Gravitational waves

One hundred years after Albert Einstein predicted the existence of gravitational waves, scientists have finally spotted these elusive ripples in space-time. In a highly anticipated announcement, physicists with the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) revealed on 11 February that their twin detectors have heard the gravitational ‘ringing’ produced by the collision of two black holes about 400 megaparsecs (1.3 billion light-years) from Earth._nature