Books

Books : reviews

P. J. E. Peebles.
Cosmology's Century: an inside history of our modern understanding of the universe.
Princeton University Press. 2020

Modern cosmology began a century ago with Albert Einstein’s general theory of relativity and his notion of a homogenous, philosophically satisfying cosmos. Cosmology’s Century is the story of how generations of scientists built on these thoughts and many new measurements to arrive at a well-tested physical theory of the structure and evolution of our expanding universe.

In this landmark book, one of the world’s most esteemed theoretical cosmologists offers an unparalleled personal perspective on how the field developed. P. J. E. Peebles was at the forefront of many of the greatest discoveries of the past century, making fundamental contributions to our understanding of the presence of helium and microwave radiation from the hot big bang, the measures of the distribution and motion of ordinary matter, and the new kind of dark matter that allows us to make sense of these results. Taking readers from the field’s beginnings, Peebles describes how scientists working in independent directions found themselves converging on a theory of cosmic evolution interesting enough to warrant the rigorous testing it passes so well. He explores the major advances—some inspired by remarkable insights or perhaps just lucky guesses—as well as the wrong turns taken and the roads not explored. He shares recollections from major players in this story and provides a rare, inside look at how natural science is really done.

A monumental work, Cosmology’s Century also emphasizes where the present theory is incomplete, suggesting exciting directions for continuing research.

P. J. E. Peebles.
The Whole Truth: a cosmologist's reflections on the search for objective reality.
Princeton University Press. 2022

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 keep 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.