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My Perpetual Motion - Would it work?

  1. Jul 19, 2011 #1
    I think of some pretty crazy ideas when I'm half asleep.

    I keep a notebook and pencil by my bed, randomly wake up and write jibberish down. Sometimes great ideas, but most of the time crazy nonsense that I have to wonder what the hell I was thinking, even though they seemed like the greatest ideas in the world at the time.

    Well anyways, I had this idea while sleeping one night, woke up half awake and wrote it down. Now, I'll be pretty honest here... I don't know just a whole lot about Physics. So, I figure it'd be a good idea to ask some people that do...

    (recreated in Photoshop exactly as written while half asleep)
    [PLAIN]http://i.min.us/icbBhq.png [Broken]

    Right, so. There's my idea. Basically discs with magnets attached like cogs, angled to direct their magnetic force at one another in opposing directions to cause one another to spin on opposite directions, further perpetuating the other's spinning and thus creating perpetual motion.

    The power created from it would be like an alternator. The kinetic energy/friction created from the magnets would create energy and then it would be stored and whatnot.

    An alternative concept would be hollow discs with a strong magnetically charged liquid metal running through them, opposite directions in each disc, the magnetic force hopefully causing the other to spin even faster.

    So yeah, would it work? If not, could you explain why?

    I imagine I'm not the first one to have the idea of putting opposing magnetic forces to work against one another. So, there must be something I'm missing.

    I know that the magnetic force in magnets is created by an electrical current passing through them, so maybe that's the hang up? Does it take too much electrical energy to pass through them to maintain a strong magnetic force, so it would be inefficient and use more energy than it creates?

    My thought was that maybe it would require an initial jolt, but once they got going, they could go with relatively no other help and would be a renewable energy, even if not a true perpetual motion.

    If anyone could explain, I would greatly appreciate it.
    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Jul 19, 2011 #2


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    Your picture doesn't show up. However, the "angle" at which you have magnets will not affect the magnetic force they apply to other magnets- and you seem to be neglecting the attraction to stationary magnets the moving magnets have just passed which will slow the motion.
  4. Jul 19, 2011 #3
    Running a current through an electromagnet to create kinetic energy is pretty much what an electric motor does. As you said though, that requires energy to do. If you have to use electromagnets you would essentially just be creating an electric motor (assuming the design is valid).

    I don't think your cogwheel design will work the way you think it will, even if you use permanent bar magnets so that you don't require electrical energy to pass a current through the whole thing. Remember, bar magnets don't just repel/attrack magnets that are directly in line with them. If I lay out some magnets as below (sorry for the crudeness): magnet 2 is going to repel magnet 3 (which is what your design is based on) but it's also going to repel magnet 1 just as much, even though they're not directly in line.

    ...........\S\ (1)

    (3) [S N]....[N S] (2)

    My intuition is that the way you angle the cogs will actually have very little effect at all. Each magnet will still attract/repel all the magnets on the other cog, and while it will vary in strength based on distance, I'm pretty sure that it will mostly, if not completely, balance out so that the magnets will generate very little force.
  5. Jul 19, 2011 #4
    Here's that image: http://i.min.us/icbBhq.png [Broken]
    Last edited by a moderator: May 5, 2017
  6. Jul 19, 2011 #5


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    It will not work. The force provided by the attraction of 2 magnets is then required to break those magnets apart again. Or in your case the energy used to push them together is equal to the energy you would get out of them repelling. Hence no net energy. Perpetual motion will NOT work, period. I suggest you don't even waste your time.
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