UNDERGROUND salt deposits could be turned into huge neutrino detectors that
might help us understand at last where high-energy “cosmic rays” come from.
Ultra-high-energy neutrinos—with energies in excess of 1016
electronvolts—are the result of interactions between photons from the
cosmic background radiation and the fast-moving particles known as cosmic rays.
The background radiation is the “afterglow” of the big bang, but where the
fastest cosmic rays come from remains a mystery.
Detecting the neutrinos is no mean feat, as they rarely interact with matter.
But inside a salt crystal, neutrinos will occasionally strike an atomic nucleus
and…
