Outside of mathematics, very little has ever been PROVED. That is not how scientific progress is made. Many theories that were once considered 'proved' have outlived their usefulness. They were never really proved in the first place; they were just the best currently available.Theories are continually tested. General Relativity has passed countless tests, but that doesn't mean it's proved. In fact, it has a glaring inadequacy — quantum theory. Quantum theory, too, has passed countless tests, but has a glaring inadequacy — gravity, or General Relativity. They're not compatible! Doesn't mean we can't use them, though. I believe there will always be unanswered questions, but progress continues to be made.