Craziness!

I totally got this from the Freakonomics blog, but this is worth reposting. There is an image of a dancer rotating, but it is unclear whether she spins clockwise or counter-clockwise. When I looked, I was 100% sure that she was spinning counter-clockwise, indicating that I am left-brained (and all these years I thought I was a right-brainer). Some people, though, can only see her spinning clockwise. I was able to retrain my eye to watch her go clockwise after looking at the shadow of her foot, but it wasn't easy. Go check it out!