Black hole singularity is a surface not a point

The paper shows that a black-hole singularity is a two-dimensional surface, not a point. Two observers falling into a spherical hole along different angles never meet at the center; they lose causal contact before reaching the singularity. For rotating holes the singular surface lies at the inner horizon, where perturbations trigger mass-inflation collapse into a spacelike singularity, implying quantum states likely reside on this surface and evolve unitarily with Hawking radiation.