The final moments in the life of a black hole binary will witness emission of highly energetic gravitational wave signals that outshine, for a moment, the entire universe in light. The discovery of gravitational waves from merging black holes by the Laser Interferometer Gravitational-Wave Observatory (LIGO) has ushered a new era in observational astronomy. This new window will help us witness, for the first time, nonlinear effects in dynamical spacetimes and test Einstein's theory in a regime where the theory has never been tested before. After a summary of LIGO observations so far my colloquium will focus on the implications of these observations for astrophysics, fundamental physics and cosmology.