Black hole

From Space Wiki

A black hole is a concentration of mass whose gravitational field is so strong that nothing can escape. Black holes are predicted by general relativity. Under the description provided by general relativity, as an object moves closer to a black hole, the energy required for it to escape continues to increase until it becomes infinite at the event horizon, the surface beyond which escape is impossible. Inside the event horizon, the geometry of spacetime is distorted in a way that makes moving closer to the central singularity inevitable no matter how the infalling object moves.

The existence of black holes in the universe is well supported by astronomical observation, particularly from studying X-ray emission from X-ray binaries and active galactic nuclei. It has been hypothesised that black holes radiate energy due to quantum mechanical effects known as Hawking radiation.