Perpetual motion

[ozi-rock]

Hi i was just wondering if you had a wheel with a single magnet, inside a frame of electromagnets which were powered by a battery and you had it set up that as soon as the magnet on the wheel reached an electromagnet it turned off and the next electromagnet along turned on.
If you had a generator connected to the wheel could the wheel continue to spin for longer than the battery would normally permit? or would the power needed to charge the battery put too much pressure on the wheel and thus it would not spin?
I am just a beginner to the idea of perpetual motion so please to kill me for asking, i know this would not generate power to go forever and i know it would never provide power for anything else

[lemit]

I hope I'm not repeating other posts. As usual, I got too excited about this to take the time to read the whole thread.

I think many of us think now in enhanced terms of entropy and depletion of energy sources. I think the original concept of perpetual motion was exactly what the name says: a machine capable of maintaining motion in perpetuity (or at least past our own lifetimes).

Another limit is that we tend to think on the level of the pecking bird or the swinging balls (a phrase I thought I'd never have reason to write).

I have two questions: could a non-repetetive perpetual motion machine--even if not workable--be conceived, and is there any way to overcome the problem of friction?

Once again, energy regeneration is not necessary. Also, in both questions I'm looking for the possibility of success, not the certainty, which might be a pretty tough barrier. I want to start a discussion.

Any takers?

--lemit

[freeztar]

Originally Posted by lemit

I have two questions: could a non-repetetive perpetual motion machine--even if not workable--be conceived

Yes!
It is entirely possible to conceive of a machine that has perpetual motion. Of course, this requires a bit of imagination and an abandonment of modern physics. See below...

Originally Posted by lemit

and is there any way to overcome the problem of friction?

Yes. You create a system in which the atoms traveling encounter no other atoms. Is this practically possible? No.

[TheBigDog]

Originally Posted by lemit

I hope I'm not repeating other posts. As usual, I got too excited about this to take the time to read the whole thread.

I think many of us think now in enhanced terms of entropy and depletion of energy sources. I think the original concept of perpetual motion was exactly what the name says: a machine capable of maintaining motion in perpetuity (or at least past our own lifetimes).

Another limit is that we tend to think on the level of the pecking bird or the swinging balls (a phrase I thought I'd never have reason to write).

I have two questions: could a non-repetetive perpetual motion machine--even if not workable--be conceived, and is there any way to overcome the problem of friction?

Once again, energy regeneration is not necessary. Also, in both questions I'm looking for the possibility of success, not the certainty, which might be a pretty tough barrier. I want to start a discussion.

Any takers?

--lemit

It needs to do more than just break even. It needs to exceed the resistance or it will eventually stop. And if it eventually stops it is not perpetual. I have even seen it stated that a true perpetual motion machine does not need to be started; it simply starts of its own accord because it has an excess of energy simply by being.

Bill

[Drewbeenius]

This is a great post! I appologize if my comment has been made previously. I was unable to read all 29 pages.

Could an isolated Hydrogen atom be considered a perpetual motion machine?
I understand that a real Hydrogen atom will interact with other matter, and thus we won't find this isolated atom in our universe. However, we can hopefully theorize and imagine here.

Or, will this isolated Hydrogen atom still occasionally release a photon? Would it eventually experience a cold collapse?
I really do not know. I am not a physicist, and I have not taken many courses in physics outside the "mechanics" type work for engineers.

Are there irreversible interactions between the electron and proton? If so, would an islolated proton (no electron) be a perpetual motion machine?
Here again, I understand that there is no practical application for such an entity.

[sanctus]

Just a quick answer to your last question since the proton seems also to have a finite lifetime I would say that this is already enough to not make it a perpetual motion machine.

[Pyrotex]

Well... I dunno. The question of the proton's half-life hasn't exactly been established beyond doubt. Last time I looked, the photochambers looking for proton "collapse" weren't seeing nearly as many flashes as predicted by theory.

If we are to avoid the implicit use of "infinity" in our discussion, what say we accept some value for "perpetual"?

If we accept a billion years, than a good sized planet in a circular orbit about a star makes a terrific perpetual motion machine (PMM). You can even extract energy from it for free! Which we do when we use a gravity sling-shot maneuver to speed up one of our deep space probes.

If we accept 15 billion years (life of the observed universe) then a spiral galaxy around a black hole would do nicely.

On the other hand, if we accept something smaller than, say, 1000 years, this might open up to engineering solutions.

[ozi-rock]

I am an engineering student and the idea of perpetual machines interests me, I understand that they will obviously degrade over time and are thus not perpetual but could it be possible to make something move by itself for even 100 years?

[Essay]

Welcome ozi-rock,

Sure it'd be possible to build something that moved for a hundred years--using a source of energy.

I thought the point of "perpetual motion" was to get more energy out, than you are putting in--which is why it won't work.

Is this the sort of 100-year motion that you want, or is it just something that'll keep moving--while it uses more energy than it produces?

[ozi-rock]

I was thinking of something that produced energy enough to keep moving even if it had no practical use.

Just worth mentioning, Alexander has pointed out a very interesting toy which is related in this thread:

http://hypography.com/forums/science...tml#post262327