Magnetism: A Very Short Introduction

Very Short Introductions #317

by Stephen J. Blundell

In this Very Short Introduction, Stephen J. Blundell illuminates the mysterious force of magnetism. For centuries, magnetism has been used for various purposes—through compasses it gave us the ability to navigate, and through motors, generators, and turbines, it has given us power. Blundell explores our understanding of electricity and magnetism, from the work of Galvani, Ampère, Faraday, and Tesla, and describes how Maxwell and Faraday's work led to the unification of electricity and magnetism—one of the most imaginative developments in theoretical physics. Finally, he discusses the relationship between magnetism and relativity, quantum magnetism, and its impact on computers and information storage, showing how magnetism has changed our fundamental understanding of the Universe.

Genres: Science, Physics, Nonfiction, History, Technology

160 pages, Paperback

First published July 5, 2012

Reviews

[Debalina · Rating 5 out of 5]

Stephen Blundell is one of my favourite writers.He is a physicist at Oxford and I have read a fun textbook by him and Tom Lancaster on QFT. He specialises in magnetism and this 'a very short introduction' of his was nothing but a beautifully gardened walk down the memory lane, and essentially a revision of classical electrodynamics, special relativity, quantum mechanic and you basic solid state physics. I am a condensed matter physicist and this book was made for me. It should definitely be a reference for undergrads in physics in general. It makes you connect different streams which you learn independently and is fun too.

I give it full five stars :D

Some of my musings, if you care to read:

Being a student of the world of condensed spin systems, this small treatise is a treat. I live the humour threaded in the first two chapters. Well, today it is easier to scoff, but this superior smugness I have hanging all around my nose in a spherical protruding shape is a result of hundreds of years of curiosity and careful elimination. A shout out to Franklin and Gilbert! Thanks guys.
~August 23, 2019

Gilbert was such a cynic. I love him! I am reading his chapters for the 5th or 6th time perhaps. Though he was right about many aspects but on many he was wrong too, but you have to appreciate the sound adherence to logic and scientific reasoning as opposed to hokum so much prevalent in those days. He was truly a man ahead of his times. Though I don't blame the others. It was a different world. Science meant a different thing then. But it is so strong today even though our understanding is almost of nothings, but it is what it is because of these men, sadly almost no women. I feel we do a lot injustice when we don't remember there pioneers as much we remember so many other Kings, Queens, Politicians, Writers, Poets. They made our world what it is today. There would be no goodreads without electricity! Huh!
~August 23, 2019, October 13, 20109

Gilbert was also prone to the human nature of over application of a good idea. He made mistakes too. But he and his confident cynicism of all the loose arguments made experiments fashionable. I, after reading his part of the story, would go further a step and say that he made verification fashionable. And that's why and how, logic, strictly adhering to the verified truth, and rechecking became the essence of science.
~August 23, 2019

You perhaps know that Mary Shelley's Frankenstein's later movie adaptations reanimate the dead body parts using electricity. But do you know that this was actually done? Except giving a corpse life part, in a macabre show by Luigi Galvani across Europe and were actually the first experimental proofs of some sort of electrical phenomenon being a part of living creatures, though they were decease here? Haah!"
~August 23, 2019

Also this proved that lightning was electrical. And the experiment was used using a dead frog as a conductor. Seems gross. But imagine the progress made by just this step. It opened a secret and what followed changed the lives for further generations from house making rules, to works on grounding homes, and so on and so forth.
~August 24, 2019

If you are a physics student already familiar with Quantum Mechanics, relativity, classical electrodynamics and magnetism, solid state physics and the usual stuff, this is an amazing and fun reversion session of a book for you. At least it is for me. Will also be a good motivator for the novice and you would be thirsty to understand more. Loved the fluidity of the language and ease of explanation.
~September 24, 2019

Impressions from before: A good, fun summary if you are a physics student especially. Am re-reading it. Now.

[Hanna]

07/12/2025 - Reading update
A thing I DO like in this book is how much the author highlights that sometimes the names we give to phenomena and theories in physics are not actually those of the people who made the discovery first! History is full of scientists whose names get erased by time :)
On another note, I am always moved by stories of scientific discovery. I cannot imagine how exciting it must have been in the 19th century to work on understanding electricity, magnetism, to formalise these phenomena for the first time, using only intuition, experiments and bits of math thus far applied to other fields :)
Wow, reading this book I’m realizing that experiments should play a much more prominent role in teaching electromagnetism in undergrad. Why should we expect students to understand equations that seem to come out of nowhere, when what led to them historically was years of collaboration between experimentalists and mathematical physicists? I suddenly got the urge, for the first time in my life, to pick EM as a course to teach if I ever become an enseignante-chercheuse, because I would like to teach EM the way I would have liked to be taught it.

06/12/2025 - Reading still in progress
As far as explaining magnetism to the layperson goes, this book is alright.
However I admit that I'm taking a bit of an issue with the tone, which to me comes off as unnecessarily smug at moments. As a hopefully-almost-scientist (as I'm reading this, I'm in my last year of grad school for condensed matter physics and I am hopeful that I will become a researcher), it is my opinion that smugness has no place in science communications.

Here's why :
- If your desired audience is people who already know about science, why would you be smug other than to share your idea of an inside joke with them? "Look at us, scientists, punching down on those who are dumber and less educated than us!"
- If your desired audience is the educated layperson, why feed a perhaps already overly confident ego who in fact, technically, still doesn't know much? The Dunning Krueger effect is a real thing, and there's nothing worse than someone who has an overinflated sense of worth because they think they know something that they actually do not. You want to inspire curiosity, not disdain for those who are less privileged than you.
- If your desired audience is the superstitious, "science-skeptical" layperson, then I can guarantee that such a tone won't do the scientific community any favours and will further convince the reader that science is elitist, dogmatic and scornful of the uneducated.

Someone with the privilege of being an Oxford professor of all things should have the maturity to switch out a few smug jokes for approachable explanations, analogies etc. And I've read a textbook by Stephen Blundell, so I know he's very good at breaking down complex topics and explaining them! So I don't really understand some of the choices he made here. Even some of the physics was, in my opinion, strangely explained, almost as if he left Easter eggs for those who know physics but that would remain undetectable for those who don't. I understand wanting to make things more entertaining while pointing out pseudoscience and the like, but I personally wouldn't do it like this. Carl Sagan wrote an entire book on dismantling pseudoscience and I never once felt like he derided his mass of readers which would very well contain those who believed in such things.

I will continue reading this, but it's too bad, because lesser known branches of physics (that are arguably more necessary, I say as a condensed matter physicist in the making :p) deserve to be explained to larger audiences with the same enthusiasm as astrophysics, relativity or quantum mechanics.

[Mark Desrosiers · Rating 4 out of 5]

One thing I did not know: the importance of frogs, or more specifically frogs' legs, in the early study of electricity and magnetism. Luigi Galvani was particularly fond of them, and his lightning detector made out of frogs legs was essential to his proof that lightning consisted of electricity.

This is probably one of the least fascinating facts that abound in another great Oxford Very Short Introduction. I was especially drawn to William Gilbert and his 1600 monograph De Magnete, which takes ample time to bash the murkiness and superstition of "science" (aka "philosophy") as it existed. e.g. his description of Lucas Guaricas: "With a veil of mathematical erudition does he cover many similar disgraceful stupidities." One wonders what a resurrected Gilbert would make of 2015 and its retractionwatch.com.

Blundell takes great care to keep us in the shallow end of mathematics (even Maxwell's equations are, somewhat miraculously, summarized in sentences) as we venture into our current understanding of magnetism. Recommended to pretty much everyone, yes including the Insane Clown Posse. Although I'm still in the dark about why magnetic monopoles don't exist.

[Daniel · Rating 5 out of 5]

Another well-written entry in Oxford's Very Short Introductions series. Professor Blundell summarizes the human experience with magnetism from ancient to modern times. To "really" understand the physics stuff, though, one would have to read considerably more of a technical nature, which Blundell cites in his references.

[Tai Ngo · Rating 3 out of 5]

When I was a high school student, I wondered why magnetism was taught. Creating iron filing patterns with magnets didn't seem to carry any universal, profound meaning and have no obvious application. I couldn't be more wrong. After reading this book, I feel magnetism is fascinating: how it and electricity are two sides of the same coin, how it is related to both relativity and quantum mechanics, why the Universe is emergent, and how it spurs many important technologies such as data storage. After reading this, I became interested in 2 topics: what a quantum mechanical spin is (it's not the usual kind of spin you see), and why we don't have magnetic monopole (yet).

Professor Blundell includes historical developments in this book, which is nice since science is hardly the lone, purely logical work of a genius, but rather a social enterprise spanning over a long period of time involving different people and intersecting with history, economics, society and politics. (Suggestion for science students: please take history of science courses.)

One way he falls short is that his explanations of the experiments and mechanisms aren't always clear. This may be due to the limits of words - they can produce scenes in your head, but these scenes are hardly detailed, and unfortunately science is always about the details. To enrich the experience of reading this book, whenever you feel stuck at an experiment or a theory you encounter in the book, I highly recommend searching for explanation vids on YouTube. My favorite accompanying channels for this book are: Veritasium, Physics Videos by Eugene Khutoryansky and 3Blue1Brown (especially for the explanation of divergence and curl - it is helpful to understand Maxwell's contribution).

[knoba · Rating 3 out of 5]

.
.
Contents
Acknowledgements
List of illustrations
1. Mysterious attraction?
2. The Earth as a magnet
3. Electrical current and the path to power
4. Unification
5. Magnetism and relativity
6. Quantum magnetism
7. Spin
8. The magnetic library
9. Magnetism on Earth and in space
10. Exotic magnetism
Mathematical appendix
Further reading
Index

[Mills College Library]

538 B6589 2012

[Arno Mosikyan · Rating 5 out of 5]

Magnetite is a mineral with chemical formula Fe3O4. It is commonly found in various locations around the world, although it gets its name from Magnesia, a region of central Greece (the names of the chemical elements magnesium and manganese, neither of which have anything much to do with magnetite, also derive from Magnesia).

Many pieces of magnetite are naturally magnetized, probably due to lightning strikes, and will therefore pick up bits of iron. This mysterious property of what became known as magnets was known by the Greeks (it is mentioned by Thales of Miletus in the 6th century BCE) and also to the Chinese (there is a reference to magnetism in literature of the 4th century BCE).

He had made the first step on the road to understanding the magnetism of the Earth. He correctly explained the tides as being due to the influence of the Moon, but incorrectly thought that the influence was mediated magnetically. Gilbert thus fell into the familiar trap that has ensnared many a genius and mere mortal alike, namely that when you get a good idea you tend to see it applying to absolutely everything.

The physicist Alessandro Volta referred to Galvani’s animal electricity as galvanism and the name has stuck; we still talk about an audience hearing a rousing speech being ‘galvanized into action’.

The first of Maxwell’s equations says that every line of electric field originates on a positive charge and ends up on a negative charge.

Maxwell was the first person to really understand that a beam of light consists of electric and magnetic oscillations propagating together. The electric oscillation is in one plane, at right angles to the magnetic oscillation. Both of them are in directions at right angles to the direction of propagation.

Any one of these developments alone was sufficient to earn him a major place in the history of physics; the combined achievement led to more modest immediate rewards: the following year, Einstein was promoted by the patent office to ‘technical examiner second class’.

However, what is important for our story is that Einstein showed that magnetism is a purely relativistic effect, something that wouldn’t even be there without relativity. Magnetism is an example of relativity in everyday life.

Einstein’s equations show that from your perspective some of the electric field is transformed into magnetic field. Magnetic fields are what electric fields look like when you are moving with respect to the charges that ‘cause’ them.

Atoms in lodestone contain electrical currents due to the electrons which orbit the nucleus and these atomic currents are indeed rather special.

Quantum mechanics possesses the curious property that it allows reality to consist of a combination of unrealized possibilities, such as Schrödinger’s unfortunate (and imaginary) cat which is simultaneously both fully alive and fully dead.

The Danish engineer Valdemar Poulsen built a magnetic wire recorder in 1899, christening his device the ‘Telegraphone’ and demonstrating it at the 1900 World Exposition in Paris. While there, he recorded the voice of Emperor Franz Josef of Austria, producing what is the oldest surviving magnetic audio recording.

A particularly impressive example of sophisticated magnetic navigation is that of the bar-tailed godwit. This remarkable bird makes a direct, non-stop flight from Alaska to New Zealand, travelling around 10,000 kilometres over the Pacific Ocean. During its heroic week-long journey, it flies only across ocean without passing over landmasses which could provide navigational markers. Furthermore, New Zealand is a fairly small target which can be missed if the initial trajectory is out by a few degrees.

Magnetic north has been approximately at its current location for nearly 800,000 years, though its exact location has wandered around considerably in the northern hemisphere during that time and is currently marching north through the Canadian Artic at a rate of about 50 kilometres per year. (It also wobbles around about its average position by up to around 80 kilometres every day due to variable electric currents in the ionosphere and magnetosphere caused by the solar wind.)

In general, it has been found that the total planetary magnetism (or to use the technical term, its magnetic moment) is approximately proportional to the angular momentum of the planet, suggesting a similar physical model to that of the Earth: a geodynamo, with the rotational kinetic energy driving the magnetic field.

[Wing · Rating 3 out of 5]

Whilst the Maxwell’s equations are listed in the Appendix, this is decidedly a non-mathematical book. The first third of the book is about the triumph of empiricism - that magnetism can be understood via good observations. The middle third is about its relation to relativity and quantum mechanics. The last chapters are on its applications and current (as at 2012 when the book was published) research programmes. Because uses no equations and there is a paucity of illustrations, at times the reader may be lost and at times find it superficial. In having said that, one does see insights in the exposition.

[Hassan Ahmed Al Lawati · Rating 3 out of 5]

I enjoyed this book and learned a great deal of new information about magnetism and its relationships to relativity and quantum mechanics.
The downside of it includes:
1- first two chapters were boring history
2- some chapters were difficult for the non-specialist reader.
3- lack of illustrations and diagrams makes it even more difficult to digest many issues.
4- probably the book needs a glossary annex at the end. Many new scientific terms to learn.
My rating ☆☆☆.

[Jon · Rating 3 out of 5]

When it was historical exposition, I wanted it to get into the science. When it got into the science, I wanted more explantion. Couldn't get what I wanted from it, whatever that may have been.

[Harry · Rating 4 out of 5]

Decent book. Good bit of history and explained some physics concepts well with lots of examples.
Also, check out page 124 for a very witty description of solid-state chemistry.

[Sara Ghotb · Rating 3 out of 5]

A compact and accessible look at magnetism : from lodestones to quantum spin. The book leans heavily into the historical development of magnetic ideas, which might feel a bit much if you're looking for more physics than timeline. But it’s likely intentional, offering context for how our understanding evolved. A good, quick read if you’re curious about the science and story behind one of nature’s most intriguing forces.

[Bojan Tunguz · Rating 5 out of 5]

Magnetism is electricity’s less appreciated twin. In our daily lives we only think of magnetism in the context of fridge magnets, magnetic clasps, or at most when considering the needle of the compass. However, magnetism is one of the most pervasive and useful natural phenomena, and in so many ways modern life would be unimaginable without it.

This very short introduction aims to give a very comprehensive account of the phenomenon of magnetism. The book goes into the history of our understanding of magnetism, describes some significant discoveries, provides theoretical explanation of magnetism, and examines some of the most significant applications of magnetism today. Some of these applications have become so ubiquitous that we don’t even think of them much any more – such as the magnetic memory that is the bases of all hard drives that are in use today. Others are a bit more obscure but no less fascinating. The book is written with a non-scientist in mind, although some degree of scientific literacy and appreciation of science will go a long way in making the most out of this material. Aside from a very short appendix, the book contains no equations and “scary” scientific graphs. There are a few neat diagrams though, that manage to explain concepts visually for those of us who like that kind of thing. Even if you are an experienced scientist, or even a physicist (like myself) you’ll find a lot of useful and intriguing tidbits of information within this short volume. This is particularly true if you happen to teach some course that deals with magnetism.

The writing in this book is very lucid and engaging. It is definitely one of the better-written popular science books. I would definitely recommend it to anyone who wishes to broaden his or her understanding of science.

[Napalmlolita · Rating 1 out of 5]

One of the worst scientific treatises ever. Never answers questions like: What is alternating current? How does it differ from radio transmitters that are also supposed to be based on 'oscillations'? What are the geometrical angles involved when magnetic and electric fields interact, and what is their origin on the atomic/subatomic scale (and consequently, why do electric motors work at all)? Why does the 'spin' property of elementary particles only manifest in unevenly strong magnetic fields? Adding only about 10 pages of appendices could have clarified these topics and made the main text understandable and enjoyable. So, because these omissions are so elementary mistakes, one star. One star doesn't mean I didn't learn anything from it, it just means the mistakes are severe beyond comprehension.

[Daniel Wright · Rating 4 out of 5]

The best kind introduction to an area of science is, like this one, historical. Science, at its best, is not just a description of the ways things are, but a description of humanity's exploratory relationship with nature. The story Blundell tells here captures the beauty of that wonderfully and absorbingly.

Chapter 1: Mysterious attraction
Chapter 2: The Earth as a magnet
Chapter 3: Electrical current and the path to power
Chapter 4: Unification
Chapter 5: Magnetism and relativity
Chapter 6: Quantum magnetism
Chapter 7: Spin
Chapter 8: The magnetic library
Chapter 9: Magnetism on Earth and in space
Chapter 10: Exotic magnetism

[TrumanCoyote · Rating 3 out of 5]

Well, perhaps it was a little TOO short (at least for me). Because I didn't really pick up much from this, other than that (somehow or other) magnetism is a relativistic effect which intrudes into everyday life. The writer has a strong, casual style, and fortunately proves to be by no means allergic to humor. However--as often seems to happen with these kinds of things--he ends up only preaching to the converted, as far too many times he glibly passes over a subject, using the sort of technical language which (doubtless) only he and his fellow professors might understand.

[Peter Tillman]

https://popsciencebooks.blogspot.co.u...

"In short, his writing is fun, compelling, delightful. He’s also clearly an expert on magnetism, and his knowledge not only on the underlying theory, but its historical development, is truly impressive."
-- Review by Alvaro Zinos-Amaro

Well, this one didn't do anything for me. I tried a couple of times, stalled, then it came die. Hell with it.

[David McMahon · Rating 3 out of 5]

I picked this up after reading the very short introduction to Quantum Mechanics. This topic is not very far away and although by different authors, the house style comes through. Explaining a fundamental force in the universe for lay folk (like myself) is no easy task but this was an example of how to make one's audience not just understand, but feel educated as a result.

[Stephen · Rating 4 out of 5]

Good, short, introduction to magnetism. As with all such works, it would have been nice if some things had been more fleshed-out, but a little here, and a little there, and then it wouldn't be a short introduction anymore.

[Tim Kimberley · Rating 5 out of 5]

Oxford's Very Short Introduction is such a great series. If time was unlimited I'd soak up the dozens of books in this series. I knew my understanding about magnetism was lacking and this book really opened my eyes to the wonders of magnetism.

[Emlen · Rating 3 out of 5]

I wish these science VSIs would spend less time on the history of science. This one was better than the Radiation one, but I still felt like every third sentence was telling me the date of someone's Nobel Prize.

[Ryan McKenzie · Rating 4 out of 5]

This brief history of magnetism, my research field, starts with the ancient Greeks and progresses all the way through to modern times. The length of the book doesn't allow for anything to be treated with any depth, but the book still manages to pack in all sorts of interesting tidbits.

[Hallie Cantor · Rating 4 out of 5]

Interesting, informative introduction to a topic that made me understand better the forces of gravity and concept of magnetic fields. Another lesson in physics that made me realize my ignorance.