Scattered throughout our universe are the ultra dense remnants of dead stars. Some of these stars spin so fast that they complete a full revolution in mere milliseconds. A narrow beam of radio waves results from the intense magnetic field and spinning of these stars.
Astrophysicists can observe these regular “pulses” of radio waves, giving them the name pulsars.
Dr. Ingrid Stairs of UBC’s department of physics and astronomy is one of the world’s experts on pulsars. Her research into pulsars is so cutting edge that The Royal Society of Canada just presented her with the Rutherford Memorial Medal — an award given out annually to Canadians for “outstanding research in physics and chemistry” since 1980.
According to a press release from The Royal Society, Stairs was given the medal for “using radio emitting neutron stars (pulsars) to study and test theories of gravity.”
The award is from the “premier intellectual organization in the country,” Stairs said, “and it is a huge honour to receive recognition from them.”
Pulsar timing is “one type of observation, that gives insight into a whole wide range of physics,” Stairs said, which is why she initially started studying them. Pulsars have proved to be an invaluable tool in studying things from neutron stars to Einstein’s theory of general relativity.
“Pulsars basically function like lighthouses,” Stairs said. General relativity makes very specific predictions about the properties of stars’ orbits and pulsar timing allows for the theory to be tested.
Furthermore, “pulsars are the most extreme environments [in the universe] that exists outside of black holes,” Stairs explained. She uses the very precise timing of the pulses in order to make tests about Einstein’s relativity as they “give us the opportunity to study matter in extreme situations.”
So far, Einstein is yet to be proven wrong.
Looking towards the future, Stairs is excited about the possibility of using pulsars to make a direct detection of gravitational waves from events such as the merging of black holes.
As black holes merge, their gravitational waves “stretch and shrink” space causing matter (like you) to move with it. If the gravitational waves are strong enough, the Earth’s motion will be “like a cork bobbing up and down in water,” Stairs said.
If the importance of gravitational waves still doesn't quite make sense to you, give it another go with what Dr. Bill Unruh told The Ubyssey last year; “If the Earth was within, let's say, a thousand kilometres, the whole Earth would be torn apart by these gravitational waves.”
Stairs’ goal is similar to what researchers in Hanford, Washington and Livingston, Louisiana are doing using the Laser Interferometer Gravitational-Wave Observatory (LIGO), which was awarded the Nobel Prize in physics on October 3.
LIGO and pulsar timing can give scientists complementary data on gravitational waves; while LIGO is looking at the merger of black holes that weigh roughly 30 times the mass of the Sun, pulsars can be used to detect the merger of black holes that weigh nearly a billion times the mass of the Sun.
By timing the incoming light from different pulsars, astrophysicists may be able to detect the merger of supermassive black holes that weigh as much as billion (with a B) times the mass of the Sun, located in galaxies far, far away. So far, only intermediate mass black hole mergers have been detected.
This goal is also shared by a large international collaboration, the North American Nanohertz Observatory for Gravitational Waves, of which Stairs is a member. Stairs thinks that the detection of gravitational waves from these supermassive black holes will occur within the next five to ten years.