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Author Topic: What is difference between Electromagnetism and Electromagnetic wave ?  (Read 9241 times)

Kiran The King Kai

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What is difference between Electromagnetism and Electromagnetic wave ?

I am always getting confused about this.. IT started with Michal Faraday !



when Faraday discovered that magnetism in a wire due to flow of charge in a wire gives us Electromagnetism.
He also suspected and said that Light too can travel in the form of Electromagnetic waves. but he failed to provide the proof with Math. cos he lacks in advanced math. his friend Maxwell studied his scientific papers and thought to prove it through math.

Maxwell made a giant leap by creating 4 equations of describing light. 



How Faraday knows that light to is a electromagnetic wave ?

What is the main difference of Electromagnetism in a wire and EM wave of light ?



Why does light is not effected by external magnetic field or electric field ?


Current too travels in Electromagnitism and light to travels in electromagnetic waves ??

Can I CALL IT AS ELECTROMAGNETIC PARTICLES when we consider light as particles ?
« Last Edit: 29/10/2009 04:39:05 by Kiran The King Kai »


 

Offline Mr. Scientist

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Electromagnetism, is the effect we have when we unify the electric and magnetic forces. In effect, the electromagnetic force field that is homogeneous to every corner of the universe, allows for electomagnetic interactions to occur, exchanged by their correct particle mediators. An electromagnetic waves are also particles - [the massless exitations of the electromagnetic field in the form of deadly gamma photons (also known as photons, and the other classes, such as th Z boson]. In special cases, the gravitational field in conjecture to the electromagnetic force can give rise to a peculiar exitation of gravitationally-stressed regions called graviphotons, which are indestinguishable from the quanta of photons.
« Last Edit: 29/10/2009 05:36:52 by Mr. Scientist »
 

Offline Vern

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We speak of electromagnetism when describing electric and magnetic phenomena because where you find one you will always find the other in equal proportions. The static fields of each of these come from the changing fields of the other. There can exist a static local field, such as a magnet. It is produced by the hidden changing electric fields within the elements in the magnet. When these changing fields are let loose in empty space, their effects always ripple through space, one creating the other. As far as we know, the effect will move through space forever.

I suspect that there is one equation, very similar to those of Maxwell, that when applied to adjacent points in space, could describe this effect completely. All of reality could then be described in terms of this equation.
« Last Edit: 29/10/2009 11:26:43 by Vern »
 

Kiran The King Kai

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Electromagnetism, is the effect we have when we unify the electric and magnetic forces. In effect, the electromagnetic force field that is homogeneous to every corner of the universe, allows for electomagnetic interactions to occur, exchanged by their correct particle mediators. An electromagnetic waves are also particles - [the massless exitations of the electromagnetic field in the form of deadly gamma photons (also known as photons, and the other classes, such as th Z boson]. In special cases, the gravitational field in conjecture to the electromagnetic force can give rise to a peculiar exitation of gravitationally-stressed regions called graviphotons, which are indestinguishable from the quanta of photons.
what is Z boson ?
is it subatomic particle ?
 

Kiran The King Kai

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We speak of electromagnetism when describing electric and magnetic phenomena because where you find one you will always find the other in equal proportions. The static fields of each of these come from the changing fields of the other. There can exist a static local field, such as a magnet. It is produced by the hidden changing electric fields within the elements in the magnet. When these changing fields are let loose in empty space, their effects always ripple through space, one creating the other. As far as we know, the effect will move through space forever.

I suspect that there is one equation, very similar to those of Maxwell, that when applied to adjacent points in space, could describe this effect completely. All of reality could then be described in terms of this equation.
Have we discovered all wavelengths of light ?
 

Kiran The King Kai

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 graviphotons ?
 

Kiran The King Kai

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so can we call electromagnetic particles ?
or just as Planck says "Quanta"
 

Offline Vern

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The W and Z bosons are Quantum Theory concepts within Quantum Electro Dynamics and Quantum Chroma Dynamics. They are considered as sub components of Quarks. They have never been observed just as Quarks have never been observed. Quarks, according to theory, can not exist outside an atomic nuclei.

 

Offline Vern

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so can we call electromagnetic particles ?
or just as Planck says "Quanta"

We cross post :) You can call the photon a particle. I think of the particle aspect of electromagnetism as simply points of maxima within the pointy waves that convey the effect.
 

Kiran The King Kai

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The W and Z bosons are Quantum Theory concepts within Quantum Electro Dynamics and Quantum Chroma Dynamics. They are considered as sub components of Quarks. They have never been observed just as Quarks have never been observed. Quarks, according to theory, can not exist outside an atomic nuclei.


We talk a hell lot about W and Z bosons and strings ??
does strings really really exist inside Quarks ? that too 12 dimensions ?
 

Offline Mr. Scientist

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The W and Z bosons are Quantum Theory concepts within Quantum Electro Dynamics and Quantum Chroma Dynamics. They are considered as sub components of Quarks. They have never been observed just as Quarks have never been observed. Quarks, according to theory, can not exist outside an atomic nuclei.



''Finally, in 1983, after innovations in accelerator physics at CERN, two experiments were able to directly observe the decay of the W boson, and Carlo Rubbia and Simon van der Meer received the Nobel Prize for the accelerator and experiment.''
http://www.bnl.gov/rhic/news/050509/story2.asp
 

Offline Vern

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We have to be careful about mixing theories. String has its own adherents. They try and expand upon Quantum theory. When developing a new theory, there is no need to include past theories; only the observations that led to them need be considered.
 

Kiran The King Kai

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We have to be careful about mixing theories. String has its own adherents. They try and expand upon Quantum theory. When developing a new theory, there is no need to include past theories; only the observations that led to them need be considered.
could there be anything smaller than strings ?
 

Kiran The King Kai

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thanks for the link Mr.scientist !
 

Offline Vern

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Quote from: Mr. Scientist
''Finally, in 1983, after innovations in accelerator physics at CERN, two experiments were able to directly observe the decay of the W boson, and Carlo Rubbia and Simon van der Meer received the Nobel Prize for the accelerator and experiment.''
There is so much that comes out of particle accelerators that they were bound to find something they could call the W and Z boson. :) What they actually found was a peak of amplitude in their detector at around 500 MeV.
 

Kiran The King Kai

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But when electricity is passed through a wire .. it generates magnetism too and than when it reaches electric bulb filament (tungsten)...
does magnetism too enters into  filament ?
and electron gets exited and when it jumps ... energy emitted as light  ! is this the same magnetism ? as it traveled through wire ?

 

Offline Vern

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We need to not stray too far from the simplicity of electric and magnetic change. An electron is a charged particle. When it moves, its field moves along with it. Points in space along its path therefore must see a change in the local field amplitudes.

When an electron is forced through a conductor by unbalanced charges, atoms in the conductor wiggle as they momentarily host the electron. The wiggles are accumulative and we sense them as heat. When a tungsten wire, or anything for that matter, accumulates enough heat, it radiates the heat as light.
 

Offline Gile na Gile

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We need to not stray too far from the simplicity of electric and magnetic change. An electron is a charged particle. When it moves, its field moves along with it.

From the above diagram of the electro-magnetic field it seems to me that there are two particles within each photon of light. Both exhibit similar properties in their movement. One is moving horizontally like a snake winding through the desert sands (electric field), the other is bouncing up and down like a beachball (magnetic field). What are these particles? Are they "electrons" or could they be even "quarks"? What is the force that keeps them bound together? Are they tied to one another in some fashion? Why don't either of them split through the "film" of the photon hide - the electromagnetic field - is there likewise a force which prevents them from doing so?
« Last Edit: 17/12/2009 15:39:02 by Gile na Gile »
 

Offline Pmb

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Quote from: Kiran The King Kai
What is difference between Electromagnetism and Electromagnetic wave ?
The term Electromagnetism, like most other words, has a meaning which depends on the context in which it is used. When I see the term defined in a text it usually refers to a branch of science, i.e. it is synonymous with The theory of the electromagnetic field. Merriam-Webster defines electromagnetism as follows

Quote
1: magnetism developed by a current of electricity

2 a: a fundamental physical force that is responsible for interactions between charged particles which occur because of their charge and for the emission and absorption of photons, that is about a hundredth the strength of the strong force, and that extends over infinite distances but is dominant over atomic and molecular distances —called also electromagnetic force — compare gravity 3a(2), strong force, weak force b : a branch of physical science that deals with the physical relations between electricity and magnetism
So in most cases, when you see the term electromagnetism used in physics it refers to the theory of electrodynamics.
Quote from: Vern
We speak of electromagnetism when describing electric and magnetic phenomena because where you find one you will always find the other in equal proportions.
We speak of electromagnetism because the electric field is related to the magnetic field in a particular way. But it's clearly possible to have a situation where there is an electric field and yet there is no magnetic field present, and vice versa.
Quote from: Vern
The static fields of each of these come from the changing fields of the other.
It's possible to have a static magnetic field in the absence of a changing electric field. For example; Suppose there is a wire which is lying at rest on the x-axis in the inertial frame S. Let there be a constant current in the wire but the net charge density is zero. Then as measured in S there will be a time independant magnetic field and no electric field. Now change your frame of reference to the inertial frame S' which is moving relative to S in the x-direction. Relativity tells us that in S' there will be a static magnetic field as well but now there's a static electric field.is moving relative to that frame there can be iform and constant
 

Offline Vern

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I am not sure it is really true that it is possible to have a static field of one of the forces without there being somewhere a related changing field of the other.

I know there are situations where it appears to be so, such as a simple magnet. But if you look far enough into the innards of the magnet you find the changing fields.

 

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