Every year, the NFL makes rule changes that affect team strategy and game outcomes. Some of these rules are designed to maintain the safety of players, while others are designed to increase the competitiveness of the game. However, there is one aspect of the game that the NFL can never change: the laws of physics.
In the new series by Forbes Science, “Football Physics,” Chad Orzel ponders how drastically different football would look if the laws of physics were to change. Taking a guide from “Newton’s Football: The Science Behind America’s Game” (Allen St. John and Ainissa Ramirez) he proposes changing the force of gravity, the speed of light, and the equivalence principle. The force felt from gravity is a consequence of where football is played, on Earth, and the speed of light is a fundamental constant of nature. The equivalence principle states that gravitational mass, which describes how two objects interact due to gravity, and inertial mass, which is related to how an object accelerates under any force, are exactly the same.
Orzel does a beautiful job of highlighting how the interplay between inertial mass, gravitational mass, and friction is incredibly important for football strategy. He paints a picture of football players being able to jump higher, and throw the ball farther, but only at the expense of the ability to accelerate using friction. Alternatively, players might be able to run faster, but lose the ability to jump or throw the ball. Along this line of thought, one can also conjure up images of players sliding around on the group if there were no friction, or bouncing around like an astronaut in outer space.
Perhaps the most chaotic scenario proposed is what would happen if speed of light were reduced. If football players were suddenly moving at relativistic speeds, they would experience effects known as length contraction and time dilation. The perceived length of the field would change depending on a player’s speed, and assigning penalties might become near impossible because time would pass differently for each player and referee. Collisions between players would not just result in a concussion, but might even create a storm of exotic particles, much like you see in collider experiments.
It is a great deal of fun to consider the changes Orzel proposes. For scientists, it’s always important to relax assumptions about constants we take for granted, and consider how remarkably different the world might look. For football aficionados, these changes could drastically change the game, resulting in different strategies and methods to protect players. However, one could envision some of these scenarios taking place in the not so far off future. As humans spend more time in space, low gravity football could become a reality.
Acknowledgements: Many thanks to Tomo Lazovich, a PhD Student in Physics, for providing his expertise and commentary on the subject.
Media Coverage: Football Physics: How Would Changing the Laws of Physics Change Football? Forbes Science
Original Article: Newton’s Football: The Science Behind America’s Game
Managing correspondent: Karri DiPetrillo