A black hole in general relativity is a region that admits infall but forbids outgoing signals. Yet interiors remain ambiguous: the Schwarzschild solution—static, uncharged, spherically symmetric—forces a swap of time and radial roles inside the horizon, producing metric sign reversals that undermine standard notions such as energy conservation and generate conceptual paradoxes. These are not mere technicalities but point to a deeper inconsistency in GR, since the Schwarzschild metric is an exact solution of GR that attributes gravity to spacetime curvature sourced by energy–momentum.
Md. Jafrul Hassan (Mon,) studied this question.