Why does current flow only in a closed circuit?

Question

Electronics

Hello.
I started studying electronics.
There is a question:
Why does current flow only through a closed circuit?
If we have electrons constantly appearing at one end of the wire, and disappearing at the other end, won't current flow through the wire?
And if the current goes, then why, when the plus of one battery is connected to the minus of another, the current does not flow, because as far as I understand, electrons always appear on the minus of the battery, and disappear on the plus?

Answer 1

Why does current flow only in a closed circuit?

Because electrons can only move along a conductor. And for movement they need an electromotive force (emf, voltage)

If we have electrons constantly appearing at one end of the wire, and disappearing at the other end, won't current flow through the wire?

go, that's how it works. but you need someone to throw electrons from one end and pick them up at the other

And if the current goes, then why, when the plus of one battery is connected to the minus of the other, the current does not go

You're a little confused here with electrostatics. remember from the school course experiments with an ebonite stick and large metal spheres? This is exactly the situation there, electrons accumulate on the sphere and by touching, or connecting with another sphere, these electrons run across. in the case of a battery and a capacitor, the situation is slightly different.
Let's say we have a capacitor. In it, a very thin plate separates two conductors - plates. When a capacitor is charged, electrons move from one plate to another. It turns out that there are a lot of electronics on one side, and a disadvantage on the other. The electrons want to go back to balance back and return to neutrality, but the circuit is broken and they can't do it. In addition, the plates are very close to each other, and electrons and "holes" are drawn to each other through the dielectric layer, but cannot connect, the barrier interferes. By the way, the more they "stretch", the more energy the capacitor can accumulate, due to this the charge is retained. So. If an electron tries to escape from this "trap", if you connect its leg to some other capacitor, it will fail! Because the capacitor will lose neutrality. "holes" on the other side of the dielectric pull the electrons back.
But if you close the circuit, then another matter! The electron will run to the reverse side of the plate through the entire circuit, neutrality will be preserved, and the charges will cancel each other out.
In a battery and accumulator, it is a bit similar, but with a taste of chemistry and reactions

Answer 2

Perhaps someone will come running and say what they know, explain with examples, digging into the physics of the quantum world or even deeper ...
But in general, scientists do not really understand this. All science is based on experiments and attempts to identify patterns and build a formula based on them that allows you to predict behavior and solve other problems, such as design.
Therefore, there is no 'why' answer, but you can find the answer 'what happens if you do it this way'.

Answer 3

Why does current flow only in a closed circuit?

Not only. If two areas with different potentials are close to each other, then a breakdown may occur and a spark or lightning will slip between the areas. This is also an electric current.

Answer 4

Why does current flow only in a closed circuit?

The principle of minimum action ? Why try to get past the kindly provided piece of wire?

If we have electrons constantly appearing at one end of the wire, and disappearing at the other end, won't current flow through the wire?

You can do it. The current will go.

why when you connect the plus of one battery to the minus of another, no current flows,

Some, negligible - until the static potentials of the batteries are equalized and their EMF is added, the current will go on for a while.