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 aWhy 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....
|Title||:||North Pole, South Pole: The Epic Quest to Solve the Great Mystery of Earth’s Magnetism|
|Number of Pages||:||288 Pages|
|Status||:||Available For Download|
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North Pole, South Pole: The Epic Quest to Solve the Great Mystery of Earth’s Magnetism Reviews
I really enjoy books about science, and particularly ones that give an historical perspective to our ongoing discovery of scientific knowledge.On the subject of the Earth's magnetism, I have to say that I was almost totally ignorant. I know that the Earth has magnetic poles, but that was basically the extent of my knowledge, and I am ashamed to say that it had never occured to me to wonder why the Earth should be magnetic. I had no idea that the entire Earth is covered in a magnetic field that protects us from solar winds and cosmic ray particles. Without this protective magnetic field, the Earth would be an uninhabitable planet.Gillian Turner is a British geophysicist, who works at Victoria University, Wellington (New Zealand). She describes this book as "the history of a scientific quest that has spanned several millenia." That quest was the drive to solve the problem of Earth's magnetism - why is the Earth magnetic? Is the magnetism generated internally or externally? And most puzzling of all, how is the magnetism sustained?The journey to understand this problem begins in 900BC, with the Greek legend of the shepherd Magnes, who went out to tend his sheep the morning after an electrical storm and found that his iron-studded boots stuck to the rocks. This was the first type of magnetism that was identified by humans - the local magnetisation of rock that is rich in magnetite, an oxide of iron, after it has been struck by lightning. This rock is known as lodestone.The interest in magnetisation really took off with the development of the compass and it's importance to ocean navigation. Why did the compass needle always point north, but not directly to the geographical north pole? Why did the variation between magnetic north and true north change from place to place across the globe? Why did the needle dip up and down at different degrees depending on latitude? The quest to answer all these questions involved some of the greatest scientific minds, and intersected with scientific discoveries regarding the calculation of longitude, the discovery of electricity and the development of geology. Scientists playing a major role in this story include Halley, Gauss, Ampere, Faraday, Coulomb, Clerk Maxwell, and many more.The final chapters in this quest for understanding are still to be written. Major breakthroughs in understanding the magnetism of the Earth have only become possible within the last 20 years. Prior to that, we did not have the supercomputers necessary to undertake the immense mathematical calculations needed to solve the equations that would explain the magnetic processes taking place within the Earth.I have to admit that a lot of the science in this book was way over my head, but I still got a lot out of it. I learnt a huge amount and I really enjoyed reading about all the scientists involved in solving this puzzle, and as always I found myself totally fascinated by the way in which scientific knowledge grows and feeds off itself in a cascading domino effect.The only thing I would have liked more of in this book would have been some discussion of the effects on life on Earth of such things as shifting magnetic polarities and the changing strength of the Earth's magnetic field. On the very last page Gillian Turner provides us with the tantalising information that in the past 200 years the Earth's magnetic field has dropped by 15% - an astonishing rate of change. What does this mean? If a weaker magnetic field means less protection from solar winds and cosmic rays, could this explain things like climate change and the hole in the ozone layer? I really wish there could have been some discussion of things like this, but perhaps this historical account is not the right place for issues like that. Maybe Gillian Turner will write another book that tackles these questions.
Although I knew most of the basic science regarding earth's magnetism from various other readings, this book tied everything together chronologically and in much more detail. In fact, after finishing it I added it to my History bookshelf as well as the Science shelf because it is so much about the various individuals that have contributed to our knowledge of magnetism since the beginning of the current epoch.I struggled between whether to give it three or four stars. There are sections that were fascinating and deserved the higher rating but overall the book did not hook me as much as I would have liked. It's difficult to say why. At times some of the math or theoretical concepts were a little vague and, for me, could have used more explanation, examples or analogies. At other times it just moved a little slower than I would like.Since plate tectonics is an area of special interest for me, I especially enjoyed the section on how the discovery of sea floor spreading and alternating bands of oppositely polarized rock contributed to the proof of the plate tectonic theory of continental drift.I think if I were a student of geomagnetism looking for an overview of the history of the science I might have given the book the higher rating.
This reviewer knows precious little about geophysics, so will not be complaining, as others have, that this book was directed at a generalist audience. I will complain however about the back cover. I realize this is out of the control of the author, and the blame rests with the publisher, but it is a pet peeve of mine when the cover descriptions do not match the content of the book. Here the back cover questions how birds and other animals navigating by magnetism. . . the book does not deal with this topic at all, aside from a brief mention of the topic in the epilog. Not should this book deal with that topic.It felt overstated for me, in my supreme ignorance, for the book to claim that certain mysteries have been solved. Indeed, theories have been proposed and are evolving. Very little has been solved. At best, we might claim that the answers have been hinted at.
This book was quite an interesting read for me. Generally, a subject like magnetism is split between various publications, classes, and other sources, and only pieces of the story are discovered. I enjoyed being able to follow the research of magnetism through time, and reading about the various scientists that contributed to our knowledge on the subject. It also took me back to the days of my historical geology in following the development of geology as a science. It is amazing how recent theories like plate tectonics and pole reversal are in the history of science.Pros: Well-written especially for a science book (not dry), well organized, comprehensive, chalk-full of interesting historyCons: Likely a bit much for folks lacking in a science and/science history background, pictures and figures may not always be the most appropriate item to include
I got almost nothing out of this book but I'm not quite sure it's the fault of the author. It took me around four months to finally finish because I started it right before summer classes started and read maybe a page or two before passing out each night, finally able to polish it off when classes were over. There are a lot of theories/terminology here that I didn't remember reading it in the piecemeal way that I did. It also required the ability to visualize experiments, theories, etc. and I am basically incapable of visualizing as I read - so personally, I needed more graphics and images to understand what she was talking about. But probably for someone who can visualize, this wouldn't necessarily be a problem.
If you are curious about the origin of the magnetic field of the earth, this is a pretty good place to start. Turner goes through the history of discovery, the basic physical ideas involved, and our evolving understanding of what turns out to be an extraordinary complicated phenomenon. This is another place which demonstrates that as much as we know about the world, we actually know a lot less than I'd like to think. For instance, when exactly are the poles going to turn? What happens when the magnetic field is a tenth of its normal size? Questions that are fairly important for our health and wellbeing, yet there are no clear answers.
This book didn't quite live up to my expectations so I ended up skimming a good chunk of it. Overall, it just felt like reading a really long Wikipedia entry: comprehensive yet condensed list of facts. I personally would have appreciated more presence from the author such as in Brian Greene or Bill Bryson's writing. The later chapters were more engaging as those covered topics that were closer to the author's own research era. In the end this is more of a history book than a book about the underlying science. Somehow a great topic and a great title just ended up as an average book.
Very detailed explanation of the history of the attempts to describe the physical forces that create the Earth's magnetic field. Interesting parallel while reading is the detailed explanations of the tools and techniques developed to help in the effort. Recommend this for anyone interested in Geology, Geodesy, Geography and Cartography.
A workmanlike accounting of the history of the science of magnetism. The early chapters are interesting and insightful but unfortunately the last chapters are sometimes unintelligible.
This book should be dedicated to all people who still believe that Climate Change is not real.