From Terry Pratchett's comic-fantasy Discworld novel The Truth:

"A thousand years ago we thought the world was a bowl," he said. "Five hundred years ago we knew it was a globe. Today we know it is flat and round and carried through space on the back of a turtle." He turned and gave the High Priest another smile. "Don't you wonder what shape it will turn out to be tomorrow?"

... parody-echoing the film Men in Black:

"Fifteen hundred years ago everybody knew the earth was the center of the universe. Five hundred years ago, everybody knew the earth was flat. And fifteen minutes ago you knew that people were alone on this planet. Imagine what you'll know tomorrow."

(cf What We Know (2006-08-15), ...) - ^z - 2020-11-16