Redshift Without Expansion

Redshift, supernova time dilation, and Tolman surface-brightness dimming are widely cited as observational evidence for the expansion of space. This paper presents a fixed-substrate framework in which these effects are reproduced without invoking metric expansion. A cumulative motion factor K(t) is introduced to track the relative state of emitter and observer. Under the assumptions of null geodesic propagation and photon number conservation, this framework accounts for the observed time-stretch of Type Ia supernovae and the Tolman dimming law. The luminosity-distance relation also follows in this approach when the effective motion rate is adopted empirically, demonstrating the background-level degeneracy of this model with Friedmann–Robertson–Walker cosmology. The analysis indicates that expansion is not the only possible interpretation of current cosmological background observations. Broader issues including the cosmic microwave background, primordial abundances, and structure formation are identified as open directions for future work.