Photo by Noah Kalina
What makes wiffle ball so, well, wiffly? Putting an advanced degree in physics to benefit all of humanity, mechanical engineer Jenn Rossmann of Lafayette College decided to do a little fluid mechanics analysis on whiffle balls:
So over the past eight years, she and her students have built the world’s most advanced Wiffle-ology lab, using wind tunnels and computer models to measure aerodynamics. The key to the ball’s unpredictability? Air flowing over the perforated side of the ball is more turbulent, as you’d expect, which pulls it in the direction the holes are facing. But two vortices of air trapped inside push it in the opposite direction. Assuming the ball isn’t spinning, external airflow wins at low speeds; the internal vortices dominate at high speeds. At 40 to 60 mph—the speed at which most casual players throw—the two forces are about equal, making it hard to predict which way the ball will break.