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Let's talk about DC, a very simple circuit: a light bulb and a battery.

Some authors say that electrons move from negative to positive and current from positive from negative.

I always thought electrons moved in a wire at the light speed, but this video says that charges move very slow in a wire, about 5 centimeter per hour (2 inches per hour).

If electrons are charge carriers, is this video saying that electrons move at 5 cm/hour????

If electrons are that slow how can circuits work?

The video says that electric fields move at light speed.

So, I am not understanding anything.

I aways thought the whole magic were dome by electrons...

What is the correct explanation for this?

Charges, electrons and current?

Is the effect similar to a newton cradle, where one ball knocks the first one and the force is transmitted through the chain?

enter image description here

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    \$\begingroup\$ One of these days I'll have to write a canonical answer, but see electronics.stackexchange.com/questions/245610/… : basically your intuition that it's like the Newtons cradle is correct. For almost all purposes you should ignore electrons. \$\endgroup\$ – pjc50 Dec 31 '18 at 16:15
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    \$\begingroup\$ The Newton's Cradle is a very good analogy. It's not exactly accurate, but it's a good way to conceptualize it. Note the "current" flowing from positive to negative is not based on any physical principle -- it would make more sense for it to flow the same direction as electrons. But "positive" and "negative" were defined before the electron was discovered, and they got it wrong. \$\endgroup\$ – Hot Licks Jan 1 at 4:31
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In a metallic wire, electricity propagates as a field, effectively. Electrons move quickly and literally bump into other atoms which (usually) dislodges another electron. This continues down the conductor so the effects of electrical current are seen very quickly.

This is not how electric currents propagate in a superconductor, though.

In that sense, the velocity of electrical propagation is very fast (in a wire it is typically about 63% of the speed of light for reasons I won't go into here. It is known as the velocity factor).

Electric fields (or more accurately electromagnetic fields) propagate at the speed of light in free space.

Any given electron does not travel very far in each of these short hops, but they do move, and a specific electron will move quite slowly. This is known as drift velocity.

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  • \$\begingroup\$ Superconductors do allow small magnetic fields through known as fluxons. \$\endgroup\$ – Scientist Smith YT Dec 31 '18 at 20:47
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A very much simplified answer:

Compare the wire to a pipe filled with marbles.

As soon as you push a marble in, immediately another marble pops out of the pipe.

But the marble you have pushed in only travels very slowly towards the end.

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  • \$\begingroup\$ Very Good. I was suspecting something like that, thanks! \$\endgroup\$ – SpaceDog Dec 31 '18 at 16:26
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    \$\begingroup\$ @SpaceDog metals are totally jam-packed with movable electrons. (It's like Ben Franklin's electric fluid! But it's there all the time.) So, an electric circuit is like a drive-belt inside a pipe. That's why currents are closed-loop circles, and require "complete circuits." Notice that the path for current is through the dynamo coils and back out again? Also, the path is through every battery ...so no charge builds up inside. Batteries are "charge pumps," so when we "recharge" them, we're filling them with chemical fuel. (Charged batteries contain just as much electric charge as dead ones!) \$\endgroup\$ – wbeaty Dec 31 '18 at 20:35

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