Does time differ from change? Philosophical appraisal of the problem of time in quantum gravity and in physics

After reviewing the problem of time in Quantum Gravity, I compare from a philosophical perspective, both Carlo Rovelli's and Julian Barbour's (before Shape Dynamics) understanding of time in Quantum Gravity and in dynamics in general, trying to show that those two relational understandings of time differ. Rovelli argues that there is change without time and that time can be abstracted from any change whereas Barbour claims that some motions are better than others for constituting duration standards and that time is to be abstracted from all change in the universe. I conclude by a few remarks on Bergson׳s criticism of physics in the light of those debates trying to show that both Rovelli and Barbour give surrationalist (as Bachelard understood it) answers to the critique of spatialized time in Physics.