Vera Rubin, a pioneering astronomer who discovered dark matter, has died. She was 88.
Her work in astronomy ushered in a revolution in how we saw the Universe. Dark matter is invisible, but it has mass, and affects the cosmos on a large scale. Rubin’s work was studying galaxy rotation curves, literally how spiral galaxies spin. When she plotted her data, she found that the graphs of rotation speed versus distance from the center could not be explained using the standard model for galactic structure. She realized that what her data showed is that there must be far more mass in the outskirts in galaxies than we can see. We now know this to be correct: Almost all galaxies are embedded in a vast cloud of invisible material we call dark matter. And these halos are truly massive; dark matter outmasses normal matter by a factor of more than 5 to 1.
Later work showed that entire clusters of galaxies had dark matter halos, and that this stuff actually helped the largest scale structures in the Universe form when the cosmos was very young. Without it, the Universe would look very, very different.
Do you see how important this is? Most of the Universe, Rubin discovered, is invisible to us, yet this material has had a profound effect on literally everything.
I didn’t know her personally, but everyone I know who did spoke highly of her. She was a mentor and role model to many, including many women. She was an advocate for women in astronomy, working for years for example to get more women into the National Academy of Sciences. Lots of people are sharing lovely stories online about meeting her and the effect she had on their lives, including Carolyn Collins Petersen and Dr. Chanda Prescod-Weinstein.
One more thing that must be said. As a woman, Rubin faced in uphill battle in much of her career. She deserved a Nobel Prize for her work but was overlooked year after year. I’ve written about this before; her work predates the discovery of dark energy by decades, yet the two teams of astronomers who made that discovery were awarded the Nobel in 2011. I do think the 2011 award was deserved, but why did the Nobel Committee skip over Rubin for so long? The last woman to win the prize for physics was Maria Goeppert-Mayer (for her work on atomic nuclear structure), and that was in 1963. The most recent woman before that was Marie Curie, in 1903. And that’s it. Just two women.
But the Nobel committee, by its own rules, does not give the award posthumously. So that’s that.
Except it isn’t. Her work lives on, and as she herself said when being admitted to the National Academy of Sciences:
Fame is fleeting. My numbers mean more to me than my name. If astronomers are still using my data years from now, that’s my greatest compliment.
How many women were inspired by her, how many structures in astronomical societies exist because of her? Even if the general public might not know her name, her positive influence will extend well beyond her own lifespan.