The Emergence of Space-Time in Quantum Gravity and Quantum Cosmology

Abstract

Our best description of spacetime is provided by general relativity – yet, this theory is not thought to be fundamental. Instead, it is expected to be replaced by a theory of quantum gravity, which may not feature spacetime fundamentally. Models of quantum cosmology use quantum gravity to describe the ‘beginning’ of spacetime from the ‘big bang’ state, as well as the evolution of the universe at the level of quantum gravity. In this essay, I discuss (I) the conditions under which spacetime might be said to emerge from the physics of quantum gravity and models of quantum cosmology, (II) the challenges that the case-study of spacetime emergence poses for our usual understanding of emergence in philosophy, and (III) the appropriate conceptions of emergence for characterising the examples of emergent spacetime from quantum gravity and quantum cosmology.