Modern standard cosmology (ΛCDM) introduces dark energy to explain the accelerated expansion of the universe. However, recent discoveries of massive early galaxies by the James Webb Space Telescope (JWST) call for alternative interpretations of cosmological observational scales. Building upon prior work (Kim, 2026) that introduced a dimensionless expansion rate coefficient, Hₖ, which couples the magnitude of cosmic expansion with the rate of time flow, this study proposes a phenomenological spacetime projection scale factor, K (z), grounded in the constancy of the speed of light. To minimize geometric distortions in conventional observation scales, we adopt the matter-dominated Einstein-de Sitter (EdS) universe model (Ωₘ=1) as a theoretical baseline and explore the phenomenological validity of incorporating a geometric correction factor driven by observer-centric projection and photon energy conservation. Furthermore, by introducing a multiscale spacetime postulate that decouples macroscopic cosmological scales from local spacetime and its derivative operations, this study formulates the proposed scale redefinition into the isotropic metric tensor framework of general relativity, providing a consistent Einstein field equation and geodesic equations. Applying the newly derived luminosity distance hypothesis to supernova observational data reveals a remarkably close agreement with the ΛCDM model, showing an error margin of 0. 05 mag or less across the z=0 to 1. 0 range. Moreover, the distance modulus deviation of +1. 0 mag calculated at the deep space (z=8. 0) region suggests that in the early universe, where the expansion rate was extremely high, the rate of time flow may have also been faster than at present. Consequently, the brief age of the early universe (roughly 600 million years) derived in standard cosmology may be a geometric optical effect induced by scale distortion, and applying the scale expansion of this model suggests that sufficient absolute physical time required for the formation of massive galaxies could be secured. This proposes a novel approach capable of explaining the observational curve of cosmic evolution without the need to introduce dark energy.
Sun-gyu Kim (Thu,) studied this question.