One of these days we might even figure out gravity.
And just think of all the practical applications we’ll invent when THAT happens! We could get gravity to do useful work. With some ingenuity, we might even be able to harness gravity to produce electricity! Or to drive flour mills. It all sounds so futuristic to contemplate, but we’re getting there!
Okay, so here’s my question about all those electrons sloshing back and forth in an AC pipe: What is the actual distance that one electron moves back and forth in a 60 Hz AC circuit?
It’s going to vary a bit depending on the current flow, the size of the conductors, etc. but it’s going to be in the neighborhood of a tiny fraction of an inch.
And if you want to know how fast the electrons in a wire move, you need to find the drift velocity, and the example in the article shows that for a 3amp DC current in a 1mm copper wire, the velocity is of the order of 1metre/hour - pretty slow.
My favorite is the Van der Graff generator (those things with a metal bulb on the end of a tall stalk), which literally moves electrons around by putting them on a conveyor belt.
Sure, sure, and practical nuclear fusion is around the bend, too, I bet.
Well, maybe not these days, but it wasn’t that many years ago that most homes had several electron throwers in Cathode Ray Tubes (TVs, Monitors), and further back, in Valves (any amplifier or radio).
These days, it’s all newfangled solid state semiconductors, got no soul. Back then, you had to boil those electrons off a filament glowing orange in the dark.
Oh, and get off my lawn … 
Yes, since there are such an enormous number of free electrons available, the average velocity of the electrons is incredibly slow. Your link estimates that, for 60 Hz AC, the maximum distance traveled before the cycle reverses is about a millionth of a meter. Bear in mind that the electrons are actually zipping around much, much faster (about 1.5 km/s), scattering off defects and phonons. So you have to imagine this incredibly dynamic sea of zillions of electrons moving with random speeds in random directions, with an average speed faster than the speed of sound, continually changing speed and direction, with an average velocity along the wire that is many orders of magnitude smaller.
Well there is an understatement.
Yea, this question has always perplexed me.
A circuit using a battery is probably a better example. As we’re all aware, free electrons are moving in the wire, with a drift velocity of around 1 mm/s. Yet there are no electrons “flowing” inside the battery. (The charge carriers inside an electrochemical cell are ions, not electrons.) Hence electrons can’t flow out of the battery, since there are no free electrons inside the battery.
So what is going on at the interface where the copper wire touches the negative terminal of the battery? Is this where the flow of electrons starts? What is creating the electrons at this interface?
I hope it isn’t like Schrodinger’s cat where if we ask too many questions all electricity will stop working. How would we watch Revolution on network TV?
I was terribly confused for a moment, then I remembered Leyden jars.
So, followup question- how many electrons can you have in a jar?
Say a one quart mason jar- how many electrons can you stuff in there?
A lot if you’re making electron jam. Less for pickled electrons.
I’ll be quiet now. 
Right, the electrons are not traveling inside the cell. They are being “lost” by the metal of the anode, travel around the circuit (note, as all of the discussion so far has pointed out, that the electrons at the end of the circuit are not necessarily the same ones as at the beginning), and combine with the metal at the cathode. Inside the battery, the current is carried by ions.
a bit of discussion here.
Even without current, electrons aren’t stationary. They drift. So even with AC, it’s possible that you’ll get some electrons from the power plant.
So that light bulb that’s been burning since 1890 or whenever is full of antique electrons moving back and forth but going nowhere for 123 years.
The generators electricity goes into a transform at the power station.
The transformer,depending on design, might not have conductor that crosses across from the primary (generator) to secondary (load/transmission line) side.
Of course, this is the transformer to put a high voltage on the transmission line near the power station. There may be more voltage increasing transformers along the way. Then more transformers to convert it back to lower voltage, to get it back to 120 or 240 volts for end users.
Transformers normally block the flow of electrons from primary to secondary quite well, but not absolutely perfectly. (depending on design, but many will be the simplest design which is to have completely separate primary and secondary windings… )
Electrons are new viewed as something like little fuzzballs rather then solid marbles. If you don’t keep them tightly contained, they tend to puff up. I dropped a mason jar full of electrons once, and it was a mess! They all swelled up to the size of tennis balls (still fuzzy) and covered the entire floor of the lab up to the height of the windows. The windows blew out, and they spilled out into the courtyard and burned the lawn, before they eventually floated up into the air and drifted off.
Okay, the other question I might have been trying to ask: What is the wavelength of 60Hz AC electricity? I might (or might not) have been thinking that the distance the electrons travel back and forth was the wavelength. Isn’t the wavelength something on the order of some small number of miles, or a large fraction of one mile, or so?