Two of the US scientists who last week won the Nobel Prize in Physics have visited Western Australia’s Gravity Discovery Centre and one of them, Kip Thorne, even has a tree named after him at the gravitational wave research facility.
The University of Western Australia’s Professor David Blair said all three researchers – Professors Thorne, Barry Barish and Rainer Weiss – had a major influence on UWA’s gravitational wave research program, which led to the creation of the ARC Centre of Excellence for Gravitational Wave Discovery, OzGrav.
Professor Blair said Professor Thorne’s work on general relativity and gravitational waves at Princeton University in the 1960s inspired a worldwide collaboration that included UWA’s research which created a niobium bar detector.
“This operated together with four similar devices in Europe and the US. Despite being the most sensitive instruments ever built, the search failed to detect any signals. However, they put limits on the strength of gravitational wave bursts and set the benchmark for the next generation of detectors.”
The concept of using laser interferometers for detecting gravitational waves was first analysed in detail by Professor Weiss in the early 1970s. Experiments by teams in Scotland and Germany eventually demonstrated practical techniques for making such interferometers in the 1980s.
“Professor Thorne emphasised the significance of searching for gravitational waves from the coalescence of pairs of neutron stars, because these would sweep up in frequency like a siren,” Professor Blair said.
Laser interferometers could be scaled up in size to gain extra sensitivity and Professor Thorne campaigned for the US to build a pair of huge laser interferometers, encouraging Australian teams at UWA and ANU to begin research in this area.
In the 1990s, with Professor Thorne’s encouragement, the UWA and ANU groups set up a collaboration, which expanded to three groups with the University of Adelaide and then became the Australian Consortium for Interferometric Gravitational Astronomy, now known as the OzGrav Centre of Excellence.
Professor Thorne advocated building a detector in Australia and played a significant role in advocating and developing the proposal for a gravitational wave observatory in Western Australia.
With his support, UWA and the Western Australian Government supported a search for a gravitational wave detector site, leading to the selection of Wallingup Plain near Gingin as an ideal site for a large-scale detector.
This led to the WA Government, UWA and the Australian Research Council jointly funding the development of the Gingin Research Centre.
In 1998 Professor Thorne, along with Aboriginal Elders, inaugurated the Gingin site beneath an ancient blackbutt tree in the middle of the pristine bushland of Wallingup Plain. On the same day he presented a lecture about black holes and gravitational waves to an audience of high school students at the Gingin town hall.
Within a few years an 80m scale laser interferometer facility was constructed at Gingin, followed later by the Gravity Discovery Centre, funded largely from donations and philanthropy. The Gingin research facility has underpinned UWA’s gravitational wave research ever since. Today Kip Thorne’s Tree is visited by many students taking part in education programs at the Gravity Discovery Centre.
In 2005 Professor Barish visited Gingin and when he saw the Gravity Discovery Centre he said: “LIGO needs to have one of these.” Some years later LIGO opened a beautiful public centre at its Livingstone Observatory.
Professor Barish was responsible for creating the worldwide collaboration that enabled Australia to become a partner in the discovery of gravitational waves. By opening the project to worldwide participation he brought new ideas and expertise to the project.
This accelerated the discovery of gravitational waves while allowing 1000 physicists to share the struggle, the dream, the disappointments and the excitement of the search. The whole collaboration was rewarded when the LIGO detectors finally achieved detection of gravitational waves on 14 September 2015.
Professor Blair said they had uncovered a surprisingly large population of large black holes and we can be certain that gravitational waves will provide astonishing new insights for decades to come.
Professor David Blair (UWA School of Physics) (+61 8) 6488 2736
David Stacey (UWA Media and Public Relations Manager) (+61 8) 6488 3229 / (+61 4) 32 637 716