In December 1871 the Prince of Wales lay dangerously ill with typhoid, the disease that had killed his father. Taking advantage of modern technology, the Archbishop of Canterbury despatched telegraph messages around the country ordering special prayers to be read for his recovery. As if by miracle, the patient began to feel better on exactly the tenth anniversary of Prince Albert’s death – but when Queen Victoria staged a grand thanksgiving service at Westminster Abbey the nation’s leading scientists declined to attend.

This episode crystallised longstanding antagonisms into hostilities that lasted decades. The first shot was fired by Sir Henry Thompson, an eminent surgeon who suggested conducting a five-year experiment in a hospital ward to determine whether an orchestrated programme of collective praying would reduce mortality rates. In what became known as the Prayer Gauge Debate, incensed Christians protested that prayer was a religious experience, not a mathematical instrument for measuring God’s power; conversely, scientists scoffed at the concept of divine intervention in a world ruled by unchanging laws. This confrontation was a tussle for power – not so much about arriving at a particular answer, but about determining who had the social authority to decide what the right answer should be. Responsibilities gradually separated into two distinct realms, the natural and the spiritual, each with its own rulers.

Sky’s the limit?

In 1912 Cecilia Payne (later Payne-Gaposchkin), a 12-year-old schoolgirl, decided to carry out her own heavenly research. She had still been in a pram when she saw her first meteorite flashing across the skies and announced that she would become an astronomer. Frustrated by the limited syllabus of her Catholic school, she divided her examinations into two groups, praying for success in one but not the other. After her highest marks fell in the control set that had not benefited from her pleas for divine inspiration, she concluded that ‘the only legitimate request to God is for courage’ and began treating the tiny attic laboratory as her private chapel where she could worship the beauty of nature. ‘Science is my religion’, she later told her mother. Braving the fury of her teachers, she insisted on studying scientific and mathematical topics until the principal lost patience, expelling her rebellious pupil with an extraordinarily inappropriate judgement: ‘You are prostituting your gifts.’

Despite this inauspicious start, by her mid-20s Payne had singlehandedly resolved one of science’s pressing debates: what are the stars made of? Her unanticipated answer to this question overturned accepted orthodoxy – and once again she found herself stymied by established authorities. Even among scientists, those supposedly objective arbiters, not everybody had the right to pronounce the truth. 

‘Dear Director’

Even as a small child, Payne resented being a girl brought up in a man’s world. Her bitterness intensified once she arrived at Cambridge, a privilege she obtained only by undertaking an intensive course of self-tuition to win a scholarship. During lectures she was obliged to sit by herself in the front row and brazen out the derisive foot stamping from male students behind her; in laboratory sessions, professors barked out instructions for women to remove their corsets in case they contained steel reinforcements that would disturb magnetic experiments. More positively, a few world-famous figures – such as the atomic pioneer Ernest Rutherford and the Astronomer Royal, Arthur Eddington, who led the experiments confirming General Relativity – paid her special attention, recognising that she was an exceptionally gifted undergraduate.

By the time of the final examinations Payne had already published an original research paper and taken over Newnham College’s small observatory, restoring its neglected equipment by fishing a chrysalis out of the clockwork. Even so, like all female graduates without rich relatives, she contemplated a future with just two options: marriage or teaching. The only possibility of pursuing an academic career lay in emigrating to America – so when Harlow Shapley, Director of the Harvard College Observatory, gave a lecture in London, she marched up to him afterwards and invited herself over. After he politely (if unthinkingly) agreed that she could work for him, she set about raising enough money to get there.

Payne’s escape across the Atlantic proved a turning-point for astronomy as well as her own career. Over the previous 40 years, Harvard had compiled an enormous number of photographic plates recording detailed observations of stars. Most unusually, they had employed women – known as ‘computers’ – to analyse these vast data sets, many of them working at home or on a part-time basis, all of them paid at very low rates for their meticulous, skilled work. Their main contribution had been to group the stars according to characteristics such as colour and size. They were stellar botanists, wrote Payne, who classified the celestial flora into separate categories.

Shapley invited Payne to continue this crucial work, but she had other plans. Trained as a physicist, she wanted to investigate what happened inside the stars by applying the very latest theories. Fortunately for her, this desire to pursue original research meshed well with Shapley’s own ambitions to expand his domain, and he persuaded Payne to pursue a PhD. As she joked with a close friend – the two women called themselves the ‘Heavenly Twins’ – their ‘Dear Director’ was determined to convert his ‘Dear Little Observatory’ into 
a ‘Great Institution.’ 

Spectral fingerprints

Physics was being overturned by relativity and quantum mechanics, and Payne seized the opportunity to test drive the recent theory of an Indian astronomer, Meghnad Saha. By introducing this state-of-the-art mathematical analysis, she revolutionised Harvard astronomy. The Observatory’s plates carried thousands of photographic images generated by a spectrometer, a more sophisticated equivalent of glass prisms that spread out sunlight into a rainbow spectrum of colours. Each photograph displayed the range of colours emitted by a star, and also carried valuable additional information encoded in dark lines superimposed upon the pattern. A line’s position among the colours revealed a particular element, while its intensity was related to two further quantities – the element’s abundance in a star and its temperature. As Saha put it, elements could be identified by their spectral fingerprints.

Payne became absorbed in her research, assigning herself a gruelling programme of measurement, mathematics and interpretation. Emerging exhausted two years later, she wrote up her results ‘in a kind of ecstasy’. Working in close proximity, Shapley and Payne became engaged in a symbiotic but unequal relationship: whereas he welcomed her role in fulfilling his dreams of academic grandeur, she elevated her ‘Dear Director’ to an almost godlike status. ‘I worshipped Dr Shapley’, she recalled later, acknowledging her jealousy when he bestowed his enthusiasm on others. Reciprocally, Shapley told a colleague that she ‘is one of the most outstanding astrophysicists of America, of any and all sexes’ – but insisted on not being quoted.

At Shapley’s bidding, Payne took the unusual step of converting her PhD thesis into a book, Stellar Atmospheres (1925). It sold 600 copies, a bestseller by academic standards. Her research gave numerical precision to previous assumptions about the structure of the stars. But there were two glaring exceptions – her estimates for hydrogen and helium were way out of line. Time and again, she went over her calculations searching for a slip, but repeatedly arrived at the same answers. In particular, her calculations showed that there was a million times more hydrogen in the sun than anticipated. If she was right, standard explanations about the formation of the solar system would have to be rejected. According to orthodox views, the sun and its planets had gradually condensed out from a swirling cloud of gas and dust, which implied that their compositions would be broadly similar. Accepting Payne’s conclusions would entail abandoning the principle of uniformity that was deeply ingrained in scientific thought. 

Taking credit

As part of the academic vetting procedure, Payne’s research had to be approved by Henry Norris Russell, director of the Observatory at Princeton and notorious for falling asleep during his own lectures. As a major defender of the uniformity thesis, Russell was appalled by the consequences of Payne’s research. On his orders, Shapley persuaded Payne to denounce her figures as spurious. Acting against her better instincts, she noted that the hydrogen and helium levels she had deduced were ‘improbably high … almost certainly not real’. 

This manipulation became darker still. Adopting a very different methodology, Russell continued to explore the composition of the stars. Four years later he produced his own book, announcing that the sun consisted of 98 per cent helium and hydrogen. Buried at the end was a small acknowledgement of a ‘gratifying agreement’ with Payne’s results. Until recently, this startling discovery was routinely attributed to him rather than to Payne.

To the end of her life, Payne blamed herself for giving in ‘to Authority when I believed I was right’. Although she remained marginalised among the observers of the heavens, her students adored this unconventional woman who chain-smoked through her lectures, gazing skywards as if conversing directly with the stars. She bequeathed them some heartfelt advice: ‘If you are sure of your facts, you should defend your position.’

Patricia Fara is an Emeritus Fellow of Clare College, Cambridge. Her most recent book is Life after Gravity: The London Career of Isaac Newton (Oxford University Press, 2021).