New Dark Matter Detector Records Rare, High-Frequency Events

The disc-shaped resonator measures lower than 2 centimeters throughout, but the innocuous gadget is eavesdropping on spacetime. It’s a newly constructed acoustic wave resonator, and in its first 153 days of operation it detected a few occasions that researchers imagine could possibly be high-frequency gravitational waves, which have by no means been recorded earlier than.

Gravitational waves had been first detected in 2015 by the Laser Interferometer Gravitational-Wave Observatory; the waves are ripples in spacetime which are produced by the motion (or collisions) of large objects, like black holes and neutron stars. But the waves thus far detected are low-frequency alerts, and, whereas it’s not but confirmed, some astrophysicists imagine that gravitational waves may additionally exist at increased frequencies, emitted by theoretical objects akin to primordial black holes or clouds of darkish matter. And if such waves do exist, they wish to discover them.

To that finish, a crew of researchers on the ARC Center of Excellence for Dark Matter Particle Physics and the University of Western Australia constructed this small resonator. The gadget consists of quartz disc conducting plates and an amplifier, positioned inside a number of radiation shields and cooled to guard from noise.

The disc vibrates when high-frequency acoustic waves go by it, and people waves induce an electrical cost within the quartz that’s picked up by the conducting plates. The amplifier makes the low-voltage sign simpler for researchers to see. The resonator detected, nicely, one thing on May 12, 2019 and November 27, 2019, and the crew’s outcomes had been published this month within the Physical Review Letters.

“It’s exciting that this event has shown that the new detector is sensitive and giving us results, but now we have to determine exactly what those results mean,” mentioned William Campbell, a physicist on the University of Western Australia and a co-author of the paper, in a college press release.

There are quite a few various things the high-frequency sign could possibly be; an enormous a part of such work is tamping down hope and making certain that you simply’ve eradicated all different potentialities. (Sherlock Holmes mentioned one thing alongside these traces, too.) Besides gravitational waves, different explanations for the sign could possibly be interference from different particles making their means by the detector, a close-by meteor, the detector itself having a technical downside, or, maybe most tantalizingly—high-mass darkish matter candidates.

A bigger downside, although, is that high-frequency gravitational waves might not exist. Currently, they’re simply an thought. It’s type of like an ecologist on the lookout for footprints of a thylacine—you’re trying to find indicators of one thing you’re not even certain is on the market.

“The question if high-frequency gravity waves exist should be investigated, because if discovered it implies new physics,” Michael Tobar, a physicist on the University of Western Australia and a co-author of the paper, mentioned in an electronic mail to Gizmodo. “Like when high-energy photons were discovered coming from the cosmos, it will lead to a new area of astronomy.”

In the experiment’s subsequent part, the crew will construct a reproduction detector in addition to a muon detector; the second detector will develop the gadget’s frequency vary and can enable the researchers to cross-correlate their findings, Tobar mentioned. If the subsequent technology of gadgets picks up a sign, then issues may get fairly attention-grabbing.

More: If We Live in a Sea of Dark Matter, This Tiny Mirror Might Be Able to Detect It