When Seeing Isn't Believing

Robert Krulwich marvels at the visual tricks of Kokichi Sugihara:

Sugihara uses no editing tricks. His props are cardboard and glue, no special effects. All he does is find the precise angle where our brain assumes an impossible act. In this case, he chooses the angle that makes down-sloping planes look like up-sloping planes. Then he changes the angle and you see how he did it. (Or more correctly, how you did it.)