What is Magnetism?

Discussion in 'Alternative Theories' started by Pascal Halbherr, Jan 4, 2018.

  1. NotEinstein Valued Senior Member

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    I encourage you to not just take my word for it, but to investigate it for yourself.

    Yes, the page loads, but the section "Two_models_for_magnets:_magnetic_poles_and_atomic_currents" isn't there (anymore). You are effectively pointing to page 300 of a book with only 200 pages.

    True, but what's "internal" about then? And why did you refer to a field as an "effect"?

    No problem; glad I could help.
     
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  3. Write4U Valued Senior Member

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    What confused me is this;
    According to this article there is a distinct difference between a ferro-magnet and an electro-magnet, both which may satisfy Maxwell's Equation, but one is a dynamic process (energy), whereas the other is a static field existing between two oppositely charged poles.
    https://en.wikipedia.org/wiki/Electromagnet
     
    Last edited: Jan 6, 2018
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  5. river

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    Indeed
     
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  7. Q-reeus Valued Senior Member

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    No. ME's can't explain ferromagnetism. For that you need QM.

    Anyone interested in following an interesting and evidently unrealized (apart fro your's truly) subtle consequence of the classical/quantum interplay is welcome to view my inputs (as kev n), beginning with:
    https://www.youtube.com/_watch?v=1bXjB0zrjp0&lc=UgzoKZ0U39pUKoiw0Dx4AaABAg
    Then as a series of replies to poster Ken Behrendt (who went off more and more into a pseudoscientific far-reaching 'dissertation') here:
    https://www.youtube.com/_watch?v=1bXjB0zrjp0&lc=UgwLPiEH3n3n9waONkN4AaABAg
    (expand the 'View all 6 replies').
    Note: direct pasting of URL's screws up in SF, so cut & paste above 'crippled' links into browser - then remove the underscore in each link!
    I did post on that matter way back here at SF, in more detail in certain respects. But won't link as the reactions were typically negative knee-jerk 'that's un-mainstream!!!' reactions.
     
    Last edited: Jan 6, 2018
  8. NotEinstein Valued Senior Member

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    The question was if situations involving ferromagnetism could be described by Maxwell's equations, which they can. You are right though that for a detailed explanation how ferromagnetism arises in the first place, quantum effects (especially spin) need to be taken into account.
     
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  9. Write4U Valued Senior Member

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    question: does "spin" also produce electric current?
     
    Last edited: Jan 6, 2018
  10. NotEinstein Valued Senior Member

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    No, not directly anyway.
     
  11. Write4U Valued Senior Member

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    So is ferromagnetism a retained memory of electric current? I read somewhere that ferro materials are more sensitive to electricity and somehow can retain faint electric influences on spin, aligning the spin in the same direction, which as I understand it is the remarkable attribute of a ferromagnet and creates the pnenomenon of oppositely charged poles.

    b) is a ferromagnetic field static or does it indicate a flow of something from one pole to the other?
     
    Last edited: Jan 6, 2018
  12. NotEinstein Valued Senior Member

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    (You'll have to ask Q-reeus; (s)he seems to be more knowledgeable about these matters.)
     
  13. exchemist Valued Senior Member

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    It is aligned spins (and orbital motion) of unpaired electrons, which you get in some materials. A circulating electric charge generates a magnetic dipole, so if you get a lot of these lined up they add to each other and give rise to a magnet. As to why they do that in certain materials, that I think is a QM effect to do with the operation of the Pauli Exclusion Principle when the orbitals of adjacent atoms overlap.

    But it is not a "memory" of an electric current: in effect, a spinning or orbital electron is itself an electric current, on a tiny scale, because it is a moving electric charge.
     
  14. Write4U Valued Senior Member

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    What then keeps a ferromagnet magnetic? Is not the retention of same spin which creates magnetism? In the absence of an electric current, why does the spin of half the atoms not reverse and create a balance which cancels the magnetic abilities of ferromagnets as it does in EM magnets. Not all ferrometals are naturally magnetic, because they naturally have a balanced spin, half left, half right (no magnetism)
    Moreover, how can "tiny" (weak) electric charges keep the spin aligned through the entire magnet to produce such a relatively incredible attractive force?
     
    Last edited: Jan 6, 2018
  15. Q-reeus Valued Senior Member

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    Why not just study a scholarly article that explains it? e.g. https://en.wikipedia.org/wiki/Ferromagnetism#Explanation
     
  16. Write4U Valued Senior Member

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  17. Q-reeus Valued Senior Member

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    Well, if you continue reading that Wiki article, the very next section in fact.....

    Please Register or Log in to view the hidden image!

     
  18. Write4U Valued Senior Member

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    OK.
    Thus it seems to be akin to a form of "memory", though it may be caused by physical constraints.?
     
  19. Q-reeus Valued Senior Member

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    Hmm... skimming through a selection, there are various less than really useful YT vids on ferromagnetism, but this one may help:
     
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  20. Write4U Valued Senior Member

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    Wonderful. Thank you for that excellent link.
    I love the narrative and illustrations. Clear and simple, and has secondary leads to boot.

    Whole independent domains (magnetic fields) whithin a ferro object can expand or contract and be manipulated for practical purposes. Neat.
     
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  21. Pascal Halbherr Registered Member

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  22. NotEinstein Valued Senior Member

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    You have answered your own question: "until we measure it": looking at a magnet under a ferrocell counts as a measurement.
     
  23. Pascal Halbherr Registered Member

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    Ehm, but what I think you are missing is that if we are looking at it, so measureing it, there is still both spins visible, not only one as if we would measure the electron
     

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