A pendulum wave is a type of kinetic art that comes from the movement of pendulums with varying lengths. Moving them all simultaneously results in fun wave shapes as well as some groupings that seem to come out of randomness. It is a neat piece of art demonstrating mathematics that cane easily be displayed on a desk.

[https://en.wikipedia.org/wiki/Pendulum_wave](https://en.wikipedia.org/wiki/Pendulum_wave)

The lengths of each pendulum should be approximately:

Pendulum 1: 60 mm
Pendulum 2: 73 mm
Pendulum 3: 90 mm
Pendulum 4: 107 mm
Pendulum 5: 126 mm
Pendulum 6: 146 mm
Pendulum 7: 167 mm
Pendulum 8: 190 mm
Pendulum 9: 215 mm

As this length can be difficult to measure with a slide caliper, I recommend simply measuring only the first pendulum and then lining the rest up in a straight line when the rack is held up. The model accounts for the extra length on each pendulum, so as long as they are in a line, they should produce the pendulum wave effect.

Be sure to use a thread that is extremely lightweight and flexible. Something like fishing wire is too rigid and doesn't allow the pendulum effect to occur. I used sewing thread and that worked well.

Be careful when moving the desktop pendulum wave because the rack can fall out, just push it in vertically and then rotate into place if that happens.

To use, simply push down on the elevated part of the rack and release!