The 2010′s is known among the cognoscenti as the Dark Matter Decade. At least among those cognoscenti who are optimists by nature. After years of effort, experimentalists have improved the reach of their detectors to the point where we might be close to directly detecting dark matter (DM) particles — at least if the DM falls into the Weakly Interacting Massive Particle paradigm, or comes close to it for some reason. (Not every dark matter model does; axions are the obvious counterexample.) Jennifer summarizes the current situation in the latest issue of Quanta; some previous updates are from Matt Strassler and Résonaances.
There are two things going on. One is that the experiments, which look for energy being deposited by a (rare but predictable) interaction between dark matter particles and atomic nuclei, are now cutting into large regions of the predicted parameter space for weakly-interacting dark matter. So if the DM is WIMP-like, we have a great chance of seeing it before the decade is out.
The other is that there are already some hints that we have seen something. But those hints are confusing. It’s unclear whether they amount to the first tentative glimpses of most of the matter in the universe, or just statistical fluctuations in the detectors.
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