A zoetrope is a device to create an optical illusion of movement out of still pictures. A cylinder is set vertically so it can spin. Along the inside are individual pictures, and the cylinder walls are pierced by slits. As the cylinder spins, your eye catches glimpses of the pictures inside in quick succession, and your brain strings these together into a moving image. The early predecessors of the zoetrope go back almost a couple of millenia, but the modern zoetrope was invented about two centuries ago. Improvement and related devices led over the course of the 1800s led to the motion picture projector, and today's movie theaters, which work on pretty much the same principle. This LEGO zoetrope by 62bricks was inspired by an earlier creation by Lego Tron.