Self-checking algorithm interprets gravitational-wave data

When two black holes merge, they emit gravitational waves that race through space and time at the speed of light. When these reach Earth, large detectors in the United States (LIGO), Italy (Virgo) and Japan (KAGRA) can detect the signals. By comparing against theoretical predictions, scientists can then determine the black holes' properties: masses, spins, orientation, position in the sky and distance from Earth.