The event horizon is a region on a black hole where the escape velocity reaches the speed of light.
it is like the edge of a waterfall beyond which space is actually falling in faster than the speed of light.
Nothing that falls below the event horizon can never escape and is lost to the universe forever, while we see falling objects freeze as time stands still at the horizon, anything that happens below the event horizon stays below the event horizon.
it’s called event horizon because it’s the horizon where space and time change their properties so events change in their sequence of what happens.
A black hole is not a celestial body like a planet or a star, there is really no substance there, other than a severely curved space time.
if you compress the sun to a sphere about six kilometres in diameter it would become a black hole
Different size black holes are determined by the event horizons – they are like sphere around the singularity.
Black hole are completely dark because light and no other form of energy can escape beyond it.
At the event horizon time stops completely due to gravitational time dilation – time slows down as gravity gets stronger .
At the event horizon gas can still radiate away, light can still escape from the black hole but radiation can’t escape.
