Automaton waves

Waves in time and space: Reubin Margolin's favourite subject material. The sculpture above, 'Yellow wiggle' (2008), demonstrates the superposition of two sine waves with different frequencies. Most of his works are 3D waves, and they really give the impression of a weightless fluid surface, in spite of their true nature.

This documentary: http://www.youtube.com/watch?v=dehXioMIKg0 shows how the sculpture above, and more like it, were designed and built. There are arrays of incredibly clever pulleys and camshafts. Many of the driving mechanisms convert circular rotation from a motor into a waveform; a reminder of the beautiful relationship between circles and sinusoids:

In Margolin's sculptures, a circular drive is used to create a wave motion. In wave energy engineering, we seek to turn wave motion into a circular drive. The diagram above reminds me of the principle of the Bristol cylinder: The wave's kinetic and potential energy oscillate out of phase. By capturing a combination of surge and heave, the Bristol cylinder moves in a circular path.

Image credits:

'Yellow wiggle', copyright Reuben Margolin: http://www.reubenmargolin.com/

'Circle cos sin' by Lucas Vieira, public domain from wikipedia: http://en.wikipedia.org/wiki/Sine#mediaviewer/File:Circle_cos_sin.gif