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, and forthcoming from Oxford University Press. Selected chapters will be posted here as they are completed. (Our publication agreement prevents us from posting all the chapters.)

Chapter One: Introduction

Chapter Two: Spacetime from causality: causal set theory

Chapter Three: Spacetime from causal sets

Chapter Four: In progress

Chapter Five: In progress

Chapter Six: A primer on string theory for philosophers (of physics)

Chapter Seven: Duality

Chapter Eight: The string theoretic account of general relativity

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

Chapter Ten: Conclusion


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.