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Infinite energy, true?

  1. Aug 22, 2009 #1
    if we take a magnet and put in space, now we take another magnet and start to revolve it around the first, the centrifugal force will make it try to push it out of the circular course we want it to stay but the magnetic force will pull it in a way that the two forces cancel each other, and because it is space therefore, frictionless, the magnet will revolve forever and we can make electricty all the time
     
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  3. Aug 22, 2009 #2

    ZapperZ

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    How do you propose to make this "electricity"?

    Zz.
     
  4. Aug 22, 2009 #3

    Dale

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  5. Aug 22, 2009 #4
    you place a metal cord between
     
  6. Aug 22, 2009 #5
  7. Aug 22, 2009 #6

    ZapperZ

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    Then you are forgetting Lenz's law, or are ignorant of it.

    Try this on your own. Take a coil of wire, connect the two ends to an ammeter.

    Now, try sliding a magnet through it. You'll find that you'll encounter a RESISTANCE against moving the magnet through the coil. Why? The induced current in the coil (your "electricity") will create its own magnetic field that OPPOSES the change in flux through the coil - Lenz's law! You will have to do work to generate that electricity!

    What this means is that once you try to harness your "spinning magnet", it will encounter a force that will oppose its motion!

    So where is your "infinite energy" now?

    Zz.
     
  8. Aug 22, 2009 #7
    So it is impossible in this universe to create free energy?
     
  9. Aug 22, 2009 #8

    Pengwuino

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    Only if you steal it from God :biggrin:

    aka yes.
     
  10. Aug 22, 2009 #9
    but a magnet has two poles, shouldn't it repel the other magnet at some point? and wouldn't it take centripetal force to keep it revolved?
     
  11. Aug 22, 2009 #10
    that is why i am asking
     
  12. Aug 22, 2009 #11

    Dale

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    Yes: energy is always conserved in electromagnetism.
     
  13. Aug 22, 2009 #12

    ZapperZ

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    Your original post:

    I see no "asking" here.

    In any case, I believe this has been sufficiently addressed.

    Zz.
     
  14. Aug 23, 2009 #13
    A dynamo apposes motion...yes it's true, but in ideal situations considering on friction, a dynamo will appose this motion, and convert this very rotary K.E to electrical energy...so your arrangement will stop someday.
     
  15. Aug 27, 2009 #14
    Well, I don't know much about Lenz's law, but I do know that in a frictionless system things will move "perpetually" but once you try to draw energy from it friction is applied because of the generator apparatus or some other thing that you use.
     
  16. Aug 28, 2009 #15
    Your idea is good up to a certain point. In total resistance free environment, perpetual motion is possible, however to extract energy you need to introduce some sort of coupling to another system, which will introduce a resistance.

    An equivalent fallacy would be: We can extract potential energy form a mass located at a high position by letting it fall to the ground. Now If I put a heavy rock on a mountain, its position will always be high, therefore we have free energy, if we simply find some way of extracting it.... which ofcause doesn't actually relie on moving the rock.

    In Denmark, a "inventor" entered and competed in TV on a show called something like Danish best inventions, with a system like this. By confusing the judges with a clever sheme of using the boyancy of a bowling ball to lift it upwards. Needless to say, he didn't get far, but it was quite entertaining.

    Most laymen are quick to discard the notion of such mechanical free energy devices, but if you add into the description som electromagnatism it's pretty easy to fool them. I once convinced a friend that superconductors could generate free energy, and he belived me simply because of the argument: "How else would they float in mid air?". Most the times, human resoning isn't that strong, that's why you need to do the math.
     
  17. Aug 28, 2009 #16
    Yup. Not to mention, I've noticed that the pursuing of perpetual motion machines is mostly by those who are at times ignorant of the most simple laws of physics. Which, really, is the only reason why they try...
     
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