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So, what is the law governing perpetual motion?

  1. Nov 17, 2003 #1
    If conservation of energy can be violated classically, a la perpetual motion machines, what is that basic process or law which supercedes it? I often hear of complex physical systems supposedly creating more energy than input, but never have seen a fundamental principle characteristic to them explained. Also, how come of the millions of widespread applications for conventional machinery, not one uses "perpetual motion." (No conspiracy theories, please.)
  2. jcsd
  3. Nov 17, 2003 #2


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    Am I missing something? Conservation of energy cannot be violated classically. What are you talking about?
  4. Nov 18, 2003 #3
    its called the second law of thermodynamics. and no..its not a conspiracy theory but says that entropy of the system+surrounding cannot decrease and has to increase.
  5. Nov 18, 2003 #4
    This is an opportunity for those who believe conservation of energy can be violated to explain, a la Occam's razor, the more fundamental argument underlying processes like perpetual motion or "free-energy" machines, rather than obfuscating such proof through Rube Goldberg contraptions.
  6. Nov 18, 2003 #5
    i am sorry. i dont understand whether u have a doubt or making a claim. if u are claiming that perp motion machines exist and its "THEM" preventing us from reaping benefits...well...less said the better.
    half the failed contraptions in any patent office forget something simple. we dont make the rules. PR and technology dont go well together. for nature cant be fooled,
  7. Nov 18, 2003 #6


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    There are two types of perpetual motion. The one called type 1 violates the first law of thermodynamics, conservation of energy. The pertpetual motion is (supposed to be) created by outputing more energy than was put in.

    The type 2 perpetual motion is created by violating the second law of thermodynamics, nondecrease of entropy in closed systems. A machine of this type "runs without friction", so that even if it conserves energy, it can "run forever".

    Loren, a paysical method of breaking the first law is with negative mass. There's an easy way to create perpetual motion that makes unlimited amounts of energy out of a system with one negative mass and one positive one. I believe there's a demonstration on John Baez's site.
  8. Nov 18, 2003 #7


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    It appears to me that he simply has a misunderstanding.
    Just to be clear, conservation of energy cannot be violated (in a real, macroscopic device), perpetual motion machines do not exst, and there is no real-world theory/technology that would suggest they can exist. All of these machines/systems that you have heard about are either hoaxes, frauds, or misunderstandings (not by you).

    Yes, there is a lot of trash out there and it is very hard to see through the smoke and mirrors.
    Last edited: Nov 18, 2003
  9. Nov 18, 2003 #8
    Extraction of energy directly from space.

    Here is one man’s explanation;

    Drawings and explanations;

    The main page is here;

    Photos of an effect;

    The "N machine", as it is called has been around since the 1970's. I know why I am skeptical and I'd like to see some of the buffs here at PF check this thing out and comment on it, but I know that isn't what you are asking in this thread. Maybe you can find one answer to your orginal question through the links provided.
  10. Nov 18, 2003 #9
    Believing that simpler to understand makes better physics, I merely wish to challenge the perpetual motion people to provide the fundamentals behind their schemes more elegant and natural than the laws of thermodynamics. This application of Occam's razor to debunk the theory behind perpetual motion, rather than attacking its machines, has not been extensively explored to my knowledge.
  11. Nov 19, 2003 #10
    I think that is an interesting take. I know of one theory, the only I veiw as an actual possibility, but it is not simple, in fact he rambles on and on for pages, and many of his papers say pretty much the same thing as his others:
    He's not much to look at, but he has good credentials, if they're not made up. And of course he is selling books.
  12. Nov 19, 2003 #11


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    The US Patent & Trademark Office has the simplest and most elegant policy on perpetual motion machines: simply set up your machine in the lobby of the USPTO office and turn it on, and if its still running in a year, they will review your patent application. No one has yet risen to this challenge.

    One man sued to have his patent application reviewed. He won, and the court selected an independent lab to test his device. Surprise, surprise, he refused to submit the device for testing. Of course that begs the question - did he know his device didn't work and it was all just a publicity stunt bluff?

    The problem with discussing the "theory of perpetual motion" is that there is no such theory. None of these devices are grounded in real science.
  13. Nov 19, 2003 #12
    It doesn't have to be real science to be a theory, it has to be real science to be a good theory. I posted a link to a theory. He has claims, a patent, and suggest many do the experiments. I will try. Some have, and got positive results. Some may have and got negative results, but didn't set up a website about it, so I wouldn't know. BTW russ, you can't leave that PWA forum for one second, Zero's being crazy and antisemitic and I just don't have the wit to combat him alone.
  14. Nov 19, 2003 #13
    no laws governing imagination

    perpetual motion was just a silly idea dreamed up by a physicist and supported by a couple prominent physicists useing numbers and equations to support his idea neglecting a basic law of the universe stating "for every action there is a reaction". perpetual motion exists only in the imagination. it's like winning the lottery without even buying a ticket.
  15. Nov 19, 2003 #14


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    Thats getting into definitions, but if something is a theory, it must be real science (and vice versa), ie follow the scientific method. Thats axiomatic - its the definition of a theory. It becomes a "theory" by following the scientific method.

    If it doesn't follow the scientific method to the point of becoming a theory, it could be an hypothesis, belief, speculation, idle daydream, etc. Just because it is a coherent idea written down does not make it a theory.

    To be a theory (by definition), an idea must:
    -be based on real data
    -make testable (falsifiable) predictions
    -be supported by the testable predictions

    To meet these criteria, you follow the scientific method:
    -gather data
    -form an hypothesis
    -test the hypothesis
    -form a conclusion (the theory) based on the test
    I haven't been there in several days. I'll check it out, but I'm not his babysitter...
    It isn't quite that bad, bblly. Originally, perpetual motion research is what led to the discovery of the 1st law of thermodynamics and the proof that perpetual motion is impossible. I can't remember who it was, but after trying to build a self-powered water-wheel, some guy came up with the idea of conservation of energy.
  16. Nov 22, 2003 #15
    the reason why no one uses perpetual motion machines is because no one is smart enough to figgure them out. the one thing i hate about this particular subject is people saying its impossible. when its completely possible, although not plausable. i had tried designing a machine for such a task, and in my head it worked. i would have built it but i didn't have the money or tools to do so. where am i going with this? i dunno thats just my 2 bits.
  17. Nov 29, 2003 #16
    As an engineer, I can assume (even can to do offers) the mechanism with efficiency close to 1. But no more.
    At a level of particles and atoms we see the same effect. They exist due to constant mutual regeneration (radiation – absorption).
  18. Dec 23, 2003 #17
    I apologize Loren. I have insufficiently deeply penetrated into essence of your thread. Now I can tell, that I see in this question very deep sense. Certainly, energy of the universe is not determined by initial energy from BB. I do not doubt, that an energy source of the universe serves the permanent oscillator. It works in extremely economic discrete mode. A secret that all real processes occur in current Planck Time only. Due to integrating digital- analog transformation we perceive these processes as continuous. In this sense perpetual motion really exists.
  19. Dec 23, 2003 #18


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    That doesn't imply to you that they may in fact be impossible? The scientist who discovered (postulated?) the 1st law of thermodynamics did so after failing to get a perpetual motion machine to work. Instead of going on to the next idea, he looked for (and found) a scientific explanation for his failure.
  20. Dec 24, 2003 #19
    I don't see why he came up with a whole theorem about it, it didn't work because it was a bad idea. I have seen many designs which were just comical and stupid. Many though were thoought provoking just because it is hard to see why they won't work, and some are just interesting to look at, like M.C. Escher's (mispell?) stuff. I have several designs that seem like they'll work, so in my free time I investigate them to see why they don't. And of course there have been no successes yet. :)
  21. Dec 24, 2003 #20
    I can explain perpetual motion

    By perperual motion I refer to for instance the moon circling aroun the earth since it's a motion that never stops(this assumes the system is isolated).I'm not addressing the type of machine that has more energy outcome then it has input.
    Here is how it works:
    Assume one object is in equilibrium state thus it performs no motion. If you want to pull it out of there you have to invest some force F>0. That force will put the object in motion. Since positive force causes positive displacement and positive distance from the equilibrium cause force reduction the object will reach maximum distance D>0 when the force will drop to zero. But since D>0 => dF<0 so the force will continue to drop until it becomes -F. At that time D=0. But since F<0 => dD<0 so the distance will drop until it reach -D. At that time F=0. Now since D<0 => dF>0 until the force become F again. At that time D=0 so the initial position has repeated and all the motion begins from the start. This is an ciclic structure. It seems like the product FD=const thus FdD=-DdF>0. Here is a table of coresponding values:
    F: f; 0; -f; 0; f; same as F=f*cos(angle)
    D: 0; d; 0; -d; 0; same as D=d*sin(angle)

    That's it.
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