There are many examples on the internet of videos of ‘pendulum wave machines’ and how to make them
(for example, www.instructables.com/id/Wave-Pendulum/
[http://www.instructables.com/id/Wave-Pendulum/] ). The machine is simply a set of pendula of
different lengths which, when viewed end on, produce wave-like patterns from the positions of the
bobs. These patterns change with time, with new patterns emerging as the bobs change phase. In this
article, the physics of the machine is explored and explained, along with tips on how to build such
a device.