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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Resonance
From: Fred Hebard
Date: 2003 Dec 26, 09:36 -0500
From: Fred Hebard
Date: 2003 Dec 26, 09:36 -0500
Not being a physicist or engineer, resonance is not a subject with which I am strongly conversant, and I finally came up with an example that might be helpful to the similarly challenged. My example is a "Slinky", which is a tension spring about 5-cm diameter, about 5-cm long compressed, stretching out to about a meter, sold as a toy in the U.S. "Slinkys" can be made to walk down stairs and do other fun things. If you hold one at the end and let it drop, a slight upward flick at just the right moment with cause it to spring back up toward your hand, whereas a similar flick at another moment has almost the opposite effect, dampening the spring action and causing it to dangle from your hand, with no satisfying spring back. I expect the flick that causes the Slinky to spring back to your hand is in phase with the natural resonance of this system, while the worst example of the other flick is one-hundred eighty degrees out of phase.