Partha Kumar Paul

The universe sometimes resembles a pot of boiling water. With enough heat, liquid turns to vapor: that's a phase transition. Something similar could have happened in the early universe: a field filling space suddenly changed its state, like water becoming gas.

Deep inside a former gold mine in South Dakota stands a tank holding ten tonnes of liquid xenon. It looks like a giant thermos, except that it catches not heat but rare nudges from invisible particles. Over two and a half years of observations, the LUX-ZEPLIN detector felt a single solitary hit that does not fit the usual noise.