This clip (2:42) of the mind-bending video game “Portal” shows it as a very cool re-imagining of M. C. Escher’s famous picture, “Relativity“.

In the game, you carry a device that can create tunnels on walls and floors through which objects and your game character can travel through. These portals do not obey the laws of gravity and physics, nor spatial-temporal reasoning.

Don’t know what I’m talking about? Here’s M. C. Escher’s picture.

M. C. Escher's Relativity

Now imagine playing in that alternate reality as a video game. Awesome.