Emergent Spacetime: Reality or Illusion?

Abstract

The contemporary physics has revealed growing evidences that the emergence can be applied to not only biology and condensed matter systems but also gravity and spacetime. We observe that noncommutative spacetime necessarily implies emergent spacetime if spacetime at microscopic scales should be viewed as noncommutative. Since the emergent spacetime is a new fundamental paradigm for quantum gravity, it is necessary to reexamine all the rationales to introduce the multiverse hypothesis from the standpoint of emergent spacetime. We argue that the emergent spacetime certainly opens a new perspective that may cripple all the rationales to introduce the multiverse picture. Moreover the emergent spacetime may rescue us from the doomsday of metastable multiverse as quantum mechanics did from the catastrophic collapse of classical atoms.