# Why are there dimples on the surface of golf balls and how do they function?

I'm not a big golfer, but many people in my family play the sport, so I'm constantly surrounded by golf equipment and lingo. I've always wondered why the golf balls being used have "dimples" on the surface. See in the picture.

I'm 90% sure they are there for aerodynamics. So if someone could clarify that I am correct, that would be excellent. But if I am correct about the aerodynamics aspect, my question is this...

In a mathematical/scientific explanation, how/why do the dimples on the surface of the ball provide better aerodynamics for the ball?

If someone could give me an explanation on how the technology actually works that would be awesome.

You are correct that this has to do with aerodynamics, more specifically drag and air friction. This article goes over all of the specifics. Ultimately, it boils down to less drag on the ball, allowing it to fly farther. The exact details and an explanation of the difference between a smooth sphere and a dimpled ball are included in the linked article.

The following image shows the difference between a smooth sphere and a dimpled ball. The smooth sphere separates the air rapidly, creating a large pressure differential between the front and rear of the ball. This creates a large wake that creates lots of drag, forcing the ball to descend more quickly. In contrast, the dimpled ball delays the separation of the air, reducing the size of the wake. This helps to also reduce the pressure differential between the front and rear of the ball, reducing the drag and subsequently allowing the dimpled ball to fly farther than the smooth sphere.

• This answer is incomplete. Since the ball is spinning (with a driver between 2000-4000 rpm depending on the player), the friction of the air over the ball changes. In the above picture, the ball is moving right to left, and the ball is spinning clockwise. Therefore, there is less friction on the top part of the ball vs the bottom of the ball, because the top of the ball is moving more slowly through the air relative to the bottom part of the ball because of the direction of airflow. This makes the top of the ball have a lower pressure relative to the bottom, creating lift. Commented Feb 4, 2016 at 12:26
• @LarryBud - That would happen on a smooth ball as well, but to a lesser degree. The main cause of lift is the deflection of the airflow around the ball by its rotation; the side of the ball rotating away from the airstream separates from the airflow later, directing the airflow on that side of the ball in the direction of rotation. Commented Jul 20, 2016 at 16:42
• I once read that the effects of the dimples were discovered by accident. Don't quote me on that, though. Commented May 8 at 17:55