Start with phenomena we already measure
Redshift, gravitational lensing, supernova time dilation, cosmic-background anisotropy and surface-brightness dimming are independently observed. Standard cosmology supplies a model that links these observations. Slow-light alternatives must reproduce the same ensemble of measurements while making additional, independently testable predictions.
The project's hypothesis asks whether photons might have a tiny rest mass and lose kinetic energy during extreme propagation, eventually contributing to an unseen, slower-moving substrate. This is a speculative interpretation, not an observed fate of light.
A map of discriminating tests
| Measurement | Question for a slow-light model | Known obstacle |
|---|---|---|
| Frequency-dependent arrival time | Does vacuum propagation speed depend measurably on photon energy? | Astrophysical plasma dispersion and source time structure |
| Distance–redshift relation | Is there a residual wavelength or distance dependence? | Must agree with supernovae, BAO and the CMB |
| Surface brightness | Does dimming follow the observed Tolman relation? | Simple tired-light models generally fail this test |
| Transient time dilation | Do distant light curves stretch in the observed way? | Must explain the observed (1+z) stretching |
| Photon mass bounds | Does the model require a rest mass consistent with measurements? | Existing bounds are extremely restrictive |
| Image sharpness and lensing | Does the model avoid unobserved scattering and blurring? | Propagation must preserve image fidelity |
A redshift explanation must be quantitative
Describing light as “getting tired” is not a mathematical propagation law. To produce a testable alternative, specify a dispersion relation, an energy-transfer mechanism, its dependence on environment, and the corresponding phase and group velocities. Then derive observables from the model and compare against the same data used to evaluate the standard cosmological model.
What the data does not currently show
There is no accepted empirical detection of vacuum tired-light deceleration that identifies dark matter as cooled photons. There is also no demonstrated mechanism for collecting such a substance with an EIT-inspired spacecraft field. This is why the project places a scientific-status label beside its exploratory claims.
Adapted from the supplied project working document(s): Measuring Slow Light Cosmology's Effects.md; Lost Light in Expanding Universe.md. Summary and cautions on this page distinguish project claims from established scientific consensus.