News Physics Scientists used a levitating magnet to hunt for dark matter The quantum-based technique could reveal the presence of hypothetical ultralight particles A magnet levitates over a superconductor. Scientists used this phenomenon in a search for ultralight dark matter. Forance/Alamy Stock Photo By Emily Conover 1 hour ago In a first-of-its-kind test, scientists used a levitated magnet to search for dark matter, the unidentified substance believed to be present throughout the cosmos. If dark matter is made up of ultralight particles, it could behave like a wave that would subtly jostle the magnet. Although no signs of such jostling appeared, a few tweaks could improve the experiment’s sensitivity to dark matter’s potential influence, the researchers report in a paper to be published in Physical Review Letters. Scientists used this apparatus to make measurements of a levitated magnet that provided a new method to hunt for dark matterDennis Uitenbroekz Scientists believe dark matter must exist to account for astronomical observations that suggest an unidentified source of mass in the cosmos. Dark matter has evaded a wide variety of detection attempts, so astroparticle physicist Christopher Tunnell of Rice University in Houston was looking for new ways to search for it. Tunnell and colleagues realized that an existing experiment, originally designed to make sensitive gravitational measurements, could spot ultralight dark matter. In the experiment, a magnet with a mass of less than a milligram was suspended within a container made of a superconductor — a material that conducts electricity without resistance. The magnet’s motion was monitored with a quantum device designed to measures changes in magnetic fields, known as a SQUID. If ultralight dark matter exists and interacts with normal matter via a new type of force, the dark matter wave would have subtly jiggled the magnet. Tunnell and colleagues reanalyzed the data from that experiment to search for dark matter’s influence, but found no evidence of it. Sign up for our newsletter We summarize the week's scientific breakthroughs every Thursday.