ECN Forum Forums General Topics of the Trade General Discussion Area electricity misconceptions

I need you guys to look at this website and tell me if this guy is knowledgeable or a idiotic lunatic. I tend to believe the idiot theory. http://amasci.com/miscon/elect.html

This guy is upset because K-6 graders are not being taught properly by their textbooks electrical theory at a engineering level.

[This message has been edited by skipr (edited 09-27-2006).]

I've only read a few bits of his articles but, based on my barely passing score in college chemistry, he seems to be correct from a scientific standpoint. Is he going a bit too far in regards to K-6 textbooks? Perhaps. But one thing I agree with him on is that a large percentage of what is taught in most school textbooks is simply wrong for one reason or another. In fact, in my opinion, most of what people consider "common knowledge" is incorrect. For example, most people believe that their car will protect them from lightning because of the rubber tires. In reality, people get electrocuted every year by lightning while in their vehicles. The charge is actually dissipated around the metal shell of the vehicle. If you happen to be touching metal when the lightning strikes, then you'll probably get shocked. After all, if 500+ feet of air can't stop the electrical discharge, how is an inch or two of rubber going to stop it?

This is but one of many, many things that people have all wrong and which are often taught in textbooks. Remember that textbooks often lag 20+ years behind in information. Even some very famous museums have been criticized for having displays showing information that was overturned 20 years ago by new evidence and study. So, I do tend to agree with this guy's mission of trying to set the record straight and don't consider him a "nut."

Kevin

When we teach, we do so in steps. Often we use simple examples to illustrate a point- knowing full well that the "model" will have to be 'adjusted' as we move on to more advanced topics.

For example, how many of us have heard electrical principles compared to flowing water? Thenm later, maybe to a closed hydraulic system? etc.

I recall reading a report, of a high-brow scientific conference. During a lecture on Relativity, the speaker compared an aspect of the theory to a 'cup and saucer.' A furious debate then arose, as some felt a better example would have been "two cups and two saucers." Let's not get silly.

The explanations in the article are fascinating. I don't think it silly to expect an accurate model or accurate use of terminology when being taught a new concept. I would rather not be taught rather than be taught something wrong, and then have to unlearn, then when I relearn, have to try to remember which version is the right one.

Some of the author's points seem to be semantical, but overall I think he has some really good points.

Reno, I love your example. While it may have been awkward or inappropriate, I'm sure that even in the debate between analogies some insight could have be gained on the true nature of relativity, which is all an analogy is good for anyway. So even an argument over the better description can in itself provide its own description.

I recall learning about electrical energy when in the 6th grade. The science teacher likened the flow to a line of students all linked by placing their right arm upon the shoulder of the one in front. He then gave the student in the back a shove, and almost immediately, the student in the front jerked forward. I always knew that any talk of flow was only an analogy, as no one really knew what electrical energy was. Also, the term electricity is simply a shortned version of electricity energy.

Do people REALLY find electricity all that confusing? I think we should just trust in their intelligence and give them the whole truth from the start. They've already learned about the atom and electrons and how photons are a wave and a particle, it's not much more of a step to talk about electron shells, band gaps and electripotential energy. I wouldn't ecpect them to remember all the details, but at least they would *understand* what happens when they throw the light switch and not have to rely on some hokey analogy. If the kids actually understand what goes on at a fundamental level (or at least feel they do), they might be less msytified over the more intangible aspects.

Really, I blame this on the way our schools work. There is too much emphisis on knowledge and not enough on understanding.

Besides, I tend to look at pipes as wires with water, and highways with traffic as current, doesn't anyone else? In fact, had an argument with the plumbing inspector the other day "But NEC allows me to take simultaity into account when sizing panels and services, why won't you let me do it with pipes??"

quote" For example, most people believe that their car will protect them from lightning because of the rubber tires. In reality, people get electrocuted every year by lightning while in their vehicles. The charge is actually dissipated around the metal shell of the vehicle. If you happen to be touching metal when the lightning strikes, then you'll probably get shocked."

Now that the truth has come out it is time for submitting code change proposals to address this issue. A code proposal for requiring a ground rod to be driven 8" into the dirt, and if more than 25 ohms of resistance is encountered a second rod driven and bonded to the first rod should do it. Then a ninimum # 8 , maximum of #6 copper conductor should be bonded to the vehicle with an approved listed terminating lug. If the gec is determined upon inspection by the local ahj to be subjected to physical damage then it must be installed into an approved conduit and bonded at both ends if the conduit is of a ferrous metal. This change would help in solving the problem.

macmikeman:

Great, now you've gone and given the Code gurus an "idear".


edited for spelling

[This message has been edited by mxslick (edited 09-28-2006).]

When I was in the Navy electronics training my instructor told us it really doesn't matter where the electrons or "holes" are flowing as long as you can figure out how to wire it up, how the parts affect the circuit and what it looks like on the scope when it is bad.
That advice served me well for over 40 years.
I don't care what that stuff is in the wire but I do have a pretty good idea how to keep it moving the right way.

macmikeman: That's just plain silly. All I did was bond a #4 bare copper grounding electrode conductor to my vehicle's frame and let it drag the ground for 100' behind me. That way I can still move. And best of all - no more getting shocked in the winter by electrostatic charge when I twist out of the seat! :-) Now if I could just figure out how to keep other cars from rolling onto the wire and ripping it off.

Kevin