Astronomer Vera Rubin Pioneered Research In Dark Matter

Vera Rubin as an undergraduate at Vassar, 1940s

Pioneering Astronomer Vera Rubin on Women in Science, Dark Matter, and Our Never-Ending Quest to Know the Universe

When trailblazing astronomer Maria Mitchell was hired to teach at the newly established Vassar College in 1865, she was the only woman on the faculty and according to the original college handbook of rules, female students were not allowed to go outside after dark. Although Mitchell fought to upend this absurd obstruction to the study of astronomy and became a tireless champion of young women in the field, lamentably little changed in the century that followed.

Exactly one hundred years later, another remarkable observer of the cosmos ushered in a new era both for astronomy itself and for women’s role in it. In 1965, astronomer Vera Rubin (b. July 23, 1928) became the first woman permitted to observe at the Palomar Observatory, home to the most powerful telescopes at the time. So began her pioneering work on galaxy rotation, which precipitated Rubin’s confirmation of the existence of dark matter — one of the most significant milestones in our understanding of the universe. (That Rubin hasn’t yet received a Nobel Prize is a testament to the systemic flaws in how these accolades are meted out.)

Nowhere do Rubin’s extraordinary mind and spirit come more alive than in Origins: The Lives and Worlds of Modern Cosmologists (public library) — a magnificent 1990 collection of interviews exploring “the ways in which personal, philosophical, and social factors enter the scientific process” by Alan Lightman and Roberta Brawer, featuring luminaries like Stephen Hawking, Alan Guth, and Martin Rees.

Like Jane Goodall, who turned her childhood dream into reality, Rubin’s cosmic career began at the very beginning:

My childhood bedroom … had a bed which was under windows that faced north. At about age 10, while lying in bed, I started watching the stars just move through the night. By about age 12, I would prefer to stay up and watch the stars than go to sleep. I started learning, going to the library and reading… There was just nothing as interesting in my life as watching the stars every night. I found it a remarkable thing. You could tell time by the stars. I could see meteors.

[…]

When there were meteor showers and things like that, I would not put the light on. Throughout the night I would memorize where each one went so that in the morning I could make a map of their trails.

By high school, Rubin knew that she wanted to be an astronomer. But she had never met a single astronomer in real life — she only knew of Maria Mitchell from a children’s book. In a testament to the power of picture-books about cultural icons to offer vitalizing role models and expand children’s scope of possibility, Rubin recounts:

I knew that [Maria Mitchell] had taught at Vassar. So I knew there wasa school where women could study astronomy… It never occurred to me that Icouldn’t be an astronomer.

Maria Mitchell

She followed in Mitchell’s footsteps and went to Vassar, got married to a fellow scientist, and went on to a graduate program at Cornell along with her new husband. Rubin relays a jarring sign of the times:

Actually, I had been accepted by Harvard. I have a letter somewhere from [Harvard Observatory director] Donald Menzel saying, “Damn you women,” handwritten across the bottom. This was a response to a letter I wrote saying that I wished to withdraw because I was getting married and going to Cornell. He scribbled across this very formal letter, thanking me for letting him know, something like “Damn you women. Every time I get a good one ready, she goes off and gets married.”

But marriage didn’t obstruct Rubin’s scientific pursuits, nor did Cornell’s nearly nonexistent astronomy department, which consisted of one man (a former wartime navigator who actively discouraged Rubin from pursuing astronomy) and one woman (who Rubin surmises was the only female faculty member at Cornell at the time). Still, the university offered an unparalleled physics program of which Rubin took advantage. Richard Feynman was on her thesis committee. The actual presentation of her master’s thesis is a poignant parable of both Rubin’s remarkable character and the Sisyphean climb required of women in just about every professional field at the time.

In December of 1950, 22-year-old Rubin was to present her thesis at the American Astronomical Society. Having just given birth to her first child and nursing the newborn, she made her way through snowy upstate New York, walked into the meeting, gave her 10-minute presentation on galaxy rotation, and left.

Spiral Galaxy M101 (Image credit: NASA / Hubble Space Telescope)

The concept of large-scale motion of the universe was a revolutionary one, twenty years ahead of its time, and it garnered the skepticism with which all such visionary ideas are at first received. Rubin’s resulting paper was rejected by the two major astronomy journals of the era. Even the few scientists intrigued by her work were subject to the limiting conventions of the time — the great theoretical physicist and cosmologist George Gamow, who would later become her doctoral advisor, contacted Rubin to inquire about her galaxy rotation work but refused to let her attend his lecture at Georgetown’s Applied Physics Lab “because wives were not allowed” there.

But Rubin remained driven by the same irrepressible curiosity with which she had peered into the night sky from her childhood bedroom, so she went on with her work, animated by that most powerful of motives — the joy of discovery:

Although several times in my career I have found myself in relatively controversial positions, I really don’t enjoy it. For me, doing astronomy is incredibly great fun. It’s just a joy to get up every morning and come to work. In a sense, the heated controversy really spoiled the fun. I mean people were really very harsh. Maybe one learns to take this. I’m not sure you do.

[…]

I decided to pick a problem that I could go observing and make headway on — hopefully, a problem that people would be interested in, but not so interested in that anyone would bother me before I was done.

Vera Rubin in 1974

That problem was dark matter, the existence of which Rubin set out to prove through observation. At the time, it was still a theoretical construct, regarded as rather inconvenient in the context of existing theories:

Many people initially wished that you didn’t need dark matter. It was not a concept that people embraced enthusiastically. But I think that the observations were undeniable enough so that most people just unenthusiastically adopted it.

Today, dark matter has become not only accepted but central to our understanding of the universe and even of our own existence. Its story is a testament to the most perennial truth of science and human knowledge, as well as to the fact that a great scientist is always more interested in understanding than in being right, both of which Rubin captures beautifully:

We’re still groping for the truth. So I don’t really worry too much about details that don’t fit in, because I put them in the domain of things we still have to learn about. I really see no reason why we should have been lucky enough to live at the point where the universe was understood in its totality… As telescopes get bigger, and astronomers get cleverer, I think all kinds of things are going to be discovered that are going to require alterations in our theories… Science consists of continually making better and better what has been usable in the past.

I’m reminded of Marie Curie, hunched over in her lab long before the first of her two Nobel Prizes, asserting in a letter to her brother that “one never notices what has been done; one can only see what remains to be done.” Amid our age of productivity, this might sound like a dispiriting sentiment — but to the scientist ablaze with curiosity, it is a source of invigoration. Indeed, one of the most wonderful aspects of science is how inherently unproductive it is — each new discovery illuminates a new frontier of curiosity, each new known unravels a myriad new unknowns, and the measure of good science is the willingness to reach for that unknown, even if it means recalibrating our present knowns.

Rubin captures this wonderfully:

I hope 500 years from now astronomers still aren’t talking about the same big bang model. I think they won’t have done their work if they are… I still believe there may be many really fundamental things about the universe that we don’t know. I think our ignorance is greater than our knowledge. I wouldn’t put us at the 50-50 point of knowledge about the universe.

Cat’s Eye Nebula (Image credit: NASA / Hubble Space Telescope)

Rubin considers the question of beauty and how it frames our direction of interest. In a sentiment that calls to mind Susan Sontag on beauty vs. interestingness and Frida Kahlo on how affection amplifies beauty, Rubin reflects:

I sometimes ask myself whether I would be studying galaxies if they were ugly. I really do, and I’m not sure. I see ugly bugs. My garden is full of slugs. I sometimes think, well, maybe if I started studying them, they wouldn’t appear to be so ugly… I put that at the other extreme. I think it may not be irrelevant that galaxies are really very attractive.

She revisits the question of gender and considers what prevented many other women in her generation, and even in her daughter’s generation, from going into science — the same concern with which a little girl once turned to Albert Einstein. Rubin reflects:

It’s the way we raise little girls. It happens very early. I think also it’s what little girls see in the world around them. It’s an incredible cultural thing. I have two granddaughters. One of them — her mother and father are both professionals, her aunt and uncle are professionals — said her toy rabbit was sick. Her uncle said, “Well, you be the doctor and I’ll be the nurse, and we’ll fix it,” and she said, “Boys can’t be girls.” And her mother realized that she never had seen a doctor who was a woman. By the age of 2, she knew that men were doctors and women were nurses. So you may talk about role models and your thinking about colleges, but this happens at the age of 2. It’s a very complicated situation.

Illustration from I’m Glad I’m a Boy!: I’m Glad I’m a Girl!, a parodic 1970 children’s book by New Yorker cartoonist Whitney Darrow, Jr. satirizing limiting gender norms

Rubin — who has three sons and one daughter, all with doctorates in science — argues that the only viable solution to this systemic problem lies in raising little girls with enough confidence to pursue their interests and withstand the limiting cultural messages about what they can and cannot be. She recounts her own conquest of the odds:

I went to a D.C. public high school. I was very, very interested in astronomy, and I just could keep myself going by telling myself that I was just different than other people, that they just had different interests than I did. I had a physics teacher who was a real macho guy. Everybody loved him — all the males. He did experiments; he set up labs. Everybody was very enthusiastic. I really don’t think he knew how to relate to a young girl in his class… He never knew that I was interested in astronomy, he never knew that I was interested in science. The day I learned I got my scholarship to Vassar, I was really excited because I couldn’t go to college without a scholarship. I met him in the hall, and probably said the first thing I had ever said to him outside of the class, and I told him I got the scholarship to Vassar, and he said to me, “As long as you stay away from science, you should do okay.” It takes an enormous self-esteem to listen to things like that and not be demolished. So rather than teaching little girls physics, you have to teach them that they can learn anything they want to.

Illustration from Bright Sky, Starry City, a children’s book celebrating women’s place in astronomy

How pause-giving to consider that science progresses much more rapidly than the cultural norms of science do. In the generation between Rubin and her daughter, who is also an astronomer, we have discovered cosmic microwave background radiation, decoded the molecular structure of DNA, and invented lasers, and yet the gender ration of science hasn’t improved nearly enough, nor has the subtle cultural messaging. What Rubin recounts a quarter century ago is still the basic reality in many rooms and in many parts of the world:

My daughter is an astronomer. She got her Ph.D. in cosmic ray physics and went off to a meeting in Japan, and she came back and told me she was the only woman there. I really couldn’t tell that story for a long time without weeping, because certainly in one generation, between her generation and mine, not an awful lot has changed. Some things are better, but not enough things.

What a poignant slogan for all human rights movements, from racial justice to marriage equality: “Some things are better, but not enough things.” And yet, like Curie, we can see this not as a lamentation but as a frontier of hope — because “what remains to be done” can be done, and it falls on us to do it.

Complement the altogether wonderful Origins, which Carl Sagan lauded as a skillful “exposition of the styles of scientific thinking,” with Vera Rubin on obsessiveness and uncertainty and her terrific 1996 Berkeley commencement address.