Physical Conceptual Foundation of Time Field Theory (TFT): The Intrinsic Connection Between Mass and Local Spacetime Reference

This paper presents a conceptual interpretation of the core physical logic of Time Field Theory (TFT). It systematically discusses the foundational status of the conservation of local intrinsic total speed, the physical connection between mass and local spacetime reference, the dual physical identity of the vacuum speed of light c, the physical origin of c² in the mass-energy relation, and the physical picture of gravity as the gradient effect of the time field. It clarifies the internal logic and unity of the core concepts within the TFT framework, providing a complete conceptual foundation for Time Field Theory.