I've heard and seen many different theories on perpetual motion. All of the devices I've seen do not work (obviously). In any event, I'd like to know if any one here thinks that perpetual motion is possible (or not) and they think so. Is it a matter of time before someone creates a device and proves everything wrong? Does such a device exist but scientists and government officials refuse to acknoledge it? What would happen if the world was introduced to a perpetual motion device?

If by perpetual you mean "as perpetual as the universe is" then I would say yes. It is possible. For example, tidal generators using the moons orbit are already in service. Not to mention solar power and wind generators.

The perpetual motion devices you talk of need greater definition by you for any one to answer you question more thoroughly.

"There's no such thing as a free lunch."

This is basically what the second law of thermodynamics says. One consequence is that it is impossible to build a machine which produces more energy than is needed to run it.

This does not rule out all perpetual motion - only perpetual motion which claims to produce excess energy. For example, you might think of the motion of an electron around a hydrogen nucleus as perpetual motion. However, the energy of the electron is constant. You can't extract energy from this system without altering the electron's motion and reducing the overall energy.

@James R
Hum,
Would that be a perpetual flow of `energy` from high to low entropy?

(and bearing in mind the Heidelberg uncertainty principle, er, or not, in a heat death ending)

It not impossible, but for humans yes

If this perpetual motion were to create energy in the process then, by our physics today, it is impossible. This is so because it would mean we would have to rewrite thermodynamics theory which has worked exceptionally well so far!

First law of thermodynamics: conservation of energy. You can't get out of a process more energy than is put in. That's why such things as tidal generators, wind, and solar power generators work- you are accessing energy already in those. Although, I disagree with Quantum Quack's "as perpetual as the universe is". The earth itself isn't going to last that long!

Second law of thermodynamics: there's always friction. In any real machine you aren't going to get as much energy out as you put in. Any machine will eventually wear out.

(One of my favorites: a wheel with "weights" on the circumference. On one side the weights were marked "9" (pounds) but when they got around to the other side they were turned over and so read "6". Of course, the wheel always turned toward the side with the heavier weights!"

(One of my favorites: a wheel with "weights" on the circumference. On one side the weights were marked "9" (pounds) but when they got around to the other side they were turned over and so read "6". Of course, the wheel always turned toward the side with the heavier weights!"

Now that's funny :D

This does not rule out all perpetual motion - only perpetual motion which claims to produce excess energy. For example, you might think of the motion of an electron around a hydrogen nucleus as perpetual motion. However, the energy of the electron is constant. You can't extract energy from this system without altering the electron's motion and reducing the overall energy.
The electron isn't really in motion around the hydrogen nucleus, except in some kind of planetary, pre-quantum model. There is simply a wave of probability in the area around the nucleus.

It is impossible to build a machine that continues to display motion, unless an external source of energy powers it. No self-contained unit can function forever, since it would eventually use up all of the energy that is powering it. This isn't a government conspiracy, but a basic rule of physics.

No self-contained unit can function forever, since it would eventually use up all of the energy that is powering it. This isn't a government conspiracy, but a basic rule of physics.

I would extend this a little by adding that according to our current understanding of physics.

I would be very surprised to see us using the same laws 100 years from now.

I would extend this a little by adding that according to our current understanding of physics.

I would be very surprised to see us using the same laws 100 years from now.

Conservation laws correspond to symmetries in the universe, from Noether's theorem. Conservation of energy implies and is implied by the laws of physics not changing over time.

Current measurements show the fine structure constant changing by less than about a part in 10^15 per year.

based on measurements taken over a 200 odd year span of time most of which are considerably more recent. Is this time span of measurements sufficient to inspire confidence in the interpretation of those measurements. Given the age of the universe?

For example the universe may appear to be stable at present thus giving us these laws. But was it or will it remain this stable so as to allow us to write these laws?

An electric perpetume mobile?

Put an anode and a cathode parallel in a vacuum tube, only microns apart. The anode is made of material that emits electrons very easily. The cathode is made of material that resists to emitting electrons. So the escaping electrons of the anode are caught by the cathode and not the other way around. When you short circuit it with a resistor, an electrical current should flow, producing electrical power. But where did the energy come from?

isn't a photon in perpetual motion?

actually I argued this point a while back dealing with curved space ......if you fired a laser towards the front of you and it avoided hitting anything it would eventually hit you on the back of the head.

Sounds absurd doesn't it

Brandon9000:

The electron isn't really in motion around the hydrogen nucleus...

Well, the electron has non-zero momentum and kinetic energy, so I'd say that means it is in motion. I agree with you that it doesn't orbit like a planet.

Two points:

1 - Most people misapply the term "Perpetual Motion". Perpetual Motion by definition is not possible. Perpetual Motion has nothing to do with extraction of power. It is a machine set in motion that remains in motion without external energy applied. In theory a perfect machine with no losses of any kind could meet that definition but would never be able to generate external energy without rapidly running down.

2 - Machines that do not need to be set in motion or that produce energy output, even perpetually are not perpetual motion. They would by necessity have to have a source of external energy, even an atypical or unknown one,

i.e. - Should a gravity device actually operate and produce power it would not be perpetual even though it might run for as long as the universe continues to operate. It would have an unknown external energy input and hence would not be "By Definition" perpetual motion.

so by definition perpetual motion is impossible simply by definition.

In other words if yo have a device in mind then what ever you do don't call it a perpetual motion device becasue what you are calling it is impossible.

Why do we use this word perpetual in the first place I wonder?

so by definition perpetual motion is impossible simply by definition.

In other words if yo have a device in mind then what ever you do don't call it a perpetual motion device becasue what you are calling it is impossible.

Why do we use this word perpetual in the first place I wonder?

Actually I have to back pedal just a bit. The following are two typical definitions.

************************************************** ***
1 - Noun 1. perpetual motion - motion that continues indefinitely without any external source of energy; impossible in practice because of friction
motion - a state of change; "they were in a state of steady motion"

2 - Definition: [n] a machine that can continue to do work indefinitely without drawing energy from some external source; impossible under the law of conservation of energy
************************************************** ***

It seems when you say simply "Perpetual Motion" The definition is as #1 above but if you say "Perpetual Motion Machine" they use the #2 definition.

so even if you constructed a machine entirely made of fixed magnets it would fail in that it could be argued that the magnetic field is generated by external sources ( at quantumm levels etc )

of even the creation of a machine theat depends on the ambience by default would fail as well

energy vs no energy......

so even if you constructed a machine entirely made of fixed magnets it would fail in that it could be argued that the magnetic field is generated by external sources ( at quantumm levels etc )

of even the creation of a machine theat depends on the ambience by default would fail as well

energy vs no energy......

Correct, by definition any machine that outputs energy cannot be perpetual, it would by necessity have an external energy source..

If energy cannot disappear then a transformation of an energy from one form to another (from a global view), is a perpetual motion.

Now we have to ask, if there is a state where energy cannot transform from one form to another.

If this state exists, then and only then a global point of view can be considered as a non-perpetual motion.

By QM the basic state of our universe is in perpetual motion because Plank constant h > 0.

If energy cannot disapeer then a tranformation of an energy from one form to another from a global view, is a perpetual motion.

That was my point. Most people see things this way but it really violates the definition of perpetual motion.

If U really wana know about a natural PMM that generates energy then instead of copypasting my post I offer U 2 read the following thread and specially my post. PMM Antagonism is dead with it.

http://www.sciforums.com/showthread.php?t=28836

Can U think about that ?

I've heard and seen many different theories on perpetual motion. All of the devices I've seen do not work (obviously). In any event, I'd like to know if any one here thinks that perpetual motion is possible (or not) and they think so. Is it a matter of time before someone creates a device and proves everything wrong? Does such a device exist but scientists and government officials refuse to acknoledge it? What would happen if the world was introduced to a perpetual motion device?

~~~High energy to low energy

~~~High pressure to low pressure

~~~High to lows...........

~~~differential of energy states

~~~Surplus of anything always flows to lack of

~~~When the states are equal, then the flow is no

~~~Energy flows to the path of least resistance

~~~You can never get more out of something than you put into it

~~~The idea of energy is simply the differential potential movement of matter/anti-matter.

RAW THINKER............you stole my idea about making sub threads. I had the idea a year or so ago. But I figured Porfiry would ban me if I did that.http://www.sciforums.com/images/smilies/mad.gif I was thinking about creating A complete Subforums within Sciforums......but didn't have the nerve to try ithttp://www.sciforums.com/images/smilies/confused.gif

one more to add to your list
a lot of a little can equal a little of a lot

If U really wana know about a natural PMM that generates energy then instead of copypasting my post I offer U 2 read the following thread and specially my post. PMM Antagonism is dead with it.
Can U think about that ?

You posted about a gravitational system with tides, objections and explanations were posted, and you basically ignored them. What's there to consider? Tapping into an energy reservoir is not perpetual motion. All you did was choose a large reservoir.

Not only do I think it is possible, I know it is. Look out the window and you see it all around you.

[

2 - Definition: [n] a machine that can continue to do work indefinitely without drawing energy from some external source; impossible under the law of conservation of energy ]


how about the superconductor rod spinning inside an earth magnet, perpetuated by low temperature in space?

Not only do I think it is possible, I know it is. Look out the window and you see it all around you.
Can you give an example of this please? I don't see it at all.

Can you give an example of this please? I don't see it at all.


headache doesnt mean to be rude by answering a question on somebody elses behalf, but i think the "gist" of it is that if you look around you, you are a witness to the ultimate perpetual machine.... that being the universe in all its highly questionable origin and destiny , and its equally questionable stability and sustainability in the face of the most outrageous improbabilityand irregularity....

And of course it ( the universe) stands as an extreme example of how our conservation laws are flawed.
Having been created seemingly spontaneously from Nothing.

So it is clear that our understanding at present is somewhat lacking.....This of course does not mean that what we understand is not of worth , only that we have to admit that there is a hell of a lot more to learn before we can make absolute statements about the validity of conservation laws and "the impossibility of PPM's"

headache doesnt mean to be rude by answering a question on somebody elses behalf, but i think the "gist" of it is that if you look around you, you are a witness to the ultimate perpetual machine.... that being the universe in all its highly questionable origin and destiny , and its equally questionable stability and sustainability in the face of the most outrageous improbabilityand irregularity....

Well....if the idea is that the earth is a pmm, then one should take into account that the fusion action in our sun, is responsible for virtually all the energy/matter conversion processes on the earth.

Is the sun a pmm? By most accounts, no.

Is the universe a pmm? Hell, I dunno.
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