News of Vera Rubin's passing on December 25 this year, in Princeton, New Jersey, at the age of 88, both saddened and relieved many of us at the Museum. She had suffered from dementia for a number of years, and there was sadness in her life, the loss of her husband Robert in 2008 and then of her daughter Judith in 2014.
But there was also great joy, and she had a knack for sharing that joy with all who came in contact with her. She shared the joy of her four children, all PhD scholars in science and mathematics. She also shared the joy of collaboration, not the least of which with astronomer W. Kent Ford, the ingenious instrument designer who developed a spectrograph that was made vastly more powerful with a new optical amplifier called the Carnegie Image Tube.
In the 1970s, Rubin took that spectrograph to telescopes at observatories in Arizona, first to the Lowell in the northern highlands near Flagstaff and then to the Kitt Peak National Observatory in the south near Tucson. Her observations with it, and her analyses, finally convinced astronomers worldwide that the vast bulk of the mass in the universe is invisible and unknown in origin and character. Today it is called, for want of a better name, “dark matter” because we cannot see it with any known form of astronomical detector, even though we can detect its presence indirectly, by how its mass distorts the behavior and motion of matter we can see, like planets, stars, and galaxies.
Given her prominence and impact worldwide, in circles far beyond astronomy alone, it is very easy to find essays and commentary about Rubin's life, work, and the challenges she faced as a woman, wife, mother, and astronomer. Based upon over 10 hours of oral history sessions with her, from the mid-1990s through 2007, I can say on balance that these essays of her life have certainly identified the major elements of her legacy, but of course in their necessary brevity, not all the nuances. Chief would be the wonderful support and encouragement her husband Bob always provided, their devotion to one another, and their great joy at seeing their children grow and prosper. She was also an avid and deeply informed collector of globes and maps, celestial and terrestrial. Her living room was an inspiration to this historian. Other bright spots were her students and colleagues, with whom she enjoyed and generously shared the pursuit of answers about the universe we live in.
Rubin's generosity extended to the National Air and Space Museum. My job as an astronomy curator put me on the lookout for stuff to collect, and people who built or used that stuff, to talk with, in structured interviews called oral history sessions. Rubin was always willing to be subjected to my inquiries, offering advice and insights. She let me rummage in the attic of the Department of Terrestrial Magnetism on Broad Branch Road in Northwest DC, and there we found the actual spectrograph that she and Ford used to assess how galaxies rotate. I collected that spectrograph for the Museum, along with extensive commentary from both Rubin and later from Ford on the instrument and the image tube at its heart. The spectrograph has been on display since 2001 in our Explore the Universe gallery in Washington, DC.
Rubin also gave her time and talents to talk to our visitors. I'll never forget the occasions, in May 2002, and again in April 2009, when she visited to deliver lectures to packed audiences in our Lockheed Martin IMAX Theater. Her 2002 lecture, for our Exploring Space series, was titled "Why Does An Astronomer Study Something She Cannot See?" Then in 2009, she asked "What IS the Universe?" This lecture series was, in fact, made possible in those years by the generous sponsorship of Jaylee and Gilbert Mead, longtime advocates for the Washington-area space sciences and arts communities. But there was a deeper link: Jaylee had been an astronomy student under Rubin at Georgetown University.
At the 2002 lecture, I recall meeting Rubin's older sister, Ruth Cooper Burg, a judge in Washington, DC. Listening to the sisters at a small reception before Rubin’s talk was utterly fascinating and revealed to me that the interviews I had taken with Rubin in 1995 and 1996 had a long way to go to capture the whole person. So I enlisted Ashley Yeager, an intern at the time, to collaborate on a series of new oral histories, recording Rubin in her office and at her home nearby. We also ended up with a session with both her and her husband, Bob, who, though he was suffering from the advanced stages of multiple myeloma, gamely chimed in.
At one of her visits, Rubin also met with a room filled with students as part of an immersion program to bring DC students to the Museum on the day of the Exploring Space lectures. We hoped that these immersion experiences would help the kids better appreciate the lecture that evening. Well, on that day, Rubin ignited the room with her enthusiasm and love for science. And as part of the experience, the kids moved into our Museum's underground parking area and became the "arm" of a galaxy. They lined up on circles of different radii, and then all started walking along their circles at a measured pace. Real soon, as Rubin told them, they were no longer in a line, but were spread out into an arc, in fact, a spiral. Then the students lined up again, but this time they all took hold of a long stiff rod. Again they were asked to start walking, but they had to keep the rod straight. Soon after, the kids on the outermost circles objected because they had to walk very fast to keep up with the kids on the inner circles. All the kids carried this experience into Rubin's talk that evening, thoroughly sensitized to the essence of her message asking, what was making those outer portions of galaxies move faster than they normally might? This exercise illustrated Rubin’s genius. With just a few kids holding hands and a metal rod, Rubin not only illustrated how dark matter was discovered, but inspired excitement in the kids.
Here are just two snippets from our recordings—they are both a part of our audio tour for the Exploring the Universe gallery.
What made it possible for you to discover dark matter?
Is being a woman in astronomy an issue for you today?