Dr. Arthur G. Shapiro, of the Department of Psychology at Bucknell University (Lewisburg, Pennsylvania), along with Zhong-Lin Lu, Emily Knight and Robert Ennis (University of Southern California, Dartmouth College, and SUNY College of Optimetry, respectively) won the 2009 award for the Best Illusion of the Year at a meeting of the Vision Sciences Society.
The 2009 contest was held on May 10, 2009, at the Naples Philharmonic Center, in Naples, Florida, during the week of the Vision Sciences Society conference.
Their demonstration, called “The break of the curveball,” explains why a baseball pitcher’s curve ball seems to break so much as it is thrown toward a batter.
The physics of a baseball states that it curves because of the topspin put on the ball. It curves gradually during its flight toward the batter’s box by a couple of feet.
However, for a player standing in the batter’s box, it seems to be going straight during the first part of its flight but then jumps several feet, later on, almost instantaneously.
Why does its trajectory appear to change so abruptly to the batter?
The animation provided by the Shapiro team illustrates why the batter sees an abrupt change in the ball.
Page two shows where to find the animation of the Shapiro team.