Physicists Just Turned The Entire Planet Into a Dark Matter Detector – And Strange Signals Kept Turning Up - ScienceAlert

Physicists in Japan devised an experiment using Earth itself as a dark matter detector, treating the Earth-ionosphere cavity as a natural resonator capable of amplifying electromagnetic waves in the mass range they wanted to study.

The search focused on the axion, a hypothetical particle first proposed in the 1970s to solve a different particle physics problem, which could also account for dark matter if it falls within a certain mass range.

Unlike many other candidates, axions are predicted to interact with the electromagnetic force and to occasionally decay into photons within strong magnetic fields, offering a potential way to detect them.

The team, whose work spans four recent papers with theoretical physicist Atsushi Taruya as an author, analyzed Earth's magnetic field data collected by the British Geological Survey between 2012 and 2022.

The analysis turned up dozens of candidate signals matching predictions for certain dark matter particles, though these still require verification and could have numerous other explanations before being confirmed as dark matter.

Dark matter remains one of cosmology's central puzzles, invoked to explain gaps between models of how visible matter moves and its actual distribution, since the unseen material neither emits nor reflects light.