Faraday, Maxwell, and the Electromagnetic Field: How Two Men Revolutionized Physics

Faraday, Maxwell, and the Electromagnetic Field: How Two Men Revolutionized Physics by Nancy Forbes and Basil Mahon “Faraday, Maxwell, and the Electromagnetic Field” is an excellent, readable book on the life and contributions of two science giants, Michael Faraday and James Clerk Maxwell. Authors Nancy Forbes and Basil Mahon join forces to provide the public a very enjoyable look at how the these two scientists built from successive ideas and discovered the electromagnetic field. This interesting 330-page book includes seventeen chapters, notes, a formal bibliography and an index. Positives: 1. Professionally written science biographies blended into one accessible narrative. 2. The fascinating topic of the scientists behind the electromagnetic field. 3. The authors have great mastery of the topic but most importantly were able create an interesting narrative without resorting to the complex mathematics involved in physics and in particular, electromagnetism. 4. Good use of diagrams to complement the excellent narrative. 5. An excellent introduction that teases the public of what’s to come. “It is almost impossible to overstate the scale of Faraday and Maxwell's achievement in bringing the concept of the electromagnetic field into human thought. It united electricity, magnetism, and light into a single, compact theory; changed our way of life by bringing us radio, television, radar, satellite navigation, and mobile phones; inspired Einstein's special theory of relativity; and introduced the idea of field equations, which became the standard form used by today's physicists to model what goes on in the vastness of space and inside atoms.” 6. In essence this book is the story of the electromagnetic field that is brought to you by blending the biographies of Faraday and Maxwell in chronological order. 7. Throughout the book, the authors methodically and chronologically go through the lives of the scientists involved as new discoveries lead to scientific knowledge. 8. A look at the history of electricity and magnetism. “Before 1800, all man-made electricity was static. The discovery of continuous currents came as a complete surprise and was in the best tradition of scientific serendipity.” 9. The fascinating life of Michael Faraday, his strengths and weaknesses as a scientist. “We shall never know what Faraday would have achieved had he mastered mathematics, but, paradoxically, his ignorance may have been an advantage. It led him to derive his theories entirely from experimental observation rather than to deduce them from mathematical models.” 10. Some of the world’s greatest inventions are highlighted in this book. “This time, the magnet revolved around the wire! Faraday had become a discoverer: he had made the world's first electric motor.” 11. This book is intended for the laypersons but it doesn’t cheat those us in the STEM (Science Technology Engineering Math) fields. The concepts are well described and satisfying. “The “quantity of electricity thrown into a current” was “directly as the amount of curves intersected.” This statement was true whether the curves were dense or sparse, converging or diverging, and neither the shape of the wire nor its mode of motion made any difference, except that the direction of the current depended on what became known as the right-hand rule. It was the original statement of one of the most fundamental laws of electromagnetism—now called simply Faraday's law of induction.” 12. The genius of James Clerk Maxwell and how he was able to describe such esoteric concepts particularly for those times. “Maxwell's imaginary fluid was weightless, friction-free, and incompressible. This last property was the key to the analogy. It meant that the fluid had its own built-in inverse-square law: the speed of a particle of fluid flowing directly outward from a point source was inversely proportional to the square of its distance from the source.” 13. Fascinating look at how Maxwell fed from Faraday’s own genius to take these concepts to a better understanding. “As Faraday had found, these substances varied in their ability to conduct electric lines of force—each had its own specific inductive capacity. For example, glass conducted electric lines of force more readily than wood. In his model, Maxwell accommodated this property simply by endowing each substance with the appropriate amount of resistance to fluid flow—the lower the resistance, the smaller the pressure gradient necessary to produce a given speed of flow.” 14. The authors capture the essence of these great scientists and help readers gain a better understanding of who they were. “Though surpassed by his later writings, Maxwell's “On Faraday's Lines of Force”10 is, surely, one of the finest examples of creative thought in the history of science. In his book James Clerk Maxwell: Physicist and Natural Philosopher, Francis Everitt shrewdly characterizes Faraday as a cumulative thinker, Thomson as an inspirational thinker, and Maxwell as an architectural thinker. Maxwell had not only found a way to express Faraday's ideas in mathematical language but also built a foundation for still-greater work yet to come.” 15. Goes over Maxwell’s manifesto, which was to produce a theory that explained all the known experimental laws of electricity and magnetism by deduction from general principles. 16. Key concepts explained and differentiated, “Maxwell distinguished between two kinds of energy held by the field: electric energy was potential energy, like that in a coiled spring; and magnetic energy was kinetic, or “actual” energy, like that in a flywheel.” “Maxwell had achieved the seemingly impossible—he had derived the theory of the electromagnetic field directly from the laws of dynamics.” 17. A look at the Maxwellians. “He straightaway wrote to Lodge to ask for a full text of his talk and soon found that he had another admirer, Lodge's friend George Francis Fitzgerald, who was professor of natural and experimental philosophy at Trinity College, Dublin. Like Heaviside, Lodge and Fitzgerald had been captivated by Maxwell's work and both had been trying, first in isolation and then with mutual support, to carry it on. Now Heaviside, the independent recluse, had gained true friendship on his own terms, and the three of them, united in a common cause, became firm friends and formed the core of the group that came to be called the Maxwellians.” 18. Einstein’s admiration for Maxwell. “As Einstein put it: Since Maxwell's time, physical reality has been thought of as represented by continuous fields and not capable of any mechanical interpretation. This change in the conception of reality is the most profound and fruitful that physics has experienced since the time of Newton.” 19. Provides a timeline and a photo insert. 20. Notes and an invaluable formal bibliography. Negatives: 1. The supplementary material that is included is good but limited. I would have included a list of all the scientists listed in this book and their discoveries. A helpful timeline is included but an additional supplements add value to the book. 2. Even at it’s most accessible, if you don’t have much interest in science, this book will be difficult to get through. Not really a negative of the book just a reality check for onlookers. In summary, this is an excellent book that the layperson will enjoy and those in the field will cherish. The authors did a wonderful job of focusing on the grand work of these curious, driven scientists without obfuscating the narrative with esoteric equations. What a wonderful way to learn about the lives of two of the most significant scientists of the 19th century and their grand contributions to our lives today. I highly recommend it! Further recommendations: “The Man Who Changed Everything: The Life of James Clerk Maxwell” by Basil Mahon, “The Electric Life of Michael Faraday” by Alan Hirshfeld, “Isaac Newton” by James Gleick, “Planck” by Brandon R. Brown, “QED” by Richard Feynman, “Seven Brief Lessons on Physics” by Carlo Rovelli, “Tesla” by W. Bernard Carlson, “Einstein: His Life and Universe” by Walter Isaacson, and “Gravity” and “The Great Physicists from Galileo to Einstein” by George Gamow.

This book is both a biography and the history of the development of an idea or, perhaps, a succession of related ideas. The two men, Michael Faraday (1791—1867) and James Clerk Maxwell (1831--1879), were together responsible for some of the greatest scientific discoveries in history: the relation between electricity, magnetism, and light and the discovery of something that cannot be known to the senses---the electromagnetic field. Although Faraday and Maxwell were separated by a generation and never worked together, this book makes it clear that their discoveries were a joint project. The two men came from very different backgrounds. Faraday, the son of a blacksmith, had very little formal education. Early on, he became fascinated by electricity and magnetism and became convinced that there was some relation between the two forces. He educated himself by reading everything he could in those fields and in the field of chemistry and then devised experiments to further his understanding of matter and energy. He invented the first electric motor and the first electric generator and hypothesized the existence of an electromagnetic force field. His weakness in mathematics, a handicap imposed on him by his lack of formal education, made it difficult for him to advance his theories and have them appreciated by the scientific community of his time. But his strengths were his genius, dogged determination, and self-discipline. He recorded the details of every experiment and published the results---successes and failures alike. The publication of this work, "Experimental Researches in Electricity," would prove to be both the inspiriation for and foundation of the work of the next genius, James Clerk Maxwell. Maxwell, unlike Faraday, was born into a social class of privilege. His father had inherited a large estate in Scotland and could afford to sent James to the very best schools in Scotland and England. Maxwell was a good student and excelled in mathematics, the area of Faraday’s weakness, and this skill would prove to be decisive in carrying Faraday’s hypothesis forward. Maxwell, like Faraday, as a young man became fascinated with electricity and magnetism and wondered if they were related. Searching out every bit of published information on these topics, he discovered Faraday’s "Experimental Researches." He was fascinated---not only by Faraday’s clear and detailed accounts of his experiments but also by the fact that the volumes were almost completely free of mathematical equations. Maxwell resolved to use his skill with mathematics to push forward Faraday’s work on electromagnetic fields and eventually show that they really did exist and what their nature was. This book was not easy to read---especially the parts about the physics of electromagnetic fields. I labored through long passages of narration and description longing for an illustration or diagram to help me make sense of the words. The book does provide drawings by Lee Bartrop at certain key places, for example, “Fig. 4.1. Faraday’s first electric motor apparatus,” which appears at location 789 in the Kindle edition. But I think the authors missed many opportunities to help the struggling reader to understand these difficult concepts. The lay reader can appreciate this book for the stories about the lives of these two great men of science, but will have to be prepared for a difficult struggle to understand the chemistry and physics, the two unexplored territories these pioneers opened up for civilization.

Faraday and Maxwell are two of the “inventors” of electromagnetic theory as we understand it today. Faraday was the experimentalist and Maxwell the one we think of in terms of the equations. From time to time I still see students walking around MIT with sweat shirts and emblazoned were; “and God said, Maxwell’s equations and then the statement, then there was light”. In many ways that is correct. Faraday did many of the groundbreaking experiments and Maxwell set them to writing in both a complex form and in a simple manner. Maxwell’s equations are four simple equations, one for electric force and one for magnetic force, the electron by itself and the electron spinning, and reduced to two equations each, one for force at a distance and one for one inducing the other. The book by Forbes and Mahon provide an interesting overview and historical perspective on these two major 19th century figures. The first third of the book focuses on Faraday and his experiments. The second half of the book discusses Maxwell and his equations. The third section of the book is Heaviside and his compatriots, with reference to Hertz from time to time. This is neither a book of science nor a biography of the principals. It is an attempt to introduce to the average reader the concepts that led to our understanding or electromagnetic waves. It is also in a manner a defense of the field theory. The first third of the book describes Faraday and his experiments. One gets a wonderful understanding of Faraday’s world and the people whom he associated with and influenced him. Ther progression of understanding the basic phenomenon of magnetism was well presented and useful for almost any reader. The second third is that of Maxwell. It leads to Maxwell’s famous equations, albeit not in the form that most engineers and physicists see them. For anyone who had read Maxwell’s works, they are long and one can sense almost an ongoing internal battle between the theoretician and the experimentalist. Maxwell’s main contribution was to introduce the displacement current concept (pp 191-195). This is a reasonably good presentation but to anyone not familiar with the field it may seem a strange artifact. Simply the use of the displacement current introduced, if you will, a capacitor across the “circuit” of free space so that if free space had no conductivity, was a perfect insulator, waves could still propagates via this displacement current or capacitor effect. The result was a wave equation that showed that electromagnetic influences travelled at a finite speed, the speed of light. The last third revolves around Heaviside. It was Heaviside who simplified the Maxwell equations to the 4 simple forms we see today and it was also Heaviside who understood what we call the “telegraph equation” about waves travelling down telegraph poles, and finally Heaviside who introduced the LaPlace transforms which changed circuit analysis. The book is generally well written and allows the reader to follow many of the intricate experiments and arguments. However, I had difficulty with several issues (I did my PhD thesis at MIT in electromagnetic theory and taught courses for several years): 1. The opening description of Hertz and his experiment is near incomprehensible. Hertz was trying to measure a standing wave via resonance. I guess if you have done this before most issues are obvious but I tried these descriptions on some High School Juniors, grandsons, and they found it equally incomprehensible. I get the point but alas many others may not. 2. There is the battle between those who believe in fields as real versus those who believe in them as artifacts. I tend to be in the latter camp. The E and H fields and the D and B fields are representations of forces. Coulombs law is a force law not a field law. The field is an artifact. However not everyone looks at it this way. This was a paradigm shift and in the context of a Kuhn type shift it would have been worth some discussion. (see pp 263-264 for a discussion) 3. It would have been useful if some discussion of the development of mathematical tools, curl, grad, div, could have been discussed. 4. The issue of the existence or lack thereof of an electron was also a key element in this world view. Here I am on shaky ground but it would have been interesting to see how that concept was developed in some parallel manner. Once understood it became a bulwark for the theory. Overall this is an excellent read but it might have prospered a bit more with the hands of someone whose career was steeped in the theory and application. I recall students often bemoaning that we started the Junior level EMT course with the fields and not the forces. Namely forces were the result of field and not the other way around. Either way the debate is worth a discussion.

Faraday, Maxwell, and the Electromagnetic Field is a readable and engaging account of the two pioneers of the subject and how they developed as individuals and developed their respective theories. Electromagnetics and the field theory that came with it is one of the most important development in physics and allowed us to move from the theory of classical physics to what is today modern physics. Nancy Forbes and Basil Mahon give the reader an account of the evolution of thinking on the subject by writing the overlapping biographies of Faraday and Maxwell. It is engaging, readable and gives the reader a sense of the subject by discussing the physical results that both characters and in particular Faraday personally discovered. In reading the book one gets a sense of the character of each and where there strengths and weaknesses lied. Faraday, born in 1791 was an incredible experimental physicist. He had the fortune early in his career to work with Davy who was a skilled experimenter as well. One gets a sense of the totally open nature of the subject during that era and how it was wide open to be explored. Faradays growing stature and influence is documented and the reader is familiarized with the deep insight Faraday had about discussing the phenomenon he was observing via a field theory rather than the action at a distance models that continental europe was focused on. The historical statements that are documented in the book give a sense of how visionary Faraday was. Despite his remarkable qualities as an experimental scientist he was not mathematically trained and the formalizing of the theory into something along the lines of newtons theory of classical mechanics was lacking. Maxwell, the Scottish prodigy, was to come along and bridge the gap. The history of Maxwell and his family is given as was his academic journey. Maxwell was a polymath and knowledgeable about a great many things without any ego. He brough methods of vector calculus to the subject of electricity and magnetism and at first proposed models purely to try to describe results rather than to figure out the actual physical processes that were occuring. Slowly though his more cumbersome models became more elegant simple mathematical explanations and Maxwell was the one who came up with the terms Div, Grad and Curl- methods fundamental to modern vector calculus and electricity and magnetism. Maxwell died young and his theory became more ane more appreciated as physicists caught up with mathematics and Oliver Heavyside simplified the equations a bit. The author briefly discuss the start of the quantum revolution as well. Faraday Maxwell and the Electromagnetic Field is fun an enjoyable to read. I found it informative both from a historical account of two remarkable physicists and also a refreshed idea of how the theory was slowly developed from experiments that were only pieces of a much larger and complicated puzzle. The two men were remarkable and the authors did a great job giving the reader a sense of their accomplishment and how it has impacted all of our lives.

I'm a retired electrical engineer, In engineering school maxwell's equation's are presented and studied in their final modern form, sans history, This book is interesting in showing how Maxwell worked the problem over several years and how his thinking progressed. Until this book I never knew that Maxwell had developed (and published) an elaborate mechanical model to aid thinking about magnetic and electric fields, (William Thompson had done something similar with his mechanical model of the aether.). The book details how maxwell's mechanical model (p 188) could be used to understand magnetically coupled loops, a simple transformer. I tried to follow it, but got lost. The book rightly points out that Maxwell in a breakthrough found he needed a 'new' current, which he called the displacement current, to make complete his electromagnetic equations. This is a current that Faraday had not seen experimentally. The displacement current arises from the changes in the electric field. This book is quite remarkable in that the author's have worked hard, and for the most part successfully, to explain a lot of the details of Maxwell's theory. (Perhaps much of this detail only EE engineers can follow.) One detail surprised me here. On p206 it says Maxwell thought the energy stored in the magnetic field was the kinetic or 'actual' energy, whereas the energy stored in the electric field was 'potential' energy. Maybe Maxwell did think this way, but this is not the modern view. In engineering school we were taught that capacitors, where energy is stored in the electric field, and inductors, where energy is stored in the magnetic fields are are comparable (duals). Also excellent is the story explaining how it was that Maxwell's great theoretical achievement in his lifetime and for years later was largely ignored. The book explains how Heavyiside made Maxwell's work more accessible by greatly reducing the complexity of his equation, and it was not, as I had always assumed, a simple rewrite, but required new mathematics that Heaviside had developed to reduce Maxwell's 8 (or 20) to the to the four equations we know today. Also I had not known that Maxwell was instrumental in setting up the famous Cavendish Laboratory and was it's first director, which is detailed in the book. While the book does not point this out, displacement currents can be seen to operate in simple circuits, such as the example of a switch being closed to charge up a capacitor from a battery through a resistor. One of the core principles of circuit theory is current always flows in loops. When the switch closes, the capacitor voltage increases as the as current flows into one capacitor terminal and out the other terminal. But ask yourself what happens INSIDE the capacitor while it is charging and the voltage is increasing. If current always flows in loops, it must be transiently flowing in the capacitor's dielectric material (or air), which is an insulator. How is this possible? Maxwell's answer is it is a displacement current. By expanding the concept of current to be not only the flow of electrons, but also regions of material (or space) where the electric field is changing, the concept of currents always flowing in loops is preserved. Indirectly the book provides perspective on how progress advances. In spite of Maxwell in the 1860's providing a detailed mathematical treatment of electromagnetics that predicted the existence of electromagnetic waves neither he nor his successors at the Cavendish tackled the task of attempting to verify they existed! Here the mantle of progress passed from scientists to a new generation of engineers (like Marconi) who figured out how to detect these waves, and who worked to make wireless communication practical by designing equipment for communication with ships at sea.

The book covers the period from 1600 (when Gilbert proposed that the Earth acts like a giant magnet) though 1901 (when Marconi sends a telegraph signal across the Atlantic Ocean) during which electromagnetic observations and experiments led to a unified theory of magnetism and electricity. The result has been better understanding of the Universe and practical devices such as communications equipment (telephones, TV, cell phones), microwave ovens, radar, and medical equipment (X-rays, CAT scans) that define our modern era. As a satellite communications radio engineer, I found it very interesting to read the history of the developments over time. The book is very well written and clear.

Excellent book on the history of Maxwell equations and related scientists, really worth of reading.

Liked how the author made the science accessible to a non-scientist. And really brought out the contrasting styles of Faraday and Maxwell. Fascinating how many things of today depend on the work of these 2 scientists.