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Offline thebrain13

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speed of charge
« on: 07/07/2006 22:10:50 »
what is the speed of electric charge? In other words if there was a positively charged planet a lightyear away, and it suddenly disappeared, would it take awhile for the charge to cease, or get here instantly? And if it does take time to travel here, would it take more time, and be less powerfull, if it travels through a gravitational field?


 

Offline daveshorts

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Re: speed of charge
« Reply #1 on: 08/07/2006 00:04:49 »
What you describe is actually light. Light is just the universe catching up with changes in where charges are. It can't do this immediately. Think of it as a pond, you change the depth of water somewhere (electric potential) this information takes a while to propagate so you get ripples (light).

So it moves at c.

Gravitational waves are similar objects but the universe catching up with changes in configuration of masses, it is believed they move at c too, I think recently a measurement was made using the gravitational lensing of some stars by jupiter and it came out to c within the error bars.
 

Offline thebrain13

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Re: speed of charge
« Reply #2 on: 08/07/2006 00:45:40 »
Um yeah, I dont think thats right. Im talking just about charge. Positive and negative. I'm talking about their respective ability to cause a particle with charge to accelerate. Light is merely caused by electrons changing their energy levels. Hence it can not be caused by positive charge.
 

Offline daveshorts

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Re: speed of charge
« Reply #3 on: 08/07/2006 10:07:08 »
Electric field is said to be mediated (carried) by an exchange of virtual photons if everything is still or moving at a constant speed the force from the photons going from A to B cancel out those going from B to A and the same amount of energy is transferred to B as was lost by A. Because the photons only move at the speed of light, if you accelerate B after the photons from A nothing quite cancels out any more and you get a slight mismatch, with some energy,  which we call light.



Propagating light is produced by any accelerating charge (think how a radio aerial works), be it positive or negative, just electrons are lighter so tend to accelerate better. You can produce light by causing charged particles to go in circles using magnetic fields, this is called cyclotron radiation. When electrons give off light they loose some energy, if they are in a quantised system they much move down some energy levels.

 

Offline heikki

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Re: speed of charge
« Reply #4 on: 08/07/2006 18:58:26 »
quote:
Originally posted by thebrain13

what is the speed of electric charge?



:)

Fine question.

My thoughts.

Speed of electricity is depent of matter where matter-particles flow.

Charge of electricity is depent of matter where electric-matter-particles  store.

So, hmm, what is speed of electric charge?

Direct current?
What is speed of electric-matter-particles?

My thoughts.
There is no positive or negative electric particles, only particles which behave and flow differents materials.

:)
 

Offline thebrain13

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Re: speed of charge
« Reply #5 on: 09/07/2006 16:57:46 »
Electric charge and light are two different things. Just because light is caused by accelerating charge doesn't mean charge is mediated, or carried by light all the time. There is a force from one charge, to the other, regardless of if one of the charges is accelerating or not. And light requires an accelerating charge simply to exist. So light can not be the cause for the phenomena of two charges applying a force to one another if neither one is accelerating. The electric field is the cause for charges accelerating each other directly, not light.
« Last Edit: 09/07/2006 22:51:58 by thebrain13 »
 

Offline heikki

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Re: speed of charge
« Reply #6 on: 13/07/2006 09:02:09 »
quote:
Originally posted by thebrain13

Electric charge and light are two different things. Just because light is caused by accelerating charge doesn't mean charge is mediated, or carried by light all the time. There is a force from one charge, to the other, regardless of if one of the charges is accelerating or not. And light requires an accelerating charge simply to exist. So light can not be the cause for the phenomena of two charges applying a force to one another if neither one is accelerating. The electric field is the cause for charges accelerating each other directly, not light.



:)

Hi.

Light and electric matter particles can maybe be different things. Our atom-theory is unfortunately so poor that it dont keep inside these matter-particles idea of these two things. Charge is something which ride from electron to other electron. Light is some kind of wave-vibration, only.

But.


What is electric charge?

What is light?

What is color?

My thought is that at 1800-century, when alternative current idea born then happend some wave-idea over-reaction with those time prism-idea. And scientist start to use ac-wave-theory to explain all matter behaving procecces. So, they develope wave-theory wich tells everything between voice to light and colors.

But, i make coupple question to my self.

1. Can wave exist without matter? No, it cannot.

2. Can matter exist without waveing? Yes it can.

I think that light is like colors, small matter-particle flowing process ( with or without waveing) and electric charge is some kind of small particle motion and charge can exist if that matter behave so that is can charge these electric particles to itselfs.
But these things maybe happends much smaller matter-particle size than our poor un-life atom-theory explain.

But is light and electric current different matter-things? Hmm. Some electric component can borned electric current when sun-light hit it. So, do light come in that electric circuit and be that electric current? If do, then light is maybe almost same matter-thing than electric current is.

Light speed cannot be constant to it's own light-travelling distance and therefore using it to measure long distances accurace is not possible. Also is unknown how light-speed changes at different matter construction, like other sun-lights, planets atmosphere, space-dust, etc.


What is matter-construction of that space-matter, that matter where planets "swim" and light or other particles and wave-motions like radiosignals flows?
Matter, which inside moon-craft can control it's direction and shuttle can push it's way to other direction.
Matter which is important cause-effect to our well knowing named, "gravity"-effects.

I think that space-basic matter size is much smaller than light-electric particle size is, but is it that real basic-matter and what is that matter particle-form or construction?

:)
 

Offline thebrain13

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Re: speed of charge
« Reply #7 on: 22/07/2006 03:57:37 »
So whats the speed?
 

another_someone

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Re: speed of charge
« Reply #8 on: 22/07/2006 05:19:49 »
quote:
Originally posted by heikki
My thought is that at 1800-century, when alternative current idea born then happend some wave-idea over-reaction with those time prism-idea. And scientist start to use ac-wave-theory to explain all matter behaving procecces. So, they develope wave-theory wich tells everything between voice to light and colors.



The wave theory of light goes back to Descartes (16th century), and alter to Robert Hooke (17th century).

The wave theory of light works well when one tries to understand detraction, which is a phenomenon that was observed with water waves.


quote:

But, i make coupple question to my self.

1. Can wave exist without matter? No, it cannot.

2. Can matter exist without waveing? Yes it can.



Quantum physicists could argue the converse.

To a quantum physicist, all matter is composed of waves.

For waves to exist, you need a variation of density but density of what?  Must it be a variation of matter?  What is matter?  Can other things exist that are not matter?

As far as quantum physicists are concerned, the wave attributes of matter are periodic variation in probability density but the probability that something exists is not itself an existence of the thing.

There are all sorts of questions about what is the nature, not only of matter, but the nature of space itself.  It seems clear that in most modern views of space, that space has attributes and properties, and is not merely a non-entity; but what exactly is it?

quote:

I think that light is like colors,



This does not really make sense.  Colour is simple a measure of the energy associated with the ligh the higher the energy, the move the colour gets closer to blue (or, if very high, then it gets into ultra violet and beyond); and the lower the energy, the closer the colour becomes to red (or, at extremely low energies, into infra-red, and further down, even into radio waves).

quote:

and electric charge is some kind of small particle motion



That is fairly much consistent with quantum field theory where it considers the small particle to be a photon that same particle that we see as light.

quote:

But is light and electric current different matter-things? Hmm. Some electric component can borned electric current when sun-light hit it. So, do light come in that electric circuit and be that electric current? If do, then light is maybe almost same matter-thing than electric current is.



Almost is correct.

Light is an electromagnetic wave (note that an electromagnetic wave has both an oscillating electric field, and an oscillating magnetic field), while an electric current is caused by the flow of electrons that create a moving electric field.  When an electric current flows (i.e. when there is a moving electric field) it also creates a magnetic field.  If this electric and magnetic field start to oscillate, then they create an electromagnetic wave.  Mostly, the electromagnetic oscillators that we produce using our electronic circuits do not have enough energy to create visible light, but they do create radio waves (which, as I mentioned above, is like a very low energy light).

quote:

Also is unknown how light-speed changes at different matter construction, like other sun-lights, planets atmosphere, space-dust, etc.



We do know how light changes over a wide variety of conditions, although we cannot ofcourse prove exactly what conditions exist in far off galaxies, or in the early period of the universe, but we do have a fair degree of evidence as to what it was likely to have been like over most of the history of the universe.  Over most of what we have good evidence for, light (in a vacuum) seems to have a constant local velocity.





George
 

Offline heikki

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Re: speed of charge
« Reply #9 on: 22/07/2006 07:29:01 »
quote:
Originally posted by another_someone


The wave theory of light goes back to Descartes (16th century), and alter to Robert Hooke (17th century).



George




:)

Yes and that is my biggest concerning worry. Scient history has locked that area so that all light-and color stuff is wave-stuff. And these theoryes has borned that time when we havent ever hear any kind of atom-idea or gene information or study our brain-cells operation system. We believe again that these theoryes are scientifical right image of how nature work? I think that if scientist believe 16-centuryes basic theoryes then scientist live this middle-age time.

Clear nature facts.

1. Matter cannot waveing without matter itself existing.

2. And matter-particle can exist without waveing.

What i mean.

I mean that wave-theory fit many electrician-things and also that kind ot technical stuff. But, i think that when we start to look light, colors, etc. then wave-theory is not fit that area. It is too simple explanation and to weak story to explain nature construction, system operations, living-forms procecces, gene-memory-storing systems, etc.etc.

But, philosophical level. Matter exist, can made living-forms, individual forms. There is no question that that matter dont exist.
Question is how all this stuff what part we are really works and if our nature-scient-basic is some 16ct scient it is quite wrong basic, IF that basic is not a image of nature-process.

:)
 

Offline lightarrow

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Re: speed of charge
« Reply #10 on: 12/08/2006 00:01:57 »
quote:
Originally posted by thebrain13

what is the speed of electric charge? In other words if there was a positively charged planet a lightyear away, and it suddenly disappeared, would it take awhile for the charge to cease, or get here instantly?



Can you accept the fact this question is not different, in principle, from the question: if that positively charged planet moves, how much time later do we perceive that movement of charge?

If you can, the answer is simple: one year.

Charges affect other charges with the speed of light. When I move a charge here, another charge there, "feels" this movement exactly d/c seconds later; d is the distance between the two charges and c the speed of light.

This is what happens between two mobile telephones, for example.

Did you post your question, maybe, because you are thinking about something which could be faster than the speed of light?
 

Offline lightarrow

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Re: speed of charge
« Reply #11 on: 12/08/2006 00:35:51 »
quote:
Originally posted by heikki


1. Can wave exist without matter? No, it cannot.

2. Can matter exist without waveing? Yes it can.




1. Light in the void is a wave that exist without matter.

2. Let's take a 1 kg block of iron. It's made of many iron atoms. Each atom is made of...waves, most of it. That is, the electrons waves. Proportionally, if the nucleus were 1 cm big, the atom would be ~ 100 meters big. This gives an idea of the fact the atom is mostly made of void; electrons in the atom are wave clouds that fill this void.

However, there still is "matter" in it: nucleus and electrons.

What nucleus is made of? Protons and neutrons = nucleons. What are they made of? Other particles immersed in a wave cloud of other particles...ecc.

Are you sure the concept of matter is more fundamental than the concept of (energy) waves?
 

Offline thebrain13

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Re: speed of charge
« Reply #12 on: 25/08/2006 22:10:13 »
Does the speed of charge ever change? for example would the speed of charge be lower (relative to the observer) if the charge were moving near a large gravitational field? ie near a black hole.
 

Offline lightarrow

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Re: speed of charge
« Reply #13 on: 26/08/2006 08:31:41 »
quote:
Originally posted by thebrain13
Does the speed of charge ever change? for example would the speed of charge be lower (relative to the observer) if the charge were moving near a large gravitational field? ie near a black hole.
No, what would change is the frequency of the electromagnetic wave radiated from the moving charge (lower).
 

Offline thebrain13

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Re: speed of charge
« Reply #14 on: 26/08/2006 16:37:16 »
Im talking about electric charge not light(aka electromagnetic wave) you can deflect light with a mirror, you cant do that with charge.

And the frequency of light would only change if the light origninated from an area of lower gravitational potential, compared to the observer. However I didnt say that the charge origninated from a lower gravitational potential, I said if it passed through an area with higher gravity, Causing time and distance to increase, during that specific portion of the trip, would the charge move slower?
 

Offline lightarrow

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Re: speed of charge
« Reply #15 on: 26/08/2006 17:46:29 »
quote:
Originally posted by thebrain13

Im talking about electric charge not light(aka electromagnetic wave) you can deflect light with a mirror, you cant do that with charge.
So, what do you exactly mean with "the speed of electric charge"?
 

another_someone

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Re: speed of charge
« Reply #16 on: 27/08/2006 06:34:49 »
I cannot answer for thebrain13, but for myself, I would understand the speed of electric charge to be the speed at which a change in the electric field would propagate through space; but ofcourse, and change in electric field also generates a magnetic field.

In practice ofcourse, electric charge in conserved, so one cannot actually change electric charge in a region of space except my introducing or removing charged elementary particles into that region of space, thus what one actually observes is the speed at which one can perceive the change in location of a charged particle at a distance through the effect of its electric field.

I would expect that such an observation would be subject to all of the laws of relativity, including the general relativistic effects of gravity, and so would be subject to the time distortions created by gravitational fields.



George
« Last Edit: 27/08/2006 10:52:12 by another_someone »
 

Offline lightarrow

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Re: speed of charge
« Reply #17 on: 27/08/2006 15:00:46 »
quote:
Originally posted by another_someone

I cannot answer for thebrain13, but for myself, I would understand the speed of electric charge to be the speed at which a change in the electric field would propagate through space; but ofcourse, and change in electric field also generates a magnetic field.

In practice ofcourse, electric charge in conserved, so one cannot actually change electric charge in a region of space except my introducing or removing charged elementary particles into that region of space, thus what one actually observes is the speed at which one can perceive the change in location of a charged particle at a distance through the effect of its electric field.

I would expect that such an observation would be subject to all of the laws of relativity, including the general relativistic effects of gravity, and so would be subject to the time distortions created by gravitational fields.
So you don't agree with me when I said in my previous post that the speed at wich the creation of a charge here affects another charge there is the speed of light?

Think about a high energy gamma photon who transforms into an electron-antielectron pair after collision with a nucleus.

Yes, the total charge doesn't varies, but the two charges of the electron and antielectron, separate each-other after creation and thus their respective electric fields are generated from nothing, affecting other charges at the speed of light; otherwise, it would have already been experimentally detected any discordance, I presume.

On the other hand, you yourself state: "but for myself, I would understand the speed of electric charge to be the speed at which a change in the electric field would propagate through space".
So, you should agree with me.
« Last Edit: 27/08/2006 15:21:42 by lightarrow »
 

another_someone

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Re: speed of charge
« Reply #18 on: 27/08/2006 16:25:24 »
quote:
Originally posted by lightarrow
Think about a high energy gamma photon who transforms into an electron-antielectron pair after collision with a nucleus.

Yes, the total charge doesn't varies, but the two charges of the electron and antielectron, separate each-other after creation and thus their respective electric fields are generated from nothing, affecting other charges at the speed of light; otherwise, it would have already been experimentally detected any discordance, I presume.



I was actually thinking about a neutron separating into an electron/proton; or a proton decaying into a neutron/positron but they are all variations on a theme.

Yes, two equal and opposite charges are created where only one existed initially, but what one observes is still only the movement of charge, not the creation of charge.

What one observes is an initial situation where a positive and negative charge exist in the same space, thus creating zero nett charge; one then observes the positive charge moving in one direction, while the negative charge moves in another direction, so one then observes the movement of charged particles (one at no time actually observed the creation of charge, but merely surmised that charge was created by the fact that when the two charges have separated, one can see them as distinct charges where previously no distinct charges existed, or if they existed, they existed in a common space and without separation in space).

quote:

So you don't agree with me when I said in my previous post that the speed at wich the creation of a charge here affects another charge there is the speed of light?

On the other hand, you yourself state: "but for myself, I would understand the speed of electric charge to be the speed at which a change in the electric field would propagate through space".
So, you should agree with me.



Yes, I do agree that the speed of charge is the speed of light what I do not agree with is that the speed of light remains constant to a distant observer when that light passes through a gravitational field that is different from the gravitational environment of the observer.



George
 

Offline lightarrow

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Re: speed of charge
« Reply #19 on: 27/08/2006 16:40:48 »
quote:
Originally posted by another_someone

Yes, I do agree that the speed of charge is the speed of light what I do not agree with is that the speed of light remains constant to a distant observer when that light passes through a gravitational field that is different from the gravitational environment of the observer.
Why? A gravitational field affects space-time geometry only, it doesn't affect its electric-magnetic properties (that is, mu(0) and epsilon(0)), as far as I know.
 

another_someone

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Re: speed of charge
« Reply #20 on: 27/08/2006 19:34:52 »
quote:
Originally posted by lightarrow
Why? A gravitational field affects space-time geometry only, it doesn't affect its electric-magnetic properties (that is, mu(0) and epsilon(0)), as far as I know.


But space/time are the parameters of velocity.

Simplest argument is that gravity can refract light (i.e. bend light), and thus it must by virtue of that alone be able to slow down light (note that I am only saying that light is slowed down according to measurements taken by someone outside the influence of that gravity they guy within the same gravitational field will still think the speed of light to be the same as it always was).



George
« Last Edit: 27/08/2006 19:36:50 by another_someone »
 

Offline syhprum

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Re: speed of charge
« Reply #21 on: 27/08/2006 19:36:14 »
Photons have mass because of the energy they carry (it is quite simple to calculate the mass of a cubic meter of sunlight close to he earth {4.8/10^26 Kg}) hence they must be affected by gravity.

syhprum
 

another_someone

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Re: speed of charge
« Reply #22 on: 27/08/2006 19:39:45 »
quote:
Originally posted by syhprum
Photons have mass because of the energy they carry (it is quite simple to calculate the mass of a cubic meter of sunlight close to he earth {4.8/10^26 Kg}) hence they must be affected by gravity.



Gravitational acceleration is independent of mass.  The force and energy associated with that acceleration is dependent upon the mass of the thing being accelerated, but the fact of their acceleration, and the rate of their acceleration, is all independent of mass thus a photon can be accelerated by gravity whether or not it has mass.



George
 

Offline syhprum

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Re: speed of charge
« Reply #23 on: 27/08/2006 20:52:17 »
Gravitaional acceleration in proportional to the combined masses, Galileo's 100Kg canon ball falls ever so slightly faster than his 1Kg one because not only is the earth pulling it down it is pulling the earth up

syhprum
 

Offline ukmicky

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Re: speed of charge
« Reply #24 on: 27/08/2006 21:08:32 »
Gravity has no effect on the photon , all gravity does is bend the pathway which the photon has to follow. there's a difference.

Also if gravity could slow down light  (which it cant) then the opposite must surly be also true, with gravity accelarating light faster than c.

Michael
« Last Edit: 27/08/2006 21:14:54 by ukmicky »
 

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