Someone apparently went up to the great philosopher Wittgenstein and said "What a lot of morons people back in the Middle Ages must have been to have looked, every morning, at the dawn and to have thought what they were seeing was the Sun going around the Earth, when every school kid knows that the Earth goes around the Sun", to which Wittgenstein replied "Yeah, but I wonder what it would have looked like if the Sun had been going around the Earth?"