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  • Writer's pictureDale DeBakcsy

She Followed the Sun: Ruby Payne-Scott, the World’s First Woman Radio Astronomer

In March of 1944, a physicist and radar specialist named Ruby Payne-Scott aimed her equipment at the sky and became the world’s first woman radio astronomer.

Within four years, she had established herself as a chief engineer of Australia’s radio interferometer revolution, and one of the world’s truly pioneering solar astronomers.

Three years later, her career was over. The woman who had contributed her engineering genius to the Australian war effort, and her keen mathematical sense to the nascent field of radio astronomy, was demoted to Temporary status, her pension revoked, and the interest on her retirement payments reclaimed, when Payne-Scott’s dark secret was uncovered by a routine departmental survey: Ruby Payne-Scott was married.

In fact, she had been since 1944, a fact which should have automatically disqualified her for a permanent position in the Australian government but which her colleagues, valuing her contributions and unique mind, banded together to help her conceal from the bureaucracy for seven years. Payne-Scott wrung every observation she could out of that time, acting as equal parts technician, astronomer, mathematician, inventor, physicist, and engineer, hefting Australian science to its first taste of international prominence in the process.

She was ‘forthright and outspoken’ with a chronic inability to back down from a confrontation when she knew herself in the right. Dubbed ‘Red Ruby’ by her colleagues for her Communist sympathies (at least prior to 1956), she was a forward thinking, shorts-wearing, equal pay advocating atheist in an era that wanted nothing more than a return to a synthetic normalcy cobbled together out of Cold War fear and Atomic Era prosperity.

Born in 1912 in South Grafton, her family had by 1915 moved to Sydney and a world of expanded opportunities for an academically gifted young girl. Her mother, a former teacher, seems to have home-schooled Ruby and her brother through the elementary level, and in 1923 she commenced her formal schooling at Cleveland Street High School, where she graduated by age thirteen with highest marks in mathematics and biology. Her star on the rise, she next attended Sydney Girls’ High School, a highly regarded institution with a university prep focus. Again, she graduated early, leaving the school at age sixteen with 1st class honours in mathematics and biology, and A’'s in every subject save French.

By age seventeen, she was attending the University of Sydney with two merit scholarships supporting her studies, and her streak of academic excellence only continued as she completed the Honours Physics track in four years with another 1st Class Honours, and a string of scholarships and awards along the way. She was only the third woman in the university’s history to take a degree in physics.

She continued on at the University of Sydney for her Master's ’where, to gain money and experience, she brought her growing expertise in physics and mathematics to the university’s Cancer Research Committee (CRC). Her work on the scattering of radiation in water was thorough, solid research that stood out favorably amongst the CRC’s mainline efforts to validate the increasingly discredited theories of the magnificently monikered Dr Wanford Moppett. Payne-Scott earned her Master's ’but a further career at the crumbling CRC was out of the question to anyone able to read the academic tea leaves.

Photo by Jessica Chapman

And so, with characteristic energy and resolve, Payne-Scott threw herself into earning yet another degree, a Diploma of Education, that would allow her to take up a career in teaching should no new work in physics prove forthcoming. She earned that degree in 1938 and took up a position straightaway as Science Mistress at Woodlands Church of England Girls’ Grammar School. She was not, however, long for the world of teaching. Students described her as quiet and dedicated, but neither then nor later when she returned to teaching after being cast out of astronomy would her teaching career provide the satisfaction of her research work.

By 1939, Payne-Scott had left Woodlands and joined Amalgamated Wireless Australia as first a librarian, then head of the measurements’ laboratory and finally, on the strength of her physics and mathematical background, as a researcher who soon displayed a gift for practical electrical engineering that spawned two published papers in 1941.

Then came World War II.

1941 saw Australia suddenly at the front lines of a massive aerial and naval contest bloodily waged between the United States of America and the Japanese Empire. One of the great strengths of the Allies in that conflict was the advanced state of their Radar detection technology. Having joined the war, Australia threw itself into erecting a string of radar defence stations and funding new research into increasing the precision of radar measurements.

Upon finding that women not only could perform the work of radar operators, but in fact routinely outperformed men in that role, the Australian government actively encouraged the training of women operators. Ultimately 599 women worked as radar operators, a number hindered only by bureaucratic unwillingness to post women in forward combat zones. With her background in physics, however, Payne-Scott was destined to contribute to the Australian radar effort on a more fundamental level as a researcher, theorist, and engineer. In 1941 she responded to a call for applications from the Radiophysics Laboratory (RPL) of the Council for Scientific & Industrial Research (CSIR).

The RPL boasted a core of engineers, but stood in desperate need of a physicist with good mathematical chops, so when Payne-Scott’s late application came in with its list of published research from her time at the CRC and AWA she was quickly green-lit to join the team. For the next three years, she devoted herself to the thorny problems of radar calibration and the pioneering of interferometry to pinpoint hostile plane positions.

This latter work Payne-Scott would apply on a cosmic scale during her solar work of the late Forties when she harnessed interferometry as the workhorse of radio astronomy. During World War II this method centred on the use of cliffside radar stations located along the coast. Ordinarily, bouncing radar waves off an incoming plane gave only a rough notion of the plane’s location. But, by sending out a pulse and then measuring the interference of the directly returning wave from the plane and the wave returning after bouncing off the surface of the ocean, operators could radically improve the accuracy of their measurements. In perfecting these techniques and mastering the myriad factors that go into the proper calibration of radar equipment and the interpretation of incoming data, Payne-Scott developed precisely the skills that made her Australia’s most valued solar observer for a half-decade following the war’s end.

1944 proved Ruby's fateful year – in March of that year she and RPL chief J. L. Pawsey turned their 10 cm receivers on the sky and so began the RPL’s historicclimb as a respected centre of a research field that as yet had no name. Those measurements were largely left to lie fallow until after the war, but Payne-Scott’s other great leap of 1944 would bring with it the potential for immediate consequences: her marriage in September to Bill Hall.

At the time, Australian law declared that women had to be demoted to temporary status, surrendering all pension benefits, upon marrying, and had to resign their position entirely upon becoming pregnant. By 1944 Payne-Scott had fought hard for a permanent position with regular promotions and an impressive string of salary increases in recognition of her skill, and she was not about to surrender that position because of a law she considered medieval in principle and draconian in practice. Though officially registered as married, and though she informed her co-workers of that fact, there was an unspoken agreement at RPL not to inform the higher-ups in the bureaucracy of her new status. This act of necessary deception bought Payne-Scott a full six years of time to work and build and, my, did she use it.

At war’s end, RPL faced a dilemma – they possessed a concentration of cutting edge radar equipment and a staff of highly specialised engineers and physicists, but what to do with them? An extension of their earlier astronomical observations seemed a logical next step except for the small fact that not one of RPL’s researchers was trained in astronomy. Payne-Scott saw the challenge before her and characteristically leapt from the top rope to subdue it, teaching herself solar astronomy and working out the adjustments to current radar technology that would be needed to make radio receivers a truly effective tool in solar observation.

In particular, she needed to tackle radar’s imprecision when used on a galactic scale. Since radio waves have such massive, sprawling wavelengths compared to visible light, getting precise locations for objects as far away as the sun was a dicey proposition unless new techniques could be developed. Wartime radar receivers, when pointed at the sun, picked up a rich potpourri of radiation signals, but had almost no ability to locate where on the sun the signals originated.

Employing cliff-side interferometry methods, Payne-Scott was able to radically improve signal localisation, discovering that one particular type of polarised signal tended to occur in areas of sunspot activity (we now refer to this as a Type I signal). But cliff-side interferometers were drastically limited in their operating time, good for basically an hour of solar observation at dawn, and then lying about useless the rest of the day. To create an instrument that employed interferometer methods with even greater accuracy and longer observational periods, Payne-Scott designed a ‘swept-lobe’ interferometer to be located at Potts Hill reservoir.

It was the world’s first interferometer that swept radio signals across a surface at a rate of dozens of sweeps per second to capture solar detail and the first to use a movie camera to record the incoming signals, and it would prove a mighty tool in Twentieth Century astronomy.

While Potts Hill was under construction, Payne-Scott worked at a different observation site she had essentially been exiled to after a clash with a fellow, male, researcher was decided in his favour in spite of the fact that she was his senior at RPL. Working with one assistant, she set herself the task of validating a phenomenon nobody could quite bring themselves to believe. This involved what we now call Type III solar signals, which she essentially discovered and elucidated over the course of 1946. Unlike Type I signals, which appear simultaneously across all frequencies, Type III signals first appear in the upper frequencies, then make their way through the lower ones, with up to 9 seconds of delay between their first arrival at a high frequency and their first detection at a lower one. Payne-Scott’s work confirmed the reality of the frequency time lag and determined the unpolarised nature of Type III signals.

Following a miscarriage that caused her to leave work for a half-year, Payne-Scott found herself in 1948 the head of a new interferometry project, one of the best paid scientists at RPL, and a researcher whose detailing of solar radio burst types was laying the groundwork for an new scientific discipline. She teased out the different strands of radio noise streaming from the sun to determine how, based purely on radio characteristics, a solar flare could be distinguished from a sunspot or an ultra-fast electron stream pushing through plasma. She was at the height of her influence and inventiveness, when suddenly a bureaucratic marital status survey in the wake of a departmental rebranding brought to light her marriage to Bill Hall.

She was swiftly demoted to Temporary Status and lost all the RPL contributions that had thus far been made to her pension. She fought against the law as a gross and unfair act better fitted for Victorian England than Space Age Australia, but there was nothing to be done. A year later, when she discovered she was pregnant, she resigned her post, never to carry out original research again in the three decades remaining to her.

She threw herself into her new family life, raising two children, a boy who followed in her footsteps to become a mathematician, and a girl, Fiona Hall, who was for a time one of Australia’s most beloved artists. During the 1960s, she returned to teaching, but between what students described as her harshly high standards and the creeping onset of Alzheimer’s, the effort was not a resounding success. For the eleven years of her employment as a teacher, she never shared her time as Australia’s leading solar astronomer with either her students or colleagues. Her memory failing and her classroom presence growing ever feebler, she retired at last in 1974, losing a little more of herself every year thereafter until, in 1981, she died in a nursing home in Mortdale.


Astronomer W.M. Goss has devoted a considerable amount of time to resurrecting the details of Ruby Payne-Scott’s life and the nature of early Australian radio astronomy. His research is laid out in two books, 2010’s Under the Radar: The First Woman in Radio Astronomy (co-authored with Richard McGee), and 2013’s Making Waves: The Story of Ruby Payne-Scott: Australian Pioneer Radio Astronomer. These are your go-to sources for work about her life, and have formed the basis of something of a Ruby Renaissance.

And if you'd like to read more about women astronomers like Jill Tarter, check out my History of Women in Astronomy and Space Exploration, which you can order from Amazon, or from Pen and Sword US or UK.


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