Vera Rubin

Astronomer

• Born: July 23, 1928
• Birthplace: Philadelphia, Pennsylvania
• Died: December 25, 2016
• Place of death: Princeton, New Jersey

Also known as: Vera Cooper Rubin

Education: Vassar College; Cornell University; Georgetown University

Significance: Vera Rubin's research on galaxy rotation and the presence of an invisible cosmic force known as dark matter propelled the scientific community into a new age of astronomical inquiry. Rubin's career earned her multiple honors and awards, and she was regularly mentioned as a possible Nobel Prize recipient.

Background

Vera Rubin was born Vera Cooper on July 23, 1928, in Philadelphia, Pennsylvania. Her father, Philip, was an electrical engineer who worked for Bell Telephone. Her mother, Rose, also worked for a telephone company but later quit. Rubin spent most of her childhood in Philadelphia before the family relocated to Washington, DC, when she was ten. Rubin had become fascinated by the stars she watched pass by her window at night. She took an interest in astronomy shortly after the move, continuing her studies through high school.

When it came time to enroll in college, Rubin decided on Vassar College because it was the alma mater of one of her idols, female astronomer Maria Mitchell. She pursued a degree in astronomy and was the only female astronomy major to graduate in 1948. She married Robert Rubin, a physical chemistry graduate student at Cornell University, that year. Rubin then attempted to enroll in Princeton's PhD program, but the school's astrophysics department did not admit women at the time and would not send her a course catalog. Rubin applied to Cornell's master's program instead, earning her degree in 1951. She and her husband moved to Washington, DC, when Robert got a job at Baltimore's Johns Hopkins University. Rubin enrolled in Georgetown University's doctorate program where she studied the properties and motions of faraway galaxies.

Life's Work

Rubin earned her PhD in 1954 and took a teaching job at Georgetown University. After a few years as an associate professor, she took a position as a researcher within the Department of Terrestrial Magnetism at Washington's Carnegie Institution for Science in 1965. She and her colleague, Kent Ford, regularly observed the activity of distant galaxies using Ford's advanced spectrometer, a device that measures properties such as wavelength, mass, energy, or light distortion. The pair primarily used the calculations from this instrument to study the rotation of galaxies neighboring Earth. Through their observations, Rubin and Ford were able to devise a method for calculating the orbital speed of stars in different parts of the galaxy.

To figure out a star's orbital speed, Rubin and Ford spread out the star's spectrum of white light as it came through the spectrometer, dividing the light into each of the separate colors of which white light is composed. They then noted how the motion of the light source shifts along the wavelength of the spectrum. If the light source moved toward Earth, the wavelength would decrease and shift to the blue end of the color spectrum. If the light source moved away from Earth, the wavelength increased and shifted to the red end of the color spectrum. They called this the Doppler effect, and their observations enabled them to measure the speed at which stars orbited around a galaxy.

Rubin and Ford's research also led to an unexpected discovery about how stars orbit the center of a galaxy. According to their calculations, the stars farther away from the center moved just as fast as those closer to the center. Rubin knew it was impossible for the mass of a galaxy to have a strong enough gravitational pull to hold the distant, fast-paced stars in orbit. She and Ford concluded that some large, invisible force must exist in the outer areas of a galaxy to keep the stars in orbit. Rubin's calculations revealed that galaxies, and essentially the rest of the observable universe, must contain more than 90 percent of this dark, unknown mass. This invisible force, which scientists came to refer to as "dark matter" and "dark energy," became one of the most compelling mysteries in the field of astronomy. Throughout the remainder of her career, Rubin analyzed the spectra of hundreds of nearby galaxies and concluded that they all contained large amounts of dark matter.

Alongside her astronomical research, Rubin also served as an associate editor for several scholarly journals between the 1970s and early 1980s. She was elected to the National Academy of Sciences in 1981 and was later awarded the institution's James Craig Watson Medal for her work on dark matter. Rubin's research continued to unveil new knowledge about distant galaxies. In the 1990s, she discovered a galaxy whose stars orbited in opposite directions, leading Rubin to wonder if perhaps two galaxies spinning in different directions collided to form one. She made similar hypotheses about strange behavior she observed in other galaxies. For example, she believed the gravitational forces emitted by galaxies were capable of disturbing the peace of other nearby galaxies. In 1993, Rubin was awarded the National Medal of Science by President Bill Clinton. She was awarded the Royal Astronomical Society's Gold Medal in 1996. Rubin was often mentioned as a potential candidate for the Nobel Prize throughout her later career but died before such an achievement could come to fruition. She died on December 25, 2016, in Princeton, New Jersey, at the age of eighty-eight.

Impact

Along with her many scientific accomplishments, Rubin was an avid feminist and repeatedly advocated for a stronger female presence within the scientific community. She also encouraged greater scientific literacy among the public, publishing several books about her research written for the layperson. Rubin's work heralded a new era of cosmic knowledge, and scientists have since concluded that the universe is comprised of five to ten times as much dark matter and energy as regular, visible matter. Theories on dark matter are routinely tested in facilities such as Geneva's European Organization for Nuclear Research (CERN), and its mystery continues to fascinate scientists around the world.

Personal Life

She married Robert Rubin in 1948. The couple had four children together—sons David, Karl, and Allan; and daughter Judy. Each of the children earned doctorate degrees in science or mathematics. Robert Rubin died in 2008. Their daughter, Judy, passed away in 2014.

Bibliography

Domonoske, Camila. "Vera Rubin, Who Confirmed Existence of Dark Matter, Dies at 88." NPR, 26 Dec. 2016, www.npr.org/sections/thetwo-way/2016/12/26/507022497/vera-rubin-who-confirmed-existence-of-dark-matter-dies-at-88. Accessed 4 Mar. 2017.

Larsen, Kristine. "Vera Cooper Rubin." Jewish Women's Archive, www.jwa.org/encyclopedia/article/rubin-vera-cooper. Accessed 4 Mar. 2017.

Overbye, Dennis. "Vera Rubin, 88, Dies; Opened Doors in Astronomy, and for Women." New York Times, 27 Dec. 2016, www.nytimes.com/2016/12/27/science/vera-rubin-astronomist-who-made-the-case-for-dark-matter-dies-at-88.html?‗r=0. Accessed 4 Mar. 2017.

"Profile: Vera Rubin and Dark Matter." American Museum of Natural History, www.amnh.org/explore/resource-collections/cosmic-horizons/profile-vera-rubin-and-dark-matter/. Accessed 4 Mar. 2017.

"Vera Rubin Who Confirmed "Dark Matter" Dies." Carnegie Institution for Science, 26 Dec. 2016, www.carnegiescience.edu/news/vera-rubin-who-confirmed-%E2%80%9Cdark-matter%E2%80%9D-dies. Accessed 4 Mar. 2017.