What is on the other side of a black hole?
A. We don’t know, other than theoretically, what might be inside of a black hole (if that is what you mean by “the other side”). Inside, we encounter the surface of the object that collapsed to make the black hole in the first place, and because we cannot tunnel inside this body, all we see is a solid surface. Mathematicians and physicists have theorized a hollow black hole that doesn’t require the collapse of a star to form it. This type of black hole is imagined to have an exotic geometry and be a place where time travel is possible.
