Astronomical observations of cosmological red-shift are currently interpreted in terms of ‘expansion of universe’ and ‘accelerated-expansion of the universe’. Whereas a straight forward derivation presented here suggests that: it is not the universe, which is expanding, rather it is the photon which is decelerating, at the rate of H0 c; here H0 is Hubble’s constant, and c is the speed of light. (As soon as a new mechanism for the ‘cosmological red-shift’ is proposed, it is argued that: tired-light interpretations of cosmological red-shift’ are not compatible with the observations of ‘time-dilation of super-novae light-curves’. So in a paper titled: “Wave-theoretical insight into the Relativistic ‘length-contraction’ and ‘time-dilation of super-novae light-curves’” [1] it has been already shown that any mechanism which can cause ‘cosmological red-shift’ will also cause ‘time-dilation of super-novae light-curves’. Therefore, we now need not remain confined to the Big Bang Cosmology, to understand the universe.) Since, as per this new interpretation of the ‘cosmological red-shift’, the ‘reduction-in-energy of the photon’ (h Δν) goes on reducing with every subsequent unit distance traveled by the photon; so the Red-shift-Distance-Curve automatically becomes non-linear, which has been creating an impression of ‘accelerated-expansion of the universe’. As a supportive evidence for this proposal, it is shown that even the space-probes Pioneer-10, Pioneer-11, Galileo and Ulysses too did decelerate at the same rate H0 c [2]. And to counter-balance this deceleration, the accelerations at the boundaries of: the nucleus-of-atom, the globular-clusters, the spiral-galaxies and the galactic-clusters too, are of the same order as H0 c. This coincidence was numerically found by Sivaram [3]; and is explained here, in terms of equilibrium between self-gravitational-acceleration of structures and the acceleration of the un-manifest-energy contained in space.