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In galvanic cells, electrons are used as the source of charge difference. This creates a current that we can use for a large variety of purposes (i.e. light up a bulb). When I think about this phenomenon there are several things uncertain to me.

Firstly, how does the electron flow heat up the filament of a light bulb?

Secondly, is this behavior caused because of the electron (so its properties are of essence for electricity) or because of the charge differences?

If the charge difference is the only factor, does this mean that any particle with a charge other than zero will create electricity when it moves?

For example, will a positron generate electricity and heat up a filament?

Can a positron even be directed like an electron? I would suppose that if this was the case, if electrons flow from left to right and so does the current, then if we want the same direction of current flow, positrons should flow the other way.

My only guess as to how light bulbs can produce light would be that electrons somehow transform into photons, but I am unsure of how they do that.

I want to understand why electric current works at a fundamental level. I am not looking for the answer "Electrochemical cells produce a voltage by making the electrons from a spontaneous reduction-oxidation reaction flow through an external circuit.", that many online sources provide. This answer is very unhelpful. I know how the electrons move and how to drive those reactions, but I don't understand why electricity really works.

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    $\begingroup$ You have too many questions for the format of this site, which is focused on one question at a time. As you are a student, have a look where some are answered here explainthatstuff.com/electricity.html $\endgroup$
    – anna v
    Jul 25, 2021 at 3:44
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    $\begingroup$ for a microscopic view of current see hyperphysics.phy-astr.gsu.edu/hbase/electric/miccur.html $\endgroup$
    – anna v
    Jul 25, 2021 at 3:50
  • $\begingroup$ @annav Yes, my "question" are really questions, but I felt they are all somewhat related. Also, my profile has old information I should update. I am not a high school student anymore... $\endgroup$ Jul 25, 2021 at 3:54

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I think you are really asking two questions.

  1. Can positrons serve as charge carriers in electric circuits?

Theoretically, yes, if you replaced every matter particle in an electric circuit with a corresponding anti-matter particle, the circuit would work the same way (except the flow of electric charge would be in the opposite direction).

However in practice this is impossible. Realistically, it's only possible to create a small amount of positrons with current technology, and if you injected these into an electric circuit the positrons would immediately collide with ordinary electrons and annihilate.

  1. How are heat and light generated as electrons move through a filament?

When electrical current flows through a filament, electrons collide with other particles in the filament and cause them to gain kinetic energy. On a macroscopic scale, this increased energy of the material is observed as an increase in temperature.

We know from Maxwell's equations that light is generated when charged particles accelerate. As charged particles in the filament gain kinetic energy from collisions with electrons, some of that energy is converted to light via this process. To correctly compute the spectrum (energy in every wavelength) of the light also requires accounting for the fact that light is made of discrete packets called photons, which have an energy proportional to their frequency. You can read more about this process by googling "blackbody radiation."

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  • $\begingroup$ So electricity is just kinetic energy, just that for some reason it's called electricity? I guess the distinction is needed to specify that the kinetic energy comes from the electrons? $\endgroup$ Jul 25, 2021 at 3:57
  • $\begingroup$ @BrianBlumberg "Electricity" doesn't really have a precise meaning in physics. The colloquial use of the word loosely describes a range phenomena associated with electric circuits. More of than not, we are interested in using electric circuits to (a) convert electrical energy into some other form of energy, or vice versa, or (b) as a way to transmit, store, or manipulate information. $\endgroup$
    – Andrew
    Jul 25, 2021 at 3:59
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This is to supplement Andrew's answer and focuses on other sub-questions. Electricity, more precisely electric current, is the flow of electric charges. Electrons are very convenient charge carriers as they move relatively easily (though not without collisions) through a lattice-like grid of nuclei in a metal (have a look at the sea of electrons model for metallic solids). However, other charge carriers may be used to conduct electricity. One example is inorganic ions such as $H^+$, $Na^+$, $Cl^-$, and $OH^-$ travelling through water. You can read more about this by looking up the salt bridge in a standard Galvanic cell.

Hopefully that helps give you more intuition on how electricity is conducted by electrons and other charged particles/molecules.

And in case it has not been made clear to you yet, electricity nearly always flows in loops. The energy is generated by the flow of electrons (or other charge carriers), not the electrons themselves. Electrons do not turn into photons, and barring very advanced physics that's not really relevant here, electrons cannot be destroyed/do not disappear. It's quite like a millwheel: the water flows through the wheel, imparting energy, and passes out the other side. Similarly electrons flow through a lightbulb, imparting energy, and pass out the other wire. Plugs always have two prongs (at least) to allow this flowing of the charge carriers.

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  • $\begingroup$ Electrons themselves do not. I was hinting at electron-positron annihilation, but I don't think that's the case. $\endgroup$ Jul 25, 2021 at 4:55
  • $\begingroup$ @BrianBlumberg Electrons do not what? $\endgroup$ Jul 25, 2021 at 14:55

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