**Date:** Fri, 15 Oct 2004 08:18:47 -0500

**Author:** "Cliff Bettis"

**Subject:** Re: localized energy mode demo, i.e pendulum revisited

**Post:**

Sam,

Is there any particular relationship between the pendulum period and the

torsional oscillator period?

Cliff

----- Original Message -----

From: "sampere"

To:

Sent: Friday, October 15, 2004 7:57 AM

Subject: localized energy mode demo, i.e pendulum revisited

> I saw the coolest demo yesterday. Al Sievers from Cornell gave a

> colloquium here yesterday and brought a demo with him.

>

> Picture a dozen small identical pendulms suspended from a single rod,

> perhaps from a bearing, so the rod does not play any role in

> transferring energy. Then, connect each of the pivot points with

> springs so that as the pendulums oscillate, the springs either wind up

> or unwind. The direction of oscillation is perpendicular to the length

> of the suspension rod, i.e., if the pendulums all dangle from rod

> horizontal and parallel to your screen, the pendulums oscillate in and

> out of the screen.

>

> So, here are two questions for you:

>

> 1) For small starting amplitudes, the initial conditions for all pendula

> being equal, what do expect to see?

> 2) Same as 1, but for very large starting amplitudes?

>

> I'll post the answer later after I hear your thoughts.

>

> Sam

>

From wonnell@pha.jhu.edu Fri Oct 15 06:28:41 2004