Saturday, April 28, 2007

Take Me Out To The Ball Game

Last week, I ALMOST caught a ball at the Yankees game. Two things happened that prevented my would-have-been magnificent catch:
1. I ducked (I really don't like fast balls coming near my head, but I still put my hand out and half expected to catch it anyway).
2. The ball curved at the last second and landed ions away from me.
Slightly relieved and VERY embarrassed that I assumed the duck-and-cover position, my friend consoled me, "Hey, it's not your fault you didn't catch the ball. It was impossible with that curve." Well, he was right. It certainly wasn't my fault that the ball didn't arrive right in the palm of my hand like I thought it should have-- it was the fault of science. More specifically, it was the fault of the ball's stitches and speed.
When I got home, of course I googled "curve balls" just so I could find an "official" reason why I didn't even come close to catching the ball. As it turns out, there have actually been a lot of studies on the curve ball situation. For example, back in 1959, Lyman Briggs, (former director at the National Institute of Standards and Technology) did a study to settle a ferocious dispute over how much a ball could curve over the course of 18 meters (the distance from the pitcher's mound to the home plate). I'm not sure what was "ferocious" about the dispute, but that's what the article said. In any case, Lyman found out that the amount of curve is determined NOT by the spin but rather by the speed of the ball.
One thing that affects the speed are the stitches. So in addition to fashion, these little notches also have a a function: they are a force of resistance as the ball goes whizzing through the air, ultimately causing the ball to slow down. The force of resistance is proportional to velocity because faster objects experience more drag. The curve depends on how the ball rotates through the air and at what speed it is going, as well as how the stitches form a "boundary layer" that reacts with the air around a moving ball. Still confused? Here's how the "Why Files" explain it:
"Consider a pitched ball rotating about a vertical axis and approaching the plate. Due to the rotation, one side is moving considerably faster through the air than the other side. The air will exert a greater force on that side, pushing the ball away from it -- toward the side with the slower relative motion. The result is a curve ball."

I find this stuff interesting, but not at all reassuring, so I plan on assuming my duck-and-cover position at the next game too. Maybe one of the players will (slowly) throw me a helmet. Honestly, with all those fast balls flying into the bleachers, it's not a bad idea. Unless you're a total math geek, you'll never be able to calculate the curve of a ball as it comes at your head. Science gives you an excuse for not catching the ball, but it's really no help otherwise. Baseball fans, the moral of the story is to protect your noggin. Wear a helmet.

1 comment:

Dennis Ogburn said...

The ball landed ions away from you? Ions are very small, many millions could fit on the head of a pin. Unless the ions in question were in the upper atmosphere of course, but then the ball would have been nowhere in sight.

I'm guessing that the ball would be positively charged, losing electrons as it zoomed through the air, and so would be attracted to any group of negative ions nearby. Considering the Yankees' record this year, that could have been in lots of places in the stadium....