Looking for a textbook that uses the electromagnetic wave view of electric current

  • #1
DrBanana
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So I watched a couple of videos on Youtube with the titles 'How Electricity Actually Works' and 'The Big Misconception About Electricity' ( and ).

The main message being that while the view of current being the flow of electrons might be useful practically, it's not an accurate representation of what actually happens, and the more accurate description is that the energy is propagated as electromagnetic waves.

I appreciate the clarification but it also brings up a lot of questions, because much of what you learn about related stuff is based on the fact that electrons flow in a significant amount through wires, such as wires heating up, or even the Peltier Effect. So I was looking for a textbook that started with this more accurate view, and gradually built on that.
 
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  • #2
DrBanana said:
The main message being that while the view of current being the flow of electrons might be useful practically, it's not an accurate representation of what actually happens, and the more accurate description is that the energy is propagated as electromagnetic waves.

I appreciate the clarification but it also brings up a lot of questions, because much of what you learn about related stuff is based on the fact that electrons flow in a significant amount through wires, such as wires heating up, or even the Peltier Effect. So I was looking for a textbook that started with this more accurate view, and gradually built on that.
While I don't have any textbook suggestions, this is a topic that has been discussed previously here on Physics Forums. For example, here is a thread that I participated in:
https://www.physicsforums.com/threads/power-flow-outside-a-wire-how-close.1053463/
Note that, while it's true that "electrons flow in a significant amount through wires", they travel so slowly that they carry very little total energy. Instead, the flow of electrons through the conducting circuit serves to create and direct the electric and magnetic fields outside of the wires, and it is those fields that transport the bulk of the energy. And this transport is not by "electromagnetic waves" in the usual sense of transversally-polarized radiation (e.g., radio waves or microwaves), since those would escape from the circuit and carry energy away to infinity. Instead, at DC or low frequencies like 50-60Hz, the energy is propagated by EM "near-fields", i.e., fields confined to the vicinity of the circuit.
 
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  • #3
I think you are asking about how transmission lines work (or "open waveguides"), there should be lots of textbooks on this subject.

Maybe try a google search?
This is some of what I found without too much effort, then I got bored and gave up. I'm not THAT interested in reliving my EM courses from several decades ago.

https://www.feynmanlectures.caltech.edu/II_24.html
http://www.corridor.biz/FullArticle.pdf
 
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  • #4
Any textbook on electrodynamics should do (except some didactics textbooks, which still promote the "water-pipe analogy" for circuits, which is completely misleading for the very reasons you discovered on Youtube, though I haven't seen these videos, so I can't judge, how reliable they are).

A very thorough discussion of the most simple exactly solvable case, the "infinitely long" cylindrical coaxial cable for a DC circuit, is in A. Sommerfeld, Lectures on Theoretical physics vol. 3. That's doable at the undergrad level.

For the more interesting case of time-dependent fields, e.g., to answer the question of signal propagation when switching on the circuit or for AC circuits, you need a bit more advanced methods. If you restrict yourself to the most simple "TEM mode" of the coax cable you get the "telegrapher's equation", which is also doable at the advanced undergrad level. The full-fledged wave-guide theory is a bit more advanced. It can also be found in Sommerfeld's books (also in vol. 6 about partial differential equations, which is anyway highly recommended).
 
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