I remember asking this in physics at high school (a scary number of years ago) but the teacher couldn’t answer it.
Imagine you have a circuit with 2 bulbs in series, a DC power source and an on-off switch. When you close the circuit, in high school physics terms, the current has to flow around the circuit from the negative terminal of the power source to the positive.
Does this mean that if you had a fast enough camera, you would see the bulbs light in sequence, the closest one to the power source lighting first? (I know, bulbs take a relatively long time to heat up compared to the speed of electrons. If necessary substitute two incredibly fast measuring devices for the bulbs). If so, why is it that when you break the circuit after the bulbs, the electrons “know” ahead of time that they won’t make it back to the positive terminal and so the bulbs don’t light at all?
I know the notion of all the electrons hurrying through the wires like cars in a tunnel is naive, given quantum mechanics etc. - so what really happens? Is this something to do with the electrons “seeking out all possible paths” ahead of time, a la two slits experiment with photons, so they know not to start on their journey if there’s a break in the circuit?
I have a good layman’s grasp of quantum mechanics (if that’s not an oxymoron) but here it seems like a macroscopic phenomenon.