Why do golf balls have dimples?

Many of you might have seen a golf ball. They are hard with a plastic surface and a cork inside. But have you ever wondered why golf balls have those tiny dimples on their surface? To disappoint you, they are not just for aesthetic purposes. Those dimples are crucial to how a golf ball rotates in flight and how much distance a golfer can hit it. Those tiny dimples optimise a golf ball’s flight, distance, and spin, thus helping it travel the distance.  

In 1800s, as golf began to emerge, it was played with smooth-surfaced balls. Those days, the golf balls were made of leather with goose feathers inside them. However, golfers realised that if there were accidental idents on the balls, it helped the balls travel further. Hence, in 1905, William Taylor, a golf ball manufacturer from England, patented dimpled balls.

The aerodynamic advantage

To put it bluntly, dimples on a golf ball help reduce the drag What is a drag, you might ask? Drag is a force that opposes the motion of the ball while in the air or tries to slow the ball down while in flight.

When a smooth ball travels through the air, it creates turbulent eddies or counterflow behind it. These eddies increase drag and slow the ball down.

But with the introduction of the dimples on a golf ball, they disrupt the airflow. Instead, those dimples create smaller, more controlled vortices that reduce drag.  

Video explanation: Science behind golf ball dimples

Adding turbulence

Stay with us if you are still finding it difficult to understand why. When a smooth-surfaced ball travels through the air, it tries to cut through the air. Hence, the air slows the ball down like in a laminar flow.

Now, dimples on the ball help introduce turbulence. What is turbulence? It is the opposite of smooth or parallel layers. When the air is chaotic with unpredictable motion, it is called turbulent air, which is also a reason behind your bumpy rides in aeroplanes. In turbulent air, the pressure and flow change irregularly.

The dimples add turbulence on the surface of the ball or the tiny layer of air around the ball. But unlike aeroplanes, the turbulence helps the ball propel farther.  

Dimples help in spin

Not only reducing drag, the dimples also help control the spin of a golf ball. In contrast to smooth-surfaced balls, the dimples provide a differential pressure on the top and bottom of the ball, helping it spin or roll. The spin helps decide the ball’s trajectory.

For example, if a golfer hits the ball with a low backspin, it will roll further. But if the ball is hit with a high backspin, it will stop more quickly once it lands on the green.