OT: Slinky Question

That's a nifty concept!

not if the escalator is going down :)

or if it's going up too quickly

Or turned off, or moving too slowly.

Lots of variable left out Jim. I sort of remember you complaining about people doing that with your classroom tests here. 8o)

Indeed, you'd need to frequency-match the slinky and escalator.

Tim

It's a question "for discussion" ;-)

...Jim Thompson

I think that's the trick, John... synchronizing. Although I puzzle over the situation where the up-rate of the escalator exactly matches the falling period... seems to be some energy violation there that I can't put my finger on.

(This question didn't originate with me. A woman called in to a local talk radio show yesterday with the question, and I've been mulling over it ever since :-)

...Jim Thompson

What's the matter there Paul? Got your panty-hose in a twist ?:-)

...Jim Thompson

I read in sci.electronics.design that Jim Thompson wrote (in ) about 'OT: Slinky Question', on Sat, 6 Mar 2004:

Yes. Someone has done this at a London Underground station. With lots of Slinkys. I forget what they charged him with. Excessive smart-artistry, perhaps.

More of a "thought-provoking metaphysical conundrum" IMV. :-)

The slinky or the escalator?

Don

Heat got to you already, huh?

Sit in the shade. Get an ice-cold beer and hold the bottle against your forehead. Try to think about glaciers.

John

: >>On Sat, 6 Mar 2004 13:23:31 -0500, "Bill Garber" : >> wrote: : [snip] : >>>Lots of variable left out Jim. I sort of : >>>remember you complaining about people doing : >>>that with your classroom tests here. 8o) : >>>

: >>

: >>It's a question "for discussion" ;-) : >

: >More of a "thought-provoking metaphysical conundrum" IMV. :-) : : What's the matter there Paul? Got your panty-hose in a twist ?:-)

Aw, leave Paul alone. He's not a bad guy. 8o)

BTW, the Slinky on the escalator bears a striking resemblance to the perpetual machine.

Bill @ GarberStreet Enterprizez };-) Web Site -

: >>On Sat, 06 Mar 2004 11:15:35 -0700, Jim Thompson : >> wrote: : >>

: >>>If you place a Slinky on an escalator, will it go forever ?:-) : >>

: >>not if the escalator is going down :) : >>

: >>or if it's going up too quickly : >--- : >Or if it's going up too slowly, so we'd need to servo the escalator to : >the slinky's period. : : I think that's the trick, John... synchronizing. Although I puzzle : over the situation where the up-rate of the escalator exactly matches : the falling period... seems to be some energy violation there that I : can't put my finger on.

Let's not forget that each Slinky will be slightly longer or shorter than another, slightly lighter or heavier as well.

: (This question didn't originate with me. A woman called in to a local : talk radio show yesterday with the question, and I've been mulling : over it ever since :-)

I've thought about this quite a number times thoughout my lifetime also, but I quickly realize that there are more important issues at hand. 8o)

Bill @ GarberStreet Enterprizez };-) Web Site -

I read in sci.electronics.design that Jim Thompson wrote (in ) about 'OT: Slinky Question', on Sat, 6 Mar 2004:

The untoppled Slinky has potential energy which, as it topples, is converted to kinetic. This applies an impulsive force on to the step below, so that the escalator is slowed momentarily by a minute amount. Part of the KE of the whole system is now stored as energy of elastic deformation in the toppled Slinky, and this energy is, through the design of the Slinky, recovered very efficiently to restore the untoppled state.

While the questioner's creativity is to be admired, that does remind me that a fool can ask a question in a minute that a wise man cannot answer in an hour. A wise woman, of course, would change the subject. (;-)

On Sat, 6 Mar 2004 13:23:31 -0500, "Bill Garber" Gave us:

Also it is a system that consumes about twenty thousand times more energy than it creates. The slinky doesn't need to "go forever", the escalator does. Send the electric bill to the OP.

On Sat, 06 Mar 2004 12:52:27 -0600, John Fields Gave us:

Start at the top with the escalator off. When the slinky reaches the bottom (near it), turn the escalator on, bring the slinky back to the top, and then turn it off again. No servo, just an on off button "server". Hehehe...

That's still a servo, hehehe...

Or too slowly.