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Comment by current123123 | Hacker News Reader

Sadly, this article does not really help you understand what electricity is. But I guess if you already know what it is in a wrong way you can read it and get some sort of negative feedback and, perhaps, get some epiphany about what it really is (or, isn't).

I was hoping for something to an article helping you understand. A list of things is it not helps, but only somewhat.

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Agreed. This collection of articles appears to be a mix of ranting about misconceptions and giving factoids, randomly marking them as misconceptions or as what's really happening. If you were not confused before reading any of it (I was not), chances are, you will be afterwords (I was).

This is the exact opposite of good pedagogy. Ironic, since it's supposedly aimed at educators.

It's not a collection of articles. Read the first line. It's raw notes, random musings, and uninspected WRONG CRAP scribbled out of order, on random bits of paper. In crayon.

> If you were not confused before reading any of it

If you watch discarded film-clips, all two seconds long and many of them backwards, expect to be confused.

The actual articles are at http://amasci.com/ele-edu.html

I agree with most of the comments here.

The article dies little if anything to help K6 educators (or students) understand electricity.

I think K6 should teach something good along the lines of safety/fun, and 6-12 something along the lines of practicality.

I learned Ohm's law when I was about 10 via "multi-kits" like so many other kids of my generation. This basic knowledge of electricity has served me well over the decades. It is seldom taught in school. Why?

I still don't really understand Maxwell's equations, but neither does your average electrician. That doesn't mean your average electrian doesn't have more knowledge about practical electricity than your average scientist who does understand Maxwell.

It's not an article. Read the first line.

The finished article(s) are listed at http://amasci.com/ele-edu.html

And heh, about maxwell, if someone claims to understand Maxwell's Equations, just sadly shake your head, then adopt an archly superior stance, and haughtily inform them that those four are HEAVISIDE'S equations, while Maxwell's were twenty equations based on the latest 1800s math-fad: Hamilton's "quaternions." If they don't understand THOSE, they don't understand Maxwell! (And now we've avoided having to admit we've never read any of them. Hee!)

It's not an article. It's not supposed to explain anything. Read the first line. It's a wad of notes, a bunch of totally-unedited crap scribbled on napkins in 1988, while THINKING about writing a proper article.

For those who didn't read:

"BELOW are my original, very crude and totally unedited 1986-1989 notes and "raw data" for...

My actual completed Electricity articles are: http://amasci.com/ele-edu.html

To truly understand electricity you have to understand the Maxwell equations. No amount of analogies using water can change that.

(Why the downvotes? Is math truly that scary for a forum of software engineers?)

Are Maxwell's equations useful? Electric wires are very unlike the situations you deal with in an electromagnetics class, and conversely there are phenomena no electrical engineer ever thinks about, like the fact that a voltage drop over a resistor means there's a nonzero charge distribution at its ends, and similarly surface charges on the wire have to carefully redistribute themselves around bends in the wire to guide the electrons along it. Unless you work with gigahertz electronics, none of the interesting electrodynamic transient behavior matters either, the circuit always instantly finds the steady state distribution.

That the water analogy works so well also has little to do with the Maxwell equations, if I'm not mistaken, I think it has more to do with the conduction electrons behaving more or less like a (highly degenerate) gas.

The water analogy works because circuits are linear systems. Pretty much all linear systems can be modeled that way, if you're willing to contort things the right way.

Water analogy works well even with non-linear components like diodes (think one-way valve) and transistors (think valve controlled by water pressure from separate tube).

Works other way too. For me the explanation of a hydraulic ram pump[1] clicked when I realized it's essentially just like a boost converter[2].

[1]: https://en.wikipedia.org/wiki/Hydraulic_ram

[2]: https://en.wikipedia.org/wiki/Boost_converter

For a layperson, Ohm's law and Kirchhoff's laws suffice.

You don't need curl and divergence to figure out whether you can turn on your microwave and coffee maker at the same time without tripping the circuit breaker.

This is only true because someone who did understand the more complicated principles designed the appliances in question. High voltage and high frequency are where the most common and intuitive understanding of electricity break down. Anything above about a megahertz or a few hundred volts and you will start to see relatively strange things happen.

My point is that few people work with high frequencies.

For most practical tasks, even the fact that we're working with AC rather than DC can be glossed over. People can plug in 120 V into Ohm's law and get the right result even though actual voltage fluctuates between -170 V and +170 V.

It seems clear to me that this article is aimed at science educators who do have a solid understanding of electromagnetism, electronics, etc., but struggle to teach high-school and college-aged students due to widespread misconceptions about “electricity” (some of which seem bizarre to an expert). The article explains what those misconceptions are because it is assuming the reader would quickly understand the scientific (or ontological) error and spend the bulk of their thought on the educational side.

This article is simply not aimed at you, it is directed towards experts. So your complaint is a bit like complaining that “C# In Depth” doesn’t sufficiently explain basic syntax.

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