Comments on the Quantum Vacuum and the Light Acceleration

The recent observations on the far quasars absorption lines spectra and comparison of these lines with laboratory ones provide a framework for explantation of these observations by considering a varying fine structure constant, over the cosmological time-scale. Also, there seems to be an anomalous acceleration in the Pioneer spacecraft 10/11 about $10^{-10} {\rm m}/{\rm s^2}$. These matters lead Ranada to study the quantum vacuum to explain these problems by introducing a phenomenological model for the variation of $\alpha$. In this manuscript we want to show that this model is not a quantum model; it is a classical model that is only in accordance with mentioned observations by adjusting some parameters and is not based on a fundamental physical intuition.