“In 1916, the year after the final formulation of the field equations of general relativity, Albert Einstein predicted the existence of gravitational waves … On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal … This is the first direct detection of gravitational waves and the first observation of a binary black hole merger. (1)”
(1) Abbott, B. P., R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, K. Ackley, C. Adams, et al. 2016. “Observation of Gravitational Waves from a Binary Black Hole Merger.” Physical Review Letters 116 (6). American Physical Society: 061102. doi:http://dx.doi.org/10.1103/PhysRevLett.116.061102.