It is a big week for WA physicist David Blair.
Not only was the UWA Emeritus Professor inducted into the WA Science Hall of Fame at the Premier’s Science Awards on Wednesday evening, days later he toasted to the one-year anniversary of one of the most exciting discoveries in modern science — a project Professor Blair played a key role in.
The physicist is renowned worldwide for his breakthrough work which contributed to the detection of a truly mind-bending phenomenon; gravitational waves.
His work already earned him election to the Australian Academy of Science, and now he joins the ranks of some of WA’s most lauded and respected researchers in the WA Science Hall of Fame.
“It’s absolutely wonderful, especially to be put amongst such other distinguished scientists,” Professor Blair said.
“I feel incredibly honoured and incredibly grateful to my colleagues but also to Western Australia which has been really good to me over my career.”
The detection of gravitational waves in 2015 was traced back to two black holes colliding, an event so extreme it sent ripples through the very fabric of space itself.
If that discovery was not monumental enough, it was followed up in spectacular fashion one year ago on Friday, when scientists used the very same method to detect gravitational waves produced this time by a collision between two neutron stars, the dense, rapidly spinning cores left behind when large stars collapse in on themselves.
The gravitational waves produced by the collision were followed barely more than a second later by gamma rays, detected by the Fermi Gamma-ray space telescope orbiting Earth.
This, Professor Blair says, is what makes the detection so exciting.
“There’d always been this hope that we could detect neutron stars – that’d always been our target,” he said.
“That discovery was absolutely momentous, all our Christmases came at once."
The gravitational waves and gamma rays had travelled for about 130 million years before reaching Earth only 1.7 seconds apart.
Professor Blair said the observation confirmed to researchers “to the most enormous precision” that gravity travelled at the speed of light, proving one of Albert Einstein’s biggest predictions.
“To think that we, in our very first observation, we find out that gravity and light travel at the same speed to this amazing precision, confirming what Einstein had predicted, is absolutely astonishing,” he said.
If that weren’t enough, the discovery also shed light on another cosmic conundrum: where gold comes from.
Scientists had been scratching their heads for years pondering what produced the universe’s stock of gold, but when researchers examined the data from the gamma rays produced by the neutron star collision, there were telltale signs of its production.
“Now from the observations we’ve had, we can see how often these things are happening and we can calculate how often they’re happening,” Professor Blair said.
“We know that black holes are coalescing about once every five minutes and neutron stars are coalescing about four times a minute in the whole universe. And we know that, for the black holes at least, we only have to make the [gravity wave] detectors about 10 times better and we’ll be able to hear the whole universe.”
Our big hope is that we will be able to hear to the very birth of the universe, and hear the universe being bornDavid Blair
Turn up the volume
There was a time when researchers believed gravitational waves would never be detected.
They had been indirectly observed, through the motion of star systems with two neutron stars, but it wasn’t until the Laser Interferometer Gravitational-Wave Observatory project became operational that scientists were able to open a new window to the universe.
As Professor Blair describes it, the project was the equivalent of a deaf person being given a bionic ear.
“We used to be able to see the universe, but as they said ‘in space no one can hear you scream’, well we always knew that we should be able to hear black holes screaming and things like that through space because gravity waves are just ripples of space that travel through space,” he said.
“Just like if you were in a forest and if you were deaf and you blocked your ears, you’d still see all the beautiful flowers and the trees, and things like that.
“But then to be able to listen and hear the wind in the trees and sticks falling down and birds calling and the sound of a river or waterfall, that’s another whole dimension to your experience, and that’s what we’ve now given humanity I believe, this new dimension for hearing the universe.”
Having already been used shed light on some of the most mind-bending phenomena in the universe, where time, space and the laws of physics descend into chaos, Professor Blair believes LIGO and gravitational-wave observations can go further, even right back to the very beginning of the universe itself.
“Our big hope is that we will be able to hear to the very birth of the universe, and hear the universe being born,” he said.
“Because we know we can’t see it, because we know light can’t travel through a certain barrier that happens about 400,000 years after the Big Bang, so you can’t see to the Big Bang, but we do know that gravity waves can pass through that, so with gravity waves we should be able to ‘hear’ the moment of the birth of the universe.”
The next generation of physicists
Partially retired, but still attending to a following of students, Professor Blair is passionate about bringing his love of physics to the next generation.
He is leading the Einstein-First Project in WA, aiming to teach young children the core tenets of Einsteinian physics.
“Just recently with a group of eight-year-olds we taught them the whole story of what we had discovered in gravity waves just one year ago [on Friday],” he said.
And this weekend the Gravity Wave Research Facility will pay homage to the neutron star discovery’s anniversary with the appropriately-named Hot To Make Gold event.
The event will take place across Saturday and Sunday, August 18 and 19, and will showcase the activities used in the classroom to teach students about the German physicist’s work — as well as shedding light on just how, exactly, a lot of the universe’s gold comes to be.
For Professor Blair, there was never any doubt gravitational waves would be discovered, and this new avenue of research fills him with excitement about what else can be seen — or “heard” — in the void of space.
“People who work on things like this have to be optimists.” He said. “And I’m an optimist, so I always knew we were going to get there — I mean, I hoped we’d get there before I died.
“It’s as if you could open up the window and hear everything going on across the entire earth; you could hear a car accident in New York, or a plane crashing in Moscow.
“In gravity waves we’re going to be able to hear every one of these extraordinary things happening in the whole universe simultaneously.”
Cameron Myles is a homepage editor with WAtoday. Prior to joining the team, he was a journalist, sub-editor and editor at several publications up and down the West Australian coast, going from the red dirt of Karratha to the vineyards and beaches of Busselton and Margaret River.