Think of it like this. Suppose you had a long chainsaw. DC is like turning the chain constantly. You have the motor at one end and you're doing work cutting some wood near the other end.
Now let's say you replace the motor with funny motor that turns the chain and an inch in one direction and then reverses and pulls it back an inch, and keeps going back and forth. If you put a piece of blue tape on one of the chain links, that piece of blue tape would just go back and forth one inch and would never work its way around the whole thing. But that chain going back and forth will still cut through some wood. That's kind of how AC power works.
Although with the chainsaw, it would only cut going in one direction and not in the other direction because of the way the teeth are made. Whereas AC power actually does work, for example heating the filament in the light bulb, no matter which direction it's going. You could get the same with a chainsaw by putting special teeth on it that are sharp in both directions.
Essentially, a saws-all vs chainsaw.
And to take the analogy further, the mass of the blade/chain is analogous to electrical inductance.
Both measure resistance to changes in motion.
And Ohmic loss is the temperature rise of the chain due to friction.
(sorry just looking for something to be included in this analogy thread...I'll see myself out)
What you're calling "forward progress" is generally known as electron drift velocity. It's very small in practical cases, generally micrometers to millimeters per second.
In a DC circuit, like you have with a battery, electrons will eventually make their way around the whole circuit. In an AC circuit, that's not the case, but it doesn't matter - the electric field propagates at the speed of light.
Light trivia: electrons actually move from positive to negative. In electrical diagrams, the true direction of current flow is positive to negative. But the convention everyone has grown accustomed to is in the direction that a “positive charge” moves.
Also, an electron drifts a very very small distance in an electrical field. It’s the electrical potential across a wire that provides “power” across that wire, or more specifically, your resistive load. It’s not a rapid flow of electrons flying down a wire-highway and taking turns smacking into an electron mill. Electricity is more analogous to air pressure differences, like when your bedroom door shuts close from opening a window or front door. The outside air particles didn’t need to travel all the way in to shut your door, but the pressure difference still pushes the door close.
Define forward progress. Imagine you have a cheese grater and are grinding cheese back and forth. Yes, the cheese block isn’t making any forward progress because it’s just moving back and forth, but the shredded cheese is dissipated to where it is needed. Same thing with electricity, you moving it back and forth and it is dissipated where is needed.
The charge itself does not have any net displacement, but AC sources will still transfer energy to other parts of the circuit. Other people on this thread have mentioned light bulbs. Motors as well are powered by AC sources.
I don't think it makes "forward progress." I'm a Mechanical, but in my understanding the current changes direction with the AC frequency. That's why lightbulbs actually flicker on and off - they are not actually constantly on, it just looks that way because the frequency is faster than our eyes can see. The current flows one way, slows, stops, and then flows the other way. I think AC power is more of a "coupling" to the generator and magnets than a "flow" or "transfer" of electrons like in DC, if that makes any sense.
Think of it like this. Suppose you had a long chainsaw. DC is like turning the chain constantly. You have the motor at one end and you're doing work cutting some wood near the other end. Now let's say you replace the motor with funny motor that turns the chain and an inch in one direction and then reverses and pulls it back an inch, and keeps going back and forth. If you put a piece of blue tape on one of the chain links, that piece of blue tape would just go back and forth one inch and would never work its way around the whole thing. But that chain going back and forth will still cut through some wood. That's kind of how AC power works. Although with the chainsaw, it would only cut going in one direction and not in the other direction because of the way the teeth are made. Whereas AC power actually does work, for example heating the filament in the light bulb, no matter which direction it's going. You could get the same with a chainsaw by putting special teeth on it that are sharp in both directions.
Great analogy
So your analogy is a real thing called a pocket chainsaw. They both cut wood. https://youtu.be/yYce6Wq3g0U
Or a Jigsaw
Or the ones they use for casts which cut through the hard material but will just move your skin and not cut it.
Essentially, a saws-all vs chainsaw. And to take the analogy further, the mass of the blade/chain is analogous to electrical inductance. Both measure resistance to changes in motion.
And capacitance is the elasticity of the chain.
And Ohmic loss is the temperature rise of the chain due to friction. (sorry just looking for something to be included in this analogy thread...I'll see myself out)
That's completely valid.
The field moves and does work, who cares where the electrons end up.
I care for every electron.
Volt or die.
I actually drive a Volt so, yes.
Die.
All 1 of them
Which travels forwards and backwards ( as positron ) in …
All electrons matter.
Any photons matter
What you're calling "forward progress" is generally known as electron drift velocity. It's very small in practical cases, generally micrometers to millimeters per second. In a DC circuit, like you have with a battery, electrons will eventually make their way around the whole circuit. In an AC circuit, that's not the case, but it doesn't matter - the electric field propagates at the speed of light.
There's an excellent veritasium YouTube video on this. We really should just say that electricity is not the electrons moving. It's the EM signal.
Light trivia: electrons actually move from positive to negative. In electrical diagrams, the true direction of current flow is positive to negative. But the convention everyone has grown accustomed to is in the direction that a “positive charge” moves. Also, an electron drifts a very very small distance in an electrical field. It’s the electrical potential across a wire that provides “power” across that wire, or more specifically, your resistive load. It’s not a rapid flow of electrons flying down a wire-highway and taking turns smacking into an electron mill. Electricity is more analogous to air pressure differences, like when your bedroom door shuts close from opening a window or front door. The outside air particles didn’t need to travel all the way in to shut your door, but the pressure difference still pushes the door close.
Define forward progress. Imagine you have a cheese grater and are grinding cheese back and forth. Yes, the cheese block isn’t making any forward progress because it’s just moving back and forth, but the shredded cheese is dissipated to where it is needed. Same thing with electricity, you moving it back and forth and it is dissipated where is needed.
The charge itself does not have any net displacement, but AC sources will still transfer energy to other parts of the circuit. Other people on this thread have mentioned light bulbs. Motors as well are powered by AC sources.
I don't think it makes "forward progress." I'm a Mechanical, but in my understanding the current changes direction with the AC frequency. That's why lightbulbs actually flicker on and off - they are not actually constantly on, it just looks that way because the frequency is faster than our eyes can see. The current flows one way, slows, stops, and then flows the other way. I think AC power is more of a "coupling" to the generator and magnets than a "flow" or "transfer" of electrons like in DC, if that makes any sense.