Vera Rubin was the American astronomer whose observations were fundamental to sustain the existence of dark matter in the universe.
In one of her last interviews, Vera Rubin said: “I observed that the galaxies revolved in a totally unexpected way“.
The great merits of astronomer Vera Rubin
She was a research astronomer at the Carnegie Institution of Washington, and a member of the United States National Academy of Sciences and the Pontifical Academy of Sciences.
On June 15, 2009, a conference entitled “Unveiling the mass of galaxies” was held in Ontario to celebrate her 81st birthday and to celebrate the achievements of her successful career.
Among these achievements is the discovery of what is called “dark matter” and that seems to constitute 90% of the existing matter in the Universe.
Childhood and family of this extraordinary astronomer
Vera Cooper Rubin, better known as Vera Rubin, was born on July 23, 1928, in Philadelphia (USA).
Daughter of immigrant Jewish parents, and the smallest of two sisters. His father, Philip Cooper, was born in Vilnius, Lithuania.
As a child, Vera Rubin showed great interest in the movement of the stars she saw from the window of the house.
Her father, an electrical engineer, encouraged her to continue with her passion, helped her build a telescope and accompanied her to meetings of amateur astronomers.
Marriage and first works of Vera Rubin
In the summer of 1947 she met Robert Rubin, a student at Cornell University, and married him the following year.
In 1948, Vera Rubin graduated in Astronomy at the University of Vassar, after which she tried to enroll in Princeton University; but he did not succeed, because until 1975 in that University women were not allowed to access postgraduate studies in Astronomy.
As an alternative, Vera requested to be admitted to Cornell University, because her husband, a member of the Navy, was assigned there to study chemistry.
In Cornell, Vera studied a Master in Physics under the direction of Philip Morrison, Richard Feynman and Hans Bethe.
For two years, her husband accompanied her to night classes, while the grandparents took care of her son David.
Beginnings of her galaxy investigations
In 1954, she obtained her doctorate at Georgetown University, under the guidance of George Gamow, known for having predicted the Cosmic Microwave Fund, as a consequence of the Big Bang.
Under Dr. Stahr’s supervision, Vera Rubin did a thesis on “the distribution of galaxy speeds“.
When Dr. Stahr offered her that, to help her for her recent motherhood, he would present his work at the American Astronomical Society meeting, she rejected the offer.
The results presented by Vera Rubin were so discussed that the Washington Post published “Young mother finds the center of creation or something similar“.
Fifty years later some friends published in the same newspaper “Grandmother gets the Medal of Science“.
Her discoveries related to galaxies
With her doctoral thesis, Vera Rubin sought to answer the question of whether galaxies are evenly distributed in the Universe.
To do this, she developed a method of statistical description of the distribution of galaxies, and applied it to a small catalog that was part of a map of the sky, which was being carried out at the Lick Observatory in California.
Noting that there was a high rate of clustering in the distribution of galaxies, she surmised that they were concentrated in certain areas leaving empty spaces between them.
The research of the British astronomer Beatrice Tinsley was very helpful for her.
Studying the movement and brightness of spiral galaxies, she concluded that there were some that seemed to travel more quickly in one direction.
These results sparked almost no interest at the time of publication, but were confirmed fifteen years later and now form the basis of the study of the large-scale structure of the Universe.
Vera Rubin teacher and mother of four Children
In the 1950s, for ten years, Vera combined teaching and research at Georgetown University with her family life, since during these years her other three children were born.
They all have a deep admiration for their mother and are dedicated to scientific research: David is a geologist, Judith astrophysics, Karl mathematician and Allan geologist.
Together with her daughter, Judith Young, Doctor of Physics, Vera Rubin published six scientific articles. It is one of the few scientific tandem, mother-daughter, of Astronomy.
In 1962, Vera Rubin met Margaret and Geoffrey Burbidge at the annual meeting of the American Astronomical Society.
Vera Rubin in the 1960s
The following year, he moved to San Diego (California) to work with them in the Department of Physics of La Jolla.
Vera Rubin said it was the first time she felt her ideas in astronomy were heard.
In 1964, she returned to Washington and accepted the work she was offered at the Department of Terrestrial Magnetism of the Carnegie Institution, where he continued working until the end of her days.
She was the first woman to use the Monte Palomar telescope legally.
Later she moved to the “Carnegie Institution of Washington” where she began collaborating with Kent Ford, in what would be the research that would culminate his career.
Kent Ford had developed a very sensitive spectrograph, which allowed measuring the speed of stars in spiral galaxies, based on their distance to the center.
Vera Rubin had already been interested in the internal movement of gas and stars in spiral galaxies, during her stay at the University of California.
But in this collaboration with Kent Ford, the study of the rotation of the stars and the gas in the spiral galaxy discs took all its meaning.
The first galaxy they examined was our neighbor Andromeda. From it they took measurements of how the gas moved in the disk.
Until then it was believed that the distribution of the mass of a galaxy was the same as the distribution of the light emitted by the stars.
In a spiral galaxy there is a brighter central part and a disk in which its luminosity decreases exponentially towards the external parts.
The brightest central part contains most of the dough; therefore, the rotation speeds of the stars should be higher in the center and decrease as they move away from the center of the galaxy.
If the speed of rotation and the distance to the center are represented in a diagram, you should see a curve with higher velocity values in the central part of the galaxy, and that they were decaying outward.
What would be the surprise of both researchers to see that, instead, the rotation curve remained flat at all points observed.
Vera Rubin began to glimpse dark matter
At first they thought it would be an anomaly of the Andromeda galaxy. However, after analyzing many more similar objects, they concluded that it was a characteristic common to all spiral galaxies.
They remembered then the work of the Swiss astronomer Fritz Zwiky.
In the 1930s, Zwiky indicated that there was a lack of mass to explain the movement of the galaxies of the Coma cluster; and concluded that there must be matter that was not seen. His work had no impact at the time, nor was that line of research followed.
Many years after these observations by Fritz Zwiky, at the meeting of the American Astronomy Society of 1975, Vera Rubin and Kent Ford announced to the entire scientific community that half of the mass contained in the spiral galaxies was not visible but was present in the form of “dark matter“.
At first, this result was received with skepticism. However, other works quickly appeared that corroborated it.
Since 1978, Vera and her team have observed more than 200 galaxies and have been able to calculate that approximately 90% of the matter in the Universe is “dark” matter, not visible, but detectable by the gravitational effect it produces.
Since the works of Vera Rubin and Fritz Zwiky, numerous tests and observations have been carried out, aimed at detecting the effects of dark matter.
Vera Rubin contributed to develop modern astronomy
With her work she opened the door to one of the great astronomical mysteries of all time: the existence of matter that we cannot see or detect with the instruments available today.
Global recognition to astronomer Vera Rubin
She was one of the great candidates to win the Nobel Prize in Physics. For some, its history embodied for years the inequality in the awarding of the most prestigious award in science.
Vera Rubin was an Honorary Doctor of numerous universities, including Harvard and Yale.
Two of the many websites that provide information about Vera Rubin are: “The Universe and the Man” and “Women with Science“.
She died on December 25, 2016, at age 88 in New Jersey. She was a truly remarkable and extraordinary woman.