London, June 8 (ANI): A psychologist has created an animation that explains why a type of baseball pitch called a "curve ball" often fools batters and is quite hard to hit.
One of the weapons in a pitcher's armoury is to give the ball a spin that causes its trajectory to curve.
The curve is smooth, but batters see the ball as if it is going straight and then suddenly changes direction, making it hard to hit.
Now, according to a report in New Scientist, psychologist Arthur Shapiro of Bucknell University in Lewisburg, Pennsylvania, has created an animation of a ball that offers clues as to why this is.
Like a real baseball, the animated ball is spinning. It is also falling vertically. Viewers who look directly at it perceive it correctly as moving downwards, while those viewing it from the corner of their eye perceive it to be moving at an angle.
This suggests that when we use our peripheral vision, the brain uses the internal motion of objects, in this case, spinning, as well as their overall direction to determine how an object is moving.
In this case, it causes the ball to appear to move to the side.
The transition from central to peripheral vision may explain why curve balls appear to change direction.
Shapiro noted that curve balls start off in the centre of a batter's vision, but overlap with the peripheral system as they come nearer.
"This transition may be why such balls appear to change direction suddenly," he said. (ANI)