Thunderbolts Forum v3.0

From huge, hypersensitive underground detectors to the search for bizarre signatures in comic rays, it seems we have tried everything within our current capacity to directly observe even one particle of dark matter.

But we do know a few things about this mystery matter—namely, that it exerts gravity, and therefore (supposedly) has mass. When gravitational forces exerted by bodies in space are beyond what is expected, dark matter is the explanation (but never the evidence).

Maybe, however, dark matter could make its presence known another way. Astroparticle physicist Christopher Tunnell, of Rice University in Houston, saw an alternative method of detecting ultralight dark matter by repurposing what was originally a precise method of measuring gravity. This method uses a magnet floating in a chamber made of superconductive material. When cooled enough to transition to a state in which they can conduct electricity without resistance, superconductors expel magnetic fields and therefore repel magnets. This explains why a magnet in the middle of a superconductive trap will float right in the middle. It is being repelled in every direction, and there is nowhere else it can possibly go.

Tunnell and his research team predicted that dark matter could be detected this way because … snip f any dark matter came close to the levitating magnet—whether it behaved like a particle meandering around or a wave flowing through—the force of gravity it exerted should give the magnet an almost negligible shake. A quantum device known as a SQUID (Superconducting Quantum Interference Device) was used to detect any shifting of magnetic fields that would happen if gravity from an unseen source interacted with the magnet.

Spoiler alert: dark matter has not been detected with this method so far.

“Our result highlights the promise of this quantum sensing technology in the hunt for dark matter,” he said.

“We hope that it fuels initiatives in advancing experimental designs of magnetically levitated setups for astroparticle physics.”