Science News

Japanese mathematics professor Kokichi Sugihara spends much of his time in a world where up is down and three dimensions are really only two. Professor Sugihara is one of the world's leading exponents of optical illusion, a mathematical art-form that he says could have application in the real world.

Three sloped ramps are aligned along three of the four sides of a square. Each ramp appears to be sloped in the same direction but when a marble is placed at one end of the ramp it seems to defy gravity.

It's called an "anti-gravity slide". Only when the the entire structure is turned 180 degrees, is the illusion revealed.