I have a model for perpetual energy which I came up with several years ago and I’ve told to various people, all of
whom have told me that it doesn’t work for various reasons. I’m submitting it to the SDMB to see what people
think and to see if I can convince anyone that it works. One request: if you tell me it doesn’t work, don’t say that because
of the law of the conservation of energy because that would be circular reasoning.
My model, in one form (there are several ways which would work) is a cylindar. Its diameter is bigger than
its width, and it’s set on an axle. It is waterproof, and there is a liquid, say water, inside. Radiating from the axle,
inside the cylandar, are several sheets (described later) going from the axle to the edge, stretching between the walls.
What this device takes advatage of is brownian motion. Robert Brown noticed that if you put pollen grains in still water and look at them under a microscope, they move around. Molecules of any substance are always in motion, due to the thermal (temperature) energy. Every once in a while, a group of molecules the size of a pollen grain happen to be going in the same direction at the same time. These groups account for the motion of the pollen grains. So basically the thermal energy is kinetic (motion) energy, only competely unorganized. What I’m doing is taking that energy and focusing it.
The sheets that make up the “spokes” of the cylandar let the groups of water molecules go one way but block it the other way. I would do this by first starting of with something like a screen, except the holes in it are on the order of the size of a pollen grain (or even smaller). Inside each hole, there is some kind of valve that lets the water flow one way but blocks it the other way. The groups of molecules are going in all directions about equally.
What happens is that the groups apply a force on one side of the sheet, and they go through without transferring much of their energy. Likewise, an equal force is applied on the other side, and all of that energy is tranferred to the sheet. The two forces give a net force that pushes it away from the side that recieves the extra molecules. The extra molecules don’t make the pressure build up and the process stop, though, becuase they are let out throgh the next
sheet, etc. around the circle.
Obviously, they key to this is the sheet. It involves mass production on a microscopic scale, which is impossible or very expensive. There has actually been one experiment that I know of to harness brownian motion, but that failed for a stupid reason not related to the concept (that was in Science News a couple of years ago, and unfortunately I don’t remember the exact date, but I’m gonna try to look in my collection when I get home in a couple of days).
I’m thinking that this machine is not actually a perpetual motion machine but a refrigeration device. This makes me violate the second law of thermodynamics (entropy always increases over time) instead of the conservation of energy. I’m not sure whether the friction would actually slow the molecules down though. If it does work as a
refrigeration device, it is almost as useful - if air conditioners and refrigerators could create electricity instead of consuming it, it would save a whole lot of energy.
Now that you all have brain hemmorages, I’d appreciate your comments.
The mysterious force you describe is not going to just occasionally point in the right direction, through your magic valve. The force is the energy of the motions of the molecules of the liquid medium. That force varies directly with the temperature of your liquid. The direction is not important.
Your valve has to entirely stop flow in one direction, and offer zero resistance in the other. Pretty specialized equipment, but lets not quibble. If the thing works at all, then the temperature on one side of the valve has to go up, every time one of the fast molecules gets through, and the temperature on the other side goes down. (Should we stop and deal with the fact that that by itself is a violation of the second law of thermodynamics? No? OK.)
As the temperature goes down, fewer and fewer molecules have the energy to pass through the magic gate. The pressure against which they have to flow goes up, too. (Pressure does apply through your magic gate, right?) In the case that your molecules are so efficiently bounced around that the temperature in the various chambers remains even constantly, you still have the problem that either the system looses energy to the surface of the membrane that does not pass molecules, or it cannot ever transfer its energy to anything. If it looses energy, it gets cool. Eventually, nothing moves. (All this ignores the fact that none of it works, mind you, just shows that if it did work, it would not do what you think it would.) If the system gains energy from outside, it is not perpetual motion. If it somehow cools itself, it must lose energy, and become cooler. Unless it is magic, of course, in which case it can do whatever you like.
Of course you could design a bunch of metal pieces which could be interlocked and arranged in a special way, so that if you set off a series of explosions, they would knock against each other, and ricochet back and forth in so complex a fashion that the entire bunch ended up moving at the same speed in the same direction, simultaneously recreating the arrangement that makes the explosions happen. Sound unlikely? It’s a car.
<P ALIGN=“CENTER”>Tris</P>
If I have not been able to see so far as others, it is because Giants were standing on my shoulders.
– ** Unknown **
So basically the tempurature on one side of the sheet is getting higher, while on the other side it is getting lower. But each chamber has one “in” side and one “out” side, so assuming all of the sheets are made the same it all balances out, and the tempurature remains constant.
David, the following is Science News search page for their site.
http://www.sciencenews.org/search.asp
David, no offense, but your plan has more holes in it than the Albert Hall. You can’t just dismiss facts like conservation of energy and thermodynamics as circular reasoning. If you want to leave them out of your system the burden of proof is on you to show that they have no effect on your invention. Tris also explained several other physical laws which would work against your plan. Personally, I hold by the same standard as the patent office; if you claim to know how to build a perpetual motion machine, I want to see a working model.
are you are trying to use heat to produce motion. If so ,as pointed out, thats how a car works, and most power plants. it is inhertantly inefficent according to thermodynamics laws.
lets take you magic paper and change it. make it very small and very light, lets say nutral boyany. could a shape be created that would allow the ‘magic sheet’ to be propelled on just shape alone (without the one way valve effect)?
the seeds you mention I believe works the same as puttng soap (i think you use soap) on the end of a toothpick. if you place the toothpick in water, it propells itself, mainly becauce the soap, as it comes off the toothpick and onto the surface ‘skin’ of the water, pushes the toothpick away.
Perpetual motion, eh?
What about an electric current flowing around a superconducting ring? I suppose the current would flow indefinitely in this perpetual motion machine of the third kind.
“If first you don’t succeed, try, try again…then quit, there’s no use in being a damn fool about it.” - W. C. Fields
I once though the superconducting ring would work, but my physicics teacher said that would be the same as a bar magnet being concidered the PMM of the 2nd kind (3rd??? see below)
for some reason electromagentic fields and atomic motion are exepmt form being PMMs.
also from what I recall
a PPM of the 1st time produced energy, a PPM of the second kind does not, but doesn’t stop either. what is thhe 3rd kind?
Snicker. Mmmph! HAW… Heehee.
I dunno what’s worse - arguing with fundamentalists or perpetual motion machine inventors? I can’t think of a better waste of time.
1st kind- a machine whose efficiency is greater than 100%, and this means the machine would do work with no supply of energy. (disallowed by first law of thermodynamics)
2nd kind- take heat from a sort of resevoir (such as a body of water) and convert it completely to work. Energy is conserved, but these are still disallowed by the second law of thermodynamics.
3rd kind- do no work, but continue in motion forever.
“If first you don’t succeed, try, try again…then quit, there’s no use in being a damn fool about it.” - W. C. Fields
Get a physics book and look up “Maxwell’s Demon”. Maxwell looked into this problem and in his explanation he postulated a “Demon” at the gate who would only let molecules of a certain kinetic energy through, very similar to your invention. However, he proved it couldn’t work. I don’t have the details here but he did not just say it violated the ban on perpetual motion, he showed why it would not work.
Aside from practical considerations, and I forget the specifics of Maxwell’s demon, I don’t see anything wrong with the device.
Unfortunately, practical considerations do make this unlikely to be useful:[ul][li]All you are doing is taking thermal energy out of the fluid and turning it into kinetic energy of the wheel.[]If you want to use that energy, the temperature of the fluid in the wheel drops.[]When it gets low enough, you will not have any brownian motion and your wheel will stop generating power.[/ul][/li]So, what do you need to do? Heat it up by burning something under it, and lo and behold you have an external combustion engine that cost bazillions of dollars to make because of the funky material of the semi-permeable membranes.
You have not built a perpetual motion machine, you have built an engine like any other known to science that takes heat and makes motion - and that’s assuming it isn’t impossible for some other practical reason which I’m not thinking of right now.
The difference between a car engine and this is that a car engine needs at least two different tempuratures to operate. If the tempurature outside of the piston was the same as the tempurature inside, the pressure would be exactly the same (besides whatever energy you put into it), and the piston wouldn’t move. My machine needs only one tempurature to work.
The difference between Maxwell’s Demon and this is that the demon actually knew the position of all of the molecules. When you operate the machine, you can’t tell the position of any particular particle.
People are saying that this is a PPM of the second kind, but what exactly is lowering the tempurature? All of the energy of the molecules striking the sheets either 1) is tranferred back to the molecules, basically they bounce off, or 2)is transferred to the sheet, which raises the tempurature, which raises the tempurature of the water, therefore the energy is conserved.
Nick, at least your getting variety
David: Firstly, conservation of energy is not a problem. You’re just converting heat into another form of energy. But it still wouldn’t work for at least 2 reasons:
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Friction. As you gain more and more energy from this machine the molecules inside it will spin faster and faster. (They will start spinning in the direction that they are allowed to flow) That’s basic conservation of momentum. The faster they flow the more friction will be generated as they go through the valves.
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You are assuming perfect valves. What usually happens in any perpetuum mobile is that any moving parts (in this case the valves) will heat up. Eventually this will cause them to stop functioning. Heat is just random motion, so if a simple valve gets hot enough it would just be randomly opening and closing and wouldn’t act as a valve any more.
[People are saying that this is a PPM of the second kind, but what exactly is lowering the tempurature? All of the energy of the molecules striking the sheets either 1) is tranferred back to the molecules, basically they bounce off, or 2)is transferred to the sheet, which raises the tempurature, which raises the tempurature of the water, therefore the energy is conserved.]
when a molecule passes through the ‘magic sheet’ no energy is transfered, when a molicule bounces off the other side, it inparts a small amount of its energy to the ‘magic sheet’ causing the ‘magic sheet’ to move a little. this motion causes the bouncing molecule to lose speed .: loose tempature.
I don’t think a fire has to be placed below and conduction/convection should bring heat in from the outside, but at a slower rate.
Also would all this controlled molecule bouncing reach a steady state with the ‘magic sheet’ moving one direction and the fluid moving the other?
Thanks for clearing up the PPM’s
Also I have heard the the US pattent office will accept PPM designs with a working model but they want the model started and just to make sure , they will only issue it if the machine doesn’t stop. Is there any truth to this, is there a building somewhere w/ a bunch of ppm machines running and someone has the job of waiting for then to stop?
Konrad, if the tempurature of the valves increases, the heat would just warm up the water a little bit, especially if the water is getting cooler.
David: That’s just a general case scenario that applies to the kind of engine you’re describing. It may or may not affect this particular example, depending on whether you let heat in or not. Don’t forget that the liquid circulating through the valves may be cold but will still heat up the valve through friction.
David, as I’m sure you realize, heat and motion are both caused by energy. So your system will start with a given amount of energy. The water and the sheets might start at the same or at different temperatures. It’s possible for heat to be transferred from one to the other. It’s also possible for heat to be transformed into motion and vice versa. But it’s not possible for one part of your system to transfer so much heat into another that the second part will then be able to transfer heat back into the first and raise its temperature back above its original temperature. You can’t have the water warming the sheets and then have the sheets warming the water.
If you have a closed system, and no energy is used for any other purpose, eventually everything in your system will have the same temperature. If anything in your system is moving, then that temperature will be lower than the total amount of heat you started with.
No, he didn’t prove it. It was an annoying hole in theoretical physics for some time. However, quantum theory shows that in order to see the molecules, the demon would need to possess a high-energy “light” (actually gamma rays) source, and that spoils the whole idea.
John W. Kennedy
“Compact is becoming contract; man only earns and pays.”
– Charles Williams