Abstract

The original cardinal law of Ampere for the force between two current elements is not Lorentz covariant.  This classical electrodynamic law of Ampere yields the same result as the relativistic Lorentz law when both are integrated around closed circuits.  To distinguish the non-covariant cardinal force law of Ampere and the relativistic Lorentz force law one may examine the force between open circuits excited by high frequency high power alternating current.  A straight wire antenna and a Z-shaped wire antenna were chosen.  They were excited at 108 Mhz with 50 watts, 147 Mhz with 150 watts, and 2450 Mhz with 500 watts.  It was observed for the first time that such antennas attract each other or arrange themselves to be perpendicular to each other.  No self torque was observed; although the self forces predicted were expected to be considerably larger than the mutual forces between two separate antennas.  The positive results on the one hand, revealing the forces between two antennas, directly proves the exclusive validity of the non-covariant cardinal Ampere force law; while the null results on the other hand, revealing no self torque on the Z-antenna, directly disproves the relativistic force for open circuits.