Here we go again...
I have strongly argued that according to SR, magnetic fields occur due to relative motion between electric charges, maybe also electric fields and an observer with a relative motion to the charge/fields. This view makes a lot of sense because you can even show that all magnetic forces are expected distortions of electric fields from motion. But I do not believe in SR one bit, and there is evidence to the contrary for this view of magnetism. First we may assume that ferromagnetism can be modelled as a lot of tiny electromagnets that create a large virtual electromagnet winding. Of course if in fact the ferromagnetic field is the results of spins, and protons on the nucleous then these arguments would be weakened somewhat as it would differ greatly in many respects. Anyway, if we set a homopolar disk into rotation in the direction of the ferromagnetic electron motion direction (the direction the electrons would move in the coil), then the relative magnetic field the disk sees from these electrons would decrease as it begins to match their velocity and the disk would see pancaking of protons instead. This would reverse the polarity of the radial voltage from the wire both from an electric field pancaking view, or from the perspective of magnetic flux lines moving with the protons view. But there would be a tell tail limit, once the electron velocity of the magnetic field source is matched (which is glacial in an air core electromagnet, but possibly very swift with ferromagnetism), no further increase of induction voltage would take place however much the RPM in increased, since any movement would lead to an equal enhancement to both the electron and proton generated magnetic field. But additionally, if the rotation direction is reversed, then no voltage would have been produced at all if in a stationary magnet the proton is not contributing to the field. The reason is that if the field is relative to the motion of the charges, and a stationary magnet relies entirely on electron motion to establish a magnetic field, then moving against the electrons motion increases the electrons magnetic inductive effect and by equal and opposite increase the proton's effect inductive effect to achieve no net effect as I understand it. Basically the induction from the protons would cancel the induction from the electrons. I have never heard of a homopolar/unipolar/n-machine generator caring which direction it is rotated. And even if the protons were responsible for some of the magnetic field in a stationary magnetic field, then it would still be unlikely that the 2 influences are balanced. Such a variation should have been noted, indeed this would even apply to hall effect measurements, where some orientations, positions and polarity of applied current would lead to no, or less hall effect being produced than seemingly identical equivalent situations. It is not impossible, but it seems very unlikely that this would have gone unnoticed. If however the magnetic field is created by relative motion of the electrons through the wires reference frame, there is no expectation for any of these issues or limits since the magnetic field would exist in all frames identically, and no magnetic field from the protons in a wire would exist no matter what your motion is relative to that wire. John Because the
