A bunch of great thinkers were playing hide-and-seek. It was Einstein's turn to seek, so he closed his eyes and started counting, while everybody else hid. Heisenberg measured his precise velocity, Descartes stopped thinking, Xeno considered how he was just a collection of infinitely small parts, et cetera. By the time Einstein opened his eyes, everybody was long since gone . . . with one exception. Newton had taken out a piece of chalk and drawn a large square on the ground, and he was standing in plain view in the middle of it. "Newton," Einstein asked, "Don't you know you're supposed to hide so I can't find you?" "Ah," Newton replied, "but you're looking at Newton over a square meter. You've found Pascal!"