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.-- egbert, Feb 14 2003 Not quite the same http://www.dwiarda....d/PendulaStart.htmlAnd not half as pretty [egbert, Oct 04 2004, last modified Oct 21 2004] In which direction do the pendulUMS swing? +-- FarmerJohn, Feb 14 2003 Sort of back and forth.
Sorry, couldn't resist. At right angles to the supporting wire, otherwise they'd hit each other.
Pendula is correct. Pendulums may be correct, too, for all I know. Is there a Guerrilla Pedant in the house?-- egbert, Feb 14 2003 Plectra, spectra, rostra, pendula. Works for me.-- angel, Feb 14 2003 Like "woik", "pendula" is popular here, but I can't find it in any dictionary.-- FarmerJohn, Feb 14 2003 I've found it on the net (link)-- egbert, Feb 14 2003 Dictionary.com has no entry for 'pendula', and gives the plural as 'pendulums', presumably because it's not actually a Latin word. The fact that it's obviously based on Latin leads me to suggest that it should follow Latin pluralization rules, but I'd hesitate to criticise the use of 'pendulums'.-- angel, Feb 14 2003 // I'd hesitate to criticise //
Is that some radical change of policy then ?-- 8th of 7, Feb 14 2003 //And then a miracle seems to occur.// Sorry, I can't erase this vision of a pendulating, miracle bra.-- FarmerJohn, Feb 14 2003 penduleyes-- thumbwax, Feb 14 2003 pendulize sounds like something don king would say.-- sambwiches, Feb 14 2003 I've heard of breasts referred to as pendula. Like in "Her pendulous breasts heaved and swayed as she breathed. . ."
Maybe the executive in American Psycho could have used women's breasts to make one of the devices you describe.-- brockbridges2, Feb 14 2003 I built one of these last week. Because some of my colleagues had advised me on materials, I took it into work to show them. There were many comments about things gently swaying, hanging, schwinging, what have you, the most common being along the lines of " Have you had a play with Ian's dangly bits yet? They're on his desk..."
This came as a bit of a surprise, since as it's intended for my dear old dad, my thought processes had been unusually smut-free throughout the whole design and build process.
Imagine My Surprise when the thoughts of my fellow bakers ran along similar lines. If this is the standard response, maybe I should consider if it's a fitting gift for a son to give his father...-- egbert, Feb 18 2003 Executive pudenda, perhaps?-- DrCurry, Feb 18 2003 If anyone's interested, I presented this gift to my father at the weekend, in front of the whole family. He seemed very well pleased, and I think I caught a glimpse of a tear in his eye. He has promised to give it pride of place. Although he didn't specify where.-- egbert, Mar 05 2003 Wow! Have you got any way of getting this on video?-- adr, May 29 2003 Well done, eggy. From ridiculous idea to baked in just a couple of weeks. Must be some sort of record. I hate executive toys, incidentally.-- DrBob, May 29 2003 random, halfbakery