How does AC electricity transfer energy if the electrons just go back and forth, and don’t actually go anywhere?
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Electrons aren’t energy, they don’t get gobbled up to power electric devices. Instead the power is conveyed through the movement of electrons and their associated electromagnetic fields.
Think about trying to spin a wheel in a machine. You might attach a belt to it and spin it that way, but the wheel isn’t *consuming* the belt to spin. You could also attach a rod offset from the center of the wheel and by alternating pushing and pulling the rod rotate the wheel. The latter is sort of like how alternating current works, the force is being transferred in the cycle of the current.
The energy isn’t transferred through the motion of the electrons (mostly). The energy is transferred through the electro magnetic fields.
A physical example: take a rope and pull it taut between your hands. Move one hand up and down rapidly. You should feel some force on the other hand. The rope vibrating back and forth transmits energy even though the rope isn’t going anywhere.
There is no EILI5 for electricity. The story we get about a firehose of angry pixies is good enough so that the average Joe on the street can wire up a light switch… But it falls apart as soon as you put any real thought into it.
The short answer is that electrons don’t transfer energy. The wire just enables “communication” between the power source and the site of power consumption. The power is actually pushed into and pulled out of the energy field surrounding everything. Does this make any sense? No. Probably not. Again, there is no EILI5 for electricity.
For a long answer, Veritasium on YouTube goes into detail on the how and why… But even he stirred up a hornets nest with other really smart people finding lots to quibble with.
How do gears transfer power if they just go around in circles, and don’t actually go anywhere?
The electrons are what’s moving they energy, they aren’t the energy being moved. Even with DC, the energy travels near the speed of light, but the electrons themselves are rather slow. If you have 1A of current in a 1mm diameter wire, the speed of the actual electrons is only about 1cm/s.
If you have a stick, you can push it to transmit power through it, and you can pull it to transmit power through it. If you do one and then the other, you can still transmit two strokes worth of energy down the stick, with the stick ending up in the same place. A direct example of this is the pistons of a steam engine. You push on one side of the wheel, and then when it’s rotated 180 degrees you pull. So both times you make the wheel rotate the same direction, even though you’re pulling and then pushing. AC motors work the same way.
This is super ELI5, so its not perfect, but it will get your mind into a better frame for this question.
How does a saw transfer energy into wood to remove it. If the metal just goes back and forth, and does not actually go anywhere?
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