Assuming the existence of a preferred frame S (i.e., absolute space), we start from a Newtonian model based on the equivalence of gravitational work and inertial energy. Microscopic processes for the absorption and emission of photons lead to frequency shifts in absolute space. The resulting expressions contain both gravitational and velocity components, but?in contrast to the conventional model?the gravitational term dominates. Redshifts are associated with very dense objects at almost any speed relative to S, and with normal stars at low speeds in S; on the other hand, blueshifts correspond to low density objects moving at high speeds in S. These results contrast with the conventional model where red/blueshifts are associated with recession/approximation from/to us. The present model predicts that photons may escape from extremely high-density objects, thus eliminating the concept of black holes. There is no connection assumed between redshift and distance, so that highredshift objects may be associated with objects having smaller redshifts. Also, our theoretical equation for frequency shifts is completely consistent with the phenomenological equation describing the observed periodicity in the redshift of quasars, suggesting that such objects may be formed by an integer number of neutron stars, moving at speeds around 0.5c relative to S.
