It's a Puzzle and a Pendulum
A fun addition to any office, dorm, or desktop, nine pendulums arranged on a frame are adjusted to have successively increasing periods.
When released simultaneously, the different periods cause the pendulums to cycle through all possible relative phase relationships, periodically returning to the starting arrangement. At intermediate times, the phase relationships of the pendulums display a moving transverse wave pattern.
The apparatus is supplied disassembled, as the assembly and adjustment processes are part of the fun and the learning experience, giving insight into the relationship between simple harmonic motion and wave motion. The rigid interlocking frame is 55cm wide and 48cm high. Though no recommended age is listed by the vendor, we believe this product is best suited for ages 13 and over.