Perpetual motion puzzles

[thefool]

Just for fun. Ill start it off.

Find the flaw

Look at the following scenario: When one side of the middle paddle heats up, a charge builds up in it, like in the sensor of a thermocouple. This then makes the paddle spin because of the stactic charge in the orbs. Now once again, the paddle will give energy to the one side while taking it away from the other. The paddle will only spin when it has the opportunity to transfer energy.


point #1 - there will be instances when hot molecules from the cold side add energy to the paddle
point #2 - there will be instances when cold molecules from the hot side reduce the energy of the paddle.
point #3 - this will change the "polarity" of the bar
point #4 - this will cause the bar to spin towards the fixed poles
point #5 - there will be an instance where a cold molecule on the hot side will take away energy from the bar. This will take away energy effectively from the cold side. The inverse is also true.

In all other instances, the bar simply wont move.

For this example the left side is the cold side and the right side is the hot side. As you can see although they start at the same temperature, they quickly become separated.

Pictures to make this make sense




i have a couple more once you guys figure this one out.

[Pneumagger]

Your picture is confusing as hell. Is it like one pic, or a pic of multiple scenarios? Could you label it or something?

Anyways, based on the fact that I have no clue whats happening all, I'll wager some guesses.


Eventually the heat would balance out to a uniform temperature throughout, and any motion would stop.

[thefool]

its several steps. Look closely at the pictures you'll see the differences. Blue means cold, red means hot, its obviously a gross simplifiaction.

[Pneumagger]

how would the "cold" side of the paddle ever heat up? Heat flows from cold to hot... always.

[y0da900]

how would the "cold" side of the paddle ever heat up? Heat flows from cold to hot... always.

Is AO in drastic need of a dodgey, or did you bomb thermo with flying colors?

[Pneumagger]

LOL, I wrote that backwards... but same argument - just a typo. I'll leave that one cause it's pretty funny.

Corrected:
how would the "cold" side of the paddle ever heat up more than the hot side to flip? Heat flows from hot to cold. So once the temperature equalizes, it would remain a constant temp.

[Pyrate Jim]

Entropy will assure that all the molecules achieve a unform temperature, but the conservation of energy will not allow you to "add" or "take away" energy from the paddle.

[PumpPlayer]

Well the main flaw is that you're using a heat engine with assumed "bottomless" temperature wells.

In any heat engine, the net transfer of energy will be from your hot source to your cold sink. Along the way, entropy is going to do its evil work and you're going to lose energy. There's just no way around it. Well, actually, there IS a way around it but you'd have to have your cold sink at absolute zero. Assuming you can do THAT, then yeah it's possible.

My buddy Carnot says bollocks on your engine and we're not even out of chapter two in the thermo book yet.
Rc = (Th-Tc)/Th

[SlartyBartFast]

No such thing as a perpetual motion "puzzle".

If you think it will work, you're just deluding yourself and ignoring a few dozen (or more) places where losses will occur.

And the biggest flaw I can see starts with point one. How can there be "hot molecules" on the "cold side"?

[thefool]

because temperature is a function of averages. It basically sets up a bell curve around a particular point in energy.

This is a puzzle because you have to find the flaw, not point to a textbook for answers that are for a different question.

This is supposed to be a mock version of a maxwell's demon. There is a flaw, in that in the amount of time it takes to turn, the charge of the rod will have already switched many many times leading to no rotation.

Thats the type of thing i was looking for, ill post up another one tommarow.

[Lenny]

Ouch. My head hurts.

[1337caesar]

i think i get it but i dont see the application to maxwell's demon. would you clarify it please?

[Warwitch]

because temperature is a function of averages. It basically sets up a bell curve around a particular point in energy.

This is a puzzle because you have to find the flaw, not point to a textbook for answers that are for a different question.

This is supposed to be a mock version of a maxwell's demon. There is a flaw, in that in the amount of time it takes to turn, the charge of the rod will have already switched many many times leading to no rotation.

Thats the type of thing i was looking for, ill post up another one tommarow.

See, thats exactly what I was going to say.........