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This question already has an answer here:

I have been recently made aware of the following motor, which uses two magnets and a wheel to generate motion, and the creator of this machine claims that this motion is perpetual.

Here is a YouTube video demonstration of the motor in action: http://www.youtube.com/watch?v=m8-Kek8Halc

Of course, I know that a perpetual motion machine could not exist due to the First Law of Thermodynamics, however, I've been struggling to find an explanation on why this particular motor seems to run so flawlessly. Obviously, in the video, sounds and friction can be heard, so some energy exchange must be happening. Where is that energy coming from?

I've been told that this machine could not be perpetual due to the fact that magnets lose their magnetism over time. While this is true, I don't find this explanation satisfying, because if demagnetization over time was the only problem, then this machine could still probably run freely for months or years.

The video demonstration is very short, and I strongly suspect that this motor would stop running after a certain amount of time, possibly a few minutes or hours. So my question is why wouldn't it work? Why is it not perpetual? Certainly, the decay of magnetic properties of a magnet is not the only answer.

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marked as duplicate by Qmechanic Feb 22 '16 at 23:14

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • $\begingroup$ How did the "inventor" cheat as in... where is the battery or other power source? Buy the machine and take it apart. Oh... wait... it's not for sale, right? :-) $\endgroup$ – CuriousOne Feb 22 '16 at 23:07
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    $\begingroup$ Best test: Just leave it running for, ya know... 1000 hours or so? $\endgroup$ – Danu Feb 22 '16 at 23:13
  • $\begingroup$ Possible duplicates: physics.stackexchange.com/q/2167/2451 and links therein. $\endgroup$ – Qmechanic Feb 22 '16 at 23:14
  • $\begingroup$ It will not work because a perpetual motion machine would have to violate the 1st law of thermodynamics. In other words, it would actually create energy. $\endgroup$ – David White Feb 22 '16 at 23:15
  • $\begingroup$ I saw the other questions and links, but they involved several static magnets, which either attracted or repelled each other. I know why those machines don't work. This one is different in that it uses only one freely moving magnet, which is not attached to anything. The whole mechanism of the machine seems to boil down to some balance between magnetism and gravity, and I would like to know the mechanism of how and why it works (or doesn't work). $\endgroup$ – Biodome Feb 22 '16 at 23:42
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The Museum of Unworkable Devices should give you a few ideas. As they say, "There seems to be a thriving cottage industry of hobbyists making fake perpetual motion devices and posting videos on the internet."

They catalog many examples, with some analysis. For a fun evening or two, visit https://lockhaven.edu/~dsimanek/museum/unwork.htm

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    $\begingroup$ Hi, Peter. This is a link-only answer, which is discouraged because in the case of link rot, the information is lost. Can you edit in the relevant information from the link? Thanks. $\endgroup$ – HDE 226868 Feb 22 '16 at 23:15
  • $\begingroup$ So should I assume that the video demonstration is fake, i.e. it involves hidden strings, motors or something like that? I wanted to give the creator the benefit of the doubt and I assumed that it was not entirely fake, and that it was simply a machine that could run for at least a few minutes. The demonstration itself is fairly believable, and that's why I wanted to know why it seems to work, when it really shouldn't. $\endgroup$ – Biodome Feb 22 '16 at 23:53
  • $\begingroup$ @Biodome, If you read through the comments on the video, several have mentioned that there is a sound just before the wheel starts. It is consistent with an air device either in or hidden by the magnet holder. Yes, you should assume the video demonstration is entirely faked. $\endgroup$ – BowlOfRed Feb 23 '16 at 0:41

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