A demonstation showing simple and complex patterns in rational and irrational numbers.

The patterns are a result of the ratio of the speeds of the blue and red arm. Speed here is defined as the number of rotations per second an arm makes about it's axis.

To explain further, there's the red arm that rotates about the very center of the pattern. Attached to the other end of the red arm is the blue arm. The point at which the blue arm touches the red arm is the axis about which the blue arm rotates. Since this point revolves around the very center of the pattern, the entire blue arm also revolves around the center of the pattern while also rotating about it's own axis.

Finally, on the other end of the blue arm is, well, a pen that traces out the path that this point of the blue arm takes. This path is the pattern observed on the screen.