Astronomers have for the first time measured the speed and direction of a newborn black hole, thanks to gravitational waves produced as it bounced away from the site of its parent black holes' merger. This first complete measurement of black hole recoil comes almost exactly a decade after the first detection of gravitational waves — tiny ripples in spacetime first predicted by Albert Einstein in 1915 — performed by the Laser Interferometer Gravitational-Wave Observatory (LIGO) on Sept. 14, 2015.
Over the last 10 years, a wealth of gravitational wave detections performed by LIGO and its collaboration gravitational wave detectors, Virgo, and Kamioka Gravitational Wave Detector (KAGRA) have painted a more detailed picture of black hole mergers than ever before. However, one of the most fascinating and dramatic aspects of these mergers has remained "unheard" by these detectors that measure the ringing of spacetime caused by the universe's most extreme events. That is the "kick" delivered to the daughter black hole birthed by these mergers.
