Cosmology / Constants
Null Propagation as the Causal-Limit Invariant: Why the Speed of Light Is a Metric Representative
This paper argues that the speed of light is not a fundamental physical quantity, despite its central role in modern physics and its exact numerical fixation in contemporary unit systems. The core claim is structural rather than empirical: the notion of speed presupposes metric structure and unit conventions, whereas the invariant physical content of relativity is carried by null causal structure , not by a numerical constant. The analysis introduces a clear criterion for fundamentality based on invariance under...