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My initial reaction to hearing ABOUT the Veritasium video on electricity energy transmission, WITHOUT having watched it or even knowing the title. Extract from the live show.
I released this for the benefit of the forum to show how it's potentially interesting to see what an initial engineering reaction is to the concept, with my mind instantly going to skin effect and that energy is in the electromagnetic field, and that "he's probably not wrong", but it's not a practical way of looking at it. Enter transmission line theory etc. All without having watched video, or knowing the title, I instantly knew it's a physics impracticality trap.
I suspect that would be most engineers initial reaction as well?
My botton line comment after having watched it:
If it was titled something like "How energy flows in electromagnetic fields", and the sensationalist title and stuff was left out, then it becomes a very valuable explanation video.
But the way it's titled and scripted, one could argue it does more harm than good. Especially for engineering students.
There is nothing new here for an engineering student. We are taught about (slow) electron drift velocity, and why and how energy is stored and transported in electric and magentic fields, it's all fundamental stuff. Ultimately this is a (simple) practical engineering question involving transmission lines, and that's what they were learning at the time with the underseas cabe thing.
It's basically just picking a physics fight like Walter Lewin did with KVL, and Electroboom calling him out from the practical engineering aspect.
The fact that transmission lines were not mentioned at all, when it is in practice a simple transmission line problem, is very disingenuous. It's borderline physics trolling.
As per the video, with the long line either side and battery and switch in the middle, the light bulb lights up briefly almost instantaneously due to the nearby distributed cable capaciatnce. Then you have a standard transmission line propagation in either direction.
The REAL question comes when you hit steady state DC. Given the question is about ENERGY transfer, how does the electromagnetic field transport the POWER/ENERGY to the light bulb under DC steady condition, with an electron drift velocity of mm/s, and a non-moving magnetic field surrounding the wire. The answer is, the power no longer flows *outside* the wire, it flows *inside* wire, obeying ohms law and basic steady state DC theory. Sure, the Poynting vector physics still works at DC, but it's of *zero practical value* to think of it this way.
So veritasium is RIGHT, but his argument is POINTLESS when it comes to steady state DC (or LF) power transfer. At HF AC the power/energy indeed travels in the electromagnetic field. It's best to think of the magnetic field as just an annoying side effect of the DC current flow in the wire.
This is why physics course don't produce practicing engineers.
I'm THINKING about doing a video on this, discussion here:
https://www.eevblog.com/forum/chat/veritasium-(yt)-the-big-misconception-about-electricity/
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