"Carrier" is short for "charge carrier", such as electron, proton, sodium ion, etc.
"Eddy currents" are "regular" conduction currents with a particular geometry, "going around".
Again, it was discovered very early that electricity, as opposed to gravitation or other effects, involved two opposite charges: the decision was made to name "vitreous" electricity (rubbing silk on glass) as positive and "resinous" electricity (fur on amber) as negative. This is a convention or definition, not a mistake. Much later, the elementary particle with a negative charge was discovered and named the electron. Currents continued to flow.
The Van der Graaf generator with a beam of alpha particles down the tube is an example of a closed circuit where different branches of the circuit involve the flow of different charge carriers.
In an electrolytic cell (like a battery, but with noble-metal electrodes that do not react chemically with the solution), when you dissolve NaCl powder in the water, the molecules dissociate into Na+ and Cl- ions that then move through the solvent (water) in opposite directions when voltage is applied to the electrodes, but since they have opposite charge the ionic current flows in the same direction. Similarly, when you dissolve HCl gas into water to make hydrochloric acid, the solute dissociates into H+, which is a simple proton, and Cl-, a negative chlorine ion.
Obviously, flow of electrons is an electrical current, but I disagree about limiting the definition of electric current to only that charge carrier.
I keep repeating myself, but the definition of electrical current with possible charge carriers was in the first week or so of my freshman college course in electricity and magnetism, and it remains with me 50 years later.
Oh no!! I've come back again!!! hahaha...
Dear Tim, I never wanted to "win" re: this topic, and I know you were not accusing me as such, but I'm still thinking that you/(others) are not *wrong*
but on another tangent/thought/statement that I was/am on?? I'm trying to understand (and mostly do!) what you are saying, (again), but please think
on a different tangent to where your mind is at. Firstly, OK, batteries are more complex a discussion, but please think about *just* a capacitor for now...
Firstly, for the sake of the discussion, let's ignore whether *current* flows from -ve to +ve or visa-versa. Don't care. Let's ignore "naming conventions"
all together!! In your 1st line above, you said... "
Carrier" is short for "charge carrier", such as electron, proton, sodium ion, etc." The Carrier is not
relevant to me, but what it is Carrying is! So you have a Sodium-Ion in solution, it could be anything, but it is carrying (in this case) a Negative charge,
meaning there is an excess Electron there, and *that* is what actually Flows! A Positive-Ion has an Electron deficiency, but It's still not relevant to me??
A 'perfect' capacitor could hold a charge indefinitely, as there is no Circuit (except atmosphere!). You need to connect that capacitor into an external circuit,
(or short-circuit it it with a wire), for the 'Electrons', (sorry, thing-a-ma-whats-its), to travel externally in order to finally return to the *deficiency* on the
other side of the capacitor?? There is nothing Flowing internally through the dielectric?? I can not fathom why this is hard to imagine/explain??
You are of course an intelligent man, but I seem to lack the ability to explain what 'I' mean here?? I know I will have to let this go though, because I do
not want to waste people's time any more... And I should concentrate my *time* on more relevant contemporary issues I have!! hahaha...