Catching the Shivers: How to Detect Ultra-High-Frequency Gravitational Waves
Pluck a guitar string, and it vibrates — the air around it carries the tremor to your ear. Spacetime vibrates differently: when a gravitational wave passes through, it stretches and squeezes slightly. Spotting such a tremor at frequencies from 10 kilohertz to 100 megahertz is the challenge that new detectors are being built for.