Have you seen these?

At first you might be surprised to see the pattern that these pendulums follow.  In this video, one experimenter filmed a complete one minute cycle.  Although a fancy word, all a pendulum means is something that is weighted and in a position to swing freely.  When released from its position it will swing until equilibrium is reached.  Here is a brief intro on what they demonstrate in this cool video:

Fifteen uncoupled simple pendulums of monotonically increasing lengths dance together to produce visual traveling waves, standing waves, beating, and (seemingly) random motion.

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.

Here is a pic of a clock using a pendulum system.  This was much more frequent obviously in the past and with grandfather clocks.

Is this what you would have expected?  Or did you think something else would have happened.

And when is the last time you can recall a pendulum being used in an application.  Hypnotism or perhaps an antique?

Feel free to comment.