Riding the gravitational wave
Riding the gravitational wave
Perhaps the most exciting discovery in fundamental physics for decades was the detection of gravitational waves at the Advanced Laser Interferometer Gravitational-Wave Observatory (Advanced LIGO) in September 2015—followed by a second detection only a few months later. These discoveries have opened up new possibilities in exploring the universe through its most enigmatic objects: black holes, while at the same time testing our current understanding of the physical laws underpinning the universe.
Theorised by Albert Einstein more than one hundred years ago, work to detect gravitational waves has continued for fifty years. The discovery in September 2015 was the result of an international effort in which Australian researchers played an important part, and to which the Australian Research Council has provided significant support. This included Linkage Infrastructure Equipment and Facilities grants for Australian researchers to travel to the USA-based LIGO experiments to install and operate instruments developed in Australia and Advanced LIGO, as well as Linkage Projects and Discovery Projects grants for specific technologies.
The first burst of gravitational waves detected by advanced LIGO are consistent with the coalescence of two massive black holes some 30 times the mass of our Sun over a billion light years away. In the second event, the black holes were closer and smaller. They represent an amazing new insight into the Universe. Converted into pitches audible to human ears, the peculiar chirping sound of the signals can be heard in this YouTube clip.
“Long-term support from the ARC was critical in enabling Australian researchers to play such a major role in the opening of this new window on the universe,” says Professor David McClelland, leader of Australia’s Partnership in Advanced LIGO.
Now, the award of $31.3 million for an ARC Centre of Excellence for Gravitational Wave Discovery led by Swinburne University of Technology will provide a massive boost to Australia’s ability to stay at the cutting edge of this new field.
The new Centre of Excellence, to be known as OzGRav, will be led by Professor Matthew Bailes, who has a background in detecting strange signals from outer space. In 2015 he was awarded a $2.8 million ARC Laureate Fellowship to develop the technology to discover ‘fast radio bursts’, mysterious and powerful radio signals that strike the Earth thousands of times per day and are thought to come from the distant universe.
“My research has been continuously supported by the ARC since I first returned from the UK as an ARC Queen Elizabeth II Fellow in 1993,” says Professor Bailes, whose team has designed the supercomputing equipment that will be used at the Square Kilometre Array radio telescope currently being built in South Africa and Australia to study radio pulsars.
Swinburne University of Technology is now building a new $3.5 million supercomputer to sift through the reams of data from Advanced LIGO, and hunt for new relativistic objects using a completely different spectrum, the gravitational waves that ripple through space time itself.
“Our new Centre brings together experts in gravitational wave instrumentation, data and theory into one cohesive national team,” says Professor Bailes. “OzGRav will have a rapid-response astronomy team to follow up gravitational wave events at other wavelengths, scientists that will help optimise the performance of the current detectors through tricks to help beat the uncertainty principle like ‘quantum squeezing’. We also have data scientists to sift through terabytes of data to search for magnetic mountains on nearby neutron stars, and astrophysicists to help explain the origin of gravitational waves and whether Einstein’s theory is the final word on gravity.”
Swinburne University of Technology’s Australian partners in OzGRav are: Monash University; the Australian National University; The University of Melbourne; The University of Western Australia; The University of Adelaide; Commonwealth Science and Industrial Research Organisation; and the Australian Astronomical Observatory.
“We stand at the dawn of a new era in astronomy, that of gravitational wave astrophysics,” says Professor Bailes. “Now the gravitational waves will allow us to probe regions of the Universe that have never been open to investigation, and OzGRav scientists and engineers can play a leading role.”
Two Black Holes Merge into One Image Credit: SXS, the Simulating eXtreme Spacetimes (SXS) project