Black holes don't live forever, but they might live long enough to look like white holes

Black holes live forever, at least according to general relativity. Once material crosses a black hole's event horizon, it is trapped forever, until the last day of cosmic time. But we know that isn't true. General relativity is a classical model. It doesn't take into account the fuzzy, indeterminate nature of the quantum. We don't have a complete and consistent theory of quantum gravity, but we do have some understanding of quantum black holes.