Absolute Cosmology 06:The Absolute Spacetime Interpretation of the Sagnac Effect

This paper constitutes the sixth installment of the Absolute Cosmology series. Building upon the absolute spacetime axioms, absolute cosmic transformation equations, and the modified Michelson–Morley (MM) experiment as a definitive test established in the preceding five papers, this work focuses on the absolute space interpretation of the Sagnac Effect. Since its discovery in 1913, the Sagnac Effect has been conventionally framed within the relativistic formalism of non-inertial corrections. However, in engineering practice—from fiber-optic gyroscopes to satellite navigation—the actual calculations rely entirely on the classical Galilean superposition formula. Based on the light-speed superposition rule of the absolute cosmic transformation, \vec{c}\,'=c\hat{n}-\vec{v}_{\text{obs}}, this paper rigorously derives the complete expression of the Sagnac time delay without invoking non-inertial frames, spacetime curvature, or ad hoc concepts such as local inertial frames, and proves that its low-velocity approximation matches the experimental formula exactly. A systematic comparison is presented between the absolute cosmology and relativity frameworks in explaining the Sagnac Effect, revealing that the relativistic approach begins with complex mathematical structures but ultimately degenerates into the elementary formula of absolute cosmology—a logical self-negation. Together with the modified Michelson–Morley experiment, the Sagnac Effect forms a dual definitive evidence for the existence of absolute space. Adhering to the Occam's Razor patch-free paradigm, this study provides a solid theoretical foundation for restoring physics from the relativistic paradigm to an absolute spacetime framework. Keywords: Absolute Cosmology; Sagnac Effect; Absolute Space; Light Speed Superposition; Non-inertial Frame; Definitive Evidence; Galilean Transformation; Ring Interferometer