North Pole, South Pole: The Epic Quest to Solve the Great Mystery of Earth's Magnetism

by Gillian Turner

Overview

The ancient mystery that, generation after generation, baffled the world’s greatest scientific minds

Why do compass needles point north—but not quite north? What guides the migration of birds, whales, and fish across the world’s oceans? How is Earth able to sustain life under an onslaught of solar wind and cosmic radiation? For centuries, the world’s great scientists have grappled with these questions, all rooted in the same phenomenon—Earth’s magnetism.

Over 2,000 years after the invention of the compass, Einstein called the source of Earth’s magnetic field one of greatest unsolved mysteries of physics. Here, for the first time, is the complete history of the quest to understand Earth’s magnetism—from the ancient Greeks’ fascination with lodestone, to the geological discovery that the North Pole has not always been in the North—and to the astonishing modern conclusions that finally revealed the true source.

Richly illustrated and skillfully told, North Pole, South Pole unfolds the human story behind the science: that of the inquisitive, persevering, and often dissenting thinkers who unlocked the secrets at our planet’s core.

Product Details

ISBN-13:	9781615190317
Publisher:	The Experiment, LLC
Publication date:	01/11/2011
Pages:	288
Product dimensions:	5.50(w) x 8.25(h) x 0.90(d)

About the Author

Gillian Turner is a senior lecturer in physics and geophysics at Victoria University in Wellington, New Zealand. The winner of numerous awards for excellence in teaching and science communication, Turner has published over fifty articles in scientific journals. This is her first book.

Table of Contents

Illustrations x

Main Characters xii

Introduction 1

1 The Mystery of Magnetism 5

2 Voyages of Discovery 20

3 Magnus Magnes 32

4 The Wandering Compass Needle 48

5 Measuring the Force 63

6 Of Forces and Fields 78

7 The Third Element 101

8 The Magnetic Crusade 114

9 The Core of the Matter 130

10 Reading the Rocks 151

11 Poles Flipped, Continents Adrift 167

12 The Story on the Seafloor 185

13 Unraveling the Record 195

14 In Search of a Solution 213

15 The Geodynamo 224

Epilogue 238

Glossary 246

Select Bibliography 257

Illustration Credits 259

Acknowledgments 263

Index 265

About the Author 272

Editorial Reviews

"A compelling narrative of the two-thousand-year scientific struggle to unlock the innermost secrets of the cosmic speck of dust we call home. Engagingly written in a lively style accessible to all."

M. E. (Ted) Evans

"By deftly combining threads from science and history, Turner weaves a fascinating geophysical tale that spans several millennia."

Science News

"She has provided a concise and interesting history of the study of magnetism, and a fascinating new perspective on one of the most important geological discoveries of the twentieth century. . . It’s well worth a look!"

Geotripper blog

"The book is as much about the history of science as it is about the actual science itself, illustrating how we are often ‘standing on the shoulders of giants.’ . . . Beautifully illustrated with maps and ancient experimental devices that helped set the focus for the study of magnetism, the book is concerned with instrumentation and innovation. . . . Certainly history and science teachers at all levels would benefit from reading it."

National Science Teachers Association

"North Pole, South Pole is a comprehensive account of one of the great forces that shapes our planet and its future."

Richmond Times-Dispatch

"A wonderful, joyful, lucid book. Turner is a natural storyteller."

Ted Irving

[An] engaging appreciation of science at work discovering the mysteries of magnetism.”
—Kirkus Reviews

"By deftly combining threads from science and history, Turner weaves a fascinating geophysical tale that spans several millennia."
—Science News

“A compelling narrative of the two-thousand-year scientific struggle to unlock the innermost secrets of the cosmic speck of dust we call home. Engagingly written in a lively style accessible to all.”
—M. E. (Ted) Evans, Professor Emeritus, Department of Physics, University of Alberta, Edmonton

“A wonderful, joyful, lucid book. Turner is a natural storyteller.”
—Ted Irving, Geological Survey of Canada

“The book is as much about the history of science as it is about the actual science itself, illustrating how we are often “standing on the shoulders of giants.” . . . Beautifully illustrated with maps and ancient experimental devices that helped set the focus for the study of magnetism, the book is concerned with instrumentation and innovation. . . . Certainly history and science teachers at all levels would benefit from reading it.”
—National Science Teachers Association

"She has provided a concise and interesting history of the study of magnetism, and a fascinating new perspective on one of the most important geological discoveries of the twentieth century. . . It's well worth a look!"
—Geotripper blog

"North Pole, South Pole is a comprehensive account of one of the great forces that shapes our planet and its future."
—Richmond Times-Dispatch

From the Publisher

Turner (senior lecturer, Victoria Univ., Wellington, New Zealand) has written a highly accessible history of the discovery and understanding of Earth's magnetism. She covers all of the major historical steps in the discovery of magnetism and presents her information in such a way that makes potentially difficult scientific concepts easy to understand and even entertaining to read. Human drama is also at play here, as many scientists throughout history have struggled to discover magnetism's many secrets. VERDICT Libraries that own Gerrit Verschuur's Hidden Attraction: The History and Mystery of Magnetism may not need to add this work, but Turner's title is recommended for popular history of science collections as well as for all readers looking to understand how we came to our current understanding of magnetism. Since it also involves long sea voyages, this book will also be an enjoyable read for those interested in the history of navigation.—Eric D. Albright, Tufts Univ. Hirsh Health Sciences Lib., Boston

Library Journal

In her debut, Turner (Geophysics/Victoria Univ., New Zealand) negotiates the slippery ground between hard and popular science in this story of magnetism.

The author begins with the ancient Greeks, as well as the Chinese, who used the compass in the art of feng shui, and continues through its deployment by Europeans (who may have independently discovered the tool) in the creation of portolan charts and rhumb lines, which allowed mariners to move beyond known coastlines. Despite these advances, the idea of magnetism was still little-understood. Enter the physicists and mathematicians, and here Turner takes no prisoners in her popular audience. To appreciate that the Earth's magnetic field is a "geocentric axial dipole," readers will have to dig through discussions of physics, chemistry, electricity, precession, nutation, perturbation, seismology and the Chandler wobble. Some of the author's knottier sentences—e.g., "the ratios of rough measurements of magnetic field strength (or, more precisely, dipole moment) and rotational angular momentum came very close to the square root of the gravitational constant—the constant, G, in Newton's law of gravitation, which had eventually been measured by Henry Cavendish—divided by the speed of light"—may be a bit much for general readers, but for the most part Turner achieves an engaging appreciation of science at work discovering the mysteries of magnetism. By the time she hits continental drift, polar wander and the geodynamo theory, readers mayeven understand what she means by saying that "the twisting and shearing caused by convection and the rotation of the Earth convert toroidal field lines into poloidal field lines and vice versa."

A mostly smooth explanation of a rarefied area of science.

Kirkus Reviews