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"Veritasium" (YT) - "The Big Misconception About Electricity" ?
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rfeecs:

--- Quote from: Naej on January 15, 2022, 09:23:10 am ---
Carpenter's theorem states that if Maxwell's equations are correct, then JV is a valid energy flow. And with JV, energy flows only in wires.

So either:
a) you find a flaw in the 3 lines proof of the theorem
b) you find a counter-example to the theorem
c) you compare Maxwell's equations to flat earth-theory.

Conclusion: the statement "energy flows only in wires" is correct.


--- End quote ---

So it seems that Carpenter's approach assumes that energy does not flow through empty space.  It only exists where charges are present.  It can get from one point to another, from a transmitting antenna to a receiving antenna for example, by the retarded potential.  All we care about is what happens to charges, anyway.  So it is perfectly useful and still completely consistent with Maxwell's equations.

If we see a high power laser beam that seems to be glowing along it's path, that's just the result of the charged particles that it is bumping into.  Not energy "flowing" along the path.

It seems a bit counter intuitive to old folk who are still used to the idea of a wave flowing through the aether.

So you have the Poynting vector which is counter intuitive for DC, and Carpenter's approach which is counter intuitive for radiation.

Both are mathematically correct models, so let's just give it up and say it doesn't matter?  Use the one that is easiest for the problem at hand?
Naej:
Exactly! These concepts are tools.
SiliconWizard:

--- Quote from: Naej on January 15, 2022, 04:14:40 pm ---Current "goes through" (and Carpenter's flow does the same) the capacitor, and on the other side, wires move energy into the bulb.
Yes the theorem is entirely true.

--- End quote ---

Well, yeah... It seems like people are suddenly discovering capacitive and inductive coupling?

Dave made a video about this way before Veritasium actually. "Does Current Flow Through A Capacitor?" =)
(Yes of course we are all running in circles.)

EEVblog:

--- Quote from: Naej on January 15, 2022, 06:43:35 pm ---Exactly! These concepts are tools.

--- End quote ---

Careful, I've been constantly put down on this thead for being a dumb arse engineer for dare suggesting that engineers have tools that solve problems, and not understanding that Poynting is the only true way that energy flows  ::)
SiliconWizard:

--- Quote from: EEVblog on January 15, 2022, 09:45:45 pm ---
--- Quote from: Naej on January 15, 2022, 06:43:35 pm ---Exactly! These concepts are tools.

--- End quote ---

Careful, I've been constantly put down on this thead for being a dumb arse engineer for dare suggesting that engineers have tools that solve problems, and not understanding that Poynting is the only true way that energy flows  ::)

--- End quote ---

That is because " Engineers are essentially dumbed-down "physicists". "
 :popcorn:
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