Eli5 How does electric current notice if there is a “connection” e. g. to the ground?

Question

Maybe not the best title to explain what I mean, English is not my first language.

I just saw pigeons in a train station, sitting on electric wires. Obviously it does not die since it does not have contact to the ground or anything else that could transmit the electricity.

But how does the electric current notice if there is a way through the pigeon (or anything else) or not? Since the pigeon is alive, the current apparently does not flow through it?

So how does the current know?

Yes, I’m not the best in physics lol

In: Physics

Answer 1

There’s no noticing. Electrons don’t have a brain. They flow in every material whether it has current flowing through it or not. Just that if you apply potential across a material with loosely bound electrons, they might still move in different directions, but there is a net flow in direction opposite to the potential.

Now, let’s say the wire isn’t insulated, and the pigeon comes and sits on it. Since both it’s legs are in contact with the wire, it provides a straight path for electrons to flow through, with potential difference across it’s legs due to the wire. Then, he is bound to feel the shock. Now let’s say the pigeon sits with one leg on the wire and another in the air like a yogi. Then, the electrons will still flow through one leg to its body, but since these electrons have nowhere to go, and nothing is there to suck off the electrons off his body (which is what a battery does), this will not persist. The electrons will flow from one leg and evenly distribute on his body until his body’s electric potential becomes same as that of the leg, which will happen pretty fast, after that there won’t be a net flow. Current is sustained flow of electrons, and since here the flow started and finished almost instantly, he won’t feel anything.

TLDR: Current doesnt know what lies on the opposite side of a wire or a material, the elctrons flow nonetheless. It’s just that to sustain a net flow of electrons, you need a source and a sink, across which is maintained a potential difference, and you need a medium which allows the electrons to move.

Edit: What’s the downvote for? This is not something you can have opinions about, these are facts. Idiots.