Importance Of Curveball

In the case of a bullet, spin increases accuracy, ensuring that the trajectory will follow an expected path. But sometimes spin can be used in more complex ways, as with a curveball thrown by a baseball pitcher.

The invention of the curveball is credited to Arthur "Candy" Cummings, who as a pitcher for the Brooklyn Excelsiors at the age of 18 in 1867—an era when baseball was still very young—introduced a new throw he had spent several years perfecting. Snapping as he released the ball, he and the spectators (not to mention the startled batter for the opposing team) watched as the pitch arced, then sailed right past the batter for a strike.

The curveball bedeviled baseball players and fans alike for many years thereafter, and many dismissed it as a type of optical illusion. The

The latter, formulated by Swiss mathematician and physicist Daniel Bernoulli (1700-1782), holds that where velocity is high, pressure is low—and vice versa. Bernoulli's principle is of the utmost importance to aerodynamics, and likewise plays a significant role in the operation of a curveball. At the top of the ball, its clockwise spin is moving in a direction opposite to the airflow. This produces drag, slowing the ball, increasing pressure, and thus forcing it downward. At the bottom end of the ball, however, the clockwise motion is flowing with the air, thus resulting in higher velocity and lower pressure. As per Bernoulli's principle, this tends to pull the ball downward.

In the 60-ft, 6-in (18.4-m) distance that separates the pitcher's mound from home plate on a regulation major-league baseball field, a curve-ball can move downward by a foot (0.3048 m) or more. The interesting thing here is that this downward force is almost entirely due to air resistance rather than gravity, though of course gravity eventually brings any pitch to the ground, assuming it has not already been hit, caught, or bounced off a