How Astronomer Jocelyn Bell Burnell Shaped Our Understanding of the Universe by Discovering Pulsars, Only to Be Excluded from the Nobel Prize
How a sole “scruffy signal” jokingly attributed to “little green men” forever changed our image of the cosmos.
By Maria Popova
In July of 1967, the month of her twenty-fourth birthday, Northern Irish astrophysicist Jocelyn Bell Burnell (b. July 15, 1943) discovered the first pulsar. This was landmark evidence that neutron stars — the collapsed core left behind by the final explosion of a dying star, first proposed a year after the discovery of the neutron in 1933 — were real. But the most significant implication of the discovery was that if neutron stars could result from stellar death, so could black holes, which even Einstein considered a neat but limited, purely mathematical, and possibly unprovable theoretical construct.
Pulsars — enormous, rapidly spinning, extremely dense spheres of nuclear matter magnetized with a strength exceeding Earth’s magnetic fields by an order of millions, even thousands of trillions — thus shaped our present understanding of the universe. Bell Burnell discovered the first four.
The groundbreaking paper announcing the discovery was published four months later, listing Bell Burnell’s name second and Antony Hewish, her thesis supervisor, first.
On October 15, 1974, the Nobel Prize in Physics was awarded to Hewish and his English colleague Martin Ryle for their work in radioastronomy. The Swedish Academy cited Hewish’s “decisive role in the discovery of pulsars” in the official announcement.
Bell Burnell was excluded from the prize.
In a 1977 speech, Bell Burnell insisted on not feeling slighted by the Nobel committee, citing the difficulty of resolving “demarcation disputes between supervisor and student” and the belief that “it would demean Nobel Prizes if they were awarded to research students.” But it is hard to read such sentiments without wondering whether there might be a kind of Stockholm Syndrome of the disenfranchised at work — after all, those systematically marginalized and discriminated against by any power structure have no choice but to rationalize injustice as a coping mechanism if they are to continue operating within that ecosystem without being broken by its biases.
Cosmologist Janna Levin explores Bell Burnell’s pioneering contribution to science, its far-reaching implications, and the complexities surrounding the Nobel controversy in a portion of Black Hole Blues and Other Songs from Outer Space (public library), which remains among one of the very finest books I’ve ever read — an altogether spectacular chronicle of how the century-long quest to detect gravitational waves ushered in a new era of astronomy.
There is nothing like plain observation to finally resolve a theoretical standoff. Jocelyn Bell Burnell found evidence of a neutron star. Added to the sheer intrinsic fascination of that discovery was the promise of even more, the promise of black holes. (An illustrious colleague is reported to have intercepted her at a meeting to declare, “Miss Bell, you have made the greatest astronomical discovery of the twentieth century.”)
With her characteristic subtlety and sensitivity to nuance, Levin shares in the skepticism about such wholesale acquittal of prejudice:
Hewish need not defend his credibility as a Nobel laureate. As the advisor he set his student to the task — even if the task was to look for quasars. Harder to comprehend is the omission of Jocelyn Bell Burnell from the list of recipients. I ask her if she thought her former advisor should have done something more, and she says with no resentment, “If you get a prize, it’s not your job to explain why you got the prize.” She also adds that the slight has worked out for her quite well. She continues to get seemingly every other prize, medal, honor, and accolade ever invented. Fair compensation she seems to imply. Dame (Susan) Jocelyn Bell Burnell: dame commander of the Most Excellent Order of the British Empire, fellow of the Royal Society, president of the Royal Society of Edinburgh, fellow of the Royal Astronomical Society, many distinguished medals, dozens of honorary doctorates etc., etc., etc.
The specter of bias had haunted Bell Burnell since the dawn of her career. According to Ron Drever — the cantankerous Scottish genius comprising one third of the famed LIGO Troika, who served as young Jocelyn’s undergraduate advisor in Glasgow — she was denied employment at England’s foremost radio astronomy center in the mid-1960s on account of her gender. Levin follows the thread:
[Drever] relays, “They wouldn’t take her on, and the story was that it was because she was a woman. But that’s not official, you see. So she was very disappointed.” He adds, hoping the absurdity was obvious, “Her second best was to go to Cambridge. You see?” He considered this a very fortuitous and happy turn. He laughs. “So she went to Cambridge and discovered pulsars. You see?”
Later in her career, Jocelyn Bell Burnell moved into X-ray astronomy to work on the team that built the British-American Ariel 5 X-ray astronomy satellite. On October 10, 1974, early in the morning, Ariel launched successfully, and at noon she heard the announcement of the Nobel Prize for the discovery of pulsars. There were two aspects of the announcement that were of particular significance to her. For one, the Nobel committee had finally acknowledged astrophysics as a subfield worthy of the Nobel Prize in Physics. In the 1920s Edwin Hubble had campaigned for such a shift unsuccessfully. For another, she was not among the recipients.
To grasp the scope of this systemic predicament: Crowning the hierarchy of British academia are the so-called “full professors,” distinguished from the vast court of mere doctors. Even at the height of her career, Bell Burnell was one of only two women among the 150 such full professors in Britain.
And yet in the midst of this maelstrom of politics and esteemed extrinsic validation is the perennial heart of science itself, that utmost intrinsic reward of curiosity — the sublime exhilaration of discovery. Levin telescopes to that luminous moment, which changed Bell Burnell’s life and changed our basic understanding of the cosmos:
As a twenty-four-year-old graduate student at Cambridge, [Bell Burnell] and her advisor, Antony Hewish, were looking for quasars, bright radio sources that looked as small as stars. At the time that she was stringing radio antennae in the field, quasars were still called quasi-stellar radio objects and the sources were a mystery. The radio antennae worked well at finding quasars, poorly at resolving their sizes, and brilliantly at changing the course of astrophysics. Among the quasars detected were many glitches and peculiarities recorded on the reams of chart paper, quantified by the length of paper in feet. She examined hundreds (thousands?) of feet of paper meticulously. Most of the anomalies were attributable to human-made sources or some form of detector interference. But one funny signal persisted. She became convinced that the source was astronomical in origin. She said the realization that she had seen something truly important came gradually. As is often reported, the regularity of the signal earned the sources the internal nickname of LGM, for “little green men.” It turns out that there are even more precise clocks than those manufactured by the civilizations of little intelligent green men. And those would be pulsars.
When Jocelyn Bell Burnell discovered the first pulsar in 1967, all she could deduce for certain was that there was a very regular series of pulses, a little over a second apart, and that they were coming from the sky.
When the second one appeared in the data, “that was the sweet moment,” she says. That’s when the oddity began to take on the features of a discovery. “Once I’d seen one scruffy signal, I was open to seeing more.” She found the first four pulsars ever discovered by human beings.
A year later a pulsar was discovered in the center of the Crab Nebula, a luminous remnant ejected during a supernova explosion. The Crab Nebula was seen from Earth and noted in historical records as an astronomical event in 1054 AD. The implication: Neutron stars are the collapsed core that remains after a dying star explodes. We now extrapolate that there are hundreds of millions of neutron stars in our galaxy, and hundreds of thousands of these are pulsars.
Black Hole Blues and Other Songs from Outer Space (which my pal Ben Folds set to song) is a terrific read in its totality. Complement this particular portion with the story of how Maria Mitchell paved the way for women in astronomy, trailblazing astronomer Vera Rubin on women in science and the endless human quest to know the cosmos, and the untold story of the remarkable women who powered the early days of NASA.
Published July 15, 2016