<h2>Golf Ball Dimples & Spin Rating</h2><p>The secret of dimples: The golf ball gets tremendous back spin from a drive shot, spinning as fast as eight thousand revolutions per minute. As the ball spins, the dimpled surface traps a layer of air that rotates with the ball, like a small whirlwind around the ball's surface.</p>
<p>Since the ball is traveling forward, the layer of air spinning on the top of the ball is moving "with the wind." And the layer of trapped air along the bottom of ball is moving "against the wind", so it is slowed by this wind resistance. As a result, air pressure builds up at the bottom of the ball, and the ball rises, much like an airplane wing.</p>
<p>The importance of the turbulence caused by the dimples is quite surprising. Without dimples, the ball would travel only about three-fourths as far. But there is a down side to dimpling--the ball has a greater tendency to hook or slice.</p>
