To celebrate International Women's Day, STFC has been taking a closer look at the lives of the women who helped make our science possible. Boulby Underground Laboratory have chosen Vera Cooper Rubin - a lifelong admirer of our universe and pioneering astronomer who not only revolutionised our understanding of the cosmos, but also inspired women globally to pursue careers in science and technology.
Born on July 23rd, 1928, in Philadelphia, Rubin developed a fascination with space and the stars from a young age.
“By about age 12, I would prefer to stay up and watch the stars than go to sleep [...] There was just nothing as interesting in my life as watching the stars every night.”
~ Vera Rubin, for the American Institute of Physics (1989).
Early on, Rubin and her sister, Ruth, were encouraged by her parents to pursue any career that they set their mind to – with Ruth becoming a judge and Vera headed into astronomy. With the support of her father, she even constructed a small telescope from cardboard, which she would use to observe the stars at D.C. Amateur Astronomer Club meetings.
Rubin won a scholarship to Vassar College in Poughkeepsie, New York, where she completed her undergraduate degree, inspired by Maria Mitchell – the first female professional astronomer in the United States – who taught there. In 1948, Rubin graduated from Vassar College as the sole astronomer in her cohort and married her husband Robert later that year.
Her master’s thesis explored the velocity distribution of galaxies, studying whether groups of galaxies moved like other objects in the universe – such as planets or stars. Following the completion of her thesis, Rubin’s thesis advisor, William Shaw, offered to present her findings under his name at the American Astronomical Society meeting. Rubin, however, refused and presented her findings herself, just three weeks after giving birth.
Soon after, Rubin became a full-time mother, but she found it challenging to stay away from astronomy for very long. Rubin would read The Astrophysical Journal while taking her child to the park, and after a short while realised she had to return to research. Encouraged by her husband, she returned to academia to pursue a Ph.D. at Georgetown University. Here, her dissertation illustrated that galaxies are not uniformly arranged throughout the universe, but rather that they “clump” and cluster together. Rubin’s conclusions were confirmed fifteen years after the completion of her dissertation.
“Women generally required more luck and perseverance than men did. It helped to have supportive parents and a supportive husband.”
~ Vera Rubin, for her autobiography.
Flat Rotation Curves and Missing Mass
In 1962, while teaching at Georgetown University and raising four children, Rubin published her first paper in collaboration with six of her graduate students in the Astronomical Journal. They found that the Milky Way’s rotation speed was flat, i.e the orbital speed of stars in the further reaches of the galaxy were faster than anticipated. Hence a plot of rotational velocity against radial distance from galactic centre yields a flat rotation curve. This strange observation suggested larger amounts of mass at the edges of the galaxy compared to the astronomical objects they could see – such as stars, planets and dust.
In the mid-1960's, Rubin met Kent Ford, an astronomer at the Carnegie Institution of Washington’s Department of Terrestrial Magnetism. Ford had developed an improved method of spectroscopy using state-of-the-art photomultiplier tubes (PMTs) which allowed finer observation of the rotation of distant galaxies. Despite initially observing quasars (galaxies with dynamic, supermassive black holes at their centres), Rubin turned to the Andromeda Galaxy (M31). Using the spectrograph developed by Ford, Rubin used some of the world’s most powerful telescopes to observe the rotations of more and more galaxies, even becoming the first woman to use the 5m telescope at Palomar Mountain Observatory. What Rubin and Ford found is that not only the Milky Way exhibited a flat rotation curve – every galaxy they observed did as well!
Rubin’s work on galactic rotation curves became the first direct evidence of dark matter – the invisible, missing mass that binds the cosmos together.
Vera Rubin’s Influence on Women in Science
Vera was a passionate advocate of women in science. She inspired and encouraged women to pursue academic careers, to run for faculty positions, and to talk at conferences in typically male-dominated fields. She was known to contact conference with little to no female speakers and encourage them to add more.
Rubin encountered her share of gender-based barriers throughout her life too. She was denied the use of the aforementioned 5m telescope at Palomer Mountain Observatory until the 1960s and was told by an undergraduate interviewer that she ought to consider a career in painting astronomical objects, rather than observing them for research purposes.
“Worldwide, half of all brains are in women”
Rubin would often reflect on her time at Palomer Mountain Observatory, just outside San Diego, as she was one of the first women to gain access. Upon finding there were no women’s bathrooms in the facility,
“She went to her room, she cut up paper into a skirt image, and she stuck it on the little person on the door of the bathroom. She said, ‘There you go; now you have a ladies’ room.’ That’s the type of person Vera is”
~ John N. Bahcall, American astrophysicist and colleague of Vera Rubin.
Rubin undoubtedly shaped countless lives for women and girls in science – and even beyond STEM, acting as a living example that anyone can become who they want to be. Rubin never received a Nobel Prize, despite countless public votes and recommendations, leaving the pool of Nobel Laureates still male-dominated.
