General relativity predicts a point of infinite density at the center of a black hole, but this likely indicates the theory is incomplete and requires new physics such as string theory.

“invoking only Einstein's general theory of relativity you get a point of infinite density right strengths theorists came along and said we got this it's not infinite density there's strings and there's another thing going on in the universe that's why you bring in string theorists”

It is theoretically possible that reaching a black hole singularity would take an infinite amount of time from the perspective of an external observer.

“it would take you a huge amount of time possibly an infinite amount of time to fall into the black hole as you because what happens is that the black holes Event Horizon grows to meet you”