Astrophiz 120: Dr Cecilia Payne-Gaposchkin

Listen: https://soundcloud.com/astrophiz/astrophiz-120-dr-cecilia-payne-gaposchkin

TRANSCRIPT:

Welcome to the Astrophiz Podcasts, My name is Brendan O’Brien and today is Tuesday 16 February 2021.

For this Episode we are featuring the life and remarkable achievements of Dr Cecilia Payne-Gaposchkin, who lived for 80 years from the start of the 20th century, and gave the world a legacy of astronomical breakthroughs that forever changed the way that we understand stars and what they are made of. And a spoiler alert is warranted here: You’ll be hearing about a continuing problem we have in scientific communities where women are not respected and begrudged their very existence in these communities and institutions

Begin:

Cecilia Payne, the eldest of three children,  was born on May 10, 1900, in Wendover, a small rural market town in England, to parents with family and occupational connections to the British intelligentsia. 

Her father, Edward Payne was a talented musician, an Oxford fellow, barrister and judge, and had her playing piano scales from the age of two and she developed perfect pitch, however her dad drowned in a canal when she was four.

Her mother was Emma Payne née Pertz, a skilled artist, who came from an academically accomplished German family. Emma was a rather stern woman, who raised her three children alone, and made sure her children were well-educated: Cecilia’s brother grew up to become an archaeologist and her sister became an architect.

At age six, Cecilia began attending a small girls’ school across the street from her home in Wendover. It was run by Miss Elizabeth Edwards, who told her classes that women were the stronger sex. 

Cecilia learned to read and became an avid reader. There were frequent exercises in mental arithmetic. Miss Edwards required her girls to learn lengthy poems by heart – Cecilia said this helped her later scientific work because it developed her memory to a very high level.

At age eight, with an interest in botany and insects, Cecilia decided to become a scientist. 

By the time she left this small school, Cecilia had learned basic Latin and could speak French and German. She had studied geometry, could do algebra up to the level of quadratic equations, and had been taught how to use a chemical balance. 
At home she became a skilled pianist. 

It had all been wonderful. And then it came crashing down

At age 12, Cecilia moved reluctantly with her mother and siblings to London. Previously accustomed to the freedom of living with plenty of space and nearby fields and hills, she hated the big, smoky city.

In London for the next 4 years, she attended St. Mary’s College, but found it inferior to her little school in Wendover. She felt there were far too many church services, leaving less time for other subjects: there was no science for a year; German was not taught; and her favourite subject – mathematics – was a whole year behind. The school believed there was a conflict between science and religion and preferred religion. Cecilia compensated by working through the only two scientific books in her home: a botany text in French and German, which she translated into English; and Isaac Newton’s masterpiece: Principia.

Cecilia studied calculus and coordinate geometry on her own, and just before her seventeenth birthday her school told her it could do no more for her and asked her to leave.

She left, and enrolled for her senior high school years at St Paul’s Girls’ School in London. It was everything she could have hoped for. Here she was positively encouraged to love science and was taught music by the famous composer Gustav Holst – the first man she had said more than just a few words to since her father’s death over a decade earlier.

She played in the school’s orchestra and Holst taught her to conduct. He urged Cecilia to become a musician, but her heart was set on becoming a scientist.

After matriculating from St Pauls, as a 19 year old, her ambition was to study science at the University of Cambridge, but with no money for this, she needed to win a full scholarship. Fortunately she achieved this formidable objective, winning the only scholarship generous enough to cover all her costs, and enrolled at Newnham College in Cambridge, where she was allowed the unusual combination of botany, physics, and chemistry. Although she entered Newnham College with the intention of reading Botany as her major, but Cecilia soon dropped botany, but retained her interest in taxonomy, and flourished in Physics, and two years later, she obtained an Honours grade through her studies in the famous Cavendish Laboratory at Cambridge where she was inspired by Ernest Rutherford, who had developed the nuclear model of atoms was the new director of the lab. Also working in this lab at the time were JJ Thompson, who had discovered the electron, and Neils Bohr was a noted visitor to the lab who developed the quantum model of energy levels for electrons in an atom.

In 1919, with the war just over, Cecilia launched herself vigorously into her studies in an exciting environment where there was a renewed interest in wider searches for knowledge and new fields of human endeavour, in Art, Music, in science and engineering, and in the application of electricity and of the internal combustion engine to both industrial processes and everyday life, including the beginnings of commercial aviation. Nevertheless, there were serious problems she had to deal with on a daily basis. Cecilia’s insatiable thirst for knowledge did not sit well with the Cambridge boys. 

During physics lectures at the University of Cambridge, she, like all women, had to sit at the front, forced to parade past male students stomping in time with her steps. Women were not allowed to sit next to men, so she had the whole front row to herself and was derided and mocked, and while being allowed to study and pass all courses and earning top grades as Cecilia did, women were forbidden by university regulations to be awarded a degree. 

In some ways, nothing has changed much. Today I watched a Zoom call where a male academic scornfully and nastily admonished a highly accomplished female researcher for not kowtowing to his mighty credentials. Astonishing!  

In this amazing environment in Cambridge then came a serendipitous turning point for young Cecilia Payne. When one of the only 4 ticket holders from Newnham College had to pull out, Cecilia received the ticket and attended at Trinity College Cambridge, a repeat of the world-shaking Royal Society lecture by Sir Arthur Eddington, Plumian Professor of Astronomy and director of Cambridge Observatory, who had announced in November 1919 the successful results of his expeditions to observe the total eclipse of the sun the previous May. These two expeditions were to the West African island of Principe, and the other to the Brazilian town of Sobral, and the aim of the expeditions was to measure the gravitational deflection of starlight from the Hyades constellation passing near the Sun during the eclipse. The exact value of this deflection had previously been predicted bb Albert Einstein in his 1911 paper, and was one of the tests Eddington proposed for Einstein’s 1915 theory of General Relativity. The deflections were exactly as predicted and widespread newspaper coverage of Eddington’s results led to worldwide fame for Einstein and his theories. Interestingly, Einstein wasn’t too fussed about the results by Eddington, for he has already decided he was right about how the universe worked lol

Cecilia was so totally enthralled with Eddington’s lecture that she raced back to her rooms that night and wrote out virtually word-for-word what she had heard, “I know I got it right,” she said, “because he later published his lecture.” She had verified her copy as being almost perfectly correct against his printed version. Such was her changed perception of the world that she did not sleep for three nights.

Oh to have an experience and exceptional memory like that! From that point on, thanks to Eddington’s lecture, Cecilia was welded to physics and astronomy, and Eddington became her mentor who gave her use of the observatory library. She always said that Eddington was “the greatest man I have been privileged to know”. 

Her undergraduate studies at Cambridge England continued and she worked with the same enthusiasm throughout 1920 and 1921, and had the help of a full scholarship for her final year.

In 1922, she was introduced to an American visitor, Harlow Shapley, the new director of the Harvard College Observatory, who she found to be most enthusiastic and encouraging about her obvious quest for new astronomical knowledge, which was quite a contrast to her general Cambridge experience where women were not encouraged or supported to apply to post-grad opportunities, study grants or research assistant positions.

Just as a little side note, from 1921 onwards as the director of the Harvard College Observatory for thirty years, Shapley was quite an influential astronomer in his own right. He had used Cepheid variable stars to estimate the size of the Milky Way Galaxy for the first time, and plotted the Sun’s position within one of its spiral arms it by using parallax observations and measurements. 

Shapely went on to be a citizen hero in other ways too. In the early 40’s he famously put the S for Science in UNESCO, then in 1946 Shapley stood up to the notorious House Un-American Activities Committee, the HUAC, and accused them of using Gestapo tactics and argued for the abolition of the HUAC.

In 1953, Shapely proposed his “liquid water belt” theory, now known as the concept of a habitable zone. Most importantly for this episode, he hired Cecilia Payne to work at the Harvard College Observatory.

Back to Cecilia in 1923, and Payne’s first paper is published in Monthly Notices. 
Eddington proposes her admittance into Royal Astronomical Society and gives her a favourable letter of introduction to Shapley who she had already met, and it’s Bye bye Cambridge England and hello Cambridge Massachusetts, and Cecilia would set sail across the Atlantic on a new life voyage, to study astronomy in America. So once again she had been urged on by Eddington, who had told her that “there was no insuperable difficulty in you making a career in astronomy”, and on her arrival at Harvard University, Director Shapley found her a modest stipend to see her through the first two years at Harvard. 

When Cecilia arrived at the American city of Cambridge in September 1923,  she found it exhilarating: this is what she said in a later interview “… coming to Harvard was intoxicating. It was partly the climate. I had never been in a climate like that before. The Massachusetts climate in the fall, well, I found it physically intoxicating. I had never felt like that before. Cambridge in England has an awful climate. Whenever you go to Cambridge, you — at least I — used to resign myself to feeling like a vegetable and aching from head to foot all the time I was there because it is so damp and so cold.”

 Now at Harvard, there was no defined graduate astronomy programme, but there was Physics, but the Chairman of the Department of Physics was Theodore Lyman, who initially refused to accept a woman candidate, but by signing her application and forwarding it to the Secretary of Radcliffe College the Harvard Astronomy Department was created de facto by Shapely.

A relevant side-note here is that the Harvard College Observatory had a history of hiring ‘Women assistants’ aka ‘human computers’ to do what was seen as the routine work of populating the seminal Henry Draper Catalogue of positions, magnitudes and spectral types of stars, and some of these, such as Annie Jump Cannon and Henrietta Swan Leavitt, had become internationally known for their work in astronomy. In episodes later in the year, Astrophiz be looking closely at Annie Jump Cannon and Henrietta Swan Leavitt because they were so much more than the ‘human computers’ they were employed as. They took the observations and data they were entering into the Draper Catalogue, understood them, saw previously unseen relationships and had indelible impacts on astrophysics and the science of the stars that still reverberate today. An irrelevant side note is that, like me, Annie Jump Cannon and Henrietta Swan Leavitt were both deaf.

Back to Cecilia again at Harvard. She began work under the guidance of Annie Jump Cannon, working on stellar spectra, and winning class prizes for her assignments. She had always been a stand-out student and she thrived in this new environment, though there were still many significant barriers, like the existence of many ‘men-only’ meetings where women were barred from attending. 

12 months later in 1924 and Payne is well into her PhD studies, and hers would soon be the first Doctorate to be awarded via the Harvard College Observatory, and in June 1924 she successfully took the preliminary PhD general examination set by Dr Shapely. 

Onwards and upwards. Shapely gave her access to the library, where the Harvard Collection of several hundred thousand glass photographs of the night sky, taken over a period of 40 years were available for Cecilia to examine. Many of these images stretched starlight into strips, or spectra, marked by naturally occurring lines that revealed the constituent elements, which Cecilia  wanted to study in light of her new knowledge of astrophysics, and applying her understanding and application of Saha’s equation of ionization to the Fraunhofer lines, those dark absorption lines in the spectrum of a star, caused by selective absorption of the star’s radiation at specific wavelengths by the various elements existing as gases in its atmosphere, thus revealing their exact chemical make-up.  There was no stopping Cecilia, a modern day COVID analogy would be to say Cecilia was doing genomic sequencing of stellar populations. 

Up to this point, no one had thought to examine all the spectra to take a census of the atoms. Doing so required Cecilia to use the new field of quantum physics to identify dozens of element signatures in thousands of spectra — a task to which Payne was uniquely suited. The work was gruelling and tedious, she once went without sleep for 72 hours, struggling to understand what the stars were telling her, but she harnessed her keen observational skills, sharp mathematical mind and rigorous physics training.

After roughly two years of nearly unbroken focus, she overturned one of the prevailing thoughts of the day: that stars were chemically similar to Earth. Instead, she found that hydrogen appeared to be a million times as abundant as expected, and helium a thousand times so. Earth, it seemed, was not the template for the universe. 

When Cecilia Payne first began her study of stellar spectra, astronomers all believed that the relative abundance of elements in the atmospheres of the Sun and the stars had to be similar to that in Earth’s crust, which was known at the time to be approx. oxygen, 45 percent by weight; silicon, 28percent; aluminium, 8 percent; iron, 5 percent; calcium, 4 percent; sodium, 4 percent and so on. This was soon to be proven wrong for, as with every other challenge in her life, Payne would not stop. Then in 1925 a breakthrough!

The output from her keen observations and meticulous calculations was that Cecilia produced an amazing  PhD thesis which she published as a monograph, “Harvard Observatory Monograph No. 1, entitled ‘Stellar Atmospheres — A contribution to the observational study of high temperature in the reversing layers of stars.” Her thesis was later nominated by the late Dr Otto Struve and others, as ‘the most brilliant PhD thesis ever written in astronomy’. Otto Struve was, by the way, one of the most distinguished and prolific astronomers of the mid-20th century with more than 900 journal articles and books to his name. He served as director of Yerkes, McDonald, Leuschner and National Radio Astronomy Observatories and was the person who hired Subrahmanyan Chandrasekhar who went on to win an explosive Nobel Prize. So praise for Cecilia’s PhD from Dr Struve was no small thing.

For those wanting to read her actual thesis, you can find it in the Harvard archives at tinyurl.com FORWARD SLASH ceciliapayne (all one word, all lower case). 

In it she establishes the abundances of the chemical elements observable in stars and proved that the huge variety of spectral types of stars resulted from temperature differences rather than differences in abundances of various elements. One key implication from her thesis research she published was astonishing. That stars consisted of an overwhelming abundance of hydrogen and helium. Payne’s results showed that for myriad stars she had so assiduously analysed, the abundance ratios were 74% hydrogen, 24% helium, and all the remaining elements accounted for only 2%. This was not like the composition of the earth at all. Today we know that 91.00% of the atoms in the sun are hydrogen and 8.87% are helium. All the atoms of other elements make up only 0.13%.

However, and here’s the rub, in her thesis on page 186 she was urged by noted Harvard astronomer Henry Norris Russell, who, along with Shapley and Eddington, was another influential proponent of similar earth/sun/star elemental abundance theory, to discount her Hydrogen/Helium results as ‘spurious’.  But they weren’t spurious at all, they were as accurate as every other data point in her research.

Russell finally acknowledged she was correct four years later, after deriving the same result himself. In his paper, although he credited Miss Payne with determining that stars had a different chemical composition from Earth, and were composed primarily of Hydrogen and Helium, and verified that Cecilia had demonstrated for the first time the chemical homogeneity of the universe.

but he was the one who was credited with the discovery. Paving the way for discoveries by Rosalind Franklin, Vera Rubin and many other women in STEM to be bypassed and appropriated. That’s a hashtag in Twitter you should look up. #WomenInStem.

So following the 1925 publication of her still remarkable thesis, Dr Cecilia Payne was awarded her PhD at Radcliffe, Harvard’s college for women. Remember, at that time Harvard was only for men, and Harvard itself did not grant doctoral degrees to women.

On completing her doctorate, after considering other opportunities, she accepted the offer to stay on at Harvard as a technical assistant to Shapley, and developed an interest in researching variable stars. In 1930 she published the first of several acclaimed books The Stars of High Luminosity.

In 1933 Europe was on edge, she was advised not to go there, but Payne visited European observatories including the Leningrad observatory, and saw the wretched conditions for Puklova astronomers, and continued on to visit Germany, where conditions were also very tense, and she met a young Russian astronomer, Sergei Gaposchkin. Despite hardships and persecution in the Soviet Union because of his political views, he had achieved success as an astronomer, and had fled Russia. However in Germany he now faced Nazi persecution, because he was Russian. He asked Cecilia to help him get to America. She was moved by his story, and, after returning home, she went to Washington and worked hard to get him a visa as a stateless person. Success! He came out and, later in 1934, they married and she became Cecilia Payne-Gaposchkin. He obtained a position at Harvard and from then onwards they successfully collaborated on studies of variable stars, so with thoroughly disparate backgrounds and different mother tongues, they formed an astronomical partnership that lasted for four decades and they had a family of three children, reckoned, possibly unfairly, by some visitors to Harvard in the 1950s as among the worst-behaved family they had experienced, but there was no doubt the old Harvard Observatory buildings were a fine play area for active children. Their children Katherine and Peter became astronomers, Edward became a neurosurgeon.

In 1938, Cecilia Payne-Gaposchkin was awarded a lectureship in astronomy at Harvard, and continued with her variable star research with Sergey, which involved an ambitious systematic investigation of 250,000 observations of variable stars up to 10th Magnitude, and published her second book , this time with Sergey, Variable Stars.


Cecilia continued her research and astronomy lectures at Harvard throughout the war years and in 1954, again with Sergey, published her third book, Variable Stars and Galactic Structure

Prior to this time, advancement to professor was denied to women at Harvard, so she had spent many years in lesser, low-paid duties, but Finally, in 1956, Dr Cecilia Payne-Gaposchkin achieved two Harvard firsts: she became the first female professor, and the first woman to become department chair. 

Over the next few years she put forward empirical patterns that helped define the exact structure of our galaxy and the paths of stellar evolution. In 1957 she produced ‘The Galactic Novae’. In the early 1960’s she and Sergey turned their attention to the two Magellanic clouds and made more than two million visual estimates of the Cepheid variable stars in these two immense cauldrons of developing stars. 

She officially retired in 1966, but continued with her research.


Her scientific output was prodigious, with 351 papers published in her life, including five during 1979, her final year of life, and nine books authored or co-authored with Sergei Gaposchkin.

In 1979, she wrote her autobiography, The Dyer’s Hand, that was later posthumously collected in Cecilia Payne-Gaposchkin: An Autobiography and Other Recollections (1984).

In her autobiography, Payne tells that while at school at St. Mary’s she created an experiment on the efficacy of prayer by dividing her exams into two random groups, praying for success only for one group, the other one being the control group. She achieved the higher marks in the control group. Later on, she became an agnostic.

She also wrote in that final year of life “Young people, especially young women, often ask me for advice. Here is is,  For what it’s worth, Do not undertake a scientific career in quest for fame and money. There are easier and better ways to reach them, Undertake it only if nothing else will satisfy you, for nothing else is probably be what you receive. Your reward will be the widening of the horizon as you climb. And if you achieve that reward, you will ask no other”

Vale Cecilia Helena Payne-Gaposchkin, who died in Cambridge, Massachusetts, on December 7, 1979. She was a smoker, and died in her sleep with lung cancer.

After her death other scientists would go on to remember her as “the most eminent woman astronomer of all time.” During a time when science was largely a men’s club, she had figured out the chemical makeup of the stars, and her work is also credited with paving the way for us to develop our understanding of stellar evolution.

The final word in this episode should go to Dr Payne-Gaposchkin herself:

In 1977 in the Astronomical Journal Vol 82, p665 Cecilia  wrote:

“The reward of the young scientist is the emotional thrill of being the first person in the history of the world to see something or to understand something. Nothing can compare with that experience… The reward of the old scientist is the sense of having seen a vague sketch grow into a masterly landscape.”

The end.

The full transcript of this episode is available at Astrophiz.com

In this episode I have drawn on her thesis “C. H. Payne, Stellar Atmospheres (published by Harvard University Press, Cambridge, MA, 1925)-Donovan Moore’s book “What are stars made of – The life of Cecilia Payne-Goposchkin” -Other resources I’ve used here include an interview transcript  with Cecilia, and her obituary, both by  Owen Gingerich, the transcript is published in the American Institute of Physics, and the obit is in the Quarterly Journal of the Royal Astronomical Society, Vol. 23, P. 450, 1982. 
Another great resource used is a wonderful article by Dr Douglas Stewart at famousscientists dot org

We’ll see you in two weeks when Dr Ian ‘Astroblog’ Musgrave will give us our March Skyguide and his fabulous astronomical tangent.

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