This guy says much of what we're talking about here. Comments on the vid also worth checking out.

And another

I'm curious if a similar question has ever been answered in the negative - i.e. no, there are a finite number of primes of some form or with some property and the largest one is x. Obviously something nontrivial, not "there are finitely many 2-digit primes".

hmm... just thinking about this for a minute given this is it obvious the bulb won't come on in the original 1 switch set up even before you flip the switch due to the same capacitive charging? I feel like after we flip the switch we're getting really nitty with induced fields etc but sort of ignoring them before.

The point is that the electric/magnetic fields only exist when the wire is charging. At t=0 we're assuming things are at steady state, i.e. the wire between battery and switch is already charged, so there are no fields. When the switch is closed current will briefly be flowing in order to charge the wire between the two switches, creating the fields for the that brief period and causing the light to receive power. It is actually the same effect that causes the light to receive power in the original case of it being a closed circuit rather than having a second break, the situations diverging only after the wire between switches would be charged.

There are definitely issues with the whole situation due to inductance/capacitance not really making a whole lot of sense with a truly 0 resistance wire but if we assume infinitesimally low resistance and accept the idea that the bulb is "on" if it's receiving any power from the battery then I think the initial Veritasium video is technically correct.

Dont supercondcting wires have zero resistance?

This is also pretty much the explanation I understood from the two videos above and a lot of the comments on them.

The consensus seems to be that the bulb will receive full power after 1s but it will receive some nonzero amount of energy (not enough to light it) after 1/c seconds due to the wires acting as a capacitor or as antennas, but that does not require the circuit to be closed anyway.

Also a lot of people seemed to be hung up on the fact it should be 1m/c seconds which I thought was maybe a little pedantic.

Yeah they do (although I think their properties when used as part of more complex circuits are still not very well understood) and I should probably have said that an RC model doesn't make sense rather saying the terms don't make sense.

This I can buy, but it's not super interesting imo. You're saying the light bulb won't actually turn on, and if we just assume wires have 0 capacitance and inductance for DC voltage (which is just as reasonable as 0 resistance) there is no voltage drop across the bulb at all? Kind of a bait and switch from the original claim in the video(!) unless we're still missing something.

This is my understanding of the explanation, and a few commenters did point out that the original Veritasium video was misleading and clickbaity.

Check out the second video I posted above, dude seems to know what he's talking about.

Just saw that second video. I think it was clearer than the original. The thing is we can basically do the experiment now. How a wire up to one end of a battery and place it 1 meter away from another wire hooked up to a light bulb and the other end of the battery. It obviously won't light up so I still have an issue with the original video. And it doesn't seem like anybody is trying to calculate how much power the bulb will actually get.

This guy did:

Ok... if I understand this guy correctly, the light bulb will light if the circuit is open on the moon, for the duration of the time it takes for the signal to get to the moon and back. But I guess this only works if the cables are parallel and physically close to each other (for some definition of "close", I guess) and wouldn't work in, e.g. a circular arrangement of the transmission line.

Basically the video was one of the worst possible ways to explain how moving charges in one location can influence charges in another location via field interactions. The vast majority of energy that gets transmitted to electronic devices does so in the common sense way of creating a closed circuit with one end at a higher potential than the other with creates a current.

After now watching about 5 or 6 videos on this topic, I would be lying if I said I fully understood it, but I think (hope!) I understand it better than from watching Veritasium's original video alone.

Probably beating a dead horse at this point, but this guy has now persuaded me that they're all wrong!

Sounds like chez was right all along!

Maybe. I'd still rather be wrong than be chez.

This is a very physicsy/mathy answer and basically the one one I defaulted to after first watching it. If the other explanations are based on there being current going through the switch pretty much right after you close it that has to be wrong. A wire connected to one end of a battery would not have any steady state current. I was willing to accept some transient induced fields that happen before you get current for some engineeringy reason as you go from 0 to 24 V abruptly…but it has to be a 2nd order effect and not because you have current going through the wire.

But that video basically brought up all the issues we did. Causality and why doesn’t it simply turn on even before the switch is closed.

Judging by the number of response videos that popped up (and keep popping up) in my feed, and the varied takes in all those videos, it looks like we were far from the only ones to be confused.

so would I. It's a tough gig.

As I understand it the bolded is not quite accurate. While it's certainly true that there is no steady state current in a wire connected to the battery, there is an electron imbalance on the wires connected to each pole of the battery. Once the switch closes there is immediate movement of electrons from higher density to lower density across the switch. The switch would be the very first point at which there would be a detectable current and the current would propagate at ~c m/s in both directions from the switch (meaning where there is a measurable current, obviously the actual current doesn't flow in both directions).

But that setup allows for faster than light communication if the current only starts flowing because the other end of the loop is connected to the other pole of the battery

The current starts flowing because there is an electron density difference between the wires on each side of the switch - the rest of the circuit is only relevant in that it is responsible for having caused the steady-state density difference before the switch is closed. If the circuit was broken a light second away at the same instant that the switch was closed there would still be current across the switch until the electron balance was restored.

I don’t really get the electron density terminology. For a normal circuit with an open switch you initially have 1 wire at 24 V and 1 wire at 0 V. Since neither wire has a potential difference you have 0 current. When you close the switch you have a single wire with 1 end at 24 V and 1 end at 0 V which creates a current. You fine with that terminology?

If someone a light second away has a switch that is simply open the whole time, you agree there can’t be any current? Even after the Earth switch is closed, all you have is 2 wires at 2 different potentials. I think if we agree on all that we are saying the same thing.