Three‑Orthogonal‑Axis Four‑Dimensional Closed Spacetime System V5

This paper is the final version V5 of an original physical theory independently proposed by Huang Yaoquan: the Three-Orthogonal-Axis Four-Dimensional Closed Spacetime System. It innovatively constructs a three-axis orthogonal coupling model of space-time-matter, the fundamental Yaoon unit and a four-dimensional topological tensor evolution system. The work completes axiom construction, geometric topology and complete mathematical tensor derivation to explain the origin of the universe, spacetime evolution and the First Cause problem. All copyright and academic priority of the entire theoretical system belong exclusively to the original author Huang Yaoquan. This paper is the official English translation of the original Chinese manuscript. The original Chinese version with the earliest original timestamp and academic priority can be accessed at: https://doi.org/10.5281/zenodo.20264090