QBism: The Future of Quantum Physics

by Hans Christian von Baeyer, Lili von Baeyer (Illustrator)

Overview

Measured by the accuracy of its predictions and the scope of its technological applications, quantum mechanics is one of the most successful theories in science—as well as one of the most misunderstood. The deeper meaning of quantum mechanics remains controversial almost a century after its invention. Providing a way past quantum theory’s paradoxes and puzzles, QBism offers a strikingly new interpretation that opens up for the nonspecialist reader the profound implications of quantum mechanics for how we understand and interact with the world.

Short for Quantum Bayesianism, QBism adapts many of the conventional features of quantum mechanics in light of a revised understanding of probability. Bayesian probability, unlike the standard “frequentist probability,” is defined as a numerical measure of the degree of an observer’s belief that a future event will occur or that a particular proposition is true. Bayesianism’s advantages over frequentist probability are that it is applicable to singular events, its probability estimates can be updated based on acquisition of new information, and it can effortlessly include frequentist results. But perhaps most important, much of the weirdness associated with quantum theory—the idea that an atom can be in two places at once, or that signals can travel faster than the speed of light, or that Schrödinger’s cat can be simultaneously dead and alive—dissolves under the lens of QBism.

Using straightforward language without equations, Hans Christian von Baeyer clarifies the meaning of quantum mechanics in a commonsense way that suggests a new approach to physics in general.

Product Details

ISBN-13:	9780674545106
Publisher:	Harvard University Press
Publication date:	10/03/2016
Sold by:	Barnes & Noble
Format:	eBook
Pages:	240
File size:	1 MB

About the Author

Hans Christian von Baeyer is Chancellor Professor of Physics, Emeritus, at the College of William and Mary.

Table of Contents

Cover Title Copyright Dedication Contents Introduction Part I: Quantum Mechanics Chapter 1. How the Quantum Was Born Chapter 2. Particles of Light Chapter 3. Wave/Particle Duality Chapter 4. The Wavefunction Chapter 5. “The Most Beautiful Experiment in Physics” Chapter 6. Then a Miracle Occurs Chapter 7. Quantum Uncertainty Chapter 8. The Simplest Wavefunction Part II: Probability Chapter 9. Troubles with Probability Chapter 10. Probability according to the Reverend Bayes Part III: Quantum Bayesianism Chapter 11. QBism Made Explicit Chapter 12. QBism Saves Schrödinger’s Cat Chapter 13. The Roots of QBism Chapter 14. Quantum Weirdness in the Laboratory Chapter 15. All Physics Is Local Chapter 16. Belief and Certainty Part IV: The QBist Worldview Chapter 17. Physics and Human Experience Chapter 18. Nature’s Laws Chapter 19. The Rock Kicks Back Chapter 20. The Problem of the Now Chapter 21. A Perfect Map? Chapter 22. The Road Ahead Appendix: Four Older Interpretations of Quantum Mechanics Notes Acknowledgments Index

Editorial Reviews

Hans Christian von Baeyer has done a wonderful job with this book. I’ve been fortunate enough to learn QBism twice in my life. The first time, it was the hard way, as colleagues and I battled out every nuance of the forming theory, always testing and retesting, tearing down and reconstructing—we had to turn our world upside down to get there. But the second time was pure pleasure as I learned the subject afresh from Professor von Baeyer’s masterful articulation of it. So many of his turns of phrase are insightful gems I never could have formulated myself. Now for the first time I believe I know how to teach the subject, and there is no better understanding one can have than that!
-- Christopher A. Fuchs, Professor of Physics, University of Massachusetts Boston, and key architect of QBism

Physicists all agree on how to do calculations using quantum mechanics and disagree markedly on what those calculations really mean. With his customary humor and elegance, Professor von Baeyer walks us through one of the more recent attempts to understand the mysterious world inside the atom.
-- James Trefil, Professor of Physics, George Mason University, and the author of Science in World History

QBism remains controversial, but scientifically inclined readers will share von Baeyer’s enthusiasm and come away with a feeling, if not a deep understanding, of quantum phenomena that doesn’t require suspension of disbelief.
-- Kirkus Reviews

Von Baeyer offers a sensible approach to this seemingly esoteric world…He has an enthusiastic presentation and style that sweeps the reader along into the world of quantum physics and makes sense of it.
-- Ralph Peterson Manhattan Book Review

QBism should be applauded as a breeding ground of ideas for multiple disciplines including physics, philosophy, and mathematics, and von Baeyer’s book offers an account accessible to all…[It] provide[s] an outstanding introduction to two of the key components of QBism (quantum theory and subjective Bayesianism), and places the reader into the mind of the QBist in a way that will aid the ongoing debate over its merit. It is a worthwhile read.
-- Kelvin J. McQueen Quantum Times

From the Publisher

QBism should be applauded as a breeding ground of ideas for multiple disciplines including physics, philosophy, and mathematics, and von Baeyer’s book offers an account accessible to all…[It] provide[s] an outstanding introduction to two of the key components of QBism (quantum theory and subjective Bayesianism), and places the reader into the mind of the QBist in a way that will aid the ongoing debate over its merit. It is a worthwhile read.

Quantum Times - Kelvin J. McQueen

Von Baeyer offers a sensible approach to this seemingly esoteric world…He has an enthusiastic presentation and style that sweeps the reader along into the world of quantum physics and makes sense of it.

Manhattan Book Review - Ralph Peterson

Physicists all agree on how to do calculations using quantum mechanics and disagree markedly on what those calculations really mean. With his customary humor and elegance, Professor von Baeyer walks us through one of the more recent attempts to understand the mysterious world inside the atom.

James Trefil

Hans Christian von Baeyer has done a wonderful job with this book. I’ve been fortunate enough to learn QBism twice in my life. The first time, it was the hard way, as colleagues and I battled out every nuance of the forming theory, always testing and retesting, tearing down and reconstructing—we had to turn our world upside down to get there. But the second time was pure pleasure as I learned the subject afresh from Professor von Baeyer’s masterful articulation of it. So many of his turns of phrase are insightful gems I never could have formulated myself. Now for the first time I believe I know how to teach the subject, and there is no better understanding one can have than that!

Christopher A. Fuchs

2016-08-09
“There is a strangeness about quantum mechanics that is rooted not in its mathematical complexity but in the paradoxes and enigmas that have bedeviled it from birth.” Since that birth 90 years ago, scientists regularly explain quantum physics, in all its weirdness, to the general public. Here’s the latest.As “a quantum mechanic in retirement,” von Baeyer (Emeritus, Physics/Coll. of William and Mary; Information: The New Language of Science, 2004, etc.), who has spent 50 years “teaching the subject in universities, operating its mathematical machinery in my research, and struggling to bring its message to the general public,” describes an ingenious new approach, QBism, that eliminates the paradoxes. Readers may have to take this on faith, but they will not regret the effort. Traditionally, quantum phenomena are measured by statistics. One can’t locate an electron; one can only determine the probability of finding it somewhere—anywhere in the universe. This oddity isn’t helped by the fact that traditional statistics says nothing about single events. Bayesian statistics (the “B” in QBism) include an observer who estimates the probability that data such as the precise location of the electron is true and then updates the probability when new information arrives. Using comprehensible analogies (none from physics), the author demonstrates how QBism eliminates quantum weirdness. Schrödinger’s famous cat is no longer both dead and alive as long as it remains unseen; the observer can calculate the odds that it’s one or the other. “QBism implies a radical change in perspective,” writes von Baeyer. “It turns the traditional top-down view upside down by offering a bottom-up depiction of the universe…[and] seeks to find the universal in particular personal experiences.” QBism remains controversial, but scientifically inclined readers will share von Baeyer’s enthusiasm and come away with a feeling, if not a deep understanding, of quantum phenomena that doesn’t require suspension of disbelief.

Kirkus Review