Electricity doesn't move at the speed of light?

In summary, the conversation discusses the misconception that electricity moves at the speed of light. It is clarified that while changes in electric and magnetic fields propagate at or below the speed of light, the actual movement of electrons is much slower. The movement of electrons is compared to sound waves and the analogy of marbles in a straw is used to explain the concept. It is also mentioned that there are experiments that can demonstrate the drift velocity of electrons.
  • #1
Cyberice
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Electricity doesn't move at the speed of light??

I recently have read (in several aticles) that have presented evidence that "electrons" do not actually flow at the speed of light (and electron movement is thought to be "electricity"). If you argue that "Yes electricity DOES flow at the speed of light", then you must specify which of the 5 definitions of electricity you picked to represent "electricity". The electrons move actually very slow in the conductor, 0.2 cm p/s I was told. But the effect of the movement across the whole of the conductor is felt at once through the kinetic energy of the movement.

There are also many logical things (That we don't ususaly think about (***Almost an Oxymoron***)) about how it is not possible for the electrons to move at the speed of light.

Number one: Electrons have mass. Nothing that has mass can travel at the speed of light.

Second: Even light slows down in a volume, it only travels at c in a vaccum. Copper or other conductors are even more dense than air(which slows down light), and thus electrons definitely could not move at the speed of light in the volume of the conductor.

Third: If they (electrons) were even moving at speeds half that of c the conductor would get so hot it would melt, the resistors would overload + burn, stuff would probably catch on fire, and (of course joking) it could even go plasma ;-)!

All my points/comments (except for the one about plasma, Duh) hold a hard to debate validity in them.

I would like to see other peoples comments on this.
 
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  • #2
I have no idea what you intend to discuss with this thread.

Conduction electrons move very quickly inside the wire, with thermal energies on the order of 3/2 kT.

In the absence of an electric field, the electrons do not have any net movement in any direction. When you apply a voltage and hence create an electric field, the electrons now preferentially move in the direction of highest potential. This net movement is slow, on the order of centimeters per second, and is called the drift velocity.

Changes in electric and magnetic fields (of which light is an example) propogate at or below the speed of light. In a vacuum, changes in the field propagate at c. In a wire, the field propagates a little slower than c.

Thus, when you throw a lightswitch, the electric field makes its presence known throughout the wire at nearly the speed of light. The electrons initially present in the wire, however, might take hours to actually make their exits, since they move towards the greatest potential on average only at their drift velocity.

It turns out that the presence of matter around the wire is really integral in determining how fast the field propagates. A wire carrying a current builds a concentric magnetic field around it. This field must propagate through the material surrounding the wire. Thus, a bare wire in a vacuum will carry electrical signals faster than will a trace buried in a printed circuit board.

- Warren
 
  • #3
To explain the "speed-of-light" part of electricity I will use some analogies. First of all you must understand that electrical "enery" is like sound waves that move throught "air". Where the waves are the energy (that move fast) and Air (which transmits the wave). Same with electrons and electrical energy.

Ok now, say you have a straw full of marbles and it is (how ever many miles it is that light can travel in a second)<--miles long. You shove a nother marble in and almost immediately the marble in the other end flies out while the rest of the marbles (electons) barely moved. It transmitted a wave (using a domino effect w/ kinetic energy) through the straw to the other end.

That is how it really works, or so I believe and has been detailed in research.

Comments?
 
  • #4
I have no idea what you intend to discuss with this thread.

That's exactly what I wanted to hear. Your opinion on my post and where you stand in light of it. For it against it, or somewhere else.

I just want to know if someone else besides be beleives this.

My dad has been an electonics technition for 20 years and he doesn't fully accept the idea of electrons moving slow after having been told (like every body else) that that move at the speed of light.
 
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  • #5
Tell your dad to pick up any first-year physics textbook. That electrons do not move at the speed of light is certainly not news. Anyone who says "electrons move at the speed of light" has absolutely no idea what they're talking about.

There are, in fact, many simple experiments that can be done to demonstrate the drift velocity of electrons. The Hall effect, for example, provides one mechanism to measure it.

- Warren
 
  • #6
There are, in fact, many simple experiments that can be done to demonstrate the drift velocity of electrons. The Hall effect, for example, provides one mechanism to measure it.

My dad said that he would consider it if he had some visible proof in the form of a research paper or experiment. Do you know any sites that you can direct me to to find this information?

Please help.
 
  • #7
Originally posted by Cyberice

My dad said that he would consider it if he had some visible proof in the form of a research paper or experiment. Do you know any sites that you can direct me to to find this information?

Please help.


I hope Warren won't object to my butting in for a moment. I just want to make sure, Cyberice, that you and your dad both understand that an electric signal can travel along a wire much faster than the electrons themselves.

Say you have a mile long two-conductor wire leading to a lightbulb. You throw a switch at one end and the lightbulb will
go on almost immediately down at the other end.

The electrons between here and there might only be going a couple of centimeters per second, as you say----some drift velocity which can (as Warren says) be measured
 
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  • #8
Originally posted by Cyberice
My dad said that he would consider it if he had some visible proof in the form of a research paper or experiment. Do you know any sites that you can direct me to to find this information?

Please help.
Start here: http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/hall.html

(Any first-year physics text will also include this information.)

You can set up your very own apparatus and measure the Hall voltage with your own voltmeter. The Hall voltage is related very simply to the drift velocity of the charge carriers.

Why don't you digest this information for a while and see if you can come up with your own apparatus that will be capable of showing you a clear, unambiguous Hall voltage?

Let me know if you need some clarification.

- Warren
 
  • #9
I've read that you can actually SEE electrons moving slowly on surface of metal wire. Iirc, electrons are what makes bare wire look "metallic", and under microscope you'd see bubble-like thingies moving.
I wonder if that's true that you can see them.
 
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  • #10
Uh... *rolls on the floor, laughing*

- Warren
 
  • #11
I wonder if that's true that you can see them.

I'm sorry, but who ever told you that lied. We got lucky just getting a picture of one *big* atom. (we have seen uranium - and I've seen the video clip of it) but seeing how uranium is 237 times bigger than hydrogen, and hydrogen has only one proton (no neutrons), and a proton is 2000 times bigger than an electron, I could safely say that we may not see an electron anytime soon (if ever).

If we could see electrons clearly heinsburg would have a hayday.
 
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  • #12


Originally posted by Cyberice
Second: Even light slows down in a volume, it only travels at c in a vaccum.
Two clarifications: the word "volume" is meaningless there. The word you are looking for is "medium."

Second, light travels at C. Period. Unforturnately the glossed over high school physics approach to explaining light leads people to the misunderstanding that light itself slows down.

It does not. Any normal medium is composed almost entirely of empty space. The volume of the elementary particles (electrons, protons, neutrons) is statistically insignificant in the total volume of an atom. And then the atoms are not necessarily touching. So its actually redundant to say "light travels at C through a vacuum." When light is light it is ALWAYS transiting a vacuum.

In a medium, light will occasionally hit something and when it does several things can happen, but to use refraction as the example, the light will be absorbed and re-emitted. The time delay for the absorption and re-emission causes the light to APPEAR to have slown down while traveling through the medium. What has actually changed is only the AVERAGE speed.
 
  • #13
(Any first-year physics text will also include this information.)

You can set up your very own apparatus and measure the Hall voltage with your own voltmeter. The Hall voltage is related very simply to the drift velocity of the charge carriers.

Why don't you digest this information for a while and see if you can come up with your own apparatus that will be capable of showing you a clear, unambiguous Hall voltage?

Let me know if you need some clarification.

- Warren



Well first of all what is the formula for it and how does it work? What elements determine the values used in the formula and what law (or laws) can be used to back up what it built upon?

I am asking strictly for proof. Other wise no convincing will come over the people I tell it to.

The way I found out that *electrons* don't move at the speed of light is that I read an article called "electricity misconceptions". It explainned that it was the electrical energy that traveled at the speed of light, not electrons.

Well, WHAT IS THAT ENERY? Certainly not Heat or light. And don't say "electrical energy", because that is using a word to to describe it self. For instance don't say in reply to the question "what is fire?": and answer "fire."

I want to know what electrical energy is. Is it kinetic motion of particles? (It is described as a kinetic wave, but what kind)? If so then how could it possibly heat up a light bulb?

Please explain to me (with as much scientific EVIDENCE as possible - assume that I am stubborn and don't believe what I hear :smile: ) what the energy is, how fast the ELECTRONS flow, what formulas and calculations does it use, what laws does it follow or build on. Please be as factual as possible. Thnx.
 
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  • #14
Well first of all what is the formula for it and how does it work? What elements determine the values used in the formula and what law (or laws) can be used to back up what it built upon?
Did you not read the page on the Hall effect? Did you not look in a first-year physics textbook as I told you to do? I'm sorry, but I don't have the time or inclination to type out here what is readily available elsewhere. Read the page to learn how the Hall effect works, and how you can measure drift velocity with it.
[I want to know what electrical energy is.
What is energy? Energy is the ability to do work.

What is work? Work is the effort it takes to roll a bowling ball up a hill, or the effort expended by a mishandled bottle of soda when it expells its contents onto your favorite shirt.

Electrons are like the bowling balls, and the electric field is like the hill. An electric field exerts a force on charged particles within it. The force they feel is expressed very simply:

F = qE

where both E and F are vector quantities, and q is the charge. q is in units of coulombs, F is in units of Newtons, and E is in units of Newtons per coulomb or (equivalently) volts per meter.

Where did "volts" sneak in? Well, voltage is a measure of potential energy per unit charge, and is thus equivalent to joules per coulomb. When a coulomb of charge moves through an electrical potential of one volt, one joule of work is done. When this work is positive, energy is released, usually as heat or sound or light.

When you roll a bowling ball down a hill, the same concepts apply. The force felt by the bowling ball is

F = mg

where m is the mass, in units of kilograms, and g is the gravitational acceleration, in units of meters per square seconds. You can identify q and m as being "analogous quantities," and E and g also.

If you want to think about the potential experienced by the bowling ball, you know it will have to be in units of joules per kilogram. You should know that the gravitational potential energy of a bowling ball at height h above the ground is

U = -mgh

Don't worry about the minus sign, it's only there to adhere to physicists' conventions.

Look at the units:

U (joules) = -m (kilograms) g (meters/sec^2) h (meters)

You can rearrange this as:

U/m (joules/kilogram) = gh (meters^2/second^2)

Lo and behold, the quantity (gh) is equivalent to both meters^2/seconds^2 AND joules/kilograms. gh is therefore a measure of the potential energy per unit mass of a gravitational field.

Remember now that voltage is a measure of the potential energy per unit charge in an electric field, and you should see at once how similar the concepts are. The only difference is that we routinely lump the electrical analogue of (gh) into one quantity, and call it "voltage." There is no special name for the quantity (gh), however.

These two sentences are analogous:

When a coulomb of charge moves through an electrical potential of one volt, one joule of work is done.

When a kilogram of mass moves through a gravitational potential of one meter^2/second^2, one joule of work is done.

In the case of a 1 kilogram bowling ball moving through a vertical distance of 1 meter on Earth's surface, where g is 9.8 meters/second^2, 9.8 joules of work are done.

Now, you plug a light bulb into the socket and a generator many miles away applies a potential to it through the connecting wires. The potential is 120 volts. The resistance of the filament in the light bulb is 120 ohms, so one ampere of current flows. An ampere is one coulomb of charge per second. Apply the relationship figured out above:

When a coulomb of charge moves through a potential of 120 volts, 120 joules of work are done. Since one coulomb of charge is moving through the light bulb every second, 120 joules of work are being done every second. The watt is the unit of power: energy per unit time. 120 joules per second is equal to 120 watts of power. Your light bulb is dissipating 120 watts of power.

When you drop a bowling ball, the energy goes into breaking the floor, making a loud noise, and scaring the neighbors.

When you turn on a lightbulb, the energy goes into jostling the atoms in the filament, causing their temperature to increase, with the ensuing radiation of visible light.
Please explain to me (with as much scientific EVIDENCE as possible - assume that I am stubborn and don't believe what I hear ) what the energy is, how fast the ELECTRONS flow
Now, exactly how big is a coulomb? Well, it takes 6.25*10^18 electrons to equal one coulomb of negative charge. A cubic meter of copper, by contrast, contains about 8.46 * 10^28 electrons, or about 13 billion coulombs.

Let's take a piece of copper wire 5 mm in diameter. The area of the cross section is 1.9*10^-5 square meters. A meter of this wire contains, 1.9*10^-5 cubic meters of copper, or about 265,000 coulombs of charge.

If you wire up your 120W lightbulb, one columb of charge per second is moving through it -- but every foot of wire contains 265,000 coloumbs of charge! You can see immediately that the charge doesn't have to move very fast. If all the charge in that meter of wire were to move through the wire in one second, all the electrons moving at just one meter per second, your lightbulb would dissipate 31 million watts of power, as much power as consumed by a large university campus. Clearly, electrons flow much more slowly than that!

Does this make sense?

- Warren
 
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  • #15
Cyberice is correct.

Let me try to explain it how I learned it.

Assume for a moment that a pipe has been filled with ping pong balls, if a ball is forced into the end of the pipe, the ball at the other end will be forced out. Each time a ball enters one end of the pipe, another ball is forced out the other end. This principle is also true for electrons in a wire. There are billions of electrons in a wire. If an electron enters one end of a wire, another electron is forced out the other end.

Again assume for the moment that a wire is long enough to be wound around the Earth 10 times. If a power source and switch were connected at one end of the wire and a light at the other end, the light would turn on the moment the switch was closed. But it would take light approximately 1.3 seconds to travel around the Earth 10 times.

What we call this phenomenon is the "impulse of electricity"
 
  • #16
1) Get a bunch of marbles in a tube, filling it from one end to the other.

2) Stick your finger in one end, and push at any rather slow speed you like.

Despite the slow motion of each marble, you will note that (if the tube was full, the marbles packed up against each other), the marble at the far end moved pretty much at the exact moment you pushed the marble at the near end.

The individual marbles move slowly. The effect moves pretty damn quick.
 
  • #17
Originally posted by Danny
Cyberice is correct.

Let me try to explain it how I learned it.

Assume for a moment that a pipe has been filled with ping pong balls, if a ball is forced into the end of the pipe, the ball at the other end will be forced out. Each time a ball enters one end of the pipe, another ball is forced out the other end. This principle is also true for electrons in a wire. There are billions of electrons in a wire. If an electron enters one end of a wire, another electron is forced out the other end.
This is an analogy. Real electrons do not behave this way.
Again assume for the moment that a wire is long enough to be wound around the Earth 10 times. If a power source and switch were connected at one end of the wire and a light at the other end, the light would turn on the moment the switch was closed. But it would take light approximately 1.3 seconds to travel around the Earth 10 times.
This is patently, egregiously incorrect. Changes in the electric field propagate at or below the speed of light, depending upon the index of refraction of the medium. The lamp would absolutely not turn on instantaneously. Such behavior would actually violate a very large number of physical laws.
What we call this phenomenon is the "impulse of electricity"
I have never heard anyone call anything, much less this non-existent effect, the "impulse of electricity." Sorry. In the future, please don't post when you don't know what you're talking about.

- Warren
 
  • #18
Originally posted by chroot
This is an analogy. Real electrons do not behave this way.

This is patently, egregiously incorrect. Changes in the electric field propagate at or below the speed of light, depending upon the index of refraction of the medium. The lamp would absolutely not turn on instantaneously. Such behavior would actually violate a very large number of physical laws.

Excuse me?
Come again?

The Impulse of electricity is a very real theory--see ELECTRON THEORY. Since you do not know what I am talking about then maybe you should shut up and listen and don't assume I am wrong without acknowledging you're own lack of knowledge on the subject--That is immature and rude!


Originally posted by chroot

I have never heard anyone call anything, much less this non-existent effect, the "impulse of electricity." Sorry. In the future, please don't post when you don't know what you're talking about.


Because you have never heard of it does that mean I am wrong? Who are you to say such a thing? If you want to debate this please go ahead but don't ever talk like that to anyone and except them to take your word for it.

ps Please follow your own advice--last sentence in your post
 
  • #19
Hey Integral,

Little help?

- Warren
 
  • #20
Changes in the electric field propagate at or below the speed of light

Changes? Changes? What changes are you talking about? Elaborate on changes. Because I want to know what DOES move at the speed of light. I believe it is the a impulse as stated earlier. If you say "changes in polarity" then that would describe voltage. What effect is felt at the speed of light? A wave? Heat? Kinetic energy? (certainly not-->) Electrons? How did we even measure it? What is IT?

I have to go with the elctrical impulse idea here, in the form of a kinetic energy wave of the whole, that is what moves at the speed of light.
 
  • #21
Here I put this in quotes from a article of research on electricity:

In a solid, the current consists not of a few electrons moving rapidly but of many electrons moving slowly; although this drift of electrons is slow, the impulse that causes it moves through the circuit, when the circuit is completed, at nearly the speed oflight. The movement of electrons in a current is not steady; each electron moves in a series of stops and starts. In a direct current, the electrons are spread evenly through the conductor; in an alternating current, the electrons tend to congregate along the conductor surface.

Notice the word *IMPULSE*.
 
  • #22
Originally posted by Cyberice
Changes in the electric field propagate at or below the speed of light

Changes? Changes? What changes are you talking about? Elaborate on changes.
Changes such as what happens when you turn on a light.
Despite the slow motion of each marble, you will note that (if the tube was full, the marbles packed up against each other), the marble at the far end moved pretty much at the exact moment you pushed the marble at the near end.

The individual marbles move slowly. The effect moves pretty damn quick.
Just to be clear, "pretty damn quick" is not instantaneous and in fact has a very specific value: the speed of sound through glass.

Here's a better analogy than the marbles ping pong balls in a pipe (though the ping pong balls in a pipe one isn't bad if you realize they STILL don't move instantly). WATER in a garden hose. When you open the valve, letting water flow in the hose (thats already full), a pressure wave travels through the pipe at the speed of sound and the water begins moving behind that pressure wave. The time it takes for water to come out the end of the hose is equal to the length of the hose divided by the speed of sound in the hose.

When you turn off the hose, the reverse happens: water keeps coming out the end of the hose until the pressure wave gets to the end of the hose. This also causes the "water hammer" effect in older buildings when a valve is closed quickly. The water keeps moving until the pressure wave can propagate backwards from the valve to the source, causing a banging noise in the pipes.
Here I put this in quotes from a article of research on electricity: "...the impulse that causes it moves through the circuit, when the circuit is completed, at nearly the speed oflight." ...Notice the word *IMPULSE*.
Heh, right. Cyberice, notice the word "nearly." Nearly the speed of light. As in, BELOW the speed of light. Far cry from instantaneous.
 
  • #23
Did you not read the page on the Hall effect? Did you not look in a first-year physics textbook as I told you to do? I'm sorry, but I don't have the time or inclination to type out here what is readily available elsewhere. Read the page to learn how the Hall effect works, and how you can measure drift velocity with it.


Well, it says that I need a hall probe to measure the drift velocity. Well, I don't have one. never even heard of one. Will a voltometer work? and will the results prove that electrons move slow, or will I be laughed off as an idiot because of the mere idea that electrons move slow?
 
  • #24
. Far cry from instantaneous


Hey, I wasn't the one who suggested that it happens instantaneously. That's impposible (according to physics). That or a paradox exists. I know it takes a short time (none-the-less *TIME*)to reach its destination.

What *I* want to know is: if electrons aren't the things moving at the speed of light, then what is? I think it is the impulse. But I'll need some serious evidence to persuade my dad and electronics teacher away from some thing they beleived for over 20 years! One little sentance won't cut it.
 
  • #25
Originally posted by Cyberice
Changes? Changes? What changes are you talking about? Elaborate on changes. Because I want to know what DOES move at the speed of light.
When you flip a lightswitch, you change the electric field present in the wires. These changes in the electric field propagate at or below the speed of light.
I believe it is the a impulse as stated earlier.
This person Danny who posted his "impulse" idea has, unfortunately, no idea what he's talking about. There is no such thing as an "impulse of electricity." In physics, an impulse is defined as the product of force and time, and is commonly used to describe collisions and the like. The impulse is equal to the change in momentum of the body receiving the impulse. None of these concepts have any analogues in electrical phenomena, and it is absolutely incorrect to use the term to describe anything electrical. There is absolutely no such thing as an "impulse of electricity" recognized in physics. If you'd like to really understand electricity, stay away from people, like Danny, who'd like to tell you that information propagates faster than light.
If you say "changes in polarity" then that would describe voltage. What effect is felt at the speed of light? A wave? Heat? Kinetic energy? (certainly not-->) Electrons? How did we even measure it? What is IT?
Changes in voltage are same as changes in the electric field -- a concept I thought I made painfully clear. Changes in the electric field propagate at or below the speed of light, as does heat (heat actually is conducted much, much more slowly than the speed of light). The term "wave" is meaningless unless you also specify what it is that is waving. Kinetic energy is a property of a body relative to some observer and does not propagate.
I have to go with the elctrical impulse idea here, in the form of a kinetic energy wave of the whole, that is what moves at the speed of light.
There is no "impulse idea," and I'm sorry that people like Danny would like to foul up your thoughts with nonsense. There is also no such thing as a "kinetic energy wave."

Do you just not WANT to understand the way things work, or what? I've spent quite a bit of time explaining how things work, but you seem to be fighting me tooth and nail.

- Warren
 
  • #26
Originally posted by Cyberice

What *I* want to know is: if electrons aren't the things moving at the speed of light, then what is? I think it is the impulse. But I'll need some serious evidence to persuade my dad and electronics teacher away from some thing they beleived for over 20 years! One little sentance won't cut it.
CHANGES IN THE ELECTRIC FIELD PROPAGATE AT OR BELOW THE SPEED OF LIGHT. One little sentence?!? I've written pages!

- Warren
 
  • #27
Originally posted by Cyberice
Well, it says that I need a hall probe to measure the drift velocity. Well, I don't have one. never even heard of one. Will a voltometer work? and will the results prove that electrons move slow, or will I be laughed off as an idiot because of the mere idea that electrons move slow?
A Hall probe is a piece of flat metal and a voltmeter.

And the people who will be laughed off as idiots are those who think electrons DO move at the speed of light.

You, on the other hand, SEEM to be seeking the truth. The idea of electrons moving at the speed of light is ABSOLUTELY RIDICULOUSLY WRONG. There sincerely is no room for disagreement.

- Warren
 
  • #28
Do you just not WANT to understand the way things work, or what? I've spent quite a bit of time explaining how things work, but you seem to be fighting me tooth and nail.

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

Oh, and Thnx for explaining the "hall probe thing".
 
  • #29
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), and perhaps even a new Dad.

- Warren
 
  • #30
All right, Chroot. I'll leave you alone and not ask you any more. i'll reflect on previous posts and gather what I can present it and walk away triumphant.

Thnx for the help.
 
  • #31
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
 
  • #32
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 :frown:
 
  • #33
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
 
  • #34
"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.
 
  • #35
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
 
<h2>1. Why doesn't electricity move at the speed of light?</h2><p>Electricity is the flow of electrons through a conductor. While electrons do have a speed, it is much slower than the speed of light. This is because electrons are affected by the resistance of the material they are traveling through, as well as collisions with other particles. As a result, the overall movement of electricity is much slower than the speed of light.</p><h2>2. How fast does electricity actually move?</h2><p>The speed of electricity can vary, but on average it moves at about 2/3 the speed of light. This means that in a vacuum, electricity can travel at about 200,000 km/s.</p><h2>3. Can electricity ever move at the speed of light?</h2><p>No, it is impossible for electricity to move at the speed of light. This is because the movement of electricity is dependent on the flow of electrons, which are particles with mass. The laws of physics dictate that particles with mass cannot reach the speed of light.</p><h2>4. How does the speed of electricity affect our daily lives?</h2><p>The speed of electricity is not a limiting factor in our daily lives. In most cases, the speed of electricity is more than fast enough to power our devices and provide us with the energy we need. However, in certain situations where extremely fast communication or data transfer is required, the speed of electricity may be a consideration.</p><h2>5. Does the speed of electricity change in different materials?</h2><p>Yes, the speed of electricity can vary depending on the material it is traveling through. Materials with higher conductivity, such as metals, allow electricity to flow more easily and therefore have a higher speed. On the other hand, materials with lower conductivity, such as rubber, will slow down the speed of electricity. This is why different materials are used for different purposes in electrical circuits.</p>

1. Why doesn't electricity move at the speed of light?

Electricity is the flow of electrons through a conductor. While electrons do have a speed, it is much slower than the speed of light. This is because electrons are affected by the resistance of the material they are traveling through, as well as collisions with other particles. As a result, the overall movement of electricity is much slower than the speed of light.

2. How fast does electricity actually move?

The speed of electricity can vary, but on average it moves at about 2/3 the speed of light. This means that in a vacuum, electricity can travel at about 200,000 km/s.

3. Can electricity ever move at the speed of light?

No, it is impossible for electricity to move at the speed of light. This is because the movement of electricity is dependent on the flow of electrons, which are particles with mass. The laws of physics dictate that particles with mass cannot reach the speed of light.

4. How does the speed of electricity affect our daily lives?

The speed of electricity is not a limiting factor in our daily lives. In most cases, the speed of electricity is more than fast enough to power our devices and provide us with the energy we need. However, in certain situations where extremely fast communication or data transfer is required, the speed of electricity may be a consideration.

5. Does the speed of electricity change in different materials?

Yes, the speed of electricity can vary depending on the material it is traveling through. Materials with higher conductivity, such as metals, allow electricity to flow more easily and therefore have a higher speed. On the other hand, materials with lower conductivity, such as rubber, will slow down the speed of electricity. This is why different materials are used for different purposes in electrical circuits.

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