Radon Hides Dark Matter
A dark matter detector is like a room where you're trying to hear a whisper while static electricity crackles nearby. This crackle is produced by radon atoms — a radioactive gas that seeps out from materials and air.
Neutrons Leave a Trace
A dark matter detector is like a super-sensitive microphone listening for silence. It picks up tiny heat jolts, phonons, that occur when a particle grazes a crystal. But instead of silence, the instruments have been hearing noise for years: a slew of weak signals below a few hundred electronvolts.
How to Tell Dark Matter from Noise
Underground, in a former gold mine, sits a tank of liquid xenon. If a dark matter particle flies through it, the xenon flashes. But it also flashes from ordinary particles, like neutrinos or leftover radioactivity. The task is to tell which flash comes from dark matter and which from noise.