ELI5
What is electricity exactly and how is it caused? I hear multiple things like it’s the movement of electrons, but that doesn’t make sense to me cause electrons are always moving. Isn’t it wave energy that travels by means of electrons?
I also don’t understand Voltage visually. I understand it’s the amount of joules in a Coulomb, but what would the difference be on a small level? What would be the difference physically and visually at 1volt to 1000volts on the atomic level?
In: Physics
Electromagnetism is the “effect” that is produced by electrical charges (+, -), like gravity is the effect that is produced by mass. Mass, charge, spin, color, etc., are properties of the basic particles of matter in physics, and they have forces and fields associated with them.
Anything that has a charge (one electron, many electrons, one proton, many protons, etc.) creates an electric field and a magnetic field, and whether you see “electric” or “magnetic” or a combination of the two depends on how you think the charge is moving.
Motion is relative, so if you’re on a train with someone wearing a bunch of electrons on their clothes, you’re seeing “static electricity”, but someone outside the train waiting at a crossroads may see a magnetic field, or a “current” (flow of electricity).
Comparing to gravity, Earth has a lot of material so it creates a strong gravity field. Other objects that move (fall or get lifted up) in this gravity field interact with it, and gain energy just from their position in the field (how high they are). They can convert this “potential energy” (energy because of their position within a field) to “kinetic energy” (energy because they’re moving) by falling down within the field.
Electromagnetism is also a field, so the same thing happens. Chemical reactions can strip electrons out of the outer orbitals of atoms (this is what a battery is), and otherwise electrons being forced to move inside an electromagnetic field (this is what a turbine does at the power plant), these create potential energy within the electromagnetic field. Voltage. The higher the voltage, the more the electrons want to move through the field (“fall” to zero “ground” level).
Compared to gravity, voltage is like “how strong the gravity feels at this position within the gravity field”. Sort of related to height, but also related to whether you’re 1 meter from the surface of the Earth vs. 1 meter from a black hole. Voltage is how strongly those charges (electrons typically) are being pulled by the electromagnetic field.
Now, one important difference between gravity and electromagnetism is that metals are just like any other material for gravity, but they’re special for electromagnetism.
Metal atoms form an ordered crystal-like structure, and the electrons in the outer layers can flow freely between the atoms, very little force is required to move them [like a river flowing between pebbles](https://www.abc.net.au/science/basics/img/Metallic-bonding.jpg). Metals conduct electricity (electron movement) very well, and we use them for that purpose. There is no equivalent material that does that for gravity (that we know of).
As an example of the opposite, plastic atoms arrange themselves [like this](https://www.sciencenewsforstudents.org/sites/default/files/scald-image/860_main_polymers.png), and it takes a high voltage to “pull” the outer electrons out and move them along the chain. Plastics, air, rocks, glass, etc., are all insulators, the electrons don’t flow unless there’s a very high voltage to pull them out and force them to jump from atom to atom.
Air is a gas, the atoms of air are far apart, so air is also an insulator. It takes a high voltage to force electrons to go from atom to atom through air, and that’s why a lightning bolt, when it discharges, it discharges A LOT of pent-up energy.
Latest Answers