Dark matter has never been seen, but scientists think it could help explain the mysteries of the universe. And one Alberta researcher is trying to build a machine to detect it.
Dark matter is a key ingredient of our universe, making up almost one-third of it, according to NASA.
“Dark matter interacts gravitationally, we can see the effects of dark matter on galaxies,” said Marie-Cécile Piro, associate physics professor at the University of Alberta.
“It’s very, very abundant.”
Our universe consists of two other components: dark energy — which is believed to drive the expansion of the universe — and ordinary matter, such as stars, planets, trees and animals, consisting of protons, neutrons and electrons.
Dark matter is invisible. It does not absorb, reflect or emit light. Some scientists, according to NASA, think dark matter exists in a vast, web-like structure that holds the visible universe together, like scaffolding at a construction site.
“We don’t know really what it is, but it could be a particle that we can detect on Earth,” Piro said.
It’s thought, dark matter is five times more abundant than ordinary matter.
Who coined ‘dark matter’?
Swiss astronomer Fritz Zwicky was trying to measure the visible mass of a cluster of galaxies in 1933, but found the galaxies were too small to prevent them from escaping the gravitational pull of the entire cluster. Zwicky concluded there must be something — like dark matter – keeping the galaxies glued together.
Since then, other scientists have used dark matter to help explain what keeps galaxies from flying apart.
Yet, it’s still unknown what dark matter is made of.
To help solve the mystery, Piro is trying to build a detector to find dark matter. She was recently awarded a Dorothy Killam Fellowship, worth $160,000, for her project.
However, it’s not an easy task.
For one, the detector would have to be extremely sensitive.
“If we take one grain of salt and let it fall from one millimetre above the floor, the force that the grain of salt will touch the floor divided by a 100 billion, is the kind of detection event we would need to detect,” said Piro.
She aims to have the detector built by the year’s end, using a bubble chamber to track the movement of particles.
Radio Active11:22Shining a light onto the dark
We talk to University of Alberta researcher Marie-Cécile Piro about her work to detect the undetectable — known as dark matter.
If successful, it could help unlock the secret to black holes, dark energy or even how the universe was born.
What if there is no dark matter?
Not all scientists agree on dark matter.
A study, published just last month from the University of Ottawa, challenges the current model of the universe, by suggesting dark matter does not exist. The study, Testing CCC+TL Cosmology with Observed Baryon Acoustic Oscillation Features, was published in the peer-reviewed Astrophysical Journal.
“Dark matter has explained so many things in the universe that people are very much attached to. But lately they are finding lot of things that cannot be explained by it,” said Rajendra Gupta, physics professor and the study’s author.
NASA’s James Webb Space Telescope, said Gupta, has poked holes in dark matter theory, by capturing images of galaxies that appear to have grown too big too fast, going against the current model of the universe.
But the galaxies’ gigantic sizes would make sense, if our universe is older, he said.
“That means now we have a lot more time to create these galaxies with or without dark matter than was possible with the original model.”
“There are so many options to the argument over dark matter.”
