Special relativity transformations and the nature of the field due to current-bearing wire

The transformation of the magnetic field due to a steady current along a neutral wire, from a laboratory frame to the rest frame of a moving charge q, leads to non-null electric and magnetic fields. However, in its rest frame, q is sensitive only to the electric field. The magnetic field explains the force exerted by current-bearing wires upon magnets and the orientation of iron fillings, but the effect of space contraction bears the conclusion that the field perceived by a moving charge has electric and magnetic components. The term with the electric component is along the radial direction, but its resulting intensity is equal to that of the field given by Ampere Laplace law. While the resulting intensity of the magnetic component is not enough to explain the force exerted by steady currents upon magnets, therefore the nature of the dominant interaction is electric not magnetic. (C) 2009 Physics Essays Publication. [DOI: 10.4006/1.3142122]