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Maxwell–Faraday equation symmetry violation

  1. Jul 12, 2010 #1
    I still wonder about this.

    A simple results of this equation is:

    If a charge has a velocity in the positive y direction [v = (0,1,0)] and it accelerates in the positive x direction (it curls) then there will be a magnetic field in the positive z direction. There will be no magnetic field in the negative z direction.

    The problem here is that negative and positive z are symmetrical, there is no physical difference, and the xy plane is orthogonal so there is no interaction with the z plane to choose one direction or another. Yet nature always chooses the same direction to put the field based on the motion of an electric charge in an orthogonal plane.

    Because of this I do not see how the magnetic field is a field at all. It only appears to be a mathematical object used for simplification in describing the physical interactions of electric charges.
  2. jcsd
  3. Jul 12, 2010 #2
    And your question is?
  4. Jul 12, 2010 #3
    How can one direction be chosen over the other for the magnetic field unless the magnetic field is not a field at all but rather a mere vector that is the consolidated collection of electric fields permeating from the accelerated charge in the z direction.
  5. Jul 12, 2010 #4
    Couldn't the same argument be used to claim a velocity can't be a velocity, since any two people with different velocities can both call their own velocity zero? Just because a velocity changes how you measure it doesn't mean that what is measured is not what it is. In fact, it's an electromagnetic field, and what you see as electric or magnetic is dependent on your perspective of the field.

    Another example would be clocks. Go fast enough and it looks like everybody's clock back home is going slow. They say it appears your clocks are slow. If they come to you, you are right. If you go to them, they are right. Does this mean clocks aren't real, or time is not real?
  6. Jul 12, 2010 #5
    However if the magnetic field is only a notation for simplifying the ability to work with electric fields in three dimensions then there would be no reason to continue the search and work related to magnetic monopoles.
  7. Jul 12, 2010 #6
    I always found the monopole search exceedingly speculative anyway. I'm still happy that such things are looked for. We should always be looking for things contrary to our presumptions, not just those that supports them.
  8. Jul 12, 2010 #7
    It is because there is proof of the possibility of a magnetic monopole, however this proof is based on the magnetic field being something of a different field (though coupled) than the electric field. So what I am saying is that the symmetry violation disproves the magnetic field as being anything more than the electric field itself which would disprove the possibility of the magnetic monopole.
  9. Jul 12, 2010 #8
    The magnetic field is as important as the electric field. Just as the H field can be viewed as an E in another frame of reference, it is also true that an E field can be viewed as H in another frame. Neither one "comes first".

    Regarding monopoles, it's hard to prove that something does not exist somply because it has not yet been observed. Maybe magnetic monopoles do or don't exist. But magnetic fields are real, they just happen to be di-polar, not mono-polar.

    Also, E fields come in 2 types, Ec (due to discrete charge particles, or "monopoles"), & Ei (due to induction). The "Ei" type of electric field is di-polar, no monopoles have yet been found. When induction takes place, the induced E field is the "Ei" type, having a solenoidal closed loop type of behavior just like a magnetic field. Yet di-polar E fields, Ei, carry energy just as H fields do.

    The lack of a monopole does not negate the fact that a dipolar field carries energy. Both types of E, as well as H field, are important. Does this help?

  10. Jul 12, 2010 #9
    The manetic field is a pseudovector. It's sign depends on the coordinate system so you are right. The key is that the forces are in the right direction regardless of which convention you adopt.
  11. Jul 13, 2010 #10
    So the Magnetic Field is or is not just components of the electric field?

    For example:

    You have two conductive coils in an inductor. According to the M equations if a current is run through one, a magnetic field will be generated and this field will generate a current through the next. However there are also accelerated electric fields that when summed over will generate a current in the second coil (the particles follow the acceleration). Add this to the magnetic field current and you would get a current that is twice that of which the M equations propose.

    So the Magnetic field is just the sum of the accelerated electric fields and this is why those fields are dropped in the equation of an inductor.
  12. Jul 13, 2010 #11
    Not. It must be an ALTERNATING current. A direct current generates a static magnetic field, B, and it doesn't generate a current in the neighboring coil. Induction of current only takes place by a time rate of change in the magnetic field according to Maxwell's eqns. (Faraday's law of induction)...
    ..............curl E = - dB/dt

    It is the induced E field that generate the current in the neighboring coil.

    What is an "M" equation? Please use standard physics terminology.

    What are you referring to as an "accelerated electric field"?? Again you are using non-standard terms. Do you means 'time varying' E fields?
    It would be better if you write the equations you are referring to.
    Last edited: Jul 13, 2010
  13. Jul 13, 2010 #12


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    Perhaps you should look at the scalar and vector potentials. The electric and magnetic fields result from different manipulations of these potentials. The manipulation of the potentials means that there are physical effects that can only be contained in the magnetic fields and some only contained in the electric fields. While we can use Lorentz transformations to show that the electric and magnetic fields can be transformed into each other by judicious choice of your frame of reference, this suggests the equivalency of the force of the fields, not the equivalency of the fields themselves. When we get down to it, we are expressing the electromagnetic force as the result of two sets of properties. We can use the electric and magnetic fields to express this or we could use the scalar and vector potentials. However, there hasn't been a theory that I have seen that can reduce this to a single field or potential.
  14. Jul 14, 2010 #13
    By M equations I meant Maxwell equations.

    By accelerated field I meant that the E field between the electrons in the coil was changing position in an accelerated way. Since the electrons in the coil are accelerating the magnetic field would be changing, same as an alternating electric current, which works fine for the point I was trying to get across as well.

    So when you have an electron accelerating around in a coil, the electric field between that electron and an electron in the other coil would be changing, which would cause the electron in the second coil to move (or follow it). What I am saying is that the summation of these movements due to an acceleration in the position of the E field is what we call the effects of a magnetic field.

    But the E field is a real field, it attracts/repels charged particles, if the magnetic field is just the change in position of an E field it should not be classified as a fundamental field.
  15. Jul 14, 2010 #14


    Staff: Mentor

    A magnetic field also exerts force on charged particles. It is every bit as "real" as an E field (although defining "real" is notoriously tricky).
    Did yoy read Antiphon's post. The answer to your OP is that the magnetic field is a pseudovector field, not a vector field. Your same symmetry violation would hold for any pseudovector like angular momentum.
  16. Jul 19, 2010 #15
    But why call it a fundamental field if it is just a pseudovector?

    And why call it the electro-magnetic field? This explains why there is a supposed magnetic field in a light wave, there isnt! It can all be explained as components of perturbation in the electric field.
  17. Jul 19, 2010 #16


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    But there is no frame where light is only composed of electric fields.
  18. Jul 19, 2010 #17


    Staff: Mentor

    What's wrong with pseudovectors?

    I have certainly never seen any theory that could describe EM in terms of the E field only. AFAIK, the best that you can do is reduce it to a four-potential. I don't know of any way to reduce it to a single scalar potential.
  19. Jul 20, 2010 #18
    I am not sure what this has to do with frames but if you sum over all the electric components you don't even have to use a magnetic field. Its far more complicated mathematics I am sure, but it is a better explanation of how charges are effected by other charges in motion since it only requires one field. That is what I have been trying to say.
  20. Jul 20, 2010 #19


    Staff: Mentor

    I don't know of any possible way that this could be correct. It is not just a matter of more complicated mathematics, it is an under-determined problem without the B field. In other words, you can have two problems with the exact same E field but different B fields and the motion of particles will be vastly different. You cannot just mathematically massage the E field to get the information out.
  21. Jul 20, 2010 #20
    Ok then back to my original question, if the Magnetic field is a real field, why is it directionally bias? Why does it always go in the same perpendicular direction.
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