The Problem With General Relativity

"We just don't know what happens inside of a black hole," he says. "General relativity predicts singularities and quantum mechanics says, nuh-uh, no dessert for you." But if they agree, then you're unifying them, right? You're bringing them together to make the same prediction. It might be the way the universe works. We do not have a guarantee that everything is unified to a complete single theory.