Executive Pendula

Two slender brass supports rise from either end of a polished rosewood base. Each support is topped by a brass filial. Cross-drillings in these carry a thin wire which runs between the supports and loops down underneath the base, where a turnbuckle applies tension. At exactly one third of the distance across the span, a wire is attached to hang vertically, supporting a small brass weight. An identical pendulum is hung at one third of the span from the opposite support.

One pendulum is set swinging. Within a few seconds, the second pendulum starts to move. No real surprise there, and very soon both weights are swinging with equal amplitude and 180° out of phase.

And then a miracle seems to occur.

The oscillation of the first pendulum will rapidly decay until it comes to a complete halt. Meanwhile, that of the second continues to increase until it is swinging at full amplitude. Then, after a second or two, the first pendulum starts to move again, slowly increasing its swing until once more both are swinging equally. Then the second one slows and stops, while the first reaches full amplitude. And so on, until friction, heat losses, stray capacitance, what have you, sap the energy from both pendula.

The brain refuses to believe until several cycles force it to accept what it sees. After that, the motion of the bright shiny things is quite hypnotic. It makes an excellent desktop diversion for busy executive and dilettante timewaster alike.