Since gravitational waves were first detected in 2015, instruments including LIGO, Virgo and KAGRA have picked up a steady stream of signals from colliding black holes, building a catalog that now numbers in the hundreds. Yet despite this wealth of data, a fundamental question has remained stubb...
Source: [Phys.org](https://phys.org/news/2026-07-gravitational-reveal-hidden-populations-black.html)