Cricket Ball Swing Explained Using a Car?
As I sat on the bleachers watching the local cricket team practice their bowling skills, I was shocked. The ball seemed to be curving through the air! I was intrigued by the ability of the ball to move through the air at such high speeds and precision. I had seen professionals manage to move cricket balls through the air with such elegance, but I always thought that they used special cricket balls. I found out that the correct term for this phenomenon was “swing balls”. Here’s a video showing some of the best examples of bowlers swinging the ball:
I wanted to understand this behavior of the ball and dive down into the physics behind it. Because let’s face it, there’s always physics behind everything.
The cricket ball is made of a dense core that is wrapped on both sides by leather material. These two pieces of leather are stitched together by a seam. In order to partake in swing bowling, you need to ruin one side of the ball…
Let me explain:
Ruining the ball for swing bowling is done by taking one side of the cricket ball and roughening it up. One can do this by scratching, rubbing, and even biting the side of the ball that you want to be ruined. The other side is meant to be shiny and new. This side can be maintained by spitting on the ball, wiping it on cloth, and keeping it shiny and clean in general. The science behind swing bowling is the following: The cricket ball is essentially launched by the bowler through the air. One side is rough while the other is shiny and clean. As air passes the cricket ball it behaves differently for each side: The air that is passing the shiny side of the ball passes around the ball very smoothly; however, the air that passes the rough side behaves very differently. This air hits the rough side and becomes very turbulent. This turbulence results in low air pressure. The low air pressure basically pulls the ball towards that side (rough side). This concept is used by airplanes and other aviation vehicles as well. Pretty cool, right?
The following is an experiment where a cricket ball was suspended in the air above a car moving fast. The fast air goes through the process explained above and results in the ball moving towards the rough side. Here is the experiment:
It’s a very interesting concept that I was finally able to understand and try out for myself.
Thank you for reading.
