Multiverse Theories: A Philosophical Perspective

Description

If the laws of nature are fine-tuned for life, can we infer other universes with different laws? How could we even test such a theory without empirical access to those distant places? Can we believe in the multiverse of the Everett interpretation of quantum theory or in the reality of other possible worlds, as advocated by philosopher David Lewis? At the intersection of physics and philosophy of science, this book outlines the philosophical challenge to theoretical physics in a measured, well-grounded manner. The origin of multiverse theories are explored within the context of the fine-tuning problem and a systematic comparison between the various different multiverse models are included. Cosmologists, high energy physicists, and philosophers including graduate students and researchers will find a systematic exploration of such questions in this important book. Cover Half-title Title page Copyright information Dedication Contents Preface Part I Setting the Stage 1 Introduction 1.1 Multiverse Theories and Why to Consider Them 1.2 Types of Multiverse Theories 1.3 Overview of This Book 1.4 At a Glance: Some Theses Defended in This Book 2 The Fine-Tuning Considerations 2.1 Fine-Tuning for Life: The Evidence 2.2 Is Fine-Tuning for Life Improbable? 3 Fine-Tuning for Life and Design 3.1 The Inference from Fine-Tuning for Life to Design as a Version of the Teleological Argument 3.2 The Fine-Tuning Argument for Design Using Probabilities 3.3 The Anthropic Objection 3.4 Which Design Hypothesis Exactly? 3.5 An Alternative Fine-Tuning Argument for Design Part II Fine-Tuning for Life and the Multiverse 4 The Standard Fine-Tuning Argument for the Multiverse 4.1 The Inverse Gambler’s Fallacy Charge 4.2 Urn Analogies 4.3 Broadening the Debate 4.4 The Fine-Tuned Planet 4.5 The Fine-Tuned Ancestors 4.6 The Lucky Civilization 4.7 A Glance at the Fermi Paradox 4.8 Back to the Multiverse 5 Problems with Priors 5.1 Bayesian Formulation 5.2 Motivating an Ur-Prior for the Multiverse? 5.3 The Double-Counting Charge Stated 5.4 The Standard Fine-Tuning Argument for the Multiverse without Double-Counting 5.5 Rebutting the Inverse Gambler's Fallacy Charge – What It Would Take 6 A New Fine-Tuning Argument for the Multiverse 6.1 The Argument from Fine-Tuning for the Multiverse as an Inference to an Anthropic Explanation? 6.2 Anthropic Reasoning: Dicke/Carter-Style 6.3 The New Fine-Tuning Argument Stated Part III Testing Multiverse Theories 7 Testing Multiverse Theories: Theoretical Approach 7.1 The Challenge of Testing Multiverse Theories 7.2 Toward a Formalization of Anthropic Reasoning 7.3 The Background Information Constraint 7.4 The Reference Class Problem (Formally) Resolved 8 Testing Multiverse Theories: Approaching Practice 8.1 Implementing the Background Information Constraint 8.2 Observer Proxies 8.3 Cosmology’s Measure Problem 8.4 Researcher Degrees of Freedom 8.5 Why Testing Multiverse Theories Is So Damn Difficult 8.6 A Way Out à la “Open Science”? 9 Puzzles of Self-Locating Belief 9.1 Troubles for Self-Locating Indifference? 9.2 Reacting to the Puzzles 9.3 Lessons for the Sleeping Beauty Problem Part IV Wider Still and Wilder 10 Other Multiverses 10.1 The Everettian Quantum Multiverse 10.2 Modal Realism 10.3 A Multiverse of Mathematical Structures? 11 Outlook 11.1 Is the Multiverse Even Science? 11.2 Whither Physics? References Author Index Subject Index