Burbidge, E. Margaret

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E. Margaret Burbidge

E. Margaret Burbidge (born 1919) appeared on the science scene quite early on, and made controversial, but important, discoveries ever since. She became recognized for the production of the first accurate estimate of the masses of galaxies, for her work with quasars, and for work she did concerning the metal contents of stars. She was also part of the committee that planned and outfitted the Hubble Space Telescope.

Early Interest in Science

Burbidge was born Eleanor Margaret Peachey in Davenport, England on August 12, 1919. She was born to Stanley John Peachey, a lecturer in chemistry at the Manchester School of Technology, and Marjorie Stott, a chemistry student there. The family relocated to London when Burbidge was almost two years old where her father set up a laboratory after he acquired some patents in the field of rubber chemistry. In this setting Burbidge was allowed and encouraged to develop her interest in science. She eventually attended the University of London where she took First Class Honors for her bachelor's degree in Science in 1939. She continued on at the University for her graduate education at the University's Observatory. Even though World War II was waging at the time, one of the Observatory's smaller telescopes was left intact and assembled and Burbidge spent the evenings doing her studies in the darkened city. Many of the Observatory's leaders were called to work for the military, and so Burbidge was appointed general caretaker, and she took her responsibilities very seriously, taking very special care of the observatory and its telescopes. She even went so far as to repair damage done to the observatory's dome during an air raid. She eventually received her Ph.D. in 1943, having done her studies on the physics of hot stars. When the war was over, Burbidge left the University while reconstruction was taking place throughout the city.

Burbidge returned to the University to continue her studies in 1947 once peace was established and London had been cleaned up. She met Geoffrey Burbidge, a fellow graduate student, at that time. They were married in April of 1948. The couple eventually had one daughter.

Burbidge took on the role of assistant director and acting director of the Observatory in the late 1940s. Then in 1951 the Yerkes Observatory of Harvard University offered Burbidge a fellowship to come study with them. She and her husband, who himself had been offered an Agassiz fellowship, moved to Cambridge to continue their separate studies there. They enjoyed America, but unfortunately had to leave and return to England when their fellowships were over in 1953.

Work with Hoyle and Fowler

In 1954 Burbidge took a job with the University of Chicago's observatory in Texas while her husband took a position at Cambridge University. It was in 1954 while Geoffrey was working at Cambridge University that the couple teamed up with the English astronomer Fred Hoyle and the American physicist William A. Fowler to study the make-up of stars. Burbidge was always drawn to the notion, which Hoyle introduced, that matter was created successively at different times in the Universe's life, rather than by one single event such as the Big Bang, so she was very excited to be working with the well-known astronomer. The four scientists started by continuing the research into the astronomical spectroscopy and evaluation of the surface layers of stars that Burbidge had done for her PhD. Through their studies they discovered that stars start out by burning lighter gases, starting with turning hydrogen into helium, but as they grow and age they build more and more complex metals, partly building on the metals left behind by previous stars. They found the only recently discovered and named element technetium in the spectral lines of the stars called red giants. Red giants are stars that are old and dying. When stars like the Sun die they grow cold and then expand until their outer skins create huge, red stars. Technetium is a complex, unstable element that could not possibly have been part of the star when it was new—this led the four scientists to the idea that the red giants must have produced this element rather recently in its life. The Burbidges, along with Hoyle and Fowler used this fact to show that stars, which start out made entirely of hydrogen, fuse these hydrogen elements together to make helium. They then fuse the helium elements together to form carbon, then nitrogen, then oxygen, and so on down the periodic table, making more and more complex elements as they go. By studying supernovae they discovered that the heavier elements, including iodine, platinum, gold, and uranium could be produced in those supernovae whose explosions—that occur when the stars are dying, which is when the stars explode outward till they are enormous and then collapse in on themselves—produce enough energy to make the heavier elements. When these supernovae explode, a large part of the old stars material is blown out into outer space to be absorbed by other stars. They also noted that the heavier elements like carbon, nitrogen, and oxygen, which are known to be found in all the living organisms on Earth, are also found inside ancient stars that have been dead for a long time. They concluded, therefore, that planets like Earth and all its inhabitants are actually composed of material from dead stars.

Both Burbidge and her husband obtained positions with the University of Chicago in 1957, although they continued their collaboration with Hoyle and Fowler. In fact, in 1957 the four published a paper on their discoveries about the composition and structure of stars that turned out to be one of the most important discoveries in modern astronomy. No one had proven before that stars were actually each a factory that produced all the elements of the universe. It was an amazing discovery that helped redirect the study of the universe and the humans' place in it. Those in the field referred to the paper simply as B2FH, with the B2 referring to the Burbidges, the F to Fowler and the H, obviously, to Hoyle.

Studied Rotation of Galaxies and Quasars

While they were doing this, the Burbidges also, in the 1950s and 1960s, together studied the rotation of galaxies. They were especially concerned with the internal dynamics and masses of those galaxies. Burbidge obtained the spectra of several spiral galaxies. She used these to measure the velocities of the ionized gas clouds in their nuclei and disks. They noted that galaxies rotated on an axis and that they managed to stay together in shapes like the Milky Way's spiral shape, and not fall apart because of centrifugal force. That is the same force that keeps water in a bucket when you spin it around in circles very quickly: the gravity keeps the water in the bucket, and the same force keeps galaxies together as they spin. They discovered that to find out a galaxy's actual weight and how the mass is distributed within it, you had to measure the rotational speed.

The Burbidges moved to San Diego, California in 1962 where Burbidge took a job at the University of California at San Diego. She became a full professor in 1964 and took over control of the University's Center for Astrophysics and Space Sciences from 1979 to 1988. Geoffrey took the position of professor of physics there. In the 1960s Burbidge turned her focus to quasars. Quasars are objects in space that have always been thought to be the farthest objects in space away from Earth, farther than the stars and other galaxies. Quasars have been demonstrated to emit vast amounts of radiation, even though they are very small, but no one knew what they were. Some of Burbidge's early discoveries were so exciting and intriguing that they led to her husband turning his focus to quasars as well, and the two worked together once again. Burbidge primarily studied the red shift of the quasars, which measures the speed at which an object is moving away from the Earth. The quasars had such a large red shift, compared to relatively closer objects like stars and galaxies that at first the Burbidges, along with scientists before them, deduced that the quasars must be at the very edge of the galaxy—the farthest things observable from Earth. And the farther an object is from Earth, the longer it takes for its light to reach Earth. Therefore, the light from the quasars that the Burbidges were seeing must have been in existence an amazingly long time ago. It was like finding dinosaur bones on Earth—the quasars were like ancient fossils, telling a story of the galaxy far different than anything closer and newer did. This large red shift of quasars has always been one of the things that scientists based their Big Bang Theory on. If everything in the universe started from one place and then there was an explosion throwing all sorts of matter into space, then the objects that were the farthest out, thrown first, would be moving at the fastest rate, just like the quasars were.

Questioned the Big Bang Theory

In order to be seen from such a distance, the Burbidges deduced that the quasars must have an enormous amount of energy, although they appeared to be quite small. This was a discrepancy that was difficult to explain, and something which bothered the Burbidges so much that they continued their studies. The quasars, oddly enough, also appeared to be grouped with nearby galaxies. After much research the Burbidges decided that the quasars, although they appeared to be a great distance away, must really be closer and have been pushed out of nearby galaxies. This was a very controversial deduction because it meant that the red shift could not be relied upon to determine how far something was away from the Earth, or for how fast the Universe was expanding. Burbidge's research with her husband eventually led to the pair challenging the truthfulness of the Big Bang Theory, which had been based on this red shift and seemingly increasing expansion of the Universe. The Burbidges published a book with their discoveries in 1967. It was called Quasi-Stellar Objects. It was and still is a very controversial study.

In 1972 Burbidge returned for a very short while to Britain where she became the first female director of the Royal Greenwich Observatory, but she quickly returned to San Diego as she preferred observing at a telescope rather than sitting behind a desk. For years after her return to the United States, Burbidge continued her observational research programs at the Lick Observatory of the University of California, working with students, fellows, and colleagues from around the world. Along with these others, she continued her research into the red shifts of quasars, the absorption lines in those quasars, and the distribution of quasars in the universe, all questions that pushed the boundaries of astronomical research and questioned old, accepted theories.

When it was proposed that there should be a telescope in space that would be able to see further than anything else on Earth could, Burbidge was very interested. She became part of the committee that designed and set up the telescope, which despite initial problems after launch has been quite successful in penetrating deeper into space than anyone on Earth has ever seen before. Over the many years of her research, Burbidge garnered many awards, including the Helen Warner Prize, which she was given with her husband by the American Astronomical Society in 1959, an organization that Burbidge herself became president of from 1976 to 1978; the Bruce Medal, given by the Astronomical Society Pacific in 1982; the National Medal of Science, given in 1984; the Russell Prize, given in 1984; and the Albert Einstein World Award of Science Medal, given in 1988. She was also elected to the National Academy of Sciences in 1978. In 1990 Burbidge became a professor emeritus.