The Arrows of Time: A Debate in Cosmology (Fundamental Theories of Physics Book 172)

The concept of time has fascinated humanity throughout recorded history, and it remains one of the biggest mysteries in science and philosophy. Time is clearly one of the fundamental building blocks of the universe and thus a deeper understanding of nature at a fundamental level also demands a comprehension of time. Furthermore, the origins of the universe are closely intertwined with the puzzle of time: Did time emerge at the Big Bang? Why does the arrow of time ‘conspire’ with the order of the initial state of the universe? This book addresses many of the most important questions about time: What is time, and is it fundamental or emergent? Why is there such an arrow of time, closely related to the initial state of the universe, and why do the cosmic, thermodynamic and other arrows agree? These issues are discussed here by leading experts, and each offers a new perspective on the debate. Their contributions delve into the most difficult research topic in physics, also describing the latest cutting edge research on the subject. The book also offers readers a comparison between the different outlooks of philosophy, physics and cosmology on the puzzle of time. This volume is intended to be useful for research purposes, but most chapters are also accessible to a more general audience of scientifically educated readers looking for deeper insights. The concept of time has fascinated humanity throughout history, and remains one of the biggest mysteries in science and philosophy. Yet a deeper understanding of nature at a fundamental level can only be achieved through a comprehension of this strange fourth dimension. Furthermore, the origin of the universe is closely intertwined with the puzzle of time: Did time emerge at the big bang? Why does the direction of time 'conspire' with the remarkably ordered initial state of the universe? This book addresses many of the most important questions about time: What is time, and is it fundamental or emergent? Why is there such an arrow of time, closely related to the initial state of the universe, and why do the cosmic, thermodynamic and other arrows agree? These issues are discussed here by leading experts, and each offers a new perspective on the debate. Their contributions delve into the most difficult research topic in physics, also describing the latest cutting edge research on the subject. The book also offers readers a comparison between the different outlooks of philosophy, physics and cosmology on the puzzle of time. This volume is intended to be useful for research purposes, but most chapters are also accessible to a more general audience of scientifically educated readers looking for deeper insights Front Matter....Pages i-v Introduction....Pages 1-3 Time After Time — Big Bang Cosmology and the Arrows of Time....Pages 5-42 Fundamental Loss of Quantum Coherence from Quantum Gravity....Pages 43-52 The Clock Ambiguity: Implications and New Developments....Pages 53-68 Holographic Cosmology and the Arrow of Time....Pages 69-108 The Emergent Nature of Time and the Complex Numbers in Quantum Cosmology....Pages 109-148 The Phantom Bounce: A New Proposal for an Oscillating Cosmology....Pages 149-156 Notes on Time’s Enigma....Pages 157-168 A Momentous Arrow of Time....Pages 169-189 Can the Arrow of Time Be Understood from Quantum Cosmology?....Pages 191-203 Open Questions Regarding the Arrow of Time....Pages 205-217 Back Matter....Pages 219-221