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A question about the fundamentality of magnetism

  1. Jun 14, 2013 #1
    I'm sorry if I may be asking an unanswerable question here, but i've looked all through the forums and the internet to find a satisfying answer to why moving electric charges create a magnetic field.

    I'm not trying to ask why electrical attraction/repulsion exists, as I take that as a fundamental force. But i am wondering which specific mechanics cause the relative motion of a flow of electrons to create an attractive or repulsive force on objects we deem magnetic.

    I guess my main question is:
    What is it about the movement aspect that is so special?

    When electrons are flowing through a copper wire, the net charge on the wire is still neutral at any given point, isnt it? So does the electron movement somehow create a temporary net charge because of the fact that the individual electrons and their static fields are changing position relative to the magnetic object? Or does magnetism have nothing to do with positive/negative net charge?

    As a note i thought of after: Photons are the force carriers for electromagnetism, right? So magnetism must be caused by some difference in how the photons affect a target when the electron that emits them is moving?
    Last edited: Jun 14, 2013
  2. jcsd
  3. Jun 14, 2013 #2


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    Staff: Mentor

    The (more) fundamental interaction is the electromagnetic interaction. We do not know why the electromagnetic interaction exists, that is just an experimental result. The magnetic fields of moving charges are a direct result of that. Special relativity is very important in that respect.
    In quantum field theory, with virtual photons, yes.
    You are mixing virtual and real photons here.

    That is a very good question, and the answer is: it depends. It depends on your reference frame, and special relativity is necessary to see this in detail.
    You do not need net charges for magnetic fields.
  4. Jun 14, 2013 #3
    You've helped ease my mind quite a bit on the subject. I'm the kind of person who cant delve into a subject unless i understand the "why", and it helps to know that it's more of a fundamental occurrence than something with a simple explanation i was missing. Thanks alot, now i can progress!
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