For the past decade, gravitational wave astronomy has opened our eyes to amazing cosmic phenomena like the collisions of black holes and neutron stars thanks to LIGO, the Laser Interferometer Gravitational-wave Observatory, that — despite its massive contribution to astronomy — is currently under threat.
LIGO is the latest in a long line of revolutionary instruments that have changed our view of the cosmos since Galileo Galilei pointed his homemade telescope skyward in 1609.
The Italian astronomer’s instrument helped transform our understanding of celestial objects from gods to moons, planets and stars.
Since then, telescopes have grown to gargantuan sizes and in some cases, have been launched into space for the clearest view possible.
The dawn of astronomy beyond visible light
In 1932, a new set of eyes on the universe were opened thanks to an accidental discovery by Karl Jansky. The young engineer from Bell Laboratories in the U.S., was looking for the source of static interference in shortwave transatlantic voice communications. Over several months, he tracked that interference as it slowly moved across the sky.
He concluded that the source of the noisy static was coming from the centre of our Milky Way galaxy outside of our solar system — and with that, radio astronomy was born.
The universe became a much more active place once we looked at it through radio eyes. Radio waves are invisible to the human eye, but they are given off by some of the most energetic events in the universe, such as supernova explosions, rapidly rotating neutron stars and colliding galaxies.
Other instruments see across the electromagnetic spectrum, through X-rays, ultraviolet light and instruments like the James Webb Space Telescope which use infrared radiation to see out to the edge of the universe and back to the beginning of time.
Every time new instruments are developed, new aspects of the universe are revealed.
Beyond the electromagnetic spectrum
In Sudbury, Ont., the Sudbury Neutrino Observatory (SNO) found invisible neutrinos given off by the sun pass through the Earth like light through a window. This earned Canadian physicist Art McDonald the Nobel prize in physics in 2015.
More recently, the neutrino observatory in Sudbury got an upgrade, allowing it to detect and learn about more exotic neutrinos.
WATCH: Visualization of two orbiting neutron stars with matter on the left and space-time distortion on the right
When Einstein predicted that space itself could be distorted by the gravitational pull of massive objects, like ripples on the surface of a pond when a boulder is dropped in, he didn’t believe gravitational waves could be detected because they would be so incredibly small.
It is hard enough to imagine the size of a single atom, its tiny nucleus and even smaller protons within it. Now imagine picking up a distortion in space-time that’s 10,000 times smaller than the width of a proton! No wonder Einstein didn’t think we would ever see them.
Thanks to years of research and remarkable engineering, LIGO made that very detection in 2015 using twin facilities equipped with laser beams that split and get reflected off mirrors down four-kilometre long tunnels set at 90 degrees to each other. As the gravitational waves pass through the Earth, it causes the fabric of space-time to elongate in one direction and shorten in the other by an incredibly tiny, yet measurable amount.
Even more remarkable is that these waves came from the collision of two black holes in the centre of a galaxy 1.3 billion light years away.
Trump cuts threaten future work
The beauty of gravitational waves is that they travel across the entire universe, uninterrupted by clouds of gas and dust the way light is. This new gravitational window has revealed hundreds of other events thanks to an international effort from LIGO and other detectors around the world, such as Virgo in Italy and the Kamioka Gravitational Wave Detector (KAGRA) in Japan.
The 10-year anniversary of LIGO comes at a bittersweet moment as U.S. President Donald Trump’s slashed 2026 budget for the National Science Foundation (NSF) of more than half may force them to shut down one of their two LIGO detectors — a move that could severely limit their overall reach and capabilities.
Teams in both the U.S. and Europe are already working on plans to develop a new generation of gravitational wave detectors both on the ground and in space. If they go forward, they’d be many times more sensitive than current detectors, allowing scientists to listen in on even quieter astronomical events.
Unsolved mysteries of the universe remain
So what is the next eye on the sky waiting to be opened?
There is something out there surrounding entire galaxies that we can’t see. We know it’s there because it exerts a gravitational pull on those galaxies, but it does not appear in telescopes. For now, scientists call it dark matter. No one knows what it is, yet it makes up roughly 25 per cent of all the matter in the universe.
Then there is dark energy, a mysterious force that appears to be causing the expansion of the universe to speed up. It makes up about 70 per cent of all the energy and matter in the universe — and again, we don’t know what it is.
In other words, the universe we do see only makes up about five per cent of what’s really out there.
Canada is on the forefront of solving the dark matter problem with more than a dozen new detectors in the expanded SNOLAB facilities deep underground in Sudbury. Who knows? Perhaps we will be first to solve the dark matter mystery.
As you will hear on Quirks & Quarks this week, there is still so much out there to discover.
