Product Description

The age of the universe has been one of the great scientific mysteries of our time. This engrossing book tells the story of how the mystery was recently solved. Written by a brilliant science writer who was involved, as a research astronomer, in the final breakthrough, the book provides details of the ongoing controversies among scientists as they groped their way to the truth-that the universe is between 13 and 16 billion years old, older by at least one billion years than the star systems it contains. In clear, engaging language, Gribbin takes us through the history of cosmological discoveries, focusing in particular on the seventy years since the Big Bang model of the origin of the universe. He explains how conflicting views of the age of the universe and stars converged in the 1990s because scientists (including Gribbin) were able to use data from the Hubble Space Telescope that measured distances across the universe.

Product Details

• Amazon Sales Rank: #976823 in Books
• Published on: 2001-02-08
• Original language: English
• Binding: Paperback
• 256 pages

From Publishers Weekly
How can we measure the age of the universe? Renowned astronomer Gribbin (Almost Everyone's Guide to Science, etc.) answers this question by describing both the early guesswork and later refinements that finally converged on an answer. He masterfully explains the techniques to measure astronomical distances available to both ancient and modern astronomers, from simple triangulation to the regular pulsation of Cepheid stars. By the 1950s, physicists understood in detail the fission reaction that occurs in the Sun and calculated its age to be 4.5 billion years. This understanding spawned new theories on the creation and ages of stars. Still, the oldest measurable star only provides a lower limit to the age of the universe. It took the realization that the universe is expanding--the measurement of the "red shift" of light from distant stars--to give a closed-ended estimate of its age. The measurement of the rate of expansion, the "Hubble Constant," is the Holy Grail that Gribbin spends the latter half of the book refining. This quest, which concludes with Gribbin's own research, does finally arrive at an age for the universe, but it is the journey, not the destination, that makes the trip worthwhile. In the end, Gribbin's conclusions seem no more mysterious than if he had determined the age of a tree by simply counting the rings. The text is written clearly and concisely for the general reader, yet nevertheless manages to educate on a wide range of topics in physics. Illustrations. (Apr.)
Copyright 2000 Reed Business Information, Inc.

From Library Journal
If you have ever wondered how scientists determine the age of the universe, then this is your book. Gribbin, one of the best science writers working today, recounts the history of the problem and describes the people who have worked on it. Since the age of the universe is inextricably linked to its size, he devotes most of his work to dealing with methods that have been used, are being used, and are proposed as future means to determine cosmic distances. Since this is intended for a general audience, the technical details and mathematical models have been omitted. However, the work is a very satisfying qualitative depiction of the state of the art. For general science collections.
-Harold D. Shane, Baruch Coll., CUNY
Copyright 2000 Reed Business Information, Inc.

From Kirkus Reviews
How old is the universe? The answer (and the story of how the answer was determined) is the subject of this demanding but not overwhelming account of astronomers at work. The prolific Gribbin (Almost Everyone's Guide to Science, 1999), an astrophysicist turned science popularizer, has a special interest in this question, for a project that he initiated at the University of Sussex contributed to the answer. He traces the search for the age of the universe from the early 17th century (when the Christian establishment pronounced 4004 b.c. to be the date of creation) through the ensuing encroachment of scientists into what had originally been the domain of theologians. He shows the difficulties faced by early geologists and physicists who grappled with the issue (Kelvin calculated the age of the sun at 20 million years, while shortly thereafter Rutherford estimated the age of the earth at not less than 500 million years) and outlines the work of the 20th-century astronomers who created the Hubble Space Telescope. The central character is Edwin Hubble, who built a cosmic distance ladder outward from the Milky Way to the globular clusters, the Magellanic Clouds, the Andromeda Galaxy, and the Virgo cluster of galaxies. The subsequent controversy over the best estimate of the number known as Hubble's Constant (from which can be calculated the date of the Big Bang) is the topic of Gribbin's later chapters. He explains why one side in the debate argued for a value twice as large as the other side, the differences in the various measuring techniques employed to find the correct answer, and the technical advances that made such work possible. The absence of unnerving mathematical formulas and the use of everyday imagesthe movement of a swarm of bees, for example, or a person walking down an up escalatorto depict unfamiliar cosmic phenomena help smooth the way for the nonscientist reader. Close attention is required, but the fascinating story Gribbin has to tell is worth the effort.-- Copyright © 2000 Kirkus Associates, LP. All rights reserved.

Customer Reviews

Measuring the Universe
Overall. I like the book. It had some short comings, and I get to those, but it did make approachable some of what astronomers do and how they do it. The book is basically a historical narrative of the science of astronomy and cosmology, and how they are continuously striving to answer some basic questions: How old is the Earth and consequently the Universe?; What is the nature of that Universe?

In this regard, the book does very well. It introduces historical figures, what they did, how they did it, who they influenced, and a few interesting side trips to historical oddities that later proved prescient. There are historically significant people, and people significant only to the field in the book. The book however, is not so much about people as the questions asked (fundamentally remaining unchanged), the answers each generation uncovered (constantly changing with new insight and new precision of the fundamental technology), and the politics of the scientific community.

The author makes approachable aspects of the theories of Einstein, Newton, Quantum Mechanics, the inner workings of stars and how this influenced astronomy. This is were the author is strongest.

The weak areas are primarily in the paucity if figures, diagrams, and pictures to highlight and illustrate key techniques, theories, and technologies.

What impressed me the most is how the science of astronomy and cosmology are built on estimates, built on assumptions, tied to just a few laws of nature or knowns. The answers the participants in the field devine from their work is constantly being refined as the estimates and assumptions are better understood or tossed out.

Measuring the Age and Size of the Universe
Questions about the age of the universe are tightly coupled to understanding the size and structure of the universe. John Gribbin, a research astronomer as well as a popular writer, tells the story of how astronomers and physicists gradually recognized that the universe was both very large and very old.

We all know today that the universe is immense, that the Milky Way is one of many galaxies, the age of the universe is measured in billions of years, and it began with a big bang. This fundamental understanding is actually quite new. In 1920 the scientific community was deeply divided over whether the Milky Way was essentially the entire universe or whether other large galaxies existed. The age of the universe was significantly underestimated. The Big Bang Theory was first considered seriously in the 1940s.

The Birth of Time is a 200-page detailed look at how this remarkable story unfolded. Gribbin writes well and his explanations are quite lucid. We learn not only about major breakthroughs, but we also explore blind alleys and dead ends. It is an exciting, intriguing story, one that definitely warrants reading.

Nonetheless, this book has one major drawback. Gribbin fails to use explanatory drawings or graphs. For example, he describes the Hertzsprung-Russell (H-R) diagram entirely in words. We laboriously read: So in a diagram (a kind of graph) where the brightness of each star (its absolute brightness, after allowing for how far away it is) is plotted against its colour, all hydrogen-burning stars lie along a single band in the diagram, a band which is called the main sequence, running roughly diagonally from top left to bottom right.

Likewise, without any diagrams or graphs, or equations, Gribbin discusses parallax measurements, the redshift-distance relation, Hubble's Constant, gravitational lensing, spectral lines, and the Cepheid period-luminosity relation. (There were eight black and white full page astronomical photos that were indeed helpful.)

I hope John Gribbin updates his work to include recent findings regarding dark matter and dark energy, and the now highly precise age (13.7 billion years) assigned to the universe.

I reviewed the 2000 edition published by Universities Press.

Interesting, but lacking
This book is an interesting history of the process of developing methods to determine the age of the stars and the universe. The author makes it very clear that there are assumpitons upon assumption, but that steady progress is being made and that different techniques are converging to common answers. Much emphasis is given to the importance of the Hubble Factor and why we still csn't call it a Hubble Constant. I found that, and the quest for refining the Hubble value very interesting.

One of the keys to these estimates is Cepheid variable stars. More explanation of what these stars are, theories about them, and how they are used would be helpful. So would some charts and diagrams. Also how they are distinguished from the other types of variable stars thta are mentioned. I have read other explanations of Cepheid stars, for instance in StarDate magazine, and know that they can be explained well even in relatively non-technical terms. I would also have liked more stragihtforward explanation of how the Hubbble factor is used, not just that it is used.