The Secret of Golf Balls
While I don’t find golf particularly riveting, or any sport for that matter, the physics involved is totally awesome. A great example of how physics is used in sport is in the design of the golf ball (and golf clubs but I’ll get to that). The most notable feature of a golf ball is of course the 250 to 400 dimples on the surface, so what do they do? These dimples act to disturb the air current around the ball and so reduce drag by making the boundary layer closer to the ball itself. This acts to make a narrower wake with a lower pressure. A smooth sphere in motion exhibits laminar flow which is a highly ordered flow, while a dimpled golf ball displays what is known as turbulent flow, in which the air currents are highly unorganized and, frankly, turbulent.
The other major factor in golf ball flight is lift. Lift is created by giving the ball backspin (which can be seen in this picture) which is imparted on the ball due to the angled slope of the golf club’s end. This channels the wake of air downwards and helps the ball to go higher and thus farther.