Voyage into the dark sector

A hidden world of particles awaits. We don't need extra dimensions or parallel universes to have an alternate reality superimposed right on top of our own. Invisible matter is everywhere. For example, take neutrinos generated by the sun, says Jessie Shelton, a theorist at the University of Illinois at Urbana-Champaign who works on dark sector physics. "We are constantly bombarded with neutrinos, but they pass right through us. They share the same space as our atoms but almost never interact." As...