Vacuum Dynamics: Spontaneous Motion Driven by Light Speed Gradient and the Physical Essence of Gravity

Based on the principle of constant speed of light and the principle of minimum energy, this paper constructs a theoretical system of vacuum dynamics, revealing a complete physical causal chain: "light speed gradient → rest energy difference → spontaneous force → spontaneous motion". The core dynamic equation is derived as . Applying this theory to the study of gravitational mechanisms, we successfully deduce Newton's gravitational expression from the light speed distribution function, achieving the unification of the mathematical form and physical mechanism of gravity at the level of energy conversion mechanism for the first time. This research not only provides a novel dynamic perspective for analyzing the physical origin of gravity but also verifies the feasibility of propellantless propulsion technology in vacuum in principle.