At Fading Motion, a swinging pendulum pours sand from its “bob” onto a variable-speed conveyer belt which moves in a direction perpendicular to the swing of the pendulum. The sand forms a wavy pattern on the belt which exponentially diminishes in amplitude due to a damping mechanism consisting of a paddle moving through thick oil. The oil reservoir may be raised or lowered (the paddle is fixed to the pendulum) to vary the amount of damping. If no damping is employed, a fairly regular sine wave is produced; the frequency of the wave depends upon the speed of the belt. Children love to draw with the sand pendulum by simply moving the pendulum with their hands. It's also fun to catch the sand as it drops off the belt into a storage container.