Physics of Time — A Modified Framework of General Relativity Based on Four-Dimensional Motion Decomposition

Conventional general relativity treats the speed of light purely as a three-dimensional spatial velocity, which inevitably leads to four fundamental theoretical difficulties: spacetime singularity at the center of Schwarzschild black holes, an incomplete definition of event horizon, lacking fundamental physical interpretation for dark matter and dark energy, and ambiguous energy origin of Hawking radiation. Additionally, optics presents a fundamental phenomenon lacking unified spacetime interpretation: photons passing through transparent media slow down and regain full energy after exiting into vacuum, with zero permanent energy loss. In this work, we establish a brand-new fundamental physics discipline: Physics of Time. The core axiom states that the four-dimensional speed of light is invariant, and total four-dimensional motion can be orthogonally decomposed into spatial motion component and temporal motion component. We define a single universal dynamical parameter: the time allocation ratio α. Within this framework, we redefine the event horizon and prove that the classical Schwarzschild horizon radius is underestimated. We rigorously demonstrate that geometric singularities do not exist inside black holes; infalling particles can only approach the center asymptotically and cannot reach the central point within finite proper time. We further propose the temporal energy storage hypothesis, which unifies dark energy, dark matter, Hawking radiation and lossless photon transmission through transparent media as different manifestations of energy stored in the time dimension. A continuous evolution equation driven by spacetime curvature is constructed for α, and the whole spacetime dynamics remains smooth and singularity-free throughout. No quantum gravity assumption is required. The theory is fully self-consistent under classical four-dimensional geometry, offering a new foundational paradigm covering microscopic optics and macroscopic cosmology for modern cosmology and black hole physics.