The Whole Truth: A Cosmologist's Reflections on the Search for Objective Reality

by P. J. E. Peebles

Overview

From the Nobel Prize–winning physicist, a personal meditation on the quest for objective reality in natural science

A century ago, thoughtful people questioned how reality could agree with physical theories that kept changing, from a mechanical model of the ether to electric and magnetic fields, and from homogeneous matter to electrons and atoms. Today, concepts like dark matter and dark energy further complicate and enrich the search for objective reality. The Whole Truth is a personal reflection on this ongoing quest by one of the world’s most esteemed cosmologists.

What lies at the heart of physical science? What are the foundational ideas that inform and guide the enterprise? Is the concept of objective reality meaningful? If so, do our established physical theories usefully approximate it? P. J. E. Peebles takes on these and other big questions about the nature of science, drawing on a lifetime of experience as a leading physicist and using cosmology as an example. He traces the history of thought about the nature of physical science since Einstein, and succinctly lays out the fundamental working assumptions. Through a careful examination of the general theory of relativity, Einstein’s cosmological principle, and the theory of an expanding universe, Peebles shows the evidence that we are discovering the nature of reality in successive approximations through increasingly rigorous scrutiny.

A landmark work, The Whole Truth is essential reading for anyone interested in the practice of science.

Product Details

ISBN-13:	9780691231358
Publisher:	Princeton University Press
Publication date:	08/02/2022
Pages:	264
Product dimensions:	6.40(w) x 9.30(h) x 1.00(d)

About the Author

P. J. E. Peebles is a Nobel Prize–winning physicist and the author of several books, including Cosmology’s Century: An Inside History of Our Modern Understanding of the Universe, Principles of Physical Cosmology, Quantum Mechanics, and Physical Cosmology (all Princeton). He is the Albert Einstein Professor of Science Emeritus in the Department of Physics at Princeton University.

Table of Contents

Preface xi

Chapter 1 On Science and Reality 1

1.1 Thinking a Century Ago 4

1.2 On Social, Empirical, and Circular Constructions 29

1.3 Philosophies of Science 35

1.4 The Working Assumptions of Physics 42

Chapter 2 The Social Nature of Physics 47

2.1 Multiples 47

2.2 Constructions 50

2.3 The Sociology of Scientific Knowledge 56

Chapter 3 The General Theory of Relativity 59

3.1 The Discovery 59

3.2 The Social Construction 65

3.3 The Early Tests 67

3.3.1 The Orbit of Mercury 67

3.3.2 Gravitational Redshift 69

3.3.3 Gravitational Deflection of Light 75

3.4 The Empirical Establishment 79

3.5 The Lessons 84

Chapter 4 Einstein's Cosmological Principle 86

4.1 Einstein's Homogeneous Static Universe 86

4.2 Evidence of Homogeneity 92

4.3 The Fractal Universe 97

4.4 Lessons 100

Chapter 5 The Hot Big Bang 103

5.1 Gamow's Hot Big Bang Cosmology 104

5.2 The Steady-State Cosmology 111

5.3 Fossils from the Big Bang: Helium 112

5.4 Fossils from the Big Bang: Radiation 119

5.4.1 Unexpected Excitation of Interstellar Cyanogen 119

5.4.2 Dicke's Quest 122

5.4.3 Unexpected Radiation in Bell Microwave Receivers 126

Chapter 6 The ACDM Theory 133

6.1 Initial Conditions 133

6.2 The Curvature of Space Sections 135

6.3 The Cosmological Constant 137

6.4 Inflation and Coincidences 144

6.5 Baryonic and Subluminal Matter 149

6.6 Dark Matter 154

6.7 The CDM Theory 159

6.8 The ACDM Theory 162

6.9 Confusion 164

6.10 Resolution 169

6.10.1 The Redshift-Magnitude Relation 169

6.10.2 Patterns in Distributions of Matter and Radiation 171

6.10.3 Quantitative Tests 175

Chapter 7 Lessons from a Scientific Advance 183

7.1 Discovery of the ACDM Theory Seems Inevitable 184

7.2 Constructions and the Science Wars 193

7.3 Multiples in the Discovery of ACDM 195

7.4 Questions 199

7.5 The Future 206

7.6 On Reality 207

References 217

Index 235

What People are Saying About This

From the Publisher

“The objective reality of this book is that P. J. E. Peebles is an outstanding cosmologist and a fine writer. To learn what he sees as the objective reality of the universe, please read the book!”—Virginia Trimble, coeditor of The Sky Is for Everyone: Women Astronomers in Their Own Words

“Over the past hundred years, our understanding of the structure of our universe as a whole has developed enormously. No one is better qualified to describe these profound and remarkable changes than James Peebles, which he has achieved magnificently in The Whole Truth.”—Roger Penrose, author of Fashion, Faith, and Fantasy in the New Physics of the Universe

“A fascinating and authoritative exploration of the development of physical cosmology by a giant of the field. The Whole Truth makes a compelling case for the power of the scientific method to lead us to the ultimate nature of reality. An engrossing read with deep philosophical insights that bed down in one’s mind.”—Hiranya Peiris, University College London and the Oskar Klein Centre, Stockholm

“Peebles shares refreshingly generous and open-minded reflections on major milestones in the physics community’s century-long efforts to learn about the structure and evolution of our universe.”—David Kaiser, author of Quantum Legacies: Dispatches from an Uncertain World

“Peebles gives us a fascinating firsthand account of how we came to our current ideas about the universe and its workings, and why they have become so compelling. In this thought-provoking book, he elegantly reveals the process of how science gets done and the intriguing way in which new ideas emerge and take hold.”—Jo Dunkley, author of Our Universe: An Astronomer’s Guide

“Written by one of the leading cosmologists of our time, this book presents a powerful argument for the objective reality of modern science. Elegantly written in a very personal style, The Whole Truth is sure to provoke thought, discussion, and controversy. A must-read for anybody interested in the truth of modern science.”—Jürgen Renn, author of The Evolution of Knowledge: Rethinking Science for the Anthropocene

“The emergence of a standard cosmological model is an amazing triumph. Peebles has been a creative force in this research for sixty years. He recounts the key stages in this enterprise: the missteps, the key controversies, and their gradual resolution, presenting them not only for their intrinsic interest but also as a case study in how the scientific community operates. No one else could have written with more authority on this theme. His book deserves wide readership.”—Martin Rees, author of On the Future and Our Cosmic Habitat

“The eminent physicist James Peebles proves Sidney Morgenbesser wrong when he quipped that pragmatism is all very well in theory, but it doesn’t work in practice. The Whole Truth is a superb insider’s account of the pragmatist idea that our best theories are approximations of objective reality.”—Cheryl Misak, author of Frank Ramsey: A Sheer Excess of Powers

“A unique and absorbing book. Peebles relates fascinating memories from six decades at the frontier of cosmology but is willing to ask deep questions about what we have really learned. Is there an objective reality that underpins our cosmological model and the observations that drive the theory? The book surveys what professional philosophers have had to say on this, but we also get the personal view of a scientist who shaped much of our current understanding of the universe.”—John A. Peacock, winner of the Shaw Prize and author of Cosmological Physics

“Written by one of the fathers of contemporary cosmology, this book provides an impressive contribution to a blossoming field of history and philosophy of cosmology.”—Michela Massimi, University of Edinburgh

Editorial Reviews

05/01/2022

Nobel Prize-winning cosmologist Peebles (emeritus, physics, Princeton Univ.; Cosmology's Century: An Inside History of Our Modern Understanding of the Universe) here writes an engaging and inviting account of the history of the physical sciences and his own involvement in the field—one that will encourage readers to share in his wonderment. His lifetime of teaching experience comes to the fore as he introduces complex scientific theories and principles for lay audiences. Although he indicates that the physical science and cosmology detailed in the book are described as simply as possible, some chapters will be challenging to fully comprehend without some background in physics. In contrast, when Peebles aims to make connections between physical sciences, sociology, and philosophy, he becomes more accessible, posing questions particularly germane to the modern relationship between society and the advancement of scientific understanding. Owing to clearly delineated sections and subsections that can largely stand alone, a reader could easily navigate between sections and forgo some of the more complicated texts without missing information critical to the understanding of Peebles's book. VERDICT Peebles thoroughly outlines the history of cosmological study and connects it to broader issues (such as the relationship between science and society); would be of interest to physics students as a foundational history of the field, or to anyone interested in the history of science.—Grace O'Hanlon

Library Journal

2022-04-13
A Nobel Prize–winning physicist tries his hand at philosophy.

Peebles, emeritus professor of physics at Princeton, has spent a career studying the universe in the first seconds after the Big Bang. Now in his mid-80s, he looks back at the triumphs of physical science, which began with Newton in the 17th century but vastly accelerated with Einstein in the 20th, and asks a question that will appeal mostly to philosophers and sociologists: Is there an objective reality, and can science describe it? Peebles has no doubt, but there is no shortage of opposition. Perhaps the most stubborn is the postmodern view that scientific discoveries are social constructs that reveal less about reality than culture, class, gender, and politics. In research facilities such as particle accelerators, sociologists have observed for long periods and concluded that the scientists involved were not the traditional seekers of truth but rather ambitious strivers dedicated to their own advancement and heavily invested in theories that owed more to the proclamations of brilliant figures in their field than to actual evidence. Peebles agrees that scientists have their foibles, but he emphasizes the importance of the scientific method, which focuses on evidence and rules that make accurate predictions possible. To illustrate his arguments, he devotes lengthy, highly technical chapters to discoveries in his field, many of which began as social constructs. The author points out that Einstein developed general relativity in 1917 from pure thought and little evidence. Physicists loved it nonetheless, and 50 years passed before evidence for the theory became overwhelming. Peebles never claims that he is writing for a popular audience, and readers unfamiliar with college physics and calculus will struggle. They will also encounter an avalanche of footnotes and quotes from journals and books, often several per page. This book may appeal to scholars, but David Deutsch’s The Beginning of Infinity offers a far more accessible analysis of how scientists arrive at the truth.

Deep thoughts but heavy going.

Kirkus Reviews

"[An] engaging and inviting account of the history of the physical sciences."---Grace O'Hanlon, Library Journal

"This treatment is marked by the author's emphasis on the theory's empirical basis, off eringmany examples of multiple researchers independently arriving at the same conclusion. Such emphasis distinguishes this book from more popularbooks on cosmology, and this alone makes it worth having in a university library."---A. Spero, Choice Reviews

From the Publisher