A few months ago, I got wind of an exhibit about women in science at the Grolier Club on the Upper East Side. The exhibit was of the old-school-glass-case variety, but the subject matter was tailor-made for me. Women scientists from the middle ages through our modern era? Yes, I’ll have some of that please.
I have an intellectual crush on the field of astrophysics as a whole and that crush got a lot more serious when I learned in the exhibit that a woman had been responsible for discovering an elemental fact about stars. To be honest, I had been looking for an excuse to write about stars, so I dashed home and started reading.
This was the intro panel for the exhibit and also a great example of why no one reads labels in museum exhibits. I didn't even read it and not only was I interested in the subject, I write these for a living!
Allow me to introduce you to a woman of imposing stature and impossible genius. Her name is Cecilia Payne-Gaposchkin-- a chain smoking, groundbreaking lady astronomer and astrophysicist who started her work in the 1920s. A pack of cigarettes and a single match were her constant lecture companions, so in her honor, I suggest you light up and keep reading.
Cecilia was brilliant, definitely the girl you both respected and hated in every class. While doing her undergrad in England she fell in love with astronomy and physics. But silly woman, said the Brits, we can’t have you traipsing about studying the cosmos and what have you.
She wasn’t allowed to get an advanced degree anywhere in England, so she headed for America. Your tired, your poor, your badass, brilliant astronomers...as I think the saying goes.
She ended up with a fellowship at Harvard where she wrote a thesis that changed the field of astronomy and astrophysics forever
Strap in for some science:
Stars emit light. Now, imagine holding a giant prism up to a star. When you hold a prism up to a white light, it breaks down into a rainbow. All those stripes of colors (What up, ROY G BIV?) are caused by light waves traveling at different speeds.
Go back to that prism in front of a star. When you look at the way light from a star breaks down, you can learn some really interesting things. Science types call this kind of study spectroscopy. By studying how wide certain parts (colors) of the spectrum are along with the location and width of any disruptions in the spectrum we can learn how big a star is, how far away it is, how hot it is, and what it’s made of.
Cecilia was the one that figured out how the ‘how hot it is, and what it’s made of’ part of that. Before her, the prevailing theory was that every type of body in the universe was made of the same basic materials. Earth, we knew, was mostly iron. So are the meteorites that come crashing down on it. It made sense to think of stars as slowly cooling balls of molten iron.
But enter Cecilia. Her dissertation showed that the different spectral readings astronomers were getting from stars were due to the stars’ temperatures, not their chemical composition as had been assumed. Not content to rest there, she went on to calculate the relative amounts of 18 elements found in stars. Here’s where this gets crazy: her results showed that all stars, regardless of size or temperature, were made of virtually the same thing: helium and hydrogen.
Think about that: stars, as massive as they are, are mostly composed of the two lightest elements in the universe. The heavier elements, including metals like iron, make up only about 2% of a star’s mass.
Our Sun has a mass about 333,000 times greater than Earth. And yet, it is made almost entirely of the two lightest elements in the universe. (Photo courtesy of NASA)
That information was nothing short of mindblowing and therefore a bit controversial. Cecilia’s advisor, Henry Norris Russell concluded that the results were “clearly impossible” and convinced her to walk her conclusions back a bit. She ended up issuing a statement that said the abundance of hydrogen and helium she had calculated was almost certainly erroneous.
Only it wasn’t erroneous at all. Within a few years, most astronomers were on board the helium and hydrogen train.
Cecilia knows you don't believe her. She doesn't care. (Photo courtesy of: Smithsonian Institution Archives)
The turning point for the acceptance of her findings was, of course, a short paper published by none other than Henry “Clearly Impossible” Russell himself. Four years after poo-pooing her results, he published a paper essentially confirming his student’s findings. In fairness to Henry, he arrived at the same conclusion through different means, but he arrived nonetheless. He acknowledged her in the paper, but who do you think got the credit? Womp womp.
It seems worthwhile to mention that three years later, in 1931, another pioneering astrophysicist would use Henry/ Cecilia’s findings to figure out that stars’ energy comes from nuclear fusion. That, my friends, is a Big Deal.
Cecilia went on to be the first person ever to get a PhD in Astronomy from Harvard. She was also the first female professor and the first female department chair.
Despite her obvious astrophysical prowess, she had to fight to be recognized for the genius she was. Cecilia, however, did more than just keep it in perspective: "I simply went on plodding,” she said, “rewarded by the beauty of the scenery towards an unexpected goal."
She firmly believed that whatever she discovered would ultimately further science and thus would be worth it, whether she got the credit or not. She maintained that in a successful scientific career, the “reward will be the widening of the horizon as you climb. And if you achieve that reward you will ask no other."
