GPS isn’t just handy for finding a local Starbucks or hitting the trails. Two physicists believe the system might also be a tool for detecting and measuring dark matter.
Dark matter remains a “mystery” according to Andrei Derevianko (University of Nevada).
“Modern physics and cosmology fail dramatically in that they can only explain 5 percent of mass and energy in the universe in the form of ordinary matter, but the rest is a mystery,” says Derevianko.
Evidence suggests dark energy represents about 68% of the mystery mass and energy. The other 27? That’s believed to be dark matter.
How exactly could GPS satellites shed light on this mystery?
I’ll let Derevianko explain.
“Our research pursues the idea that dark matter may be organized as a large gas-like collection of topological defects, or energy cracks,” Derevianko said.
“We propose to detect the defects, the dark matter, as they sweep through us with a network of sensitive atomic clocks. The idea is, where the clocks go out of synchronization, we would know that dark matter, the topological defect, has passed by. In fact, we envision using the GPS constellation as the largest human-built dark-matter detector.”
The research by Derevianko and his colleague, Maxim Pospelov, was published in the journal Nature Physics.
The researchers will now test their idea using clock data from 30 GPS satellites. They will be looking for any time discrepancies within the atomic clocks.
Fellow physicist, Geoff Blewitt, went into further detail on how atomic clocks within GPS satellites could help in the hunt for dark matter.
“We know the dark matter must be there, for example, because it is seen to bend light around galaxies, but we have no evidence as to what it might be made of,” he said. “If the dark matter were not there, the normal matter that we know about would not be sufficient to bend the light as much as it does. That’s just one of the ways scientists know there is a massive amount of dark matter somewhere out there in the galaxy. One possibility is that the dark matter in this gas might not be made out of particles like normal matter, but of macroscopic imperfections in the fabric of space-time.”
“The Earth sweeps through this gas as it orbits the galaxy. So to us, the gas would appear to be like a galactic wind of dark matter blowing through the Earth system and its satellites. As the dark matter blows by, it would occasionally cause clocks of the GPS system to go out of sync with a tell-tale pattern over a period of about 3 minutes. If the dark matter causes the clocks to go out of sync by more than a billionth of a second we should easily be able to detect such events.”
Image: Quantum physicist Andrei Derevianko, Credit: University of Nevada, Reno