Spacetime Substantivalism 37: The Physical Essence of Light-like, Time-like, and Space-like Intervals as Validated by Multi-Messenger Astronomy — Also on the Ontological Reduction of the Null Geodesic Condition (ds²=0), the Deconstruction of Local Light Cones, the Weak Equivalence Principle, and the Substantive Genesis of Kinetic Energy and Momentum

Spacetime Substantivalism 37: The Physical Essence of Light-like, Time-like, and Space-like Intervals as Validated by Multi-Messenger Astronomy — Also on the Ontological Reduction of the Null Geodesic Condition (ds²=0), the Deconstruction of Local Light Cones, the Weak Equivalence Principle, and the Substantive Genesis of Kinetic Energy and Momentum Abstract As the 37th installment of the Cui's Substantival Spacetime Dynamics (CSSD) research lineage, this paper aims to perform a dynamical reduction of the core foundation of general relativity—the spacetime interval ($ds$)—at the ontological and underlying protocol levels, and to systematically critique and revise the classical conclusion that "the photon's proper time is identically zero." Based on the physical fact of the 1.74-second macro-scale arrival time difference recorded in the observations of the GW170817 gravitational wave event and the gamma-ray burst (GRB 170817A), this paper points out that traditional theory, in explaining this lag, falls into the ontological logical paradox of "subtracting zero proper time values yielding non-zero coordinate time" (i.e., $0-0=1.74$ seconds). This paper demonstrates that the null geodesic condition (ds²=0) essentially characterizes the initial state property of the substantive spacetime background lattice (i.e., zero local displacement time), rather than a dynamic indicator for free photons. By introducing the substantive material dynamics models of "Snow-Wall Compaction" and "Traffic Jam Ahead," this paper redefines the light-like, time-like, and space-like intervals, with the space-like interval precisely defined as the void beyond the Spacetime Construction Frontier where the laws of this universe do not exist. This paper aims to liberate modern cosmology from geometric causal narratives and return it to the track of substantive material science, characterized by a rigid cosmic foundation and unified aetheric absolute time. 摘要 作为崔氏实体时空动力学(CSSD)研究谱系的第 37 篇研究成果,本文旨在从本体论与底层协议层面,对广义相对论的核心基石——时空间隔 ($ds$)——进行动力学还原,进而对“光子本征时间恒为零”的经典结论提出系统性批判与修正。结合 GW170817 引力波事件与伽马射线暴(GRB 170817A)观测中记录到的 1.74 秒宏观到达时差这一物理事实,本文指出,传统理论在解释该滞后现象时,陷入了“本征时零值相减却产生非零坐标时”(即 $0-0=1.74$ 秒)的本体论逻辑佯谬。本文论证表明,零测地线条件 (ds²=0)