The Physics of Bowling

Bowling is often viewed as a fun game for families and friends, and the idea that it is a sport is often laughed at. Nonetheless, the simplicity of the game “has made it ripe for technological innovation”, and, with this innovation, there are the scientific explanations for the various phenomenon over the course of a game.

In its most simplest form, bowling can be traced back to the Ancient Egyptians, around 5,000 BC. The Egyptians would roll stones at objects, attempting to knock them over, and the winner would be the one that was able to knock over the most objects. Today, bowling has evolved into a much more rule oriented and consistent game, but the premise remains the same. In ten pin bowling specifically, a bowling ball with a maximum weight of 16 lbs is used to try to knock down all ten pins for a strike. Regulations require lanes to be 41.5 inches wide, bordered by gutters, and 60 feet long. A bowler is allowed 10 frames to attempt to knock down the most pins, with frames 1-9 being comprised of two rolls and frame 10 comprised of up to three, with a bonus roll awarded should the bowler get a strike in one of two rolls. Bowling has a scoring system that keeps track of the pinfall in the current frame as well as the pinfalls in the previous frames, with the maximum score being 300.

Bowling may seem simple, but the physics behind it are anything but. For one, the making of a bowling ball is extremely complex and time consuming, and makers take everything into consideration. A bowling ball’s core is typically made from polyester infused with barium sulfate or calcium carbonate, and its hard outer shell can be composed of urethane, reactive resin, plastic, or a combination of these materials. The outer shell may seem unimportant, but its composition is carefully designed to increases the amount of friction that the ball creates on the lane. This, in turn, increases the angle that the ball can hook and give the bowler a greater chance to land the ball in the “pocket” of the pins.

The shape of the ball’s core is also important, and core shapes can be divided into two main categories: asymmetric and symmetric. A symmetric core is, as the names suggests, symmetric about its centerline. Similarly, an asymmetric core is so named because it is not symmetric about its centerline. Neither type is viewed as superior to the other, but the shape does determine the location and position of the thumb and finger holes. Moreover, the shape of the core lowers the ball’s inertia by concentrating its weight in the center, translating to the ball being able roll faster and with less resistance, and the irregularity of the core helps create sidespin, allowing the ball to curve down the lane. Makers of bowling balls also analyse how long it takes the ball to reach pure rolling (a state in which there is no acceleration and the ball follows a linear path) as well as the transfer of energy from ball to pin. Ball makers measure the ball and pin speed prior to the initial collision to ensure that no more than 35% of the ball’s energy is transferred to the pin.

Additionally, the throw and angle of impact can be taken into account by a bowler in his or her attempt to get a better score. First, a bowler may increase his or her throw’s energy by releasing the ball at a greater height from the floor. However, this energy does not affect the throws speed very much and much of the energy gained is converted to sonic reverberations. As such, bowlers try to keep the ball as close to the floor as possible.

Moreover, for bowlers attempting to hook the ball, a greater potential energy upon release causes the ball to ball, and this means that the ball has less time to gain friction between it and the lane. For the greatest transfer of energy to occur, the bowler must release the ball perfectly horizontal; this is because horizontal velocity is independent of vertical velocity and thus any energy in the vertical direction is squandered. This leads to the angle and location of the ball’s initial impact with the lineup of pins. For a right handed thrower, the shot should make contract with the “pocket” at the optimal angle of six degrees with respect to the lane boards. With this said, the need to curve the ball is obvious. In order to achieve an angle of six degrees by throwing the ball straight, a bowler would have to be standing around 6.3 ft to the side of the pocket, and this is more than halfway across the adjacent lane.

If you watch professional bowling, you will see that the competitors attempt to hook the ball rather than throwing it straight down the lane.

This is because of conservation of momentum. In order to maximize the transfer of energy between the ball and the pins, the ball must collide between the head pin and one of its neighboring pins at an angle so that the momentum of the collision sends the ball and pin at angles that will cause them to collide with other pins. If the ball hits this “pocket” in just a straight roll, the force exerted on it from the pin will usually send it away from the rest of the pins, leading to a bad score.

Physics is a part of everyday life, and bowling is no different. Next time you go bowling, take these physical premises into account in your path to a 300.