Reinterpretation of Redshift in Light Universe Theory: Explaining Cosmological Redshift via Intrinsic Changes in Light Without Assuming Spatial Expansion

This work presents a conceptual reinterpretation of cosmological redshift that does not rely on the assumption of spatial expansion. Within the framework of the Light Universe Theory, redshift is understood as arising from intrinsic changes in the energy state of light itself, rather than from the stretching of space. In this approach, light is treated as a fundamental constituent of the universe, while space and time are regarded as secondary concepts defined through the behavior and relationships of light. As the universe evolves and its average energy density decreases, light that is not bound to matter undergoes a state-dependent transformation, resulting in an increase in wavelength observed as redshift. This process does not require redshift to accumulate deterministically in proportion to distance; instead, the observed redshift–distance relation is interpreted as a statistical tendency. The same conceptual framework is applied to the cosmic microwave background (CMB). The extremely long wavelength of the CMB is interpreted as a remnant of the high-energy-density conditions of the early universe, encoded in the energy state of light rather than produced by spatial wavelength stretching. This paper does not challenge the observational validity of redshift or the CMB, but reexamines their theoretical interpretation. By shifting the focus from space to light, it proposes an alternative conceptual foundation for cosmology that remains consistent with empirical observations while relaxing the necessity of spatial expansion.