Peter went over to Danny. “A hand-waver,” he said, “is somebody who hasn’t worked out his ideas and can’t defend them. So when he presents at a colloquium, and he comes to the parts he hasn’t worked out, he starts waving his hands and talking fast. Like the way someone waves their hands and says, ‘Et cetera, et cetera.’ In science, hand-waving means you don’t have the goods.”
