Ripples in spacetime caused by accelerating massive objects, such as merging black holes. Predicted by Einstein in 1916 and first detected by LIGO in 2015. They opened a new window for observing the universe.
A region of spacetime where gravity is so strong that nothing, not even light, can escape once past the event horizon. B...
The collapsed core of a massive star after a supernova, with 1.4-2 solar masses in a sphere about 20 km across. Incredib...
Einstein's 1915 theory describing gravity as curvature of spacetime caused by mass and energy. Confirmed by light bendin...
Dive deeper into gravitational waves and related concepts on Cosmos Observatory.