Wild About Math! Making Math fun and accessible

14Dec/093

Very disturbing optical illusion

I really like optical illusions. Until recently, my favorite was this one. But, I have a new favorite now.

Here's one that bothers me. See if it bothers you.

Look at the image below. Which square is darker, A or B, or are they the same color?

A hat tip to John Cook for blogging about this illusion.

23Dec/0767

Optical illusion: the spinning girl

Here's an optical illusion that's making its way around the net and has now become my very favorite illusion. Look at the animated gif below. What direction is the girl spinning in, clockwise or counterclockwise? Can you make her change directions with your mind? Can you see her spinning either clockwise or counterclockwise at will? What is going on?

Spinning girl optical illusion

I don't know who to credit since there are lots of copies of this image around. The first one I found was here.  That web-site and a number of others you can find via this Google search claim that this is a right brain vs. left brain test but not everyone agrees about what is going on here. You can read more about lateralization of the brain (the functions of the two sides of the brain) in this Wikipedia article.

If you like optical illusions, check out Might Optical Illusions, a pretty comprehensive collection of such things in a blog format. This site even has an Optical Illusion of The Day Widget so say can effortlessly get your daily fix.