"Did you know you can ask very simple questions to the scientists who claim that dinosaurs lived millions of years ago? You could say to them, in a very nice way of course, "Excuse me, were you there?" You are actually asking them, "Were you there to see the dinosaurs when they first came into existence? Were you there to see them alive? Were you there to see them die out?" Obviously, they weren't there, so how could they really know everything about them?"