This Pit and Pendulum from ThinkGeek creates “art out of science”. Available now, priced at $59.99. See it in action after the jump.
By sharpening the mass to a point and having it describe its path through a shallow dish of sand, you can see the track the pendulum takes on its regular rhythmic cycle. Back and forth, to and fro, the pendulum swings into gorgeous elliptical loops and whorls