Gareth, Sentientfx - Innovative music plugins. http://sentientfx.com/
> Date: Wed, 28 Sep 2011 15:17:06 -0700
> From: firstname.lastname@example.org
> To: Loopers-Delight@loopers-delight.com
> Subject: Pendulum LOOP
> Beautiful visual loop showing visual pattern consonance and dissonance
> What it shows: Fifteen uncoupled simple pendulums of monotonically
> increasing lengths dance together to produce visual traveling waves,
> standing waves, beating, and random motion. One might call this kinetic
> art and the choreography of the dance of the pendulums is stunning!
> Aliasing and quantum revival can also be shown.
> How it works: The period of one complete cycle of the dance is 60
> seconds. The length of the longest pendulum has been adjusted so that it
> executes 51 oscillations in this 60 second period. The length of each
> successive shorter pendulum is carefully adjusted so that it executes
> one additional oscillation in this period. Thus, the 15th pendulum
> (shortest) undergoes 65 oscillations. When all 15 pendulums are started
> together, they quickly fall out of sync—their relative phases
> continuously change because of their different periods of oscillation.
> However, after 60 seconds they will all have executed an integral number
> of oscillations and be back in sync again at that instant, ready to
> repeat the dance.
> Setting it up: The pendulum waves are best viewed from above or down the
> length of the apparatus. Video projection is a must for a large lecture
> hall audience. You can play the video below to see the apparatus in
> action. One instance of interest to note is at 30 seconds (halfway
> through the cycle), when half of the pendulums are at one amplitude
> maximum and the other half are at the opposite amplitude maximum.