Pendulum Waves
An array of fifteen independent pendula with varying lengths. Each pendulum's length is adjusted such that periods are very slightly different by a constant factor. When started in phase the pendula exhibit a sequence of traveling waves, standing waves, and random motion.
The Pendulum Waves Machine was designed and built by Gary Jarrette, Wayne Easterling, and Tim Cook of ASU. An article discussing pendulum wave machine physics (and our machine) can be found here.
Here is a brief explanation of how to get the pendulum waves started (see picture of controls for reference):
- Set the left-most switch to OFF
- Set left-most TIMER switch to between 1% and 10%. 1% will release and return the balls more rapidly, while 10% will introduce a delay between cycles and make each cycle last longer (about twice as long per cycle than 1%).
- Set the right-most TIMER switch to 1% (minimum value)
- Set the left-most switch to AUTO
- Depending on where in the automated cycle it was left at, this may release the balls in a few seconds, or take some time to bring the magnets out, then the arms, and then release the balls. Either way the balls will be released, it will just vary with the settings chosen.
- Enjoy! If left on AUTO the cycle will repeat endlessly. You can switch over to MANUAL to stop the cycle, or OFF if you have concluded your fun.
NOTE: The RELEASE switch is only used when the machine is in the MANUAL mode. In order to prepare the machine for a release, it must be run in AUTO mode and switched back into MANUAL mode once the eddy current magnets have begun rising up to slow the balls. If kept in MANUAL mode, the procedure should continue until the balls are at their highest position. At this point pressing the RELEASE switch will release the balls.