Electricity Is Magnetism
realworldtech.com
realworldtech.com
I can't help but feel that "electricity doesn't travel along the wires" is a somewhat unhelpful "well, actually" explanation that kind of misses the point. And you can tell it misses the point because you can't actually carry electricity without free electrons.
And at least in part the confusion seems to focus itself around the concept of stray capacitance, which makes it doubly confusing when you illustrate it with circuit diagrams where stray capacitance is deliberately left out. See also ElectroBOOM's rebuttal [1] where he illustrates how the situation can be explained by explicitly drawing in the stray capacitance.
"Oh but what about that tiny bit!" That's capacitance. Sending "electricity" through air is not new, it's called Radio.
It may not be useful to the everyday end user, like most computer chips only using binary, but still a fundamental truth that has sometimes obscure real world implications, like float rounding?
The premise of his video is that the energy goes across to the bulb at the speed of light without using the circuit.
The real answer is there is a very small response at the speed of light because the moment the battery is connected there is effectively an antenna or capacitor set up between the two wires.
The light will turn on after the time it takes the energy to pass around the entirety of the circuit.
As for the Poynting vector 'demonstrating' that the energy goes straight across rather than being confined to the wires, there is a tiny bit of truth in that, but he fails to say (or to understand) that in reality the field lines running from battery to bulb would be SO ABSOLUTELY MINUTE compared to the very strong field lines confined to the circuit path.
So in short, there is a TINY amount of current flow at the speed of light because there is an antenna set up between the wires. It doesn't even matter if the wires are connected at their ends or not - you've built an antenna.
But this will NOT turn the light on because the energy received will be extremely small.
The light turns on after the energy has travelled the entire length of the circuit, and not before.
It doesn't have to be very small. The pair of wires form a transmission line and if the characteristic impedance of that line is low enough the current will be much higher. You appear to understand that so I'm not telling you anything.
But there is still value in proposing this because if one were to perform this experiment with really low Z coax (12 ohm or something) the bulb would instantly light to nearly full brightness, yet the 'mystery' would be dispelled or at least trivial to explain: the instantaneous current is supplied via the distributed LC circuit inherent to the transmission line.
To get this result, is it necessary that the wires are very close?
ElectroBOOM has a good response https://youtu.be/iph500cPK28
This video is playing word games, trying to treat an AC phenomenon as if it were DC, which it isn't.
Power in a DC circuit ONLY flows in the conductors. Here's a very simple way to tell if the electricity is actually flowing the the wires or not... stretch the wire to the point where the conductor breaks, but the insulation doesn't... current will drop to zero, unless you have enough voltage to cross the gap.