The Essence of Field (Experimental Verification Paper) — A Thought Experiment for Verifying Instantaneous Action of Static Fields Based on Step Voltage from High-Voltage Line Grounding

Taking the natural phenomenon of step voltage generated by grounded high-voltage lines as the prototype, this paper constructs a thought experiment and verification platform to test the action mode of static fields. The core of the experiment is to monitor the time sequence of potential changes at multiple synchronous measuring points, so as to distinguish two physical models: the "mediator particle propagation model" and the "full-domain instantaneous gradient field model". Due to technical barriers that prevent direct observation of synchronous dissipation of gravitational fields after instantaneous elimination of celestial mass, this paper carries out logical analogical deduction by utilizing the common law that both electrostatic fields and gravitational fields are point-source fields decaying in inverse proportion to the square of distance. The experiment strictly distinguishes two different physical processes: the ontology of static field, and charge motion, electric current and field disturbance. Meanwhile, it analyzes potential doubts about interference caused by dielectric environments, providing phenomenological and experimental support for the fundamental theory of fields.