Physics is big factor in outcome of U. vs. Y.

Science is probably not the reason the throngs of the true-blue and red-blooded will gather today for the annual revival of the BYU-Utah rivalry at Rice-Eccles Stadium, but physics will be in on every play, determining everything from the arc of the coin toss to the predictably unpredictable bounce of that so-called ball.

Isaac Newton, one physicist equally intrigued by unpredictable bounces, said about three centuries ago that gravity and motion follow strict behavior patterns but can be wildly unpredictable under the variables of mass, force, momentum, torque and velocity.

Something he didn't foresee is what happens when a football is put in motion, but he couldn't have developed a better way to show off universal gravitation and the three laws of motion he formulated into the basis for classical mechanics and modern engineering.

He would have never taken sides, but perhaps it's proper to invoke the possibility of larger things being under way the day he almost got his bell rung by a red thing coming out of the blue.

He put it this way: An object in uniform motion tends to stay in uniform motion unless acted upon by a net external force. Taking his second and third laws a step further, experts on Newton and the physics of football — Timothy Gay of Nebraska and David Haase from North Carolina — have some decidedly unbiased football footnotes to today's program:

• Brigham Young University quarterback Max Hall will factor in about 47 physics-based decisions in the standard three seconds after the ball is snapped. The guy might be hearing "Throw the stupid ball," but Hall is gauging distance, wind, where the strings of prolate spheroid are in relationship to his fingertips all while evaluating the speed and potential angles of potential impact of opposing forces who aren't evaluating anything but whether a quarterback's number can be permanently imprinted in the FieldTurf.

• If per chance University of Utah running back Darrell Mack gets squashed between Y. linebackers David Nixon and Matt Bauman colliding at full-speed, the impact is not unlike the booing fan trying to catch a bowling ball dropped from the top of the end-zone bleachers.

• A hit from U. linebacker Nai Fotu moving at about 20 mph — he's going that fast because he relies on velocity over the mass of those who make up the line he's backing — feels about like reaching the end of a fall from a 15-foot ladder. In the ensuing collision, gravity joins in, that is if the defensive player hits low enough, energy radiates from the lower extremities, causing a dynamic shift in gravitational pull exhibited in the ball carrier by sudden loss of balance and impeded forward motion — better known as a tackle.