A Physical Analysis of Displacement Current in a Vacuum Capacitor Based on Near-Field Coupling

Experiments on alternating current parallel plate vacuum capacitors have long been regarded as key evidence confirming Maxwell’s electromagnetic wave theory. The mainstream physical interpretation holds that an alternating electric field within the plate gap independently excites an alternating magnetic field in vacuum; the alternating magnetic field in turn generates a new alternating electric field. Electromagnetic fields reproduce alternately to form electromagnetic waves that carry energy across the vacuum, and this mechanism is adopted to explain the origin of displacement current. This paper re analyses the working process of a vacuum capacitor based on the near field force coupling mechanism and establishes a new physical interpretation. Photon energy packets inside wires alter the electric potential energy of electrons on the plates. Periodic reciprocating perturbation of electric charges forms an alternating Coulomb electric field force. Within the gap, the alternating Coulomb electric field acts as the dominant medium, accompanied by weak, local incidental magnetic fields. The electric and magnetic fields near oscillating charges originate simultaneously from the charges themselves, rather than an alternating electric field independently producing a magnetic field in empty space. In reality, there exists no physical process in which alternating electric and magnetic fields alternately reproduce and propagate over long distances in pure vacuum without charge carriers. This scenario is merely a theoretical conjecture and has not been verified by exclusive experimental proof. The alternating electric field perturbs electric charges on the opposite plate from a distance and achieves energy coupling via Coulomb force. The force decays rapidly with distance and has a critical effective operating range. This paper strictly distinguishes the energy transfer difference between steady direct current electric fields and dynamic alternating current electric fields, and contrasts the essential distinction between magnetic field coupling in transformers and electric field coupling in capacitors. The huge scale mismatch between wavelength and plate gap disproves the model of self generating electromagnetic wave propagation in vacuum. The conclusion is drawn that light is not an electromagnetic wave and that photons are not field mediators. Maxwell’s equations possess value for engineering mathematical fitting, yet the accompanying physical picture of alternating reproduction and propagation of electromagnetic fields in vacuum conflicts with objective facts.