DC currents and voltages obey simple rules when flowing through insulated copper wire. Also, the DC voltages and currents stay within the confines of the copper wire. RF, however, prefers to flow on the outside surface or skin of the copper wire and will not flow within the copper. Furthermore, RF does not like to make sharp turns when flowing down the surface of the copper wire, but prefers to make gradual turns. Additionally, with the correct circuitry, RF can be transmitted into the air where it no longer needs copper wire.