Visit Your Local PBS Station PBS Home PBS Home Programs A-Z TV Schedules Watch Video Donate Shop PBS Search PBS
Scientific American FRONTIERS Logo
TV Schedule
Alan Alda
For Educators

Future Shows
Special Features

On the Ball

  Segment 3 Baseball Tech
Photo of  baseball players

At one time or another, every baseball fan has disagreed with a call at the plate. Recently, 3-D graphics on televised games have vindicated some armchair umpires. In "Baseball Tech," Alan takes a look at a similar tool an aerospace company designed for real umpires that will provide objective, post-game self-analysis.

Engineer Paul Baim demonstrates the Umpire Information System (UIS) at Boston's Fenway Park. But first, Alan gives umpping a try and sees firsthand what a challenge finding the strike zone can be.

The UIS uses pairs of cameras to track pitches. One set in the rafters above the first base line, and one above the third base line. Using the images collected by these cameras, the system produces a 3-D graphic that shows the predicted and actual path of the ball to the plate.

To define the strike zone, two additional cameras in the dugouts take a snapshot of the batter just after the pitch. Applying a model of the physics of the baseball in flight to the camera images, the system extrapolates the path of the ball through the strike zone very accurately--within a half-inch.

Not intended to replace umpires or publicly second-guess them, this scientific system is meant to help umpires refine the art of calling pitches. After the game, the UIS generates a CD-ROM that allows the umpire to review any pitch. Baim hopes to have one third of all major league parks equipped with the system for the 2002 season.

Science is working for the batters, too. The National Collegiate Athletic Association (NCAA) replaced oft-broken wooden bats with long-lived aluminum in the early 1970s to save money. But the switch raised a new issue: aluminum bats hit the ball much harder and faster than wood.

Concerned that players might be injured, the NCAA set a ceiling on aluminum-bat speed. Scientist Jim Sherwood came up with a simple solution: keep aluminum bats from hitting any faster than wooden ones.

But speed isn't the only difference between wood and aluminum. There's also sound--the familiar "crack" versus the "ping."
Photo of scientist recording baseball hits  
What does the sound say about a swing?  

Bob Collier and his colleague Ken Kaliski are trying to differentiate how the sound of a bat changes depending on where it's hit. A wooden bat vibrates when struck. Vibrations are minimal at a point about six inches from the tip--what players often call the "sweet spot"--so the crack is sharpest when the bat is hit there. Anecdotal evidence suggests that sound helps fielders predict where the ball will fly.

Do aluminum bats react the same the same way? Apparently not. Collier and Kaliski have found that, despite slight differences in loudness, the quality of the ping is almost identical for different hits.

For more on this topic, see the web feature:
The Best Medicine

return to show page




A Quiet Eye Brainy Putting Baseball Tech No Limit Resources Teaching guide Science hotline video trailer Contact Search Homepage