The Metaphysical Challenge of Loop Quantum Gravity

Abstract

Many consider the apparent disappearance of time and change in quantum gravity the main metaphysical challenge since it seems to lead to a form of Parmenidean view according to which the physical world simply is, nothing changes, moves, becomes, happens. In this paper, I argue that the main metaphysical challenge of Rovelli’s philosophical view of loop quantum gravity is to lead exactly to the opposite view, namely, a form of Heraclitean view, or rather, of radical process metaphysics according to which there is becoming (process, change, event) but not being (substance, stasis, thing). However, this does not entail that time is real. Fundamentally, time does not exist. I show how Rovelli’s understanding of loop quantum gravity supports the view that there is change without time, so that the physical world can be timeless yet ever-changing. I conclude by arguing that it is such a process-oriented conception that constitutes the revolutionary metaphysical challenge and philosophical significance of loop quantum gravity, while the alleged Parmenidean view turns out to be nothing but the endpoint of a long-standing metaphysical orthodoxy.