Alum Analyses Baseball Through Physics Lens

by Liam Farrell | Illustration by Jason Keisling

When Yankees’ rookie sensation Aaron Judge hit a baseball with the wildly vibrating handle of his bat during the playoffs last week, Alan Nathan ’68 saw more than an amazing display of power and athleticism. He saw a physics problem.

“When I get a chance, I want to analyze what happened with that collision,” says the University of Illinois physics professor emeritus.

Besides making an academic career out of nuclear physics, Nathan is a go-to expert on the science of baseball, researching everything from how far a human could hit a home run under optimal batting conditions with no wind (492 feet, according to his calculations) to why knuckleballs are so hard to hit (unlike other pitches, they have an unpredictable break). He runs the Physics of Baseball website and gets quoted in outlets such as NPR, ESPN, Popular Mechanics and Newsweek.

Although he grew up in Maine back in the 1950s and ’60s playing baseball and watching the Red Sox, Nathan hadn’t considered combining his science and sport interests until nearly 20 years ago when he was trying to come up with a presentation for an Illinois community outreach program. He cracked an unread book that had long been parked on a shelf—1990’s “The Physics of Baseball” by Robert Adair—and started looking at scholarly work on the sport, and producing his own.

Since then, Nathan estimates he has worked with about half the teams in Major League Baseball, helping them understand data such as the exit velocity of a ball coming off the bat and the launch angle that separates a home run from a pop fly. He also was part of a committee that changed the composition of bats for NCAA baseball in 2011, aiming to limit offense, game time and the velocity of batted balls.

“It really has changed the college game in a significant way,” Nathan says, noting college home runs have fallen by half. “We more or less predicted what would happen.”

He has delved into baseball’s history as well. In one study, Nathan considered the tale of Mickey Mantle hitting a home run 565 feet out of Griffith Stadium in Washington, D.C., during an April 17, 1953, game against the Senators. Using newly available information uncovered by journalist Jane Leavy and calculations based on ball speed, launch angle and the day’s strong wind, Nathan concluded the ball likely traveled, at a minimum, 538 feet.

For his next project, Nathan is interested in exploring the recent uptick in home runs. Just don’t expect him to be crunching data when the first pitch is thrown at Fenway Park next year.

“If I’m watching the Red Sox play,” he says, “I’m far too emotionally involved.”