The probelm is the following: There is a uniform I current measure in a rectangular loop while this is moving in a speed V close to c in the system where this loop is stationary (let's call it S'). The loop is parallel to the speed (this is, two of it's sides are parallel to the speed and the other two perpendicular) If we make the measurements in another system (S) in which the loops is moving with speed V, the current will change according to Lorentz transformations, an so will the length. Is it possible that the charge is accumulating there and an electric dipole is created? If so, how is it possible? What happens with that charge? Is it staying static?