Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: thinhnghiem on 21/10/2014 06:58:56
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First of all, I would like to say that this model is NOT a perpetual motion. It will stop eventually. What I want to say here is that the output useful work seems to be greater than input energy
My system consists of 2 elements. Each element is a cylinder put on an axle. There are two permanent magnets stuck on each cylinder, with their north poles are faced outside. In the youtube clip that I will show you below, you can see the magnets of the first element are painted in blue, while those of the second one are crossed with X.
I turn the cylinders slightly so that the north poles of the magnets are faced each other. Then, the thrust between magnets make the cylinders rotate.
A single cylinder on an axle itself is not the system. It is an element of the system, which consists of 2 at all. Therefore, the thrust between magnets is not external force which affect system. It is comprehended as internal force between 2 elements of the system. The thrust from the first cylinder makes the second rotate, and the thrust from the second, in its turn, make the first rotate. Each component act as the cause to make the other rotate, and it acquires the affect from the other to rotate.
While the input work of the system originates from a small force making cylinders moving short arc, and make magnets facing each other, the output dynamic energy is much higher. You can see in the clip that both cylinders rotate many circles, which create output useful work much greater than the work to make the magnets facing each other.
Here is the link of my clip
Your comments are welcomed to determine that if energy conservation is violated in this case or not
Thanks
Thinh Nghiem from Vietnam
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It's a pretty toy, and nicely made.
Have you calculated or measured A the energy required to move the magnets from their rest position to the point at which they start moving by themselves?
Have you calculated or measured B the energy taken off from the system, or dispersed by the system through friction and atmospheric drag?
Unless B > A, you have not violated energy conservation.
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While the input work of the system originates from a small force making cylinders moving short arc, and make magnets facing each other, the output dynamic energy is much higher.
What do you mean by "output dynamic energy"? Also, what evidence do you have that this so-called "output dynamic energy" is much higher than the initial energy which was input?
The laws of electrodynamics and conservation of energy imply that your claim is wrong. Only nature can prove that law to be wrong.
Here's how the expression of the conservation of energy is derived in electrodynamics:
http://home.comcast.net/~peter.m.brown/em/poyntings_theorem.htm
Have you measured those quantities, i.e. the energy densities and the momentum flux?
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Hi all,
Unfortunately no. The limit of my experiment is that I made conclusion based on observation. This experiment is done by me, an amateur experimentalist, at home; not in a well equipped laboratory.
However, I simply make a assertion that I just use a small force to move the cylinders to go a short arc, while they rotate many rounds after that.
If I can improve my model to rotate longer, for example 10 minutes, you can see the different
Thanks for your feedback
Thinh Nghiem
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... Here is the link of my clip
Your comments are welcomed to determine that if energy conservation is violated in this case or not
The kinetic energy in the system is converted into stress/tension in the magnetic field, then back into kinetic energy, (aka movement).
The magnetic field is an invisible store of energy, like an invisible spring , which can give the false-impression that kinetic-energy (movement) is being created from nothing , (which would violate conservation of energy).
A similar device is the magnetic pendulum ...
[ BTW even if you could eliminate friction from your apparatus, which you can't , energy would be lost from it via eddy-currents (http://en.wikipedia.org/wiki/Eddy-currents) which will heat up the magnets , so it would not be in perpetual-motion (http://en.wikipedia.org/wiki/Perpetual-motion) ]
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Hi all,
Unfortunately no. The limit of my experiment is that I made conclusion based on observation. This experiment is done by me, an amateur experimentalist, at home; not in a well equipped laboratory.
However, I simply make a assertion that I just use a small force to move the cylinders to go a short arc, while they rotate many rounds after that.
If I can improve my model to rotate longer, for example 10 minutes, you can see the different
Thanks for your feedback
Thinh Nghiem
As RD suggested, you have to take into account the electromagnetic energy. Did you do that?
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The magnetic field is an invisible store of energy, like an invisible spring , which can give the false-impression that kinetic-energy (movement) is being created from nothing , (which would violate conservation of energy).
A similar device is the magnetic pendulum ...
I've just remembered a better demonstration of magnets acting as a springs ...
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Hi all,
Unfortunately no. The limit of my experiment is that I made conclusion based on observation. This experiment is done by me, an amateur experimentalist, at home; not in a well equipped laboratory.
However, I simply make a assertion that I just use a small force to move the cylinders to go a short arc, while they rotate many rounds after that.
If I can improve my model to rotate longer, for example 10 minutes, you can see the different
Thanks for your feedback
Thinh Nghiem
As RD suggested, you have to take into account the electromagnetic energy. Did you do that?
Sorry no :-)
I just take into account the mechanic energy.
However, I think this model can be used as a rotor of generator. We only need to use small manual force at the beginning, and the system will generate electric current, without fuel. Provided that This model must be improved to rotate longer
Am I right?
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Any moving magnet can be used to induce an electric current in a conductor, but "without fuel" is not possible if you are going to use that current to do work.
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Any moving magnet can be used to induce an electric current in a conductor, but "without fuel" is not possible if you are going to use that current to do work.
This can get confusing if you're not careful. Please keep in mind that a magnetic field cannot do work! Quite often it seems like it can but under close scrutiny it always comes out to be something else. E.g. if you use one magnet to push another magnet thus increase its kinetic energy and thus work is done on the magnet. But its not the magnetic field doing work.
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Good on you thinhnghiem, keep on thinking. you're doing more than many here.