Preface

I took my first serious course on electromagnetics 23 years ago. My favorite professor introduced us to our main textbook - a very famous primer, as I learned several years later. Even though I am not good at remembering conversations, particularly scientific ones, I still recall the following, with some dramatic visual details probably contributed by my imagination:

• This book is actually quite good.
• But?
• Well. It is the starting point. Electrostatics. Magnetostatics. I would be happier to start with Maxwell's.
• Then why don't you write your own book, Professor? (This was a bit provocative, I admit.)
• Maybe someday.

I completed my BSc and PhD at the same university, spending a total of eight years on top of five undergraduate years, and I had a chance to be a teaching assistant for numerous electromagnetics courses. We used the same book in all the undergraduate courses. In fact, I am still addicted to it, without any regret!

Even Feynman Could Not Do It!

After some adventures in mathematics abroad, I returned to my current location in 2013 as a member of the faculty. The Middle East Technical University has a deep-rooted history, and the Department of Electrical and Electronics Engineering is one of the best in the country. In addition, the electromagnetics group has always been strong in this university, with full professors when I arrived. I, a 33-year-old man, was like a kid in a candy store, where "candy" refers to things I could do. For the undergraduate courses, I was happy to accept materials from my seniors, Prof. Özlem Aydın Çivi and Prof. Nilgün Günalp, as they were well prepared and optimized (some notes were older than me). In fact, they saved my life. But, thinking about teaching electromagnetics, I always shared the feeling with others that something was not right. Certainly it was difficult to describe; it seemed to be felt only by humans who taught electromagnetics. I had a chance to speak to many professors, instructors, and

teaching assistants, not only from my university but also from diverse universities all over the world during scientific conferences. Conversations related to teaching materials often reached the same point, already familiar to me:

• We could teach electromagnetics better.
• How?
• Well. What if we could start with Maxwell's.

The force that made me write this book appeared in one of these conversations, with remarkable words from a respected professor.

• But even Feynman could not do it!

To be honest, I still do not know if Feynman ever tried to teach electromagnetics in this way, which I now call the correct order. Whenever I start to investigate, I find myself studying electromagnetics in the amazing world of this extraordinary scientist. In fact, whether Feynman taught this way is not important. The message I got was that this is a task so important that even Feynman - a man who can teach everything - might not complete it. This is a task that I must do.

All Electromagneticians Are Authors

If an instructor is reading these sentences, I am sure that s/he has an idea for a new book on electromagnetics, if it is not already written. And this is amazing, considering that the material has been more or less the same for decades. Any instructor of an electromagnetics course at some point thinks that the material given to her/him (usually by her/his senior instructors) could be taught in a better way. But any attempt to change the classical order of basic/fundamental electromagnetics surprisingly evolves into a complicated task, discouraging the instructor from embarking on an adventure. We have to accept that writing a book on basic electromagnetics is an ambitious task, for several reasons:

• There are many potential readers - i.e. undergraduate students who will become engineers and researchers - so one must consider their variety (age and background) as well as the new habits of the young students of the twenty-first century.
• Many instructors are simply not happy with the available books (not related to their quality), and they have competitive projects, often having the spirit of this book.
• Ironically, books are available, some of which are excellent (discouraging potential authors), but none of which actually present the topic as the instructors wish.

This book is the end product of an attempt to complete this ambitious task. It presents the well-known topics that all instructors would naturally include in their syllabus, while using the correct order (a novel approach). What I found was stranger than the problem itself. This correct order becomes possible only with a necessary pedagogic approach, ironically considering the typical learning behaviors of the students of the new millennium instead of the traditional mechanisms.

What This Book Is

Before explaining the exact structure of this book with the so-called correct order of topics, I should indicate for whom it is written. This book is for undergraduate students who wish to or have to learn electromagnetism for the first time. It is also for senior undergraduate and graduate students who wish to go deeper in primary topics. In addition to Maxwell's equations and their basic applications for canonical problems, the material presented in this book also contains information on the transmission of electromagnetic waves with fundamental details on antennas, waveguides, and transmission lines. These topics must be covered for completeness of the basic knowledge, but readers should understand that each is the topic of individual books that cannot be merged into a single one. Vector calculus and similar fundamental information are also provided and discussed where necessary, but readers are expected have a background in basic calculus.

As already revealed, this book presents basic electromagnetics from the perspective of Maxwell's equations, which is possible via a new pedagogic approach. To further clarify, we may consider a particular example, such as the topic of gradient. In this book, gradient is introduced in Section 3.6.1 (Chapter 3), after Gauss' law, Ampere's law, and much more material.

In typical textbooks, the concept of gradient is explained much earlier - usually at the very beginning - since it is a fundamental mathematical tool. Readers may find very specific books where gradient is explained in later chapters, but this is merely an example. In this book, the same strategy is used for all tools: e.g. for dot product, cross product, divergence, curl, etc. To describe the approach in one sentence, in this book, a tool is presented whenever it is required, not earlier or later. Continuing with the same example, if gradient was explained earlier (e.g. in the preliminary (zero) chapter of this book), then we would encounter the two major issues of the traditional approach:

• Related examples to teach gradient can be superficial and indirectly related to electromagnetism, since it is actually not the time to use gradient.
• When it is the right time to use gradient in the context of Maxwell's equations, gradient becomes an old topic (often not well understood), and revision is needed.

It should be noted that gradient is not used in Gauss' law and Ampere's law (at least, not directly), so it can be placed in Faraday's law. This is the idea.

Based on the described approach, the sequence of material in this book is optimized. Specifically, readers will frequently find text such as the following (from Chapter 3):

To understand the integral form of Faraday's law, we need the concepts of differential length with direction (Section 2.2.1) and circulation of vector fields (Section 2.1.2). These are in addition to the concepts of dot product (Section 1.1.2), differential surface with direction (Section 1.1.1), and flux of vector fields (Section 1.1.3). Therefore, no new tool is required before we focus on the meaning and application of the integral form of Faraday's law.

All tools and concepts are carefully defined so that readers will know exactly which tools are needed to understand the topic ahead.

As also mentioned above, the structure of this book is suitable for young students of the new millennium. As some instructors might have realized, and I will describe directly, students of the new generation have (good or bad) a pragmatic learning behavior. According to this strategy, learning is a recursive approach of opening boxes inside larger boxes until the required information is reached. Continuing with examples, a student who desires to learn the differential form of Faraday's law needs Stokes' theorem. If s/he does not know Stokes' theorem, s/he must learn it (that is, immediately under the section of the differential form of Faraday's law in this book). But at the second level, Stokes' theorem needs the dot product, curl, circulation, and flux concepts. As all these concepts are also used in Gauss' and Ampere's laws, so the student is forwarded to these tools (in case information is missing). Of course, by adapting this strategy, my aim is not to generate lazy students. The arrangement of...