On the Reversed Primary-Secondary Relationship of the Poynting Vector

Abstract

Traditional electromagnetic theory uses the Poynting vector to describe electromagnetic energy transmission. It holds that electromagnetic energy is mainly transmitted in the field outside conductors, and conductors only serve to guide electromagnetic fields. This paper adopts the physical criterion: energy loss occurs only when work is done on external substances; if no external work is performed, energy remains and transmits inside the system. Combined with practical engineering phenomena including open circuit circuits, shielded cables and corona noise of high voltage transmission lines, analysis is carried out. It shows that electromagnetic fields outside conductors are mostly secondary disturbances derived from charge motion. When such disturbances do work on external substances, those regions are exactly where energy dissipates, rather than the main channel for energy transmission. The Poynting vector treats leaked secondary disturbances as the primary energy transport path, resulting in reversed physical causality. The mechanism of shielded cables reducing loss by suppressing external disturbances doing external work and corona noise of high voltage lines caused by electromagnetic disturbances dissipating electric energy through work on air molecules can be self consistently explained by the work loss criterion. The external magnetic field is merely a secondary side effect generated by electron flow inside wires. Even if this side effect enables accurate current measurement, it cannot be equated with the main carrier of energy transmission.