There are Four Physical Laws of Black Holes.
- At the event horizon of a black hole the gravity is constant everywhere om the event horizon.
- The change in mass of a black hole is equal to the surface gravity times the change in area.
- The surface of the event horizon can never decrease only increase. For example, if two black holes collide they fuse together becoming one larger black hole and can never split apart.
- It is impossible to lower to the gravitational force to zero at the event horizon by any physical process
Can we see Black Holes in space?
Black holes can not be seen with normal vision but can be seen be the light produced by ionized gases surrounding black holes. The gas particles become ionized by the extreme gravity of the event horizon.