Book contents
- Frontmatter
- Contents
- List of contributors
- Foreword
- Editors' preface
- Preface
- Acknowledgments
- Part I An overview of the contributions of John Archibald Wheeler
- Part II An historian's tribute to John Archibald Wheeler and scientific speculation through the ages
- Part III Quantum reality: theory
- Part IV Quantum reality: experiment
- 11 Why the quantum? “It” from “bit”? A participatory universe? Three far-reaching challenges from John Archibald Wheeler and their relation to experiment
- 12 Speakable and unspeakable, past and future
- 13 Conceptual tensions between quantum mechanics and general relativity: are there experimental consequences?
- 14 Breeding nonlocal Schrödinger cats: a thought-experiment to explore the quantum–classical boundary
- 15 Quantum erasing the nature of reality: or, perhaps, the reality of nature?
- 16 Quantum feedback and the quantum–classical transition
- 17 What quantum computers may tell us about quantum mechanics
- Part V Big questions in cosmology
- Part VI Emergence, life, and related topics
- Appendix A Science and Ultimate Reality Program Committees
- Appendix B Young Researchers Competition in honor of John Archibald Wheeler for physics graduate students, postdoctoral fellows, and young faculty
- Index
16 - Quantum feedback and the quantum–classical transition
from Part IV - Quantum reality: experiment
Published online by Cambridge University Press: 29 March 2011
- Frontmatter
- Contents
- List of contributors
- Foreword
- Editors' preface
- Preface
- Acknowledgments
- Part I An overview of the contributions of John Archibald Wheeler
- Part II An historian's tribute to John Archibald Wheeler and scientific speculation through the ages
- Part III Quantum reality: theory
- Part IV Quantum reality: experiment
- 11 Why the quantum? “It” from “bit”? A participatory universe? Three far-reaching challenges from John Archibald Wheeler and their relation to experiment
- 12 Speakable and unspeakable, past and future
- 13 Conceptual tensions between quantum mechanics and general relativity: are there experimental consequences?
- 14 Breeding nonlocal Schrödinger cats: a thought-experiment to explore the quantum–classical boundary
- 15 Quantum erasing the nature of reality: or, perhaps, the reality of nature?
- 16 Quantum feedback and the quantum–classical transition
- 17 What quantum computers may tell us about quantum mechanics
- Part V Big questions in cosmology
- Part VI Emergence, life, and related topics
- Appendix A Science and Ultimate Reality Program Committees
- Appendix B Young Researchers Competition in honor of John Archibald Wheeler for physics graduate students, postdoctoral fellows, and young faculty
- Index
Summary
Exploring quantum reality?
Twentieth-century physics bequeaths us an unruly enigma in the equivocal dichotomy between quantum and classical. Mesoscopic systems: which are they, or when? To some this distinction is but a matter of modeling convenience; to others, the partition bears ontological weight. Whichever one's stance, debates on this issue sharpen our introspection on “Why the quantum?” by demanding rigorous justification for choices of calculative consequence, intuitively made on every day in every field of physics.
The limits seem clear. For few particles, left to their own devices, quantum mechanics runs rampant with its nonclassical phenomenology, viz. superposition, tunneling, and entanglement. But for the largish objects of our everyday experience, the sensory familiarity of classical mechanics holds sway: each object has its (singular) place, and every obstacle must be gone round or over. Strange, then, to ponder how big things are made from small! Somehow the assemblage of perceivable matter inevitably converts quantum constituents to classical collective, as if the ordering of the universe were ruled by atoms' aversion to the public embarrassment of quantum behavior writ large. It's a shame in a sense, for the senses slighted of paranormal experience, but superposition … what would it look like anyway?
- Type
- Chapter
- Information
- Science and Ultimate RealityQuantum Theory, Cosmology, and Complexity, pp. 329 - 344Publisher: Cambridge University PressPrint publication year: 2004