Electricity doesn't move at the speed of light?

[chroot]

Originally posted by Cyberice
More like I'm not understanding how I am going to prove this to some one else.

I suggest that you not bother, and purchase them a first-year physics textbook.

- Warren

 

[Cyberice]

Oh, and by the way -- if your Dad (who is also your electronics teacher) would like to teach you that electrons move at the speed of light in a wire, you should really attempt to get a new electronics teacher (a real professor, not an "electronics technician," would be a good bet),

HELLOOOOOOO?? My electronics teacher is not the same person as MY DAD! I meant literally "My electronics teacher at school".


and perhaps even a new Dad.

That was mean

 

[chroot]

Your electronics teacher at school believes that electrons travel at the speed of light in wires?!

Call up your principal right now and request that this idiot be fired on grounds of professional incompetence!

This makes me wonder what kind of education this teacher received.

A physicist knows that electrons cannot move the speed of light as a consequence of relativity; they also know that to accelerate an electron to close to the speed of light would require a huge amount of energy. A flashlight wire filled with billions of electrons traveling at nearly the speed of light would be carrying enough energy to blow down a skyscraper.

An electrical engineer knows that electrons cannot move at the speed of light, because his microcircuit designs often deal with the timing concerns of signals moving back and forth across his chip. He also knows that semiconductor devices in general depend upon the (slow) diffusion of charge carriers, and could never work if electrons travel at the speed of light.

Any general science education major who learned about electricity should have come across the Hall effect sooner or later. It's literally in every first-year physics textbook ever published, and I'd hope that all general science education majors would have to take first-year physics!

Unless this teacher got his degree in English, there is absolutely no excuse for him to NOT KNOW HOW ELECTRONS MOVE IN WIRES. I am aghast!

- Warren

 

[Danny]

"It has been estimated that a single electron moves rather slowly at a rate of approximately 3 inches per hour at one ampere of current flow. But the impulse of electricity is extremely fast. It is assumed that the speed of the electrical impulse is 186,000 miles per second, which is the speed of light. When one electron enters a conductor with billions of electrons, the impulse must be fast to knock one out the other end of the conductor and move billions to do so.

If you should attempt to count the electrons in one ampere of current for one second, you would have to count 1000 electrons per second for 190 million years without stopping.

Water and electricity flow under very similar conditions. That is to say, each of them must have a channel, or conductor, and each of them requires pressure to force it onwards. Water however, being a tangible substance, requires a hollow conductor; while electricity, being intangible, will flow through a solid conductor. The metal of the water pipe and the insulation of the electric wire serve the same purpose; namely that of serving to prevent escape by reason of the pressure exerted."
Taken from: www.code-electrical.com

I have an electricity textbook at home that says basicly the same thing. I don't understand why you are being so ignorant. If you never heard of it atleast leave it at that but you have to keep this "Danny knows nothing" attitude. I am confident about this subject enough to keep this going--but before I do I am asking you to please look it up.

 

[chroot]

Yes, Danny, "code-electrical.com" was one of the two sites google found when I searched for "impulse of electricity."

Now, you apparently need a lesson on how to judge the quality of sources. First and foremost, this website is not an authority on physics. It's a website designed to teach electricians how to wire up receptacles. It's not surprising at all that it's wrong.

A) It is the solitary example of anyone ever using the term "impulse of electricity," a term not recognized by any physicist. As I've explained before, the word "impulse" has a specific meaning in the vocabulary of physicists, and this ain't it! The author of this page used the word "impulse" simply because he didn't know how better to describe "the propagation of changes in the electric field." The use of the word "impulse" is incorrect, and this website is spreading misinformation.

B) This website also says that it's assumed that changes in the electric field propagate at the speed of light -- which is true only in a vacuum. In a real wire, it's somewhat less. For the sake of a buttcrack-brandishing electrician, it's probably close enough -- but it's still wrong.

C) You yourself claimed that changes in the electric field propagate not at the speed of light, as your hallowed electrical-code website says, but INSTANTANEOUSLY.

If you pick a stupid website and misunderstand its stupid contents, I have every right to call you stupid. You really ought to be a little less confident!

- Warren

 

[FZ+]

Ok, ok... calm down people...

 

[chroot]

Who said I wasn't calm?

- Warren

 

[Integral]

Hey, guys let's not be so hard one electronics technicians. I are one!

My Navy training from 32 years ago taught about electron drift, and how the actual electron speed was way slow in comparison with the signal speed.

The whole Electron drift idea lived among tech as an expression for someone who was so lost in is thoughts that he might bump into a wall or generly appear to be wandering aimlessly, we called this type (not to uncommon amoung techs after 6 months at sea) DRIFTY, as electron drifts though a conductor, bumbing into things pretty much wandering, but with a general drift.

I also ran into this type of person during my years at a University Physics department.

 

[russ_watters]

Originally posted by Integral
My Navy training from 32 years ago...

Navy??! I knew I smelled something funny.

I got out last year.

Anyway as far as that site goes, an expert in electrical codes really should know the terminology, but the physics behind the actual motion of electrons isn't something he would have to work with and he probably forgot. Its not a big deal, but its not the place to find out about the mechanism behind the flow of electricity.

In any case, Cyberice and Danny, set chroot's crass manner aside and listen to what he has to say. If nothing else, we've established already that there were some misconceptions at work here - ie, the "instantaneous" thing.

 

[Danny]

I have listened to what he has to say, and really he sounds very ignorant. There is nothing wrong with the webpage I provided--if you really want to bash it please provide another that says what you are trying to get us all to believe.

You can sit there and argue all you want, but sooner or later you will need to back your arguments up which to say the least has been very limited.

So please go ahead and start typing away on how bad I am or that webpage because really it's very entertaining.

Before I forget, you said "not an authority on physics". Hmm and you are? If that's what you believe then please back that statement with something proving your point. All you do is talk; I at least show examples and references.

 

[chroot]

I have listened to what he has to say, and really he sounds very ignorant.

I'm ignorant? Why? Because I'm saying something you don't agree with? Are you joking?

There is nothing wrong with the webpage I provided--if you really want to bash it please provide another that says what you are trying to get us all to believe.

The webpage you provided is incorrect. As far as references that agree with me: open up an introductory physics textbook -- ANY introductory physics textbook. How about Halliday & Resnick for a start?

Or look here: http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html

In fact, as best I can tell, every website in existence that talks about the microscopic mechanism of electrical conduction agrees with me, EXCEPT the one you provided! Guess what that means?

And what's this "all of us" crap? The only person here who believes your bull**** is YOU. Everyone else understands reality. You're the only one saying I'm wrong, bucko.

Before I forget, you said "not an authority on physics". Hmm and you are? If that's what you believe then please back that statement with something proving your point. All you do is talk; I at least show examples and references.

I'm working on my doctorate in physics at the University of California, Santa Cruz. How about you?

- Warren

 

[meister]

I don't think either of your egos could possibly get any bigger.

 

[drag]

May I suggest that you people listen to chroot and
kindly stop this waste of perfectly fine laser energy
used to burn this thread on PF's server hard drives (which
do cost money)...

 

[chroot]

Whoa! PF's hard drives use lasers?? I wonder how fast the electrons move through the laser beam.



- Warren

 

[Greg Bernhardt]

This topic has concluded