Systematic Reasoning on the Essence of Photons and Their Basic Motion Properties

As the fundamental energy unit constituting the universe, the photon is a core basic issue in physics regarding its motion properties and physical essence. Most existing theories focus on phenomenological summaries, lacking systematic logical reasoning starting from the inherent attributes of photons. Based on objective observational facts and rigorous deduction, this paper systematically explains the essence of photons, motion characteristics, origin of wave properties, relationship between energy and frequency, as well as interactions between photons and matter. It clarifies that a photon is a pure energy unit with no rest mass and no internal structure, demonstrates that the constant speed of light is an intrinsic property, reveals that wave-particle duality originates from the 360° periodic oscillation of photons themselves, and expounds the one-to-one correspondence between photon energy and frequency. This paper forms a concise, self-consistent and experimentally consistent basic theory of photons, providing a clear and unified physical interpretation for understanding photon behaviors.