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View Poll Results: Do you think a material exists that is neither attracted to nor repelled by an electrically charged

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Thread: Material blocking electric field?

  1. #1 Material blocking electric field? 
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    Experiment: When I rub a balloon on a cloth, the balloon becomes static-electrically charged. I see that the balloon attracts both dielectrics (carpet, glass, etc.) and conductors (steel, etc.) just the same. When I do the same with a second balloon then approach the two charged bodies towards each other, they repel.

    Question: Is there a material that is neither attracted nor repelled by an electrically charged body, but also blocks the electric field from passing through it?

    Note: When I say "block" the electric field, I mean that the charged body will be neither attracted to nor repelled by another body when this mysterious material is placed in between. Of course, if there were such a material, it would be VERY easy to build a perpetual motion machine...


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  3. #2  
    Forum Radioactive Isotope MagiMaster's Avatar
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    http://en.wikipedia.org/wiki/Faraday_cage, though obviously it can't be used to build a PMM. Then again, that may not be what you're talking about.

    Anyway, if you can show how a material with property X can be used to build a PMM, then you've just proved that no material with property X can exist.


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  4. #3  
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    An object that already has an electrical charge will be attracted or repelled, depending on the sign.
    If an object does not have an electrical charge, it's surface will become charged by the presence of the charged balloon and attract it.

    Perhaps if you take a conductive material with a particular geometry and charge such that there is an equilibrium point at which the attraction to the induced surface charge balances out the overall repulsive force. My intuition tells me that it's either impossible or unstable, but I'm too lazy to try to figure it out.

    That wouldn't be a material property though, and as MagiMaster explained, it certainly wouldn't allow you to create a PMM.
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  5. #4  
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    First, MagiMaster, according to http://en.wikipedia.org/wiki/Faraday_cage#Operation, the Faraday cage, when getting polarized in order to cancel out the field inside the cage, gets attracted to the source of the field (not good).

    Second, I think bashing PMM because they does not follow Newtonian laws of thermodynamics is the same as bashing Einsein's theory of special relativity because it doesn't follow Newtonian laws of mechanics http://en.wikipedia.org/wiki/Newtoni...ial_relativity.
    So please don't transform science into religious dogma.

    But I digress...

    Here is a simple picture of what I'm thinking of:

    http://www.flickr.com/photos/41401677@N02/

    Second, Bender, you definitely understand what I'm talking about when you say
    Perhaps if you take a conductive material with a particular geometry and charge such that there is an equilibrium point at which the attraction to the induced surface charge balances out the overall repulsive force. My intuition tells me that it's either impossible or unstable.
    We need to elaborate on that idea a little further.[/url]
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  6. #5  
    Forum Radioactive Isotope MagiMaster's Avatar
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    Thermodynamics is not Newtonian, and comparing PPMs to relativity is just dishonest. PPMs do not and cannot work. Period. Full stop. If you think you've got a PPM, look again, because you don't. This isn't religion. It's science. Science says PPMs don't work. (I can't understand why this is so hard for people to accept.)

    I'll repeat myself. The statement "A material with property P will allow the creation of a PPM" implies "There is no material with property P".
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  7. #6  
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    So thermodynamics isn't Newtonian, but in any case...

    Let's completely leave it out of this topic forever, and forget that I ever mentioned PMMs at all...

    Now back to the question at hand....

    Can we figure out the following:

    Is there a conductive material with a particular geometry and charge such that there is an equilibrium point at which the attraction to the induced surface charge balances out the overall repulsive force?
    Or is it the other way around?

    Is there a conductive material with a particular geometry and charge such that there is an equilibrium point at which the overall attractive force is balanced out with the repulsion to the induced surface charge?
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  8. #7  
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    PMM? What does this stand for, Perpetual Motion Machine?
    Wise men speak because they have something to say; Fools, because they have to say something.
    -Plato

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  9. #8  
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    That is correct Arcane... now no more mention of it please.... we have more specific questions to answer.
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  10. #9  
    Forum Bachelors Degree Waveman28's Avatar
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    Quote Originally Posted by MagiMaster
    Thermodynamics is not Newtonian, and comparing PPMs to relativity is just dishonest. PPMs do not and cannot work. Period. Full stop. If you think you've got a PPM, look again, because you don't. This isn't religion. It's science. Science says PPMs don't work. (I can't understand why this is so hard for people to accept.)

    I'll repeat myself. The statement "A material with property P will allow the creation of a PPM" implies "There is no material with property P".
    Lol. Amen.

    In regards to the OP, I think that a material such as the one you described is indeed possible. A way that this may work is that the material would contain an equal amount of equally distributed charges which would make it neutral. However, the negative charges (electrons) would be positioned so that they could not move and were locked into their original positions. This way, when it is placed near an electrostatically charge body, the surace which is facing the charged body could not become charged itself and thus could not be attracted or repelled. Whether or not it would actually block the field from passing through to its other side I am not sure of.
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  11. #10  
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    Quote Originally Posted by Waveman
    In regards to the OP, I think that a material such as the one you described is indeed possible. A way that this may work is that the material would contain an equal amount of equally distributed charges which would make it neutral. However, the negative charges (electrons) would be positioned so that they could not move and were locked into their original positions. This way, when it is placed near an electrostatically charge body, the surace which is facing the charged body could not become charged itself and thus could not be attracted or repelled. Whether or not it would actually block the field from passing through to its other side I am not sure of.
    As far as I know, charges cannot be locked in space. Even if no electrons can escape their place around an atom, which is the case in dielectrics (non conductive materials), the electrons (or electron clouds or electron distributions, if you prefer) can still shift more towards one side of their atom.

    Even if charges could be locked in space, it wouldn't stop an electric field.

    Even if there is some strange material that does block an electric field, without being attracted itself, it still wouldn't allow a PMM, because you always have to climb the potential energy mountain again, and it would be just as high as the hill you came down from. Combined with your drawing this can be used to show in a "proof by contradiction" that a material that blocks an electric field without being attracted cannot exist in the universe as we currently understand it.
    This is what MagiMaster was saying. Although we can't say with certainty that a PMM is impossible, because we cannot be 100% certain that the laws of thermodynamics will never be broken. The fact that they have never been broken, despite numerous attempts, makes it less and less likely that they ever will be.
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  12. #11 neutral to slightly positive? 
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    It's funny Bender; I reached the same conclusion concerning electron clouds last week (I hadn't checked this forum in a while).

    The electron cloud is the problem, and as the source of the electric field gets closer or further, the deformation of the cloud, and hence the force, varies.

    So something like the following happens: having the electrostatic source charge close to the material strongly warps the cloud and results is strong attraction, while having the two further apart results in less warping of the cloud and less attraction.

    Now I wonder...

    Can we 'dope' the conductor with 'positive charges' (perhaps with stable ions, and electret, or something like that) so that, at any given distance between the material and the electrostatic source charge (as shown in the drawing), the net force would either be:

    a) neutral when close to one another
    or
    b) repelling when further from each other

    Would this "neutral to slightly positive' material be sufficient so that the machine depicted by my drawing could keep on rotating/pushing in the same direction?
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  13. #12  
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    1)Even with the distribution of the charges remaining exactly the same, the force would decrease with distance.

    2)You can hardly call the Van der Waals force "strong attraction".

    I don't think that what you propose is possible. Giving a material a possitive charge (no need to dope it, rubbing the balloon will do) will make it repuls other positive charges, more so if the distance decreases.

    Even if it is possible, approaching the charge in your rotation device would require exactly as much energy as you could get from the repulsion phase. (and a bit more to overcome losses)
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