中文摘要: 经典电磁学以麦克斯韦方程组为数学基础,在实验与工程领域取得极高精度,但始终未能揭示电磁场的物理本体,亦无法为真空中的非接触相互作用提供自洽的物质载体。本文基于空间流宇宙理论,以基础演化线为宇宙唯一基底实体,构建全域连续、可形变、可振动、可拓扑扭结的空间流网络模型。本文核心贡献:1) 从基础演化线的张力动力学严格导出麦克斯韦方程组;2) 从电子线扭结的集体环流排列导出磁场的涌现本质;3) 从线网络的拓扑不变量导出电荷守恒与库仑定律;4) 从空间流的内禀波速自然给出光速不变原理。电磁感应、电场与磁场的耦合转化、真空电磁传播性、洛伦兹力机制等可复现实验现象,均被证明为空间流网络动力学与拓扑结构的必然结果。本文最终实现电磁学从现象描述理论向本质解释理论的跨越,为统一电磁相互作用、引力、量子力学提供具有最小公设、无自由参数、全域兼容的物理框架。 Abstract (English): Classical electromagnetism, with Maxwell's equations as its mathematical foundation, has achieved extremely high precision in experimental and engineering fields, yet it has failed to reveal the physical ontology of the electromagnetic field and provide a self-consistent material carrier for non-contact interactions in vacuum. Based on the Spatial Flow Cosmos Theory, this paper takes the Fundamental Evolutionary Line as the only fundamental entity of the universe and constructs a globally continuous, deformable, vibrational, and topologically knottable spatial flow network model. The core contributions of this paper are: 1) Rigorously deriving Maxwell's equations from the tension dynamics of the Fundamental Evolutionary Line; 2) Deriving the emergent nature of the magnetic field from the collective circulation arrangement of electronic line knots; 3) Deriving charge conservation and Coulomb's law from the topological invariants of the line network; 4) Naturally deriving the principle of the constancy of the speed of light from the intrinsic wave velocity of the spatial flow. Reproducible experimental phenomena such as electromagnetic induction, the coupling transformation of electric and magnetic fields, vacuum electromagnetic propagation, and the Lorentz force mechanism are all proved to be inevitable results of the dynamics and topological structure of the spatial flow network. This paper finally realizes the leap of electromagnetism from a phenomenological descriptive theory to an essential explanatory theory, providing a physical framework with minimal postulates, no free parameters, and global compatibility for unifying electromagnetic interaction, gravity, and quantum mechanics. Terminology Evolution Note: The "Spatial Flow Cosmos Theory" proposed in this paper is a deepened and unified renaming of the "Line Universe Theory" previously put forward by the author. In the earlier work, the "Line Universe Theory" emphasized the core idea that the universe is composed of the microscopic entity of "Fundamental Evolutionary Lines". In contrast, the "Spatial Flow Cosmos Theory", while retaining "Fundamental Evolutionary Lines" as the microscopic structure, more precisely reveals the nature of the universe as a continuous, flowing fundamental medium at the macroscopic level. The two are completely identical in their physical core; the "Spatial Flow Cosmos Theory" is the formal, unified, and more physically intuitive named version of the "Line Universe Theory".