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I Conceptual Question About Magnetism

  1. Aug 9, 2016 #1
    I'm trying to get a handle on what magnetism really is. I know that charge in motion generates a magnetic field. I know that objects and particles can be permanent magnets when the magnetic fields of their elementary particles "line up." But how do stationary elementary particles have the own individual magnetic fields? I've heard some people make the case that magnetism is just electrostatic forces with special relativity taken into account. Is that true? I've heard that electricity and magnetism are the same thing. Some people say there is a clear distinction between the two. Which is it?

    I know that charged particles can exist as monopoles and magnetism requires two poles. But what is at the poles? What makes the poles negative and positive? The answer I'm expecting is that the magnetic dipole moments at the poles line up to make them either north or south. But what is actually happening there? What would happen if you took away one of the poles? What are you left with? In electrostatics we work with charged particles, positive and negative. But magnetic monopoles haven't been proven to exist. I know that's why the magnetic field is defined differently than the electric field, but it doesn't conceptually mean anything to me. With the magnetic field being defined as the velocity vector of a moving charged particle when the force acted on it is 0, it's almost seems like it's just completely made up to describe something we observe, but don't really understand. But what are we observing? What is the observed difference between electricity and magnetism?

    The top commenter of this thread, Chris White, makes the argument that magnetism is just electrostatic forces with special relativity taken into account.


    But several comments down Francisco Muller refutes him, and even if this were true, it doesn't account for the magnetism of individual stationary elementary particles.

    At this point I'm completely lost. How is electricity and magnetism different? What is magnetism really?
  2. jcsd
  3. Aug 9, 2016 #2
    I do not know whether this helps but let me try. Any concept in Physics should be tackled from the simplest level . Remember all great scientist were always trying to tell us that fundamental laws of nature are the simplest ones ( like F= ma or E = mc^2). Let me address some of your questions. What is at he poles? What are lines of force. To me they are just models to explain the behaviour of magnets. My take is that when scientista are trying to study the nature of unknown the first step is to find a model and test whether it is based on correct conceptions and agrees with experimental results. For example, if we want to study the nuclear reactions taking place in Sun we simply can not set up a laboratory there and conduct a test. So we device some model equations and verify it experimentally and tally with the observable facts.To me the idea of poles, field lines are all consequences of a model which agrees with observed facts. The origin of magentism is similarly explained by movement f charged particles in substance. The motion of electron in a n atom gives rise to magnetism. Since all substances contain electrons then why only certain substances exhibit the property? For that the model is spin up and down for magnetic moments.Well one could go on and on . My request is not to get entangled with too many concepts at the same time. One thing at a time may help. Happy studying Physics. It is a great subject.
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