GRAVITATIONAL WAVES FROM COLLIDING BLACK HOLES
Gravitational waves have not been directly detected so far, there is strong indirect evidence.
In this simulation, the spatial distortions effected by gravitational waves are shown as expanding, colored regions. The collision and merger simulated here involves two black holes.
Simulation by scientists of the Max-Planck-Institute for Gravitational Physics. Image: W. Benger AEI/ZIB. (via Einstein Online)