Pioneering astronomer who confirmed the existence of dark matter
AS A child she would spend hours gazing at meteor showers wheeling past her bedroom window and at 10, she built her first telescope with rolled linoleum. The study of the universe was Vera Rubin’s calling and she pursued it with absolute determination. Girls were not supposed to study science, let alone astronomy but Rubin, who has died aged 88, not only did both but her work helped change the way we view the cosmos, blazing a trail for women scientists along the way.
She didn’t have it easy: for years she was shunned by the exclusively male astrophysics élite and her work was denigrated by other astronomers. So Rubin decided to find “a problem that nobody would bother me about.” It would result in the discovery of dark matter, the invisible material that makes up more than 90 per cent of the universe.
A theory about invisible missing mass had first been put forward back in 1933 by a Swiss astrophysicist, Fritz Zwicky but had never been scientifically backed up. So Rubin decided to make it her problem. Together with Kent Ford, a colleague at the Carnegie Institution which she had joined in 1965, she started studying the Andromeda galaxy looking at the orbital speed of stars at different distances from the centre of the galaxy.
According to Newton’s theory, the further an object is, the slower it orbits: in our own solar system the distant Pluto takes 248 years and the much closer Mercury a mere 88 day to go around the sun.
However, Rubin and Ford found that stars far from the centre of the galaxy travelled as fast as those near it. Either Newton’s theory was wrong or there was some other invisible mass out there speeding up the stars. Rubin and Ford studied several more galaxies in the next few years and discovered that each spiral galaxy is embedded in a “halo” of dark matter which does not emit light, containing five to 10 times as much mass as the part emanating light. What is visible to us is just the tip of the cosmic iceberg.
Vera Florence Cooper was born in Philadelphia to Jewish immigrants. Her father Philip, was a Lithuanian. Born Pesach Kobchefski, he worked as an engineer at Bell Telephone; her mother Rose Applebaum also worked at Bell until her marriage. The family moved to Washington when Vera was ten.
Vera chose to study at Vassar College because Maria Mitchell, the first professional female astronomer in the US, had taught there. She graduated, the sole astronomer in her class, in 1948, the year she married Robert Rubin, a graduate student in physical chemistry at Cornell whom she would later describe as her greatest ally.
After being snubbed by Princeton — whose astrophysics department did not admit women and declined even to send her the course catalogue — she chose Cornell for her master’s degree. She followed it with a PhD from Georgetown University in Washington where the Rubins had moved after Robert‘s work took them to Baltimore.
Bringing up a family while continuing to study and research was tough, but even harder was carving a path in an environment where women were just wives. Yet Rubin, with family support, never wavered.
Robert would drive her to Georgetown University, wait in the car and drive her back while her parents babysat. They once drove Vera and her new baby all the way to Philadelphia to allow her to present her master’s thesis to the American Astronomical Society — who gave the 22 year-old a lukewarm reception.
But Rubin was undeterred and continued to combine part-time teaching and research with raising four children. She refused let discrimination stop her.
She famously had to battle to gain access to the telescope at the Mount Palomar Observatory from which women were banned, supposedly to allow male astronomers to isolate themselves from their families. When she finally became its first authorised female user, she discovered there were no ladies lavatories so she fashioned a skirt out of paper and stuck it on to the men’s toilet door.
Rubin consistently fought for a bigger role for women in sciences and conducted a long-running battle with the National Academy of Sciences. In 1996 she became only the second woman to be awarded the Gold Medal of the Royal Astronomical Society. Often mentioned as a possible Nobel winner, she wasn’t interested: “Fame is fleeting,” she remarked. “If astronomers are still using my data years from now, that’s the greatest compliment.”
She also saw no conflict between her Jewish faith and science: ”I’m Jewish and religion to me is a kind of moral code and a kind of history. I try to do my science in a moral way and I believe that, ideally, science should be looked upon as something that helps us understand our role in the universe.”
Robert Rubin died in 2008. A daughter, Judy Young, died in 2014. She is survived by her sister Ruth Cooper Burg, her sons Allan, David and Karl; five grandchildren and a great-granddaughter. JULIE CARBONARA