Redshifts of cosmological neutrinos as definitive experimental test of Doppler versus non-Doppler redshifts

The observed cosmological redshifts of electromagnetic photons have been interpreted as due to Doppler recessional velocities and/or space-expansion. However, energy-loss interactions between light and intervening matter can also lead to redshifts. It is proposed that experimental observation of neutrino redshifts compared with photon redshifts will provide distinctive definitive evidence for the validity of a Doppler versus non-Doppler mechanism as the cause of any observed redshift. A Doppler and/or space-expansion effect will yield comparable photon and neutrino redshifts. Whereas, a non-Doppler mechanism arising from an energy-loss interaction with intervening matter will yield a very small neutrino redshift compared to a photon redshift. Consistent with Type 1A Supernova observations, any non-Doppler light mechanism will also yield a significant time delay in light arrival at Earth compared to neutrino arrival.