Philadelphia.--If the starter in a track meet fires his pistol in the usual spot, does this give the runner in lane one any edge over the competitor in lane eight?

Of course, says professor Ramanand Jha of India's Institute of Physics. And especially in a sprint. He points out that the starter's infield position is next to lane one, on the inner side of the track.

"The typical width of a lane is one meter," the physicist notes, "and the velocity of sound is 340 meters per second.

"So an athlete in lane eight hears the shot two hundredths of a second later than an athlete in lane one."

Focusing on minutely split seconds is not like splitting hairs. Another physics whiz, Peter J. Brancazio of Brooklyn College, says the higher the level of sports competition, the more vital those split seconds are likely to be.

The academic world's leading authority on split seconds in the world of sports, Dr. Brancazio has written and spoken at length on such esoterica as the acceleration of Olympic sprinter Carl Lewis as he nears the finish line, the velocity of Nolan Ryan's fastball from the mound to the plate and the apparent gravity-defying hang time Michael Jordan achieved on his monster dunks.

To show just how lengthy a full second is, Dr. Brancazio cites the old touch-football rule of counting five Mississippis before rushing the passer: "One Mississippi, two Mississippi," etc.

Check it against your watch and you'll observe that 10 Mississippis, when clearly pronounced, do come close to 10 full seconds.

Then imagine how many quick moves you could fit into just one Mississippi.

Carl Lewis could run the 100-meter dash in only 9.92 seconds. That averaged out to 33.1 feet per second. But for a world-class sprinter, Mr. Lewis was a notoriously poor starter -- even when he was in lane one, right next to the starter's gun. On nearing the finish line, however, he was able to compensate for his slow start by accelerating to the amazing speed of 36 feet per second.

How much difference can a few hundredths of a second make?

In the National Football League, a wide receiver who runs 40 yards in 4.4 seconds may go to the Pro Bowl, while a defensive back who runs the same distance in 5.0 seconds goes on the waiver wire.

Of course, the difference between them is only six tenths of a second. But the 4.4 receiver flies 9.1 yards per second, while the 5.0 defender averages 1.1 yards per second less. On a deep pattern, that receiver gets to spike the ball in the end zone, while that defender can't get close enough to him to make the TV replay.

In baseball, the pitcher's mound is 60.5 feet from home plate, but the motion of the pitcher's delivery cuts that down to 55 feet when he releases the ball. Thus, one of Nolan Ryan's 95-mph fastballs takes only 41 hundredths of a second to cross the plate.

Less than half a Mississippi.

The 85-mph fastballs thrown by the Phillies' Mitch Williams in postseason play took 46 hundredths of a second to arrive.

That difference of five hundredths of a second was all Toronto's Joe Carter needed to get around on the home run that ended the Phillies' World Series dreams.

Basketball fans thought Michael Jordan could hover in air for 2 full seconds. But Dr. Brancazio, who checked out Mr. Jordan's hang time on countless videotapes, found he was subject to the same laws of physics as other mortals.

"Hang time" is determined by the height of the vertical jump. By immutable mathematical formulae, that height equals four times hang time squared.

To hover for 2 full seconds, Mr. Jordan would have had to jump the impossible vertical height of 16 feet instead of his merely exceptional 3 feet. Far from staying aloft for 2 full seconds, Mr. Jordan's average hang time was actually 87 hundredths of a second.

What made him look miraculous, Dr. Brancazio says, was the remarkable variety of moves he made with the ball while airborne and the seemingly casual ease of those moves.

Jack McKinney is a columnist for the Philadelphia Daily News.