Key points
- Ruby Payne-Scott was one of the world's first radio-astronomers.
- She faced plenty of challenges as a woman in research.
- She has been recognised in many ways for her research and her work in women's rights, including with our Ruby Payne-Scott Award and a new Sydney ferry.
Unlike optical astronomy which goes back thousands of years, radio astronomy is very new. The field of study originated in the 1940s and much of it in Australia, thanks to a group of researchers at the University of Sydney and the Council of Scientific and Industrial Research, now CSIRO.
One of those in the group was Ruby Payne-Scott, a determined and bold physicist who paved the way for women researchers and recognised the future of radio astronomy.
“She was the best mathematician in the group and a very gifted physicist, at a time when women taking on physics degrees was very rare,” CSIRO radio astronomer Dr Elizabeth Mahony said.
“Her skillset and passion led her to become one of the early pioneers of radio astronomy, and helped create this entire new field of research which is still active today.”
Detecting a new direction
During World War II, many physicists were recruited to work on radar technology to help countries detect incoming planes and ships. Ruby was one of these recruits, developing lightweight radar equipment that could be flown to posts among the Pacific Islands.
Strange, unexplained radio signals were detected with radars throughout the War. They appeared to be coming from the Sun – but no one was really sure how that could be possible.
Once the War was over, much of the leftover radar equipment was turned towards space, to understand more about the Sun’s radio signals and any others detected in space. In 1946, Ruby, along with Joe Pawsey and Lindsay McCready, used radar stations along Sydney headlands overlooking the ocean.
“This measurement was really critical because it was the first time anyone had been able to pinpoint exactly where these radio waves were coming from,” said Elizabeth.
Here, they detected and measured radio waves coming from the Sun – both directly and bouncing off the sea – with a process called interferometry. It was the first ever radio interferometer used to detect an object in space: they had discovered the signature of a Sunspot.
“Ruby and the group at CSIRO went on to develop the technique of radio interferometry, a new way of looking at objects in the Universe in much higher detail. This is used by many radio telescopes around the world today.”
CSIRO continues to be a world-leading organisation for radio astronomy. The Australia Telescope National Facility is a network of radio telescopes, data archives and experts that builds on this rich history of discovery. Elizabeth uses these telescopes to uncover how distant galaxies and their central supermassive black holes evolve over time.
CSIRO is also the operations partner to the SKA Observatory for their SKA-Low telescope at Inyarrimanha Ilgari Bundara, our Murchison Radio-astronomy Observatory. Thanks to CSIRO's experience in radio astronomy, the organisation has played a key role in the vision, development and design of the telescope too. Once completed, the SKA-Low telescope will be the biggest radio interferometer ever built, a fitting continuation of the technology Ruby had a huge part in pioneering.
Fighting for women’s rights in the workplace
At CSIRO Ruby faced many challenges. She was part of a professional trade union for CSIRO employees, where they addressed issues of women’s pay, and she fought for more egalitarian policies.
As a government organisation in the 1940s, we implemented policies that were unfair to women: they could not be paid the same as men and lost continued employment once they married. To avoid this, Ruby married in secret.
It wasn’t her only subversive act. Women were supposed to wear skirts, but she regularly wore shorts.
When challenged on the dress code, Ruby’s reported to have said: “Well, this is absurd. We’re climbing up on ladders, up on aerials every day. I’m not going up on a ladder with a skirt on. The shorts are much better attire for us.”
Elizabeth added, “When told women weren’t allowed to smoke, she’d do precisely that at key moments just to make a point, even though she wasn’t a smoker. Ruby also wrote to the staff bulletin encouraging women to stick together until discriminatory rules were dismantled.”
Despite her efforts, the rules and legislation which made it so difficult for women to continue in research careers persisted. As Ruby’s impressive research abilities were well known, the discovery of her marriage did not end her work at CSIRO but she did lose her permanent position, pay level and pension. Her pregnancy a year later forced her retirement at a time when maternity leave was never even a consideration.
“The fact that by simply getting married a woman would be demoted from a permanent position seems outrageous in this day and age,” said Elizabeth.
“I'm sure this seemed outrageous to Ruby, and it is due to leaders like her that being a working mother is not an usual thing today.”
Building a more supportive future
A change in legislation in 1966 enabled married women to hold jobs in the public service, and paid maternity leave was introduce in 1973.
CSIRO has been working to ensure no one’s talent or career is halted due to their gender, health or family situation. The Ruby Payne-Scott Award was introduced in 2008, awarded to staff returning to work after a prolonged period of leave. It supports the recipient with funds to upskill quickly, such as attending conferences with their family, or travelling to meet research partners around the country. Elizabeth has been a recipient of the award.
“I have support and opportunities that weren’t available to Ruby. I have been able to re-establish collaborations and kick-start my career after I returned to work following periods of maternity leave, but doing so in a way that also works with my family commitments. I haven’t had to make the choice many women before me did,” she said.
Ongoing recognition
Multiple awards, infrastructure and now even a Sydney ferry have been named in Ruby’s honour.
In 2025, Transport for NSW launched a new fleet of ferries named after notable Sydney scientists and engineers. One of these is the Ruby Payne-Scott.
It is a fitting way to recognise Ruby, as the sea played an important technical role in those first radio interferometry measurements of space. But for astronomers like Elizabeth, it’s their work that continues Ruby’s legacy.
“I get to do incredible research, using radio telescopes to explore the Universe. Ruby took some of the first radio measurements of our Sun and now I’m studying galaxies deep in space.
“The field of radio astronomy has come a long way since Ruby made those first measurements in 1946. It’s just as exciting now as it was then.”