Theory on the Essence of Gravity: Photon Confinement Mechanism and Instantaneous Action at a Distance

Current mainstream theories of gravity cannot consistently explain the instantaneous and long-range nature of gravity, and some studies have gradually deviated from objective observational reality and fallen into the misunderstanding of subjective fiction. Based on measured and observational facts, this paper proposes a new viewpoint on the origin of gravity: photons are the fundamental primordial substance of the universe; when free photons are confined to form matter with rest mass, they lose their free motion at the speed of light and simultaneously generate universally instantaneous gravity. Gravity is an intrinsic instantaneous action at a distance, requiring no transmission medium or propagation time, unrestricted by the speed limit of massive particles, and its intensity strictly follows the inverse-square decay law of distance. This theory has a logical closed loop and conforms to the real operation of the universe, which can perfectly explain core gravitational phenomena such as the stable operation of galaxies and the maintenance of celestial orbits. It abandons illusory and fictional concepts, returns to the truth-seeking nature of physics research, and provides a subversive train of thought for the study of gravity in fundamental physics.