The center of the black hole—the actual “rip” or “pinch” in the fabric of spacetime—is called the singularity. It is a single point that has no volume but infinite density. Amazingly, the laws of physics as we understand them simply do not work at the singularity of a black hole the way they do in the rest of the universe.

Surrounding the singularity is a boundary called the event horizon. This is the place of no return, where the escape velocity for the black hole is the speed of light. The more massive the black hole is, the farther the event horizon is from the singularity, and the larger the black hole is in size.