Football Physicist

Football fans pay close attention, trying to see every epic pass, soaring field goal, and thrilling touchdown. Gay does too—but he also thinks about the forces behind those plays. For example, a quarterback throws a football so it spirals through the air. At the start of the throw, the ball’s nose points up. Then it gradually tips down as it arcs overhead. For about 20 years, Gay puzzled over why this happens. Recently, he figured it out: It turns out that drag—a slowing force caused by air molecules pushing against a moving object—causes the spinning ball to shift position (see “A Perfect Spiral,” Science World, November 15, 2021).

Gay uses physics to teach about the science of football. He’s even written a book on it. Recently, Science World spoke with Gay about his love of physics and football—and how he combines the two.

What led you to become a physicist?

As I was growing up in the 1960s, the U.S. launched the first astronauts into space. My whole school gathered around one TV in the cafeteria to watch. It was inspiring and began my interest in science. Then, when I was in third grade, I read a biography of Marie Curie, the physicist who discovered that certain elements give off radiation—high-energy particles or rays. I thought her experiments were very cool. Ever since then, I wanted to be a physicist like her.

How did you get started applying physics to football?

I’ve always loved watching football on TV. In high school, I was the manager for my school’s football team. I got an up-close look at all the games. In college, I was even closer to the action: I played on the team!

I went on to get my Ph.D. in physics and became a professor at the University of Nebraska. One day, a TV producer from the school’s athletic department came by the physics department asking, “Do you have any physics professors who love football and love to talk?” Everyone in the department suggested they speak to me. It turns out the producers wanted to make educational videos to play on the Jumbotron during football games. I started creating one-minute videos called “Football Physics,” explaining how physics relates to different parts of the game.

Can you explain some of the physics that happens during a football game?

Physics happens everywhere in football! One example is when two players collide in a tackle. To find the force of the impact, we can use Newton’s second law of motion—which says that an object’s force depends on its mass and acceleration. Two big football players running at top speed collide with 680 Newtons (1,500 pounds) of force. That’s like having a cow sit on top of you!

Has your research ever helped any professional football teams improve how they play?

There have been a few coaches who read my book and used the physics in it to help their coaching, including Bill Belichick, the former head coach for the New England Patriots. Most coaches know from experience the best things to tell their players to do. But my book explains why those are the best decisions.

What do you research other than football?

In my laboratory, we study atoms. Everything in the world is made up of these tiny particles. At the center of every atom is its nucleus. Negatively charged electrons orbit around an atom’s positively charged nucleus. I examine what happens when we shoot electrons at atoms. This has helped scientists build better lasers and improve their understanding of how the sun works.