Think the universe is just made up of stars, planets, asteroids, comets and space dust? Think again.

Scientists now believe dark matter, so far only detected through its gravity-based effects in space, makes up about a quarter of the total energy of the universe, and about 80 per cent of all mass. 

However, it is composed of particles that do not absorb, reflect or emit light so they can’t be detected by observing electromagnetic radiation. So dark matter is material that cannot be seen directly. 

Dr Ben McAllister is a physicist at the UWA Node of the ARC Centre of Excellence for Dark Matter Particle Physics (CDMPP) and The University of Western Australia’s Quantum Technology and Dark Matter Research Lab.

He spends a large part of his working life trying to unlock the mysteries of dark matter and is at the forefront of a free public event for Dark Matter Day this Saturday, 30 October.

“It’s the biggest mystery in the universe – many scientists around the world are trying to unlock the big cosmic mystery of what dark matter actually is using lots of different methods,” Dr McAllister said.

The Forrest Prospect Fellow is one of the West Australian researchers at the forefront of the search, as part of the Australia-wide ORGAN Experiment to detect a particle called the axion.

“To do this we use what’s called a microwave cavity haloscope, which is basically an empty copper can placed in a very strong, very cold magnetic field,” Dr McAllister said.

“If axions are dark matter and exist all around us, one might enter the resonant cavity, react with the magnetic field and transform into a particle of light – a photon.”

Image: Members of the Quantum Technology and Dark Matter Research lab use UWA's haloscope in a bid to unlock the mysteries of dark matter.

If you’re interested in hearing more about Dr McAllister’s work and the search for dark matter, tune in to Dark Matter Day – a live, virtual and all-ages event this Saturday 30 October from 2pm to 4.30pm.

“There will be lots to see and explore including an introduction to dark matter, talks about dark matter, live Q&A’s and kids activities and competitions, as well as a chance for a virtual tour of the UWA labs,” Dr McAllister said.

To register and receive a link to the ARC Centre of Excellence in Dark Matter Particle Physics ‘Gather town’ (the virtual meeting place), click here.