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I Can we mimic a perpetual motion machien?

  1. Nov 30, 2016 #1
    Good day to all!

    I read a small article in MIT's engineering.edu page. The article talks about perpetual motion machines, it says that we cannot create one, but we can mimic it.
    My question is: how can we mimic this perpetual motion machine? Has it been mimicked before? And if yes, how?
    I hope you can help me answering these questions.
    Thank you!

    Oh! The article I read was this:
    http://engineering.mit.edu/ask/it-possible-construct-perpetual-motion-machine [Broken]
     
    Last edited by a moderator: May 8, 2017
  2. jcsd
  3. Nov 30, 2016 #2

    Ibix

    User Avatar
    Science Advisor

    All he means is that we can build things that take a long time to stop whatever motion they are supposed to do. A pendulum that will stop swinging in seconds if left to its own devices can run for a week off the energy stored in a spring or a lifted weight.
     
  4. Nov 30, 2016 #3

    jedishrfu

    Staff: Mentor

    Or a Foucault pendulum may appear to some as a perpetual motion device until you understand how it works:

    https://en.wikipedia.org/wiki/Foucault_pendulum

    Please note that some of these pendulums may have motors to keep them in motion to counter air resistance:
     
  5. Nov 30, 2016 #4
    Has it been mimicked with electromagnetism or some mechanism that uses magnets?
     
  6. Nov 30, 2016 #5

    jedishrfu

    Staff: Mentor

    I imagine you could hook up the motor to a solar panel and keep it recharged enough to run for a very long time which would be an approximation to perpetual motion.

    If the system does some kind of work (moves against a frictional force as an example) then it will lose energy unless its replenished externally and that's why perpetual motion machines can't exist in nature (see link and quote below).

    https://en.wikipedia.org/wiki/Perpetual_motion

     
  7. Nov 30, 2016 #6

    DrClaude

    User Avatar

    Staff: Mentor

    The answer in given in the article:
     
  8. Nov 30, 2016 #7
    Thank you for all the fast replies!!
     
  9. Nov 30, 2016 #8

    jedishrfu

    Staff: Mentor

    Thanks for all the responses so far, I think we have answered the OP's original question and now we can close this thread before perpetual motion can take over the discussion.

    -- Jedi
     
  10. Nov 30, 2016 #9

    Ibix

    User Avatar
    Science Advisor

    You forgot to lock it, so I'm just going to repeat the OP word for word and see what happens... :wink:
     
  11. Nov 30, 2016 #10

    jedishrfu

    Staff: Mentor

    Closed now so as not to perpetuate the perpetual motion notion for another cycle of posts...
     
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