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by lchengify 874 days ago
Only tangentially related, but I highly recommend watching Veritasium's YouTube video on electricity if you're curious as to how Maxwell's fields create the current / amp abstractions in EE [1].

It's a common misconception that electrons or current transfer energy. In reality it's the electric field that exists between the wires that is doing the heavy lifting, the electrons in the wires are just controlling the field.

This has always confused me and I was very irritated when I first learned electromagnetics about how rote all the initial learnings are. I wish more work was put earlier into making everything relate back to Maxwell's equations to make it make sense.

[1] https://www.youtube.com/watch?v=bHIhgxav9LY
2 comments
simonbarker87 874 days ago
I always explain it to people like waves in the sea. The bobbing up and down isn’t the water molecules travelling they are simply going up and down as the wave moves through the water. People seem to accept this analogy as, even if the water thing is new information to them, it’s easier to visualise.
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lupire 874 days ago
That's not what PP and Derek Veritasium Muller are harping on.

It's not about the misconception about "AC is vibrating so how can electrons be delivering their energy from the power plant to the light bulb far away?"

They are talking about how the electric field is outside the wires almost entirely.

Their argument is that in the water wave analogy, the wave wouldn't be in the water at all, because it's "actually" transmitted via an invisible field in the space above the water, which pushes back on the water farther away.

Most respected electricity/physics YouTubers disagree with Veritasium's emphasis on this perspective, by the way. The think he conflated the first misconception I mentioned with the second idea, which is about how you model electric circuits.

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lupire 874 days ago
It's a practical simplification, not a misconception.

It's the same argument as "Einstein corrected the misconception that Newtonian mechanics is how bodies interact, and it's irritating how rote mechanical engineering of a car is."

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