This book surveys the science at a semipopular, Scientific American-level. It is even-handed with regard to competing directions of research and philosophical positions. It is hard to get even two people to agree on anything, yet a million billion water molecules can suddenly and abruptly coordinate to lock themselves into an ice crystal or liberate one another to billow outwards as steam. The marvelous self-organizing capacity of matter is one of the central and deepest puzzles of physics, with implications for all the natural sciences. Physicists in the past century have found a remarkable diversity of phases of matter―and equally remarkable commonalities within that diversity. The pace of discovery has, if anything, only quickened in recent years with the appreciation of quantum phases of matter and so-called topological order. The study of seemingly humdrum materials has made contact with the more exotic realm of quantum gravity, as theorists realize that the spacetime continuum may itself be a phase of some deeper and still unknown constituents. These developments flesh out the sometimes vague concept of the emergence―how exactly it is that complexity begets simplicity.
Author(s): George Musser
Series: SpringerBriefs in Physics
Publisher: Springer
Year: 2022
Language: English
Pages: 103
City: Cham
Acknowledgements
Contents
About the Author
1 Introduction
1.1 What is Emergence?
1.2 Is Emergence Fundamental?
1.3 Weak Versus Strong Emergence
References
2 Emergence in Condensed Matter Physics
2.1 Introduction
2.1.1 Just a Phase They’re Going Through—Landau’s Theory of Phase Transitions
2.1.2 Tipping the Scales
2.1.3 Non-equilibrium Phases of Matter
2.2 Soft Matter
2.3 Quantum Phases of Matter
2.3.1 Quantum Physics
2.3.2 Frozen yet Mobile—Superconductors, Bose–Einstein Condensates, and Strange Metals
2.3.3 Critical Symmetry
2.3.4 “Twistronics”—Graphene’s Magic Angle
2.4 Topological Phases of Matter
2.4.1 The Hall Effects
2.4.2 Topological Insulators and Topological Nanomaterials
2.4.3 Hunting for New Topological Materials—Can A.I. Help?
2.4.4 Entangled in More Ways Than One—Topological Quantum Computing
2.4.5 Topological Inspiration for Other Areas of Science
2.5 Condensed Matter and the Unification of Physics—The String-Net-Liquid Model
References
3 Emergence of Space
3.1 Introduction—Is Spacetime Doomed?
3.1.1 Einstein’s Space
3.1.2 Hints that Space Is Emergent
3.1.2.1 The Black-Hole Information Paradox
3.1.2.2 Quantum Entanglement
3.2 Space from Entanglement
3.2.1 The Universe as a Hologram—The AdS/CFT Duality
3.2.2 Why Entanglement?
3.2.3 How Entanglement Reproduces Space
3.2.4 Space as Error Correction
3.2.4.1 The Causal Wedge Paradox
3.2.4.2 Modeling Emergence with Qubits
3.3 Black Holes
3.3.1 Down the Wormhole—Resolving the Black-Hole Information Paradox
3.3.2 Island Rule
3.3.3 Complexity and Black Holes
3.3.4 Testing Emergence in the Lab: Black Hole Scrambling
3.4 Extending Duality
3.4.1 Going Beyond AdS/CFT
3.4.2 Loop Quantum Gravity
3.4.3 Causal Sets
3.4.4 Causal Dynamical Triangulations
References
4 Lateral Thinking—The Holographic Principle in Condensed Matter
4.1 Introduction
4.2 Dualing Theories
4.2.1 Nuclear Plasmas and Holography
4.2.2 Quantum Phases and Holography
4.3 The SYK Model—Creating Spacetime from Particles
References
