Since the birth of physics, "force" has always been regarded as an independently existing interaction entity in the objective world. From Newton's universal gravitation to the three quantum forces of the Standard Model, physicists have attempted to describe four different "realities" with four different mathematical structures. Based on the algebraic ontology and UV-IR holographic duality framework established by the author, this paper puts forward a fundamental subversive proposition: the four fundamental interactions are not four independent physical entities, but four projection readings of the same underlying algebraic manifold — the modular quantum flag manifold — at different observer energy scales. Gravity is not an independent interaction; it is the holographic blurred projection of strong interaction at the infrared end (low energy scale). Through rigorous gedankenexperiments and the UV-IR spectral duality theorem, this paper proves that when the observer's energy scale is continuously raised from the macroscopic scale to the Planck scale, "gravity" continuously decoheres into "strong nuclear force", "weak force" dissolves into a projection filter operator of symmetry breaking, and "electromagnetic force" reduces to the U(1) phase curvature of energy scale gradient. The four forces are ontologically unified at the fundamental algebraic level, and their phenomenological differentiation originates exclusively from the energy scale position of the observer’s anchor point. This paper thus proposes that "unified field theory" does not mean merging the four forces, but recognizing that they were never separated.
Zheng Xinyu (Sat,) studied this question.