Like most people, I believed that the energy used by an electric circuit flowed within the conductors (or at least on their surface, due to the skin effect).

But that's a misconception, and anyone who learned Maxwell's equations in school already has the key to guess why:

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@codewiz I really want to see the experimental proof for this one, because I have a thought experiment to counter it. If we put the light bulb at the far end, at 1 light second away, I thinkwe would agree that it takes 1 second to light it, because even the EM field propagates at c. But what if we put the light bulb back and instead place a switch at the far end? The switch will be closed first, but we will open it less than 1s after connecting the battery, before the EM field reaches the switch

@codewiz so if the light bulb lights, doesn't that violate causality?

@codewiz seems like my question has been answered here: at around 30min he says that it would work the same even with an open circuit, so I guess that means the wires act like giant wireless antennas, and in my example the light bulb would light immediately and continue shining even with the distant switch open (AC) or just blip immediately and then stop (DC).

@chebra Found a 2 year old video explaining the same principle, and visualizing how, in DC, energy actually flows _into_ the wires from the surrounding space... and also explaining where this energy ultimately comes from:

@codewiz @chebra

There are no "particles" at the atomic level. Not as idealized point sources or "billiard balls".

Those are just abstractions for discrete values of various fields when you measure them in a particular manner in some time and place.

@codewiz That's a very interesting video with a clickbait header. Obviously, in the given example, energy DOES flow in wires. There are no inductivity in a circuit or smth. Cut or remove any wire and bulb will always turn off.

@1lyaP My understanding is that only the electric field flows inside the wires, inducing a magnetic field around them, and the energy flows perpendicular to both (outwards from the generator and inwards into the load).

@codewiz it is not exact picture, if I understood correctly.

Wires are metal. There are billions of electrons in there, which oscillate thus creating electromagnetic field in and around. Energy IS the force of billions e- synchronized in a conductor.

I mean: wires are the key. It's the conductor who holds vibrating electrons, which are the source of the fields. Remove wire and em field will shrink to a small area around metallic conductors of the battery itself, plus and minus connectors.

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