Light Never Slows Down: The USP Field Theory Explanation

This document challenges the common misconception that light slows down in materials like glass or under the influence of gravity. According to USP Field Theory, photons are not classical particles or simple waveforms — they are packets of spin-tension resonance that always travel at a constant speed. What appears as a slowdown is actually an increase in travel distance due to geometric field effects such as electron re-emission or gravitational lensing. This document offers a precise explanation of why the speed of light never changes, supported by field-based logic, and clarifies how this principle holds true across all physical environments — from dense materials to massive cosmic structures. This work also marks a foundational perspective in the USP Field Theory series, reinforcing the idea that light is not slowed — only curved.