Nothing but light
What Remains Inside a Black Hole was created in 1996.
Nothing can escape from a black hole.
Inside a black hole, time behaves differently than outside. Time slows down as you get closer to the center of a black hole, eventually stopping completely at the singularity. This means that time inside a black hole is essentially frozen.
No, they are not the same. A singularity would be inside a black hole.
It disappears forever
For all scientific reasons, no astronaut had went inside a black hole. It would take many earth years to visit the black hole, so reaching a black hole is impossible.
No.
no
A black hole can't really form inside of another black hole. If you think of a black hole forming after a star goes supernova, then there isn't really a star to go supernove inside of the already created black hole. In fact, there isn't even any space inside of the blak hole for anything to happen. Two black holes can join together, but they wil eventually go to one.
It is impossible to know what is present inside a black hole, though it is theorized that a singularity is located at its centre.
An "event horizon." This is the range from the black hole at which not even light can escape the pull of gravity. If the black hole is low-mass, this will be sharp, but the horizon of a supermassive black hole might have stars, worlds and people inside going on about their business. However, none of this could be known to anyone outside the horizon.
At the center of a black hole is a mass that has collapsed to an infinitely dense point.