Xian-Hui Ge

Gravitational waves — the cosmic tremors from distant cataclysms — are so faint that detecting them is like trying to hear a whisper in a hurricane. But a black hole can amplify that whisper many times over.

A black hole cooled to nearly absolute zero resembles a musical instrument with only a limited set of possible notes. Strike it, and it will respond not with any sound, but only with a strictly defined set of frequencies.