Cubology

There's more in the above picture than you'd think. Depending on how you look, you can see : a room with a box in it, a cube with a smaller cube cut out, or a big cube with a smaller cube in front of it.


Then there's the Necker cube:



Is the green side on the front of the cube or at the back ? Keep looking at the cube and you'll find that it switches a few times. First described by Professor L. Necker, hence the name.

Cool cubes.