Out of Nowhere: The Emergence of Spacetime in Quantum Theories of Gravity

Out of Nowhere is the monograph co-authored by Nick Huggett and Christian Wüthrich, which appeared in 2025 from Oxford University Press. Selected chapters are posted here. (Our publication agreement prevents us from posting all the chapters.)

Chapter One: Introduction: the emergence of spacetime

Chapter Two: Spacetime functionalism

Chapter Three: Spacetime from causality: causal set theory

Chapter Four:  The emergence of pacetime from causal sets

Chapter Five: The road to loop quantum gravity

Chapter Six: The disappearance and emergence of spacetime in LQG

Chapter Seven: A string theory primer

Chapter Eight: Duality

Chapter Nine: The string theoretic account of general relativity

Chapter Ten: The ’emergence’ of spacetime in string theory

Chapter Eleven: Conclusion: whence spacetime?

Synopsis

The book starts out from the recognition that in quantum theories of gravity, spacetime disappears in some sense or other and investigates the philosophical implications of a fundamentally non-spatiotemporal world, as well as how spacetime is thought to re-emerge in various of the main approaches to quantum gravity.

It argues that in theories of quantum gravity, the spacetime of experience and existing physics ’emerges’ from essentially non-spatiotemporal structures. We present for philosophers several central research programs in quantum gravity, and investigate their philosophical significance in two directions. First, we explore the different ways in which spacetime ‘disappears’ in the theories. Since many philosophical concepts–particularly in metaphysics–assume classical space or time, our analysis of these worlds without spacetime (for which there may be scientific evidence) points to profound consequences for philosophy. Second, it seems remarkable–perhaps incredible–that something as apparently basic as spacetime could be non-fundamental, and so we investigate the derivations of spacetime structures in quantum gravity. The crucial point is to identify the new explanatory criteria of the theory, those that sort physically salient derivations from the merely formal. In addition, the book argues that investigations of concepts and explanatory principles are essential to the creation of new science: the book is also intended as a contribution to the scientific development of quantum gravity.