The Essence and Origin of the Speed of Light

This paper conducts a systematic investigation into the core issues of the speed of light, focusing on analyzing why light has a constant propagation speed as soon as it is generated, the internal root of the constancy of the speed of light, and the essential meaning of the measured value of the speed of light. Based on the intrinsic properties of light, this study proposes that the essence of light is an energy form of 360° omnidirectional three-dimensional vibration; no rest mass, no inertia, and continuous propagation are the core intrinsic properties of light. It also clarifies that the specific measured value of the speed of light is obtained based on the human-defined basic units of meter and second, which is only a quantitative description of the intrinsic motion property of light and does not change the motion essence of light itself. This paper also refutes the view that electromagnetic force and universal gravitation can change the speed and propagation direction of light, forming a complete understanding of the essence of the speed of light and providing a new theoretical perspective for understanding the motion law of light.