Eli5 : After seing the meme of a guy going back in time and unable to answer to the question “how is this so-called electricity made?”, I’m actually really asking myself the question.
In: Engineering
Late but whatevs. I WANT to offer an answer so I’m gonna..
Electrons in wire are like water pressure in a pipe. So first, let’s look at how water moves, flows, and behaves.
Water is not compressible. You put it in a balloon and deform the balloon, and it will have the same volume as before, just in a different shape. Air? Not so much. Try putting a balloon full of air in the fridge if you don’t believe me.
This is important to the analogy, because electrons in a wire can’t be compressed either.
So if I were to take a long pipe, fill it full of water, and shove hard on the water, the water in the pipe would push on the other water, until it came out the other end with the same force I shoved with.
Now, electrons have regions around the atoms that they will be hanging around, as a function of their Energy Level. Some atoms, like those of conductor materials, have electrons that are rather easy to shove into their neighboring atoms. But any atom can only sponsor so many electrons at once in any particular region, and some regions are very hard to get shoved to, requiring great force, just like a section of pipe can only hold so much water, and if you put too much in you may swell or even burst the pipe.
So, now that you are thinking of pipes, *the wire acts as a pipe for the electrons*.
Finally, electrons are influenced by magnetic fields. If you see a magnetic field, that is the product of a moving electron… Though sometimes the field is created by spinning more than moving per se. If you generate a magnetic field around a wire, you are shoving the electrons in it because when a magnetic field changes, electrons are changing.
So by moving a magnet across a wire, you push on the electrons. If the wire doesn’t have a “closed circuit”, you will have a hard time of it because there is nowhere for you to push those electrons and they will swirl around like water in the pipe, just making it hot. If the wire creates a closed loop, you just shove the electrons around the loop. Shoving electrons around, by changing magnetic fields around them, specifically to create this turbulent motion of electrons, is how induction heating works.
In addition to being able to actively “pump” electrons through the wire “pipe” using a magnetic field, you can also do something akin to putting a water tank on your roof and letting gravity draw the water through the pipe. This is how batteries work, though the force that draws the electrons “down” through the “pipe” is still electromagnetic: one chemical has electrons and is separated from another chemical that wants them. They want to exchange electrons (this is how most chemical reactions work!), And by connecting the ends of a wire to each pool of chemical, you allow the electrons to flow between them, from where there are “too many” to a place where there is “too much”.
Finally, how do we get work done with this arrangement? Well, you know how I said shoving around electrons causes the magnetic fields to change? Magnets can pull on other magnets, and you can make a magnet exist (or not!) By whether you are moving electrons around. Want to create a magnet temporarily to pull on a bit of iron? Shove some electrons through a loop of wire, and you can pull on stuff! Install another coil, and you can pull it back the other direction (or to the center) depending on which coil you shove them through, such as “both”.
Want light? Shove the electrons through a tiny space, and they will be forced to “crowd around” and get shoved up to higher energy states than normal, and then when things calm down a little for them, they will pop back down, and the distance they move (moving electron) creates a moving *wave* in the electric and magnetic fields, and that’s what light is!
For the lazy:
Spinning electrons are magnetic. All electrons “spin”. Therefore all electrons are magnetic, and can be shoved with magnets. Metal wires have fixed electron counts, but you can shove them around inside the wire, because magnets can shove other magnets, and as a result, you can express that magnetic force that you shove into the wire elsewhere along the wire to do work.
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