It seems that, just after I posted some critical opinion about physics Youtubers, they reached a new low.
In a recently published video by Veritasium, he essentially claims that conducting wires play no role in electric circuits. Go watch his video and have a good laugh:
"The Big Misconception About Electricity" by Veritasium
I initially wanted to write a Youtube comment rebutting him, but then I refrained from doing that. Why? Because the comment section was already flooded with fans praising him for how his video blew their mind. Can it be that their mind have been blown so often recently, that they now no longer have one? Well, there are critical comments, but those comments received few likes, and are probably going to sink deep down into the comment section.
I'd rather write my "comment" here because this way I will be able to find it later. Here's what I would have written:
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Your explanation about the Poynting vector is correct, but the application to this scenario is plainly wrong.
Imagine removing the conductors at the two ends of the circuit, exactly at the moment when you close the switch. In the next 1/2 seconds, the light bulb has no way of knowing that the ends have been removed, because the information about the ends being removed has not yet propagated to the vicinity of the bulb. Therefore, in the first 1/2 seconds after closing the switch, the bulb will behave in exactly the same way as if the ends hadn't been removed. If your conclusion in this video were correct, the light bulb still turns on almost immediately. But in the present scenario, there is no circuit at all. How can the bulb possibly turn on?
The problem with your reasoning is that, while there are electric and magnetic fields present at the position of the bulb almost immediately after closing the switch, such fields are radiation fields too weak to power up the light bulb. It is only after the charges in the circuit redistribute themselves, so as to establish a static electro- and magnetic field, that the light bulb can be reliably turned on. But the establishment of static fields takes time, as these fields are sensitive to the geometry of the entire circuit.
To sum up, just as another viewer pointed out, what is the point of those copper wires, if the light pops on immediately?
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By the way, I have downloaded this video, because I know he will delete it some time in the future. I will upload it here if that happens.