Wow! And I know what bowlers will start doing next!
Posted by Dave Bath on 2009-06-03
Some illusions are fairly easy to figure out why they work, such as the line that seems to be different lengths depending on whether it has standard or “reverse” arrows on its ends.
But the winner in the optical illusion awards this year, and an independently discovered correlate, is simply stunning.
And some sports, particularly cricket, will either have rule changes or the participants will change tactics dramatically.
The winning illusion (for those without flash) has a spinning ball, with the ball having different shades of grey. If you look at the ball directly, it seems to fall vertically, while looking to the side makes it appear to go at a significant angle.
The "stripe" on the ball is vertical, and the axis of rotation is vertical. Make these horizontal, and the effect disappears.
In the correlated illusion, a number of such balls are spinning about a common central point – either clockwise or counter-clockwise depending on where you look.
You can bet bowlers in cricket will no longer be rubbing one side of the white ball used for one-day and night matches on their pants to smooth one side, as much as they will be rubbing one side to remove grass stains – using psychology rather than physics.
The bowlers might even do something odd during the flight of the ball to get the batsperson to look momentarily look away from the ball and increase the effect of the illusion.
I’m interested to see if some ball sport introduces this illusion as an essential part of the game – it would certainly be incredibly difficult to try and hit the ball!
Perhaps readers who play tennis can color their own balls in a similar manner and see what happens when they play, and whether they can control their own eyes to totally confuse their opponent – or merely use it to have a bit of fun.
I wonder if a ball manufacturer will produce such balls as a novelty item.
- If you enjoyed these illusions, you’ll probably enjoy the following post: "Wow! The impossible is now real!" (2009-01-22)