General > General Technical Chat
Veritasium "How Electricity Actually Works"
rfeecs:
I thought it might be good to start a new thread for Veritasium's new video, the follow up to the "Big Misconception" video:
He carries out his own experiment, much like AlphaPheonix.
He gives a lot of credit to Ben Watson and other YouTubers including EEVBLOG and Electroboom, etc.
I thought a new thread might be warranted, since the thread on the previous video wandered so off topic into pseudoscience trolling that it is probably being ignored. :rant:
rfeecs:
One quibble is that several times he says there is an electric field inside the wires but other times he says the electric field inside the wires is zero.
HuronKing:
--- Quote from: rfeecs on April 29, 2022, 04:48:40 pm ---One quibble is that several times he says there is an electric field inside the wires but other times he says the electric field inside the wires is zero.
--- End quote ---
Could you elaborate on this quibble? I thought he was pretty clear when its zero and when its not zero - electrostatic versus electrodynamic conditions. :)
PS
I thought this was a very nice follow up video - especially in addressing all the specific objections people had to his description of the original thought experiment. What a lot of work to explain how an antenna works. ;)
PPS
It's still too bad though that Heaviside's work with coaxial cables didn't have time to get mentioned - that's the most immediately practical application of Poynting Theory beyond it being a mere theoretical curiosity.
rfeecs:
--- Quote from: HuronKing on April 29, 2022, 05:34:34 pm ---
--- Quote from: rfeecs on April 29, 2022, 04:48:40 pm ---One quibble is that several times he says there is an electric field inside the wires but other times he says the electric field inside the wires is zero.
--- End quote ---
Could you elaborate on this quibble? I thought he was pretty clear when its zero and when its not zero - electrostatic versus electrodynamic conditions. :)
--- End quote ---
One point that sounded odd to me is at 8:00 he talks about a python simulation of a DC circuit. He talks about there is an electric field in the center of the wire. Maybe I misunderstood what he is trying to say.
At 11:14 he says at the instant that the switch closes, the electric field inside the conductor is no longer zero. So I guess this would be the electrodynamic condition? OK, but this condition only exists for attoseconds until the charges move and the field disappears.
We typically assume the boundary conditions for a perfect conductor include: the tangential electric field at the surface is zero, and the electric field inside the conductor is also zero. This applies both for static and dynamic conditions. But I suppose this is only an approximation and neglects the attoseconds long period when charges re-arrange themselves.
Then again, in both cases he may be assuming the wire is not a perfect conductor and has some resistance.
snarkysparky:
What pushes the charges inside the wire if there is no electric field inside the wire and the electrons don't push themselves.
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