Over the past decade, gravitational wave astronomy has opened our eyes to amazing cosmic phenomena such as black hole and neutron star collisions, thanks to Ligo, a laser interferometer gravitational wave observatory that—despite its enormous contribution to astronomy—is currently in jeopardy.
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 at the sky in 1609.
The Italian astronomers’ instrument helped transform our understanding of celestial objects from gods to moons, planets, and stars.
Since then, telescopes have grown to magnificent sizes and, in some cases, have been launched into space to get the clearest possible view.
The dawn of astronomy beyond visible light
In 1932, a new set of eyes were opened to the universe thanks to an accidental discovery by Karl Jansky. The young engineer at Bell Laboratories in the US was searching for the source of static interference in shortwave transatlantic voice communications. Over the course of several months, he tracked this interference as it slowly moved across the sky.
He concluded that the source of the noisy static came from the center of our Milky Way galaxy, outside our solar system – and thus radio astronomy was born.
The universe became a much more active place when we looked at it through radio eyes. Radio waves are invisible to the human eye, but they are released by some of the most ancient events in the universe, such as supernova explosions, rapidly rotating neutron stars, and colliding galaxies.
Other instruments see the entire electromagnetic spectrum, using X-rays, ultraviolet light, and instruments like the James Webb Space Telescope, which uses infrared radiation to see 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 discovered.
Outside the electromagnetic spectrum
In Sudbury, Ont., the Sudbury Neutrino Observatory (SNO) detected invisible neutrinos emitted by the sun through the earth, like light through a window. This earned Canadian physicist Art McDonald the Nobel Prize in Physics in 2015.
Most recently, the Neutrino Observatory in Sudbury received an upgrade, allowing it to detect and learn about more exotic neutrinos.
WATCH: Visualization of two circular neutron stars with matter on the left and space-time distortions on the right
https://www.youtube.com/watch?v=e8yt7o7bluc
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, he didn’t believe gravitational waves could be detected because they would be so incredibly small.
It’s hard enough to imagine the size of a single atom, its tiny nucleus, and the even smaller protons within it. Now imagine a warped space 10,000 times smaller than the width of a proton! No wonder Einstein didn’t think we’d ever see them.
Thanks to years of research and remarkable engineering, Ligo made this discovery in 2015 using twin chambers equipped with laser beams that split and reflect off mirrors in four-kilometer-long tunnels set at 90 degrees to each other. When gravitational waves pass through the Earth, they cause the fabric of space-time to stretch 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 at the center of the galaxy 1.3 billion light years away.
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The beauty of gravitational waves is that they travel throughout the universe, continuously through clouds of gas and dust the way light does. This new gravitational window has revealed hundreds of other events thanks to the international efforts of LIGO and other detectors around the world, such as Virgo in Italy and the Kamioka Gravitational-Wave Detector (Kagra) in Japan.
Ligo’s 10th anniversary comes at a bittersweet moment, as US President Donald Trump’s 2026 budget cut to the National Science Foundation (NSF) by more than half could 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 US 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 ahead, they would be many times more sensitive than current detectors, allowing scientists to listen in on even quieter astronomical events.
The mysteries of the universe remain unsolved.
So what is the next eye in the sky waiting to open?
There’s something around all galaxies that we can’t see. We know it’s there because it exerts a gravitational pull on those galaxies, but it doesn’t show up in telescopes. For now, scientists call it dark matter. No one knows what it is, but it makes up about 25 percent of the universe.
Then there’s dark energy, a mysterious force that seems to be causing the expansion of the universe to accelerate. It makes up about 70 percent of all the energy and matter in the universe—and again, we don’t know what it is.
In other words, the universe we see is only about five percent of what’s actually out there.
Canada is at the forefront of solving the dark matter problem with more than a dozen new detectors at the expanded Snolab facility deep underground in Sudbury. Who knows? Maybe we’ll be the first to solve the mystery of dark matter.
As you will hear on Quirks & Quarks this week, there is still so much to discover.
