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Gravity and Permanent Magnetism as energy sources

  1. Jan 7, 2009 #1
    I'm an IT person - non-scientist - but this problem has challenged me ever since high school physics:

    If two permanent magnets - pole to like pole - repel each other, the magnet suspended possesses potential energy. If a material can be found (that is non-magnetic and without any power source) that can disrupt the magnetic lines of force between the two magnets to where the magnets' separation decreases, then gravity would be providing the second source of energy (kinetic energy). You would basically have a new form of motor. Would it really be considered a perpetual motion device since gravitity and magnetism are both supplying energy?

    It seems like new materials are being developed everyday. I just read about pyrolytic carbon and diamagnetism. Has something (not yet tried) been developed recently that can address this question? Is it just not feasible?
  2. jcsd
  3. Jan 7, 2009 #2


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    Similarly if a material could be found that blocked gravity you could make a perpetual motion machine with a pulley. That rather suggests such a material is impossible.

    ps. This thread will get locked now, we don't allow discussion of perpetual motion machines since it tends to bring out the cranks.
    Nothing personal and please don't feel got-at!
  4. Jan 7, 2009 #3
    No offense. Like I said I'm no scientist. I just read about frogs suspended in strong magnetic fields and superconductivity where a current can last nearly forever, and wondered - No one would have believed these events possible in the past - so what else is possible. Einstien mentioned it's impossible to go faster than the speed of light, but it doesn't stop people from trying to find ways to do it. Science is always full of new surprises.
  5. Jan 7, 2009 #4


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    Since nobody has locked it yet ....
    Magnets are weird (even to people who are supposed to understand them) so are a prime topic of crackpottery, gyroscopes are the other!

    Suspending a frog above a magnet is the same as suspending a frog on a shelf, you put the energy in by lifting it up there - there is no magnet energy holding it.
    The frog doesn't spin naturally you have to give it a nudge.

    Actually the frog on a magnet is breakthrough in theoretical physics - it was calculated 150years ago that you couldn't do it without spinning the frog (it would fall out of the field) then it was actually tried and you can do it with a stationary frog. It turns out the moving charges inside the fluids inside a frog are enough, this led to a bunch of new discoveries!
  6. Jan 7, 2009 #5

    Andrew Mason

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    This is a common misconception (as mgb_phys points out) that has been the basis of many perpetual motion machines. A fellow named Richard Willis was hawking his machine on the CBC Dragon's Den program and a dragon (Brett Wilson, originally an engineer!) actually offered him a million dollars for it if it worked. No chance he will lose his million. See http://www.cbc.ca/dragonsden/pitches/magnacoasters.html".

    The http://pesn.com/2007/02/18/9500457_Perendev_update/" [Broken] is the classic case. It is a similar fraud. The principle is just as you described - he has a device that shields magnetism. The problem is that you cannot block magnetic field without using energy. Anyone who tells you otherwise is a fraud or a fool or both. Many people have lost a lot of money investing in this motor.

    Last edited by a moderator: May 3, 2017
  7. Jan 7, 2009 #6


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    Welcome to the PF, exwso2001. Discussions about perpetual motion machines are not permitted here, so I'm going to have to lock this thread. Hope your questions were answered.
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