For the general public, magnetism often seems more the province of new age quacks, movie mad scientists, and grade-school teachers than an area of actual, ongoing scientific inquiry.
But as Ronald Merrill reveals in Our Magnetic Earth, geomagnetism really is an enduring, vibrant area of science, one that offers answers to some of the biggest questions about our planet's past – and maybe even its future. In a clear and careful fashion, he lays out the physics of geomagnetism and magnetic fields, then goes on to explain how Earth's magnetic field provides crucial evidence for our understanding of continental drift and plate tectonics; how and why animals, ranging from bacteria to mammals, sense and use the magnetic field; how changes in climate over eons can be studied through variations in the magnetic field in rocks; and much more. Throughout, Merrill peppers his scientific account with bizarre anecdotes and fascinating details, from levitating pizzas to Moon missions to blackmailing KGB agents – a reminder that real science can at times be stranger, and more amusing, than fiction.
A winning primer for anyone who has ever struggled with a compass or admired a ragged V of migrating geese, Our Magnetic Earth demonstrates that education and entertainment need not be polar opposites.
Chapter 1. Magnetism and the Present Magnetic Field
Chapter 2. Magnetic Field Reversals
Chapter 3. Earth’s Internal Composition and the Origin of Earth’s Magnetic Field
Chapter 4. The Sun-Earth Connection
Chapter 5. Magnetic Orientation and Navigation by Animals
Chapter 6. The Effects of Geomagnetism and Plate Tectonics on Climate and Paleoclimate
Epigraph Some Parting Comments
Appendix: Rock Magnetism Fundamentals
Ronald T. Merrill is professor emeritus of earth and space sciences at the University of Washington. In 2002 he was awarded the John Adam Fleming Medal of the American Geophysical Union.
"Ronald Merrill skillfully weaves his professional expertise in geomagnetism with related scientific issues and personal anecdotes to create a broad intellectual tapestry that, in its many fascinating diversions and anecdotes, gives insight into how the mind actually works while exploring a question of abiding interest. Reading this book will be a learning experience for almost everyone – and an unfailingly pleasant one at that!"
- Robert Coe, University of California, Santa Cruz
"Part science, part history of science, and part personal experience, Our Magnetic Earth seamlessly draws together a variety of seemingly unrelated topics – from climate to space weather to geologic time to the Sun – under the grand heading of magnetism. [Readers will be amazed to learn] just how much the field of magnetism has contributed to earth sciences and to our current understanding of our planet's past, while they also enjoy the many wonderful anecdotes from working scientists with which Merrill sprinkles the book. Ultimately, we come away from this book understanding both much, much more about magnetism and about the importance of scientific literacy in today's society."
- Bruce Moskowitz, University of Minnesota