The History and Design of Tennis Balls

Tennis is an old sport and has a long history. It was an ancient Arabic sport, and it became popular in France in the 1000s, and it was also romanticized by the English royalty as the Sport of Kings. In the 1400s, the first tennis ball was invented, and the material it was made out of is quite different from today. It was simply a ball made out of leather that had human hair, horsehair, or wool stuffed inside it.

Early Scottish people had used the stomach from animals such as sheep or goat, and wrapped it with wool or tied with ropes. Then, in the 1700s, pieces of wool were wounded tightly around the core of the tennis ball that was created from a cork. Tennis balls with cork nuclei and cloth coverings are used in Real Tennis(court tennis). Charles Goodyear, who was famous for his rubber products like tires created the first rubber tennis ball. It was made out of rubber and had felt stitched on the outside. That was created right when the rubber vulcanization process became popular.

The ball was designed to play on a grass surface. Walter C. Wingfield was responsible for standardizing the rules for lawn tennis(grass surface) and Alexander Cartwright popularize the rules. People, later, discovered that if the core of the ball was hollow, the playability would be improved. In 1900, the first lawn tennis championship was created, and it was called the Davis Cup. It attracted a lot of attention to the international tennis community. Nowadays, tennis balls use rubber and complex chemical composition that makes the ball better. The color of tennis balls used to be black or white but in 1972, the International Tennis Federation changed the color to yellow since the color yellow made tracking the ball easier for players and the spectators.

Currently, there are different types of tennis balls that are designed to do better at certain things. Pressureless tennis balls have a solid nucleus and usually last longer than a pressurized tennis ball. It also doesn’t lose their bounce as easily but, the felt comes off faster. Pressurized tennis balls use an empty core that is filled with gases such as nitrogen or air. They usually come in a sealed can with several tennis balls. But, once the can gets opened the ball slowly loses their bounce. If the ball is brand new it has a better bounce than a pressureless tennis ball. A pressurized tennis ball has air inside that moves around and fills up the space it occupies. So when the tennis ball hits the ground, the ground exerts a force upon the ball, which pushes the bottom of the ball inwards, which makes the tennis ball bounce. When the force is exerted, the air inside of the tennis ball becomes compact, and then the force is fully exerted the air inside of the ball begin to start expanding and return to its normal shape. This action is like a spring and that’s what pushes the ball upward.

The pressure of the air inside the ball affects how high the ball bounces and also a higher temperature leads to higher pressure. That means a higher temperature would make the tennis ball bounce higher since the temperature makes the air molecules inside the core of the tennis ball expand so when the tennis ball hits the ground, and the ground exerts the force, the air inside the tennis ball would become tighter. That affects the height the tennis ball can bounce since heating up the ball would make the action like a tight spring. This also goes for the opposite. When the temperature of the ball decrease, the air molecules inside of the tennis ball would contract, therefore it has less energy and it would more slowly than a heated ball. That causes lower pressure and lower pressure leads to a lower bounce of the ball.