ISAAC NEWTON AND THE CURVE BALL.

ISAAC NEWTON AND THE CURVE BALL. This article by Sharon Begley begins by noting that Isaac Newton in 1671, after watching numerous games of tennis, observed that spin makes balls curve. Three hundred years later, scientists still haven’t worked out equations which will describe what spin does to a ball. Says one scientist: “The equations are very complicated. Using computers to solve them by brute force doesn’t work too well….” There is still a debate whether it is easier to hit a home run off a curve ball or a fast ball. As fans have observed, the faster a ball goes in, the faster it goes out. But hitting a curve ball provides more backspin and therefore more lift; a lot of home runs are simply “big flies”. Of course all fast balls have some spin. (A ball without spin behaves like a knuckle ball.) Apparently it all depends on the numbers: how much spin and how much velocity. In the meantime, there is an explanation for why a catcher circling under a pop foul will wait for it to come back toward the field of play: some pop fouls have lots of backspin.