Rather than say he's an atheist, a friend of mine says, 'I'm a tooth fairy agnostic,' meaning he can't disprove God but thinks God is about as likely as the tooth fairy.
We cannot, of course, disprove God, just as we can't disprove Thor, fairies, leprechauns and the Flying Spaghetti Monster.
The point of an experiment is not to arrive at a predetermined end point, to prove or disprove anything, but to deliver a poem that reveals much about the process taken.
You can't prove any hypothesis, you can only improve or disprove it.
When you look at the calculation, it's amazing that every time you try to prove or disprove time travel, you've pushed Einstein's theory to the very limits where quantum effects must dominate. That's telling us that you really need a theory of everything to resolve this question. And the only candidate is string theory.
My own view is that this planet is used as a penal colony, lunatic asylum and dumping ground by a superior civilisation, to get rid of the undesirable and unfit. I can't prove it, but you can't disprove it either.
I had set out to disprove quantum field theory - and the opposite occurred! I was shocked.
You make observations, write theories to fit them, try experiments to disprove the theories and, if you can't, you've got something.
The true scientist no longer attempts to disprove the pull of gravity, or the rotation of the earth, or the motion of heavenly bodies, or the sequence of the seasons, or man's need of food and water, or the function of the heart.
To succeed with the opposite sex, tell her you're impotent. She can't wait to disprove it.