E-Mail This Article to a Friend FORCE VECTORS Football for geeks BY NICK A. ZAINO III

It’s only natural that geeks would love the Super Bowl. Football is a game of variables, strategy, and nifty costumes (like full-contact Dungeons & Dragons). It’s X over O, friction, speed, mass, leverage — a bouquet of everything the kids in science clubs used to love. At least that’s how Timothy Gay, PhD, author of Football Physics: The Science of the Game (Rodale, 2004), sees the game.

Gay explains everything from the motion of the players and the ball to the science of draft day. In his reading, virtually no part of the game escapes the reach of physics. When Warren Sapp hits Doug Flutie, Gay says, Newton’s Third Law dictates that they exert an equal and opposite force on each other. The reason the quarterback goes flying is that the 310-pound Sapp transfers his momentum to the 180-pound Flutie, and momentum equals mass times velocity. To break it down for guys who may have actually kissed a girl in high school, large times fairly fast equals ouch.

With a little practice, you can use the book on Super Bowl Sunday. Substitute Sapp and Flutie for hard-hitting Patriots safety Rodney Harrison and Philadelphia Eagles cheerleader Terrell Owens (and remember, egos don’t weigh anything, so you can just use the stats listed on NFL.com to find Owens’s mass). Harrison is officially listed as 6’1", 220-pounds; Owens 6’3" and 226. A non-gimpy Owens has the advantage over Harrison when they are one-on-one in man coverage, simply because Owens is taller. Once Owens comes down with the ball, Harrison’s height is an advantage. He has a lower center of gravity, and if he hits Owens squarely, he should bring him down. In geek speak, Harrison wins because his torque and center of gravity cause Owens to rotate around two pivot points — his feet.

On the other side of the ball, Tom Brady has a reputation as a tough, smart player with a group of workmanlike receivers. Brady doesn’t have a cannon arm, and his receivers don’t have blazing speed. So how are they able to beat the opposing defense so often? Gay would say it’s a matter of momentum. If Deion Branch is running a step ahead of the cornerback covering him, Brady can adjust and hit Branch in stride. If Branch doesn’t have to stop his momentum, he can stay one step ahead of his man and run to daylight. It’s the difference between a good gain and a touchdown, that extra lift that got the Pats into the Super Bowl in the first place.

What does that have to do with physics? Everything, even if it’s intuitive for the players. Gay points out that the players might not be solving equations on the field, but they have to have an intrinsic understanding of physics on a practical level. Joe Montana may not have been able to diagram the force vectors that made it so difficult for him to toss a touchdown to Dwight Clark for "The Catch" in the 1981 NFC Championship, but he wouldn’t have been able to make the throw if he didn’t understand them on some level.

In his foreword, Gay’s former teammate at Andover Academy and wicked smaht Pats coach Bill Belichick illustrates. "Punt returners, the good ones like Troy [Brown], have learned and internalized these subtle physics lessons through countless hours of practice and game experience. After reading this book, you’ll understand what they know by instinct."

That includes busting a few myths. Jacksonville’s Alltel Stadium is a long way from Foxborough, in muggy Florida. The general perception is that higher humidity makes for a tougher kicking game. So should Belichick think twice about counting on his Super Bowl–hero kicker, Adam Vinatieri? Not according to Gay, who points out that high humidity actually means slightly better kicking conditions, if anything, because wet air is less dense than dry air.

Gay offers lots more insight on turf, helmets, crowd noise, and the mechanics of the game. And since it’s generally easier to get your friends together for a Super Bowl party than to get them to create a kick-ass valkyrie or explain how to use a 20-sided die, learn to love football for what it is — a game of science.