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Magnets phenomena, please give explanation

  1. Apr 8, 2014 #1
    Hi everyone,

    Can someone please explain to me what happens here? Why does the polarity reverse? My friend explains it like this, I quote: "as opposed to what is taught in schools, magnets have a centralized force field". Is there something to this? What happens here?

  2. jcsd
  3. Apr 8, 2014 #2
    By the way, this is not a joke. I know about the bs surrounding this field, I just would like to know what exactly happens here.
  4. Apr 8, 2014 #3

    jim hardy

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    facebook says "content unavailable"
  5. Apr 8, 2014 #4
    Sorry my fault.
  6. Apr 8, 2014 #5


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    Staff: Mentor

    No idea what your friend is trying to say, but the beginning of his statement would make me disregard the rest of his statement as BS.

    I can think of a couple ways to make that trick "magnetic wand" thing. One would be to but batteries and an orientation switch to change the polarity of an electromagnet (the end toward the target). I don't have sound on the laptop I'm watching the video on, though, so there are probably other clues if I could listen to the explanation.

    Jim -- Do you have a Facebook account? I had to sign into my account to see the video.
  7. Apr 8, 2014 #6
    It's just that the magnets repel each other, then as he turns it upside down as shown, they attract each other. Isn't that only supposed to work with the opposite poles? Or is it like there's a different pole at each corners as well? If you know what I mean.
    Last edited: Apr 8, 2014
  8. Apr 9, 2014 #7


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    Did you understand what I said about a way to do this magician's trick?
  9. Apr 9, 2014 #8
    Yes, but I'm the guy filming it, there is no such trick. I have the magnets in my hand right now, without the frames, just the magnets. It still works. I turn them as shown in the video and they switch from repelling to attracting each other, like if I'd turn one to the opposite pole.
  10. Apr 9, 2014 #9

    jim hardy

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    thanks Berkeman--
    i dont frequent facebook, but the video did play..

    my guess would be he has magnets with multiple poles on their surface
    as in lower right image

    courtesy integrated magnetics, http://www.intemag.com/magnetics_101.html

    so one way the poles attract, other way they oppose

    but it's sure a complex structure ! One wonders what sort of gizmo it came out of.
  11. Apr 9, 2014 #10


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    Not sure if this was said already.

    Seems obvious to me.

    I describe the configuration as long magnets extending radially from a hub.

    N and S are oriented along the circumference, that is through the thinnest part of the magnet, rather than radially, along the longest axis (which is the "normal" orientation). So one wide flat side is north and the other is south. As you go around the circumference you see NSNSNSNSNS etc.

    In the pictures above, it would be "parallel to thickness".

    A compass can prove this, as can a "normal" magnet with known poles (which is what a compass is).
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