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Reading this talk. Mind blown. It explains how the concepts of special relativity and length contraction between inertial reference frames converts magnetic forces to electrostatic forces depending on your frame of reference.

I am inclined to believe, after reading this, that there really is no magnetic force at all, only an electrostatic force. What we call a magnetic force is nothing more than an illusion, a consequence of special relativity as charged particles are moving at near speed of light relative to other charged particles. Am I correct in this conclusion? Permanent magnets are essentially alligned magnetic moments of individual atoms with aligned unpaired valance electron spin (I think I explained that right) so their fields should be also be explained using quantum and special relativity theories.

I wonder though, if the magnetic force/field isn't really there at all, then why the search for magnetic monopoles? Also, is magnetic permeability then just how the charged particles of the material aid or hinder alignment to the magnetic moment?

Doug Coburn
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    I think you could have done some research on this before asking. There are so many questions on this topic already answered here. The motivation for magnetic monopoles is deeper than typical classical electrodynamics "arguments" would suggest. See http://physics.stackexchange.com/questions/261246/what-is-the-explanation-of-the-non-existence-of-magnetic-monopoles/ and http://physics.stackexchange.com/questions/4784/why-do-physicists-believe-that-there-exist-magnetic-monopoles – Arturo don Juan Nov 17 '16 at 07:33
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    Upon investigating the two questions you referenced, I found that my exact question has already been asked and answered here http://physics.stackexchange.com/questions/182309 – Doug Coburn Nov 17 '16 at 14:13

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The problem with your approach is that the electrostatic theory you propose is not Lorentz covariant. Similarly a theory proposing that the magnetic field was fundamental and the electric field is derived from it has the same problem. To get round this we assume there is an electromagnetic field described by the electromagnetic vector four potential.

The theory constructed this way is Lorentz covariant. In any reference frame the electric and magnetic fields are obtained by differentiating the four potential. In some frames the result will like like an electric fied, in others like a magnetic field but more generally will look like a mixture of the two. The Wikipedia article I linked above explains how to do the calculation, though I suspect this is a deeper level of detail than you want.

The point is that the field is electromagnetic i.e. it combines both electric and magnetic properties into a single field. You cannot usefully choose to consider only the electric field, as you suggest.

The existence or otherwise of magnetic monopoles is not related to the construction of the electromagnetic field. Whether magnetic monopoles exist or not does not affect the mathematics.

John Rennie
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Magnetic fields are definitely real, even if they are explained by special relativity, length contraction, and electric charges. If there were magnetic monopoles, then moving magnetic charges would make electric fields just like moving electric charges make magnetic fields.

EL_DON
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