The break of the curveball

2009 First prize
Arthur Shapiro, Zhong-Lin Lu, Emily Knight, & Robert Ennis

American University, University of Southern California, Dartmouth College, SUNY College of Optometry, USA

In baseball, a curveball creates a physical effect and a perceptual puzzle. The physical effect (the curve) arises because the ball’s rotation leads to a deflection in the ball’s path. The perceptual puzzle arises because the deflection is actually gradual but is often perceived as an abrupt change in direction (the break). Our illusions suggest that the perceived “break” may be caused by the transition from the central visual system to the peripheral visual system. Like a curveball, the spinning disks in the illusions appear to abruptly change direction when an observer switches from foveal to peripheral viewing.

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Rating: 8.6/10 (2004 votes cast)
The break of the curveball, 8.6 out of 10 based on 2004 ratings
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