, Silent Spring, published in hardcover in 1962 and softcover in 1964, was her most influential book. Her scientific expertise, ability to synthesize and articulately explain disparate existing studies along with her clear, griping yet poetic writing allowed her to draw the attention of a much wider audience to the dangers of DDT use. In 2012, the American Chemical Society made Silent Spring a National Historic Chemical Landmark for its role in spurring the modern environmental movement.

She found many scientists were documenting both health and environmental impacts of DDT use and tapped her network of government scientists to get access to confidential data. She found scientists were divided into those who dismissed the cause for concern about pesticides without conclusive data and those who did not and advocated investigating tools other than pesticides like biological pest control. A group of biodynamic agriculture organic market gardeners, advised by soil scientist Dr. Ehrenfried Pfeiffer had had a suite of legal actions against the government over pesticide use, and shared their compiled evidence and trial transcripts with Carson. In 1959, the USDA's Agricultural Research Service made a public service film called "Fire Ants on Trial" which Carson called "flagrant propaganda." She wrote a letter to the Washington Post about the decline in and "silencing of the birds" due to pesticide use. Meanwhile, the 1957, 1958, and 1959 US cranberry crops were found to be high in the herbicide aminotriazole (a known carcinogen in rats) and the sale of crops were halted in what was known as the "Great Cranberry Scandal." Carson attended the resulting FDA hearing on revising pesticide regulations and was upset to hear aggressive testimony by chemical industry representatives which she knew did not represent the consensus in the scientific literature and worried about financial inducements behind pesticide plans. On the health front, she found that many pesticides had been shown to be carcinogens by the National Cancer Institute and researcher and environmental cancer section founding director Wilhelm Hueper. Carson found the evidence clear and convincing though still controversial outside the community studying pesticide carcinogenesis. She also documented hundreds of individual pesticide exposures and resulting illnesses and ecological damage. 

In 1960 a duodenal ulcer kept her bedridden for weeks, and then she discovered a cyst in her left breast and had to have a mastectomy, described as merely precautionary. By December, she had found her tumour was malignant and had metastasized. Her health slowed her revisions, but she chose to hide her condition, fearing chemical companies would use her cancer to argue she was biased. She knew that her book would face push-back. It called into question the post-WWII paradigm of American scientific progress. It made the case that pesticides are in fact more broadly biocides whose effects negatively impact health and environment, often through bioaccumulation, beyond their effect on target insects. Further, she was accusing the chemical industry of spreading disinformation and the government of accepting their claims unquestioningly. She warned that target pests would develop resistance and weakened ecosystems would be at risk to invasive species. She made the case for biotic controls and alternatives to chemical pesticides, but did not call for an outright DDT ban, acknowledging the risks of insect-borne diseases. She quoted Holland's Plant Protection Services which advocated spraying as little as possible rather than to the limit of capacity. She and her agent tried to gather as much advanced support for the book as possible, knowing she would be undergoing radiation therapy and not have the energy to defend her work. They provided copies to attendees of the 1962 White House Conference on Conservation and Supreme Court Associate Justice William O. Douglas who had argued against the court's rejection of the Long Island pesticide case. Interest spiked when she serialized the work in The New Yorker and when it was selected as the Book for the Month for October (complete with endorsement from William O. Douglas). Positive editorials started to come out. 

She had caught the chemical industry and their lobbyists' attention. Attacks were swift, personal and gendered. She was called a "spinster," a "bird and bunny lover" and a "woman out of control." Dupont collected a report on press for the book. Monsanto published an apocalyptic parody of her warning, The Desolate Year, in which farmers are unable to feed the populace without pesticides and herbicides, and people would die of preventable diseases, mocking her poetic style. Velsicol Chemical Corporation threatened legal action against her publisher Houghton Mifflin, The New Yorker and Audubon unless they cancelled the book and features. They put out their own brochures arguing for pesticides, which only succeeded in raising public awareness of the controversy and eventually to accidentally leading to increased book sales. Luckily, Carson and colleagues were confident in how carefully the book had been vetted and they proceeded as planned with publication. American Cyanamid biochemist Robert White-Stevens claimed, "If man were to follow the teachings of Miss Carson, we would return to the Dark Ages, and the insects and diseases and vermin would once again inherit the earth" and called her the "fanatic defender of the cult of the balance of nature." Former US Secretary of Agriculture Benson told Eisenhower that, as an unmarried woman despite being attractive, she was "probably a Communist." Critiques wrongly insisted she was calling for an absolute pesticide ban, rather than responsible and limited use, but academic researchers defended her work and the public was swayed in her favour. CBS Reports hosted a TV special called The Silent Spring of Rachel Carson, where she read calmly from her book and it was her loud insistent critics who were perceived to be the alarmists, not her. She faced this expected backlash with courage, feeling it was her duty and knowing she "could never again listen happily to a thrush song if I had not done all I could." This resulted in a congressional review of pesticide use and dangers and a report from President Kennedy's Science Advisory Committee. 

Testifying for the Committee was one of her last public appearances; their May 15, 1963 report largely backed Carson's claims. She was able to testify to a US Senate subcommittee on policy recommendations, despite debilitating pain, and to appear on The Today Show, but had to decline most invitations to speak due to deteriorating health. She received several awards including the Audubon Medal, the American Geographic Society Cullum Geographical Medal and an induction into the American Academy of Arts and Letters. Breast cancer and its treatment had weakened her. She became ill with a respiratory virus in January, 1964. By February she was diagnosed with anemia from the radiation. By March her cancer had reached her liver. In April, she died of a heart attack at home.  

After Carson's death her brother Robert insisted her ashes be buried next to their mother in Maryland, but Carson had wanted to be buried in Maine. As a compromise, he split her ashes, and sent half to Dorothy Freeman, her agent Marie Rodell and editor Paul Brooks to follow Carson's final wishes. Dorothy was able to spread her ashes in Sheepscot Bay, Maine, by her beloved sea, as Rachel had wished. Rodell was able to usher her essay The Sense of Wonder, into publication as a posthumous book illustrated with photographs, which encourages parents to introduce their children to the "...lasting pleasures of contact with the natural world... available to anyone who will place himself under the influence of earth, sea, and sky and their amazing life." Biographer Linda Lear also edited the posthumous book of her unpublished writings as Lost Woods: The Discovered Writing of Rachel Carson. 

Silent Spring electrified the fledgeling environmental movement and influenced the rise of ecofeminism. She brought the public's attention to the fragility and interconnectedness of nature, which includes us. The Environmental Defense Fund was formed in 1967 to argue a "citizen's right to a clean environment" and with others, secured a phase-out of DDT except in emergency situations within the US, by 1972. Carson had highlighted the conflict of interest between the USDA representing the agricultural industry and regulating pesticide use without being responsible for environmental impacts. This changed in 1970 when the Environmental Protection Agency was formed and its early work, enforcing the 1972 Federal Insecticide, Fungicide and Rodenticide Act, could be traced to Carson's influence. Government regulations had previously only extolled the effectiveness of pesticides without also considering environmental impact and this change can be tied to the effectiveness of Carson's message. Her impact was seen in popular culture; in 1970's Big Yellow Taxi, Joni Mitchell was inspired by Silent Spring when she wrote the lyrics "Hey farmer - put away the DDT. Give me spots on my apples, but leave me the birds and bees. Please!" She had become the most celebrated science writer of her generation. She was inducted in to the Women's Hall of Fame in 1973. She posthumously received the Presidential Medal of Freedom in 1980. Many schools, buildings, awards, colleges, societies, research vessels and conservation areas have been named in her honour. May we remember her and heed her advice that, "Wonder and humility are wholesome emotions, and they do not exist side by side with a lust for destruction." Science must be moored to morality, ethics and attention to its impacts, both planned and unforeseen. 

References

Carty, Ryan. Loud and Clear. Chemical Heritage, Summer 2012.

Conis, Elena. Beyond Silent Spring: An Alternate History of DDT, Distillations Magazine, Science History Institute Museum & Library. February 14, 2017.

DDT, Wikipedia, accessed January, 2026.

Leonard, Jonathan Norton. Rachel Carson Dies of Cancer; 'Silent Spring' Author Was 56, Obituary, New York Times, April 15, 1964.

Michals, Debra. Rachel Carson. National Women's History Museum. 2015.

Popova, Maria. The Story Behind "Silent Spring": How Rachel Carson's Countercultural Courage Catalyzed the Environmental Movement, The Marginalia, January 27, 2017.

Popova, Maria. Undersea: Rachel Carson's Lyrical and Revolutionary 1937 Masterpiece Inviting Humans to Explore the Earth from the Perspective of Other Creatures, The Marginalia, January 27, 2017.

Rachel Carson, Wikipedia, accessed January, 2026.

Silent Spring, Wikipedia, accessed January, 2026.

Enlightenment Physics Professor Laura Bassi

Laura Bassi, linocut by Ele Willoughby, 2026, on 10.75" x 13.75" Japanese paper with deckle edge

The third Printer Solstice prompt is one, so I have selected a woman in science who was often the first, number one. 

The first woman to earn a doctorate in science was physicist and professor Laura Maria Caterina Bassi Veratti (née, and known throughout her life as Bassi, 1711-1778). She was the second woman be a Doctor of Philosophy (after her countrywoman, philosopher Elena Cornaro Pisccopia in 1648), and when employed by the University of Bologna, became the first salaried female university instructor. Eventually she was their highest paid employee. She was the first woman admitted to the Bologna Academy of Sciences, one of Italy's leading academies. She was instrumental in spreading Newtonian physics to Italy through her outstanding teaching, her experimental research and wide correspondence with natural philosophers. She was called and depicted as Minerva, the goddess of wisdom and was elected to the Academy of Sciences of the Institute of Bologna at age 21. Her high profile brought attracted visitors from across Europe, to learn from her. She was not satisfied being a mere symbol, perceived as the 'marvel of her sex' who augmented the fame of Bologna. She was tenacious in pushing against the bounds placed on her as a woman, to gain the freedom to pursue her passion for physics, to teach and to research like her male peers. 

Laura Bassi illustration showing the first dispute sustained by Laura on 23rd Feb 1734 inside the Archiginnasio Anatomical Theatre, she is the figure in black. (via here)

Born to lawyer Giuseppe Bassi and wife Maria Rosa Cesari, Laura was her parents' only surviving child. Bologna was called "a paradise for women" because of a history of successful women in otherwise male professions. Laura was privately educated by her cousin Father Lorenzo Stegani. He taught her not only to read but to write and speak Latin, as well as French and mathematics from the age of 5. Laura was able to lecture and publish in Latin throughout her career. Her mother was often ill so the family doctor, Gaetano Tacconi, a professor of medicine at the University of Bologna, was a frequent visitor, who noticed Laura was studious, bright and had a facility for Latin. From age 13 to 20 she was also taught anatomy, natural history, logic, metaphysics, philosophy, chemistry, hydraulics, mechanics, algebra, geometry, ancient Greek, Latin, French, and Italian by Tacconi.  He wanted to teach her the uncontroversial Cartesian science but Laura's imagination was captured by the new Newtonian physics when he added Newton's Optics to her readings. Rather than Descartes' belief in deriving knowledge through rational principles, Bassi was attracted to the Newtonian approach of deducing laws of nature through observation. Tacconi invited his colleagues and fellow members of the academy to the Bassi home to debate Laura. Her intellect was noticed. She found a patron in Prospero Lorenzini Lambertini, who became Archbishop of Bologna in 1731 and then later Pope Benedict XIV.  A supporter of both the education of women and of sciences in general, he wished to forge an alliance between science and faith and was an important and powerful patron. His arrival was timely; Tacconi was trying to steer her to studying ethics but with Lambertini's support she was able to pursue her own interest in physics.

In 1732, when Laura was 20, Lambertini arranged for Laura to have a public debate with four professors. She defended her forty-nine theses on Philosophica Studia at the Sala degli Anziani of the Palazzo Publico on April 17. The University of Bologna awarded her a doctorate, the first woman with a doctorate in science. June 27 she defended a further 12 theses on subjects like chemistry, hydraulics, refrangibility (optics), mathematics, physics, mechanics and methodology at the Archiginnasio, the main university building, in a bid to get the university senate to award her a teaching position. The University held that women should lead private lives so she remained more constrained than her male peers, typically only giving a single yearly public lecture and composing poetry for public events. She was treated as a prodigy and a novelty, but she wanted to have the same treatment as the men. When she reached 24 in 1735 she obtained Vatican permission, like her male peers, to access forbidden books including those by Galileo, Kepler, Descartes, and Bacon and was finally able to study infinitesimal calculus. Her request to access these books did shock many. Realizing her education had been deficient in advanced mathematics, she began studying higher mathematics and Newton's physics with mathematician Gabriele Manfredi (whose own sisters Teresa and Maddelena both studied astronomy, mathematics and Latin and taught in their home). She also became an apprentice to Jacopo Bartolomeo Beccari, professor of experimental physics and chemistry. By improving her skills she hoped to be allowed to teach regularly. 

Six years later in 1738 she married Doctor Guiseppe Verrati, a very progressive lecturer in medicine at the University of Bologna especially interested in the therapeutic use of electricity. She was criticized for marrying as pursuing her role as wife and mother rather than learning, blemishing her role a virginal "Minerva," but as an unmarried woman spending time with men to teach or learn had made her the focus of gossip.  She wrote, "I have chosen a person who walks the same path of learning, and who, from long experience, I was certain would not dissuade me from it." Verrati became an affectionate and loyal ally in her bid to be allowed a greater role as scientist and professor and they collaborated for decades. Through her marriage she was allowed some more freedom to appear publicly than an unmarried woman, and with her husband she was able to share a laboratory in her home and really pursue experimental physics. Unusually for the time, she did not need to rely on him for her education as her knowledge of mathematics and literature exceeded his own, and this resulted in a marriage of equals between two scientists. But the flip side was the toll that motherhood took on her health. They had at least eight children, five of who survived infancy. Further, the public disapproved as lecturers were not supposed to marry, but in reality, Bassi was only really able to lecture regularly after her marriage.

In 1739 Lambertini and Flamino Scarselli, secretary to the Bolognese ambassador to the papal court, supported her plea for normal teaching duties. The University denied her request but allowed her to give private lessons. In 1745 Lambertini, who had become Pope Benedict XIV formed an elite group of 25 scholars called the Beneditti (named after himself). Bassi argued hard that she should be included but the men had mixed reactions. Lambertini made her an additional member but denied her the voting rights of the men. Though, like the men, she was expected to submit a yearly paper to the pope; she submitted On the compression of air (1746), On the bubbles observed in free flowing liquids (1747), and On bubbles of air that escape from fluids (1748). Because of Bassi, the Bologna Academy also started admitted other women, at least as honorary members, including French physicist Émilie du Châtelet in 1746 and Milanese mathematician Maria Gaetana Agneissi in 1748, long before other scientific academies. In 1749 she opened a school in her home including 8 months of daily lessons and hands-on experiments, which was more in-depth than the natural history taught at the university or the weekly demonstrations at the Bologna Institute.

Laura Maria Caterina Bassi. Lithograph by A. di Lorenzo via JSTOR

In 1755 she complained to Francisco Scarselli, "As for my physical experiments, and in view of the fact that the continual expense that arises requires some form of assistance if I am to advance and perfect them, I am almost in despair," though she was at the time tied for the highest salary at the university. The university granted her funds for experiments performed in her home in 1759, recognizing the importance and utility of her work. Thus she was allowed to follow her research interests outside of the University's constraints. Meanwhile they wanted to use her position for public relations and required her to attend public events like the annual public dissection called The Carnival Anatomy, which she attended from 1734 onwards. From the 1760s, she and her husband performed experiments in electricity and natural philosophy and hosted a lively salon in their home lab, attracting researchers like Abbé Nollett to Bologna to study. Her primary interests, Newtonian physics and Franklinian electricity were not even on the university curriculum, but Bassi taught courses on these subjects for 28 years in her home, and she was a key figure in introducing Italy to Newton's physics. She wrote 28 papers on physics and hydraulics, 4 of which were printed. Sadly, the vast majority of her unpublished work was lost during the Napoleonic era.  She also taught students studying for the priesthood experimental physics at the Collegio Montalto from 1766-1778. She corresponded with the the luminaries of science and philosophy, in Italy and surrounding nations, including experts in electricity like Nollet and Volta, and Voltaire in France who wrote, "There is no Bassi in London, and I would be much happier to be added to your Academy of Bologna than that of the English, even though it has produced a Newton." Her home became a stop on the Grand Tour of for any scientists visiting Italy.

In 1772, professor of experimental physics, to whom her husband served as assistant, Paolo Balbi died quite suddenly. Bassi made the case that she could take on his mantle, and in 1776, at age 65, she was appointed Chair of Experimental Physics, with her husband as her assistant. 

She died in 1778 at 66 likely of a heart attack, her deteriorating health attributed to all her pregnancies and childbirth complications. Silver laurels were placed on her head at her funeral and she was interred by the tomb of fellow scientist and investigator of electrical phenomena and her student, Luigi Galvani. Her husband took over her professorship after her death and their youngest son Paolo followed the his parents' lead and became a physician and an experimental physicist too. Her example helped inspire the next generations of women scholars across Europe and beyond, over the last 250 years.

References

Cavazza, Marta. Laura Bassi and Giuseppi Veratti: an electric couple during the Enlightenment. Contributions to Science, 5 (1), 115-128 (2009) Institut d'Estudis Catalans, Barcelona. DOI: 10.2436/20.7010.01.67

Cavazza, Marta. The Biographies of Laura Bassi in Writing about Lives in Science (Auto)Biography, Gender, and Genre. pp. 67-87. Paola Govoni and Zelda Alice Frnaceschi (eds.) V & R unipress. ISBN: 978-8471-0263-2. 2014.

Cifarelli, Luisa and Miriam Focaccia. Laura Bassi - Emblem and Primacy of Settecento science. Physics News, Bulletin of the Indian Physics Association, Vol. 51 (3), July-September, 2021

Findlen, Paula. Laura Bassi and the City of Learning. Physics World, August 29, 2013

Findlen, Paula. Science as a career in Enlightenment Italy - The Strategies of Laura Bassi. Isis, 84: 441-469. The History of Science Society. 1993.

Focaccia, Miriam, Laura Bassi - the world's first female university chair, Archivi della Scienzia, accessed December 2025

HLB, Laura Bassi Scientist, Intriguing History, July 12, 2016.

Laura Bassi, Wikipedia, accessed December, 2025

Museo Galileo - Institute and Museum of the History of Science, Piazza dei Giudici 1- 50122, Florence, Italy.  

O'Connor, J J  and E F Robertson. Laura Maria Catarina Bassi, MacTutor, December 2021.

The Bassi-Veratti Collection, Stanford University Libraries, accessed December, 2025.

Wellcome Collection, 183 Euston Road, London, NW1 2BE

See also:

https://www.youtube.com/watch?v=yu6UdSXpaDY

https://www.youtube.com/watch?v=lhLcVLp_8sU

Bibha Chowdhuri, from the heights of the Himalayas down into the mines, studying cosmic rays and discovering mesons

Bibha Chowdhuri, linocut, 11" x 14" by Ele Willoughby, 2025

The second Printer Solstice prompt is 'even', so I made a portrait about the discovery of mesons. When students are introduced to quarks, the fundamental particles, usually they learn how nucleons, that is, protons and neutrons are each made of trios of quarks. Quarks are weird because they have fractional charge (like +/- a third or two thirds of and electron's charge), and we only ever observe integer charge (say, things have, for instance -1e, 0 or +1e charge). They come in perfectly ridiculously named flavours: up, down, top, bottom, charm and strange (and of course, anti-up, anti-down, anti-top, anti-bottom, anti-charm and anti-strange). Little groups of three quarks can be stable and long-lived, and in fact, a significant proportion of the mass of regular, every day matter, what we call baryonic matter, can be explained by trios of quarks in neutrons and protons. So you can make a proton (+1e) with two up quarks (+2/3 e each) and one down quark (-1/3 e) and the math works out. But it's also possible to make matter with even numbers of quarks. These unstable particles are called mesons. Usually they are made with quark-antiquark pairs, but there are also some exotic mesons with four quarks. Long before we had developed the Standard Model and before quarks themselves were proposed (by Gell-Mann and Zweig, in 1964) as an explanation for baryonic matter, mesons were proposed as an explanation for nuclear forces (what held the neutron and the proton within the nucleus - a real mystery as this force must overcome electromagnetic repulsion) by theorist Hideki Yukawa in 1934 and they were first observed by Bibha Chowdhuri (1913-1991) and her supervisor Debendra Mohan Bose in 1940. In the early days of particle physics, before physicists were accelerating and smashing particles together at incredible speed and energies, the easiest way to observe these particles was in naturally occurring cosmic rays or high-energy ionizing radiation from space which rains down on our atmosphere. Physicists literally climbed mountains and used hot air balloons to get as much altitude as possible to measure these particles. At the time, Chowdhuri, Bose and others called these particles they observed in cosmic rays "mesotron showers" but we now know them as mesons. Seven years after Chowdhuri and Bose published their discovery another physicist, Cecil Powell performed similar experiments. He was granted the 1950 Nobel Prize for working on photographic methods of studying nuclear processes and his subsequent "discovery" of the pi-meson. He had access to higher quality of photo emulsion than his Indian colleagues did during WWII, but his measured mass for the particle was very similar to their results. He did acknowledge their work during his Nobel acceptance (well, he called her "Chaudhuri") but essentially, he repeated their discovery with somewhat higher precision, as well as observing muons decay into electrons. The photographic emulsion method itself, in turn, was pioneered by another under-appreciated woman, Marietta Blau (and her student Hertha Wambacher). Blau was also nominated for, but did not win, the 1950 Nobel Prize. Blau discovered what she called "disintegration stars" which were particle tracks of high-energy cosmic rays nuclear reactions recorded in photographic plates; as a Jewish Austrian scientist, her research was interrupted in 1938; mercifully, she was able to secure a position in Oslo and leave Austria, but having to flee for her safety negatively impacted her career and delayed recognition of her research. One could easily argue that Chowdhuri, Bose, and Blau were at least as qualified to win the 1950 Nobel as Powell.

Bibha was born in Kolkata, to a family of the landlord Zamindar class. Her father Banku Behari Chowdhuri was a doctor. Her mother, Urmila Devi's family were followers of Brahmoism, a reformist religion which branched off of Hinduism, rejecting polytheism, rituals and the caste system.  To marry her mother, Banku had to convert and was outcast from Hindu society. He even lost the right to his parent's property. Education of women in India at that time was quite rare, but Brahmo Samaj, the societal aspect of the Brahmoist religion, promoted education, especially of women and girls. Several of the Chowdhuri children (Bibha had four sisters and one brother) were highly and equally educated, while in pre-independence India, the education of girls was so extremely rare as to be virtually non-existent; their expected role was to marry and serve their husbands. None of the Chowdhuri siblings married, which was a rare privilege at the time for the girls.

Detail of my screen print "Cloud Chamber" showing particle trails in yellow
as recorded in a Wilson Cloud Chamber against a cloudy blue sky.

She studied physics at the Rajabazar Science College of Calcutta University, where she was the only woman in a class of 24 to graduate with an M.Sc. in 1936. She joined the Bose Institute in 1939 to study cosmic rays with the legendary Debendra Mohan Bose, who had worked with C.T.R. Wilson to build the Wilson Cloud Chamber (a tool for recording the tracks of high energy particles in a supersaturated cloud-like vapour or water or alcohol).  He has been reluctant to take her on as a student, and told her he did not have any projects suitable for a woman, but she persisted. He had built a cloud chamber on his return to India, and was building his reputation as India's first cosmic ray physicist. She published her paper in the Transactions of the Bose Institute based on photographic plates exposed to cosmic rays for four months at an altitude of 12,000 feet (3600 m) atop Sandakphu, a mountain peak in Nepal, shown in my portrait. She set up the instrumentation at each site and gathered the exposed plates afterwards for analysis, travelling on horseback - a potentially scandalous action for an unmarried Indian woman in the 1930's. Her research showed the superiority of using photographic plates to employing cloud chambers, and the Bose Institute thenceforth adopted photographic plates.

Next, she proceeded to expose Ilford R2 and the new halftone photographic plates at three different altitudes at Darjeeling at 7000 feet (2000m), Sandakphu at 12,000 feet (3600 m) and Pharijong at 14,000 feet (4300 m), to study what they called "mesotron showers." Yukawa had proposed the particles we now call mesons, to explain the strong nuclear forces which confine protons and neutrons within the nucleus, just a few years previous, and the race was on to confirm their existence. She exposed plates directly to air, and some under paraffin wax or water. Plates were exposed for 150 to 202 days. Using a high-power microscope, she and Bose examined the lengths, spacing and scattering of the recorded tracks to determine the mass, energy and momentum of the particles they recorded. Scattering angle could be linked to mean energy, and the mean grain spacings along tracks could be used to calculate velocities. They found that most tracks were from particles of higher velocities and lower kinetic energies than protons, suggesting, importantly that they were lower mass than protons, as expected fro Yukawa's theoretically proposed particle. She published four papers in Nature from 1940-1942 with her results. Bibha Chowdhuri was the first person to measure the mass of a meson and she quickly published even more precise results. She realized they would need improved photographic plates to continue the research, but these were unavailable due to imposed WWII restrictions. Cosmic ray research at the Bose Institute stopped. 

Chowdhuri went to England to pursue her doctorate and join the cosmic ray research laboratory of Patrick Blackett in 1945, with thesis advisor J.G. Wilson, when extensive air showers in cosmic rays was the hot topic in particle physics. She recorded the spectrum of penetrating extensive air showers taking photographic plates within a cloud chamber surrounded by Geiger counters. She defended her thesis, "Extensive Air Showers associated with Penetrating Particles," in 1949. Extensive Air Showers refers to the cascade of subatomic and ionized nuclei particles that we get when cosmic rays enter our atmosphere from space and collide with the nuclei of various air molecules (discovered by Bruno Rossi in 1934); it then extends itself through several more generations of collisions as shown in my portrait. Interviewed by the Manchester Herald, Bibha said, "Women are terrified of physics - that is the trouble. It is a tragedy that we have so few women physicists today. In this age when science, and physics particularly, is more important than ever, women should study atomic power; if they don't understand how it works, how can they decide how it should be used? I can count the women physicists I know, both in India and England, on the fingers of one hand." The same year, Blackett had won the Nobel for "his development of the Wilson cloud chamber method, and his discoveries therewith in the fields of nuclear physics and cosmic radiation." 

Chowdhuri applied to do post-doctoral work in Paris at École Polytechnic with Louis Leprince-Ringuet on photo emulsions, seeking financial support from the government of India. She had a letter of recommendation from J.G. Wilson who was one of her thesis examiners. Her application was sent to Homi Babha for comment and he wrote Wilson to inquire whether it would really be worth the investment for her to study photo emulsions for 6 months when her doctorate was on extensive air showers. Both men seem to have forgotten her prior world-class research on photographic methods with Bose, and Wilson backed off his prior recommendation and replied that, "Miss Chowdhuri cannot be regarded as a first-class physicist but she can make good progress under fairly done guidance" and as she had done good work on air showers, she should "not be encouraged to go into a new field of work." Yet, it was photo emulsion work which led to Powell's Nobel.

After her brief stay in Paris she returned to India to work at the Tata Institute of Fundamental Research (TIFR), with a glowing recommendation from Blackett (in complete contrast with Wilson's lukewarm support). She worked as a Research Fellow with the Experimental Physics Group for 5 years, the first woman at TIFR. This was the lowest rank at which they could hire her; all the contracts were written with the presumed pronoun for a physicist of "he." She was in charge of the Cloud Chamber Group investigating penetrating particles in extensive air showers.

She decided to apply for a Senior Research Fellow position in the cosmic-ray project at Bengal Engineering College, Shibpur in 1954. The post had a lower salary and the college was not known for basic research. Her reasons for this decision are unclear, as are Bhabha's for writing her a letter or recommendation but not trying to persuade her to stay. Perhaps she wished to be closer to home, but within a year she left for Paris where she worked with Leprince-Ringuet and studied many new K mesons in cloud chambers in the Alps. While in Paris, her American colleague, a Visiting Fullbright Scholar Wayne Hazen invited her to teach at the University of Michigan. She spent two years working with him and as a Visting Lecturer in physics at the University of Michigan, then worked briefly in Bruno Rossi's MIT lab working on Plastic Scintillators for detecting large air shows and collaborating on planning a new extensive shower array in New Mexico. 

In 1961 she joined the Physical Research Laboratory (PRL) in Ahmedabad. Despite her two decades of experience she was only offered a temporary position as a Senior Research Fellow but she was interested and took the job. After beginning her career studying extensive air showers high in the Himalayas, at PRL she investigated  high energy muons in cosmic rays at a depth of 700 feet (2000 m) in the Kolar Gold Field with simultaneous measurements at ground level at TIFR in collaboration with Vikram Sarabhai, director of PRL. She and her students and technicians donned miner's hats to descend daily in the elevator cage down to their instruments, sometimes carrying their own oxygen if conditions were unsafe. Sarabhai's untimely death interrupted her future research plans. Once again she saw her research interrupted by factors beyond her control.

After retiring from PRL she returned to Kolkata and continued her research, collaborating with colleagues at Calcutta University, the Saha Institute of Nuclear Physics, the Variable energy Cyclotron Centre and the Indian Association for the Cultivation of Science looking at nucleus-nucleus interactions at relativistic energies to learn about  astrophysics and cosmic rays.

She was publishing research until the end of her life, though after returning to India, she chose to publish only in Indian journals. She was never made a fellow of any of the Indian scientific societies. She was woefully under-appreciated during her lifetime; it seems likely she faced gender discrimination and was underestimated by her male peers. She became less and less remembered internationally, and when she died in 1991 no obituary appeared in any scientific journal, but her story and accomplishments have begun to be recognized posthumously. In 2019, the International Astronomical Union named a star "Bibha," Bengali for "ray of light," in her honour. In 2020, when then Indian government decided to establish 11 named research chairs after famous women scientists, the physics chair was named after Bibha Chowdhuri.

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Jacob, Julie. Bibha Chowdhuri: A Missed Nobel Prize and an Unfulfilled Prophecy. The Lovepost. January 14, 2021.

Mondal, Naba K. Bibha Chowdhuri and Her Remarkable Scientific Endeavours. Resonance. Vol. 28, no. 10, DOI: https://doi.org/10.1007/s12045-023-1686-1. October, 2023

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Roy, Suprakesh and Rajinder Singh. Bibha Chowdhuri - The First Woman Scientist at the TIFR. Physics News Tata Institute of Fundamental Research, Vol 51 (1-2), Jan-June, 2005

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