They had a fun section for optical illusions. Funny thing is, optical illusions are surprisingly hard to photograph. In this one, they are projecting an image (which you can see on the wall) and your job is to wave this white stick up and down fast enough to make the image APPEAR to be complete without there actually being a complete surface for it to project onto. I got close, but I think I should get full credit because I was waving the stick AND trying to photograph it at the same time.