Inertia is a fundamental phenomenon underlying classical physics, relativity and quantum gravity. Nevertheless, physics over hundreds of years has failed to establish a complete ontological explanation for its origin. Newton regarded inertia as an intrinsic property of matter; Mach’s principle attributed inertia to long-range coupling among cosmic masses; general relativity described inertial motion via geodesic equations; string theory, loop quantum gravity and other mainstream quantum gravity candidates only reproduce inertial behaviors at the effective level, without addressing the origin and existence boundary of inertia.Based on the PFUSRC 11-dimensional triple coaxial bicone topological unified system, this paper takes four-dimensional flow-variables as the fundamental ontological unit of the universe and constructs a three-state topological evolution model. The core original conclusion is proposed: inertia is not a permanent inherent property of mass, matter or spacetime. Instead, it is an intermediate dynamic topological latching effect emerging when flow-variables form stable closed bicone topologies prior to the structure reaching absolute solidification.In the vacuum ground state with freely dispersed flow-variables, no closed topologies are formed, and mass, gravitation and inertia are entirely absent. At the moment bicone topologies close and stabilize, mass, gravitation and inertia emerge simultaneously from identical topological latching processes. Once topological structures are extremely latched, fully solidified and lose room for deformation, inertial effects vanish completely.In essence, inertia represents the potential barrier response of stable closed topological structures against external perturbations and reconstruction of topological loops. It only exists within a transitional dynamic interval where topologies are closed and susceptible to breaking and reconstruction. This paper strictly distinguishes inertial potential and observable inertial phenomena, differentiates topological adaptive deformation from forced topological breaking, and reinterprets the topological nature of Newton’s bucket experiment and the equivalence principle. Through horizontal comparison with string theory, loop quantum gravity and entropic gravity, we demonstrate that all existing physical theories remain limited to phenomenological fitting and effective geometric description, lacking the underlying ontological logic of topological hierarchy. This work closes a core gap in the PFUSRC dynamic system, forming a complete ontological closed loop covering the generation, persistence and annihilation of inertia, and achieving unified interpretation of inertial behaviors across micro, meso and macro scales.
Zhenmin Wang (Fri,) studied this question.