from Amazon
Thursday, May 14, 2009
World’s Best Illusion: the curve ball
(Hat tip: Peter)
This year’s winning illusion, created by Arthur Shapiro of Bucknell University in Pennsylvania, may explain this phenomena. His animation shows a spinning ball that, when watched directly, moves in a straight line. When seen out of the corner of the eye, however, the spin of the ball fools the brain into thinking that the ball is curving.
So as a baseball flies towards home plate, the moment when it passes from central to peripheral vision could exaggerate the movement of the ball, causing its gradual curve to be seen as a sudden jerk.