In order to explain the Hubble diagram for quasars, an alternative to ΛCDM is proposed, namely, a simple Newtonian cosmological model where the loss of photons along the line-of-sight mimics the cosmic distance-duality relation, up to z ≈ 0.2. According to this model, after ≈ 3 Gyr of travel, half of the photons emitted by a galaxy have been lost.