The three best visual illusions in the world were chosen at a recent gathering of neuroscientists and psychologists in Florida.

The winning entry may help explain why curve balls in baseball are so tricky to hit.

From the point of view of a batter, curve balls seem to "break," or move suddenly in a new direction.

The winning animation shows a spinning ball that, when watched directly, moves in a straight line, but when seen out of the corner of the eye, the spin of the ball fools the brain into thinking that the ball is curving. So as a baseball flies towards home plate, the moment when it passes from central to peripheral vision causes its direction to appear as a sudden jerk.

See this illusion as well as the other winners here:

http://www.aip.org/isns/reports/2009...lillusion.html

This curve ball thing I have seen demonstrated on TV whereupon a pitcher actually threw the ball past an interposed obstacle.

Most balls in sport do arc, and not by virtue of gravity, but by actual rotation being imparted by throwing them, or striking them. You simply couldn't serve or strike a tennis ball as hard as any pro does without copious amounts of spin being applied. Hit flat, the ball would likely land in the next county. The rotation applied by a right handed person is clockwise, and counter clockwise by a lefty. To throw a pitch the opposite of this would require rotating the wrist inward, try that sometime. They change the handedness of the batter when they change the handedness of the pitcher because of the way the ball will "break" in or away from different combinations of players.

So, while there may be somewhat of an optical illusion involved, a baseball throw by a major league pitcher clears the distance from the mound to the plate in less than the average persons reaction time, and that's why you can't hit it.

A fastball traveling @ 90MPH = 132 Feet per second.
Distance from the pitching rubber to the back of home plate, 60' 6"
So, since the pitcher's follow through may extend past the front of the rubber, and the batter's swing targets the center of the plate, the actual distance may be a tad shorter.
Travel time, a tweak less than 1/2 second from release to catcher's mitt.
Avg reaction time 1/4 second (star athelete) to 3/4 second. 1+ second, idiot on drugs or talking on a cell phone.

........the greatest optical illusion in baseball was Rollie fingers Mustache.

No, it was Bob Uecker's career

Captain's point on a tennis server is a good, simple proof.
Draw a straight line from the point of impact of the ball w/racket to the top of the net
and allow one millimeter clearance --

if the ball travels this line where does it hit the ground?

BEYOND the service line -- do it again and it's love-15

The captain’s point on curve balls is of course correct. A spinning ball makes the air on one side move faster than on the other. This causes the ball to phsically move along a gradual curve.

However, in addition to the above physical effect, there is also the visual effect illustrated by the winning illusion. That is, the curve ball seems to suddenly change direction of movement.

It seems to me, a batter’s lot is not a happy one.

The "Knuckleball", very hard to throw.
The "Spitball". very hard to get away with.

The first one best thrown by Tommy John....until he needed Tommy John surgery.......

the second best thrown by Phil Niekro........until his younger brother Joe showed him how to use a nail file for maximum Knuckle ball.....so he wouldn't need Tommy John surgery.

I thought this was interesting...in a trivial sort of way: From Wikpedia

"Hit flat, the ball would likely land in the next county"

If the next county was "close enough".