There is a hypnotic tendency in the observation of waves. While I often think of waves in terms of sound, waves are everywhere and in everything, whether in terms of the oceans or in descriptions of the sub-atomic worlds. Perhaps, it is their pervasive presence across the directly and indirectly observable universes that intrigues.
Here is a neat video demonstrating a series of pendulums - each one designed to oscillate one time less than the last: