Main Question or Discussion Point
are all laws of physics break only at singularity Or laws of physics break even after event horizon?what is the difference
Is quantum mechanics valid beyond event horizon?The singularity is the point (and it is important to understand that it is a mathematical point -- it has no dimensions) at which density becomes infinite. Clearly, shoving anything into zero volume will produce an infinite density. This is where modern physics begin to have a problem.
The event horizon, on the other hand, is a fictitious radius around the black hole at which not even light would be able to escape in any fashion. This represents a "point of no return" because, as nothing can travel faster than light, nothing can escape the fate of falling into the black hole beyond this radius.