Ancient rocks hidden deep underground could hold important clues about the nature of dark matter – according to physicists in Sweden and Poland. The idea is that dark-matter collisions should create nanoscale defects in the crystalline structure of rock – and this damage could be measured using modern microscopy techniques. Indeed, the team estimates that hundreds of thousands of defects could be present in just one cubic centimetre of rock.
A wealth of astronomical and cosmological evidence suggests that dark matter accounts for about 85% of matter in the universe, however, physicists have yet to make a direct detection of dark-matter particles. One possible candidate for dark matter are the weakly-interacting massive particles (WIMPs), hypothetical particles that only interact with normal matter through weak or gravitational forces.
While physicists have built a number of WIMPs detectors worldwide, none have managed to observe the elusive particles. These detectors tend to use large volumes of material and run over several years in the hope of seeing just a handful of collisions between WIMPs at atomic nuclei.
Now, Patrick Stengel at Stockholm University and his colleagues propose a simpler approach. They ...