Does a photon carry a magnetic field?

In summary: Unfortunately that is also the problem with so many other subjects...I see. But in any case, I think we should stick to what the theory tells us. Classically, light is described by Maxwell's equations, which describe light as waves.
  • #1
Kalrag
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Started doing some research into photons latley. I was wondering if photons actually carried a magnetic field.
 
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  • #2
Magnetic fields are created by moving charges. A photon in the classical sense is just a quanta of light which is propagated out as electromagnetic waves when one has an oscillating charge.
 
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  • #3
Kalrag said:
I was wondering if photons actually carried a magnetic field.
Yes. Photons are quantized excitations of the electromagnetic field.
 
  • #4
Kalrag said:
Started doing some research into photons latley. I was wondering if photons actually carried a magnetic field.

To clarify what the posters before me mean:

It depends on what you mean by "carry".

The photon itself doesn't produce a magnetic field, so in this sense it doesn't carry one.
The magnetic field however can be quantized, and its quantum would be the photon.
 
  • #5
So in any way can photons create a magnetic field?
 
  • #7
DaleSpam said:
The magnetic field is photons.

If that statement is true than how is a magnetic field made up of photons?

(Im still learning as an begginer)
 
  • #8
the photon (light)is an electromagnetic wave
 
  • #9
Kalrag said:
So in any way can photons create a magnetic field?

No.

An accelerating electric charge generates a magnetic field. An accelerating electric charge also creates a wave in the electrostatic field. So when you find a wave in the electrostatic field you will also find a magnetic field.

The quanta (smallest measurable change) of the electrostatic field is a photon. So where you find a photon you find a magnetic field, the source is not the photon, it is the accelerating charge.
 
  • #10
The magnetic force is mediated by a field. That field can be quantized. One quantum is called a photon.

Your question is like asking "how is water made up of H2O?". H2O is the name of the smallest piece of water, a photon is the name of the smallest piece of an electromagnetic field.
 
  • #11
The photon has an oscillating E and B field.
 
  • #12
cragar said:
The photon has an oscillating E and B field.

Not really. The oscillating electromagnetic field is made of photons, but photons themselves are not the sources of any such fields.
 
  • #13
Polyrhythmic said:
Not really. The oscillating electromagnetic field is made of photons, but photons themselves are not the sources of any such fields.

I am talking about classical E&M, The EM wave has an E and B component. I am not saying photons are the sources of the fields, charges are the sources. Let's say we have a changing E field the induces a changing B fields and the cycle continues . Light is a self sustaining Em field.
 
  • #14
Dalespam nailed several different views...

If you need more, check Wikipedia, PHOTON...
 
  • #15
cragar said:
Im talking about classical E&M, The EM wave has an E and B component. I am not saying photons are the sources of the fields, charges are the sources. Let's say we have a changing E field the induces a changing B fields and the cycle continues . Light is a self sustaining Em field.

But classically, there is no photon.
 
  • #16
Polyrhythmic said:
But classically, there is no photon.

The problem is that people love the idea that the original 'corpuscular' theory of light was 'replaced' by a wave theory and then photons were re-introduced back into the theory to explain the quantum nature of things. SO . . . photons had to be, by popular demand, Corpuscles, again. People crave the 'little bullet' model for photons. We are fighting a losing battle here, I fear.
 
  • #17
sophiecentaur said:
The problem is that people love the idea that the original 'corpuscular' theory of light was 'replaced' by a wave theory and then photons were re-introduced back into the theory to explain the quantum nature of things. SO . . . photons had to be, by popular demand, Corpuscles, again. People crave the 'little bullet' model for photons. We are fighting a losing battle here, I fear.

I see. But in any case, I think we should stick to what the theory tells us. Classically, light is described by Maxwell's equations, which describe light as waves.
 
  • #18
Absolutely. Hear hear.
But try to tell that to more than half the contributors to these pages who use the word Photon as it they knew exactly what it means.
 
  • #19
sophiecentaur said:
Absolutely. Hear hear.
But try to tell that to more than half the contributors to these pages who use the word Photon as it they knew exactly what it means.

Unfortunately that is also the problem with so many other subjects...
 
  • #20
Polyrhythmic said:
I see. But in any case, I think we should stick to what the theory tells us. Classically, light is described by Maxwell's equations, which describe light as waves.

heresy, heresy I cry :wink:

so you don't agree with any of the Richard Feynman teachings and explanations ?

Dave
 
  • #21
I think you missed the key word "classically". I.e. not quantum mechanically. There are no photons in classical EM, by definition.
 
  • #22
Polyrhythmic said:
To clarify what the posters before me mean:

It depends on what you mean by "carry".

The photon itself doesn't produce a magnetic field, so in this sense it doesn't carry one.
The magnetic field however can be quantized, and its quantum would be the photon.

No the magnetic quantization is not a photon, it's a monopole. A photon is a distortion in the electromagnetic field.
 
  • #23
Polyrhythmic said:
I see. But in any case, I think we should stick to what the theory tells us. Classically, light is described by Maxwell's equations, which describe light as waves.

And yet why deny they are particles as well?
 
  • #24
Goldstone1 said:
No the magnetic quantization is not a photon, it's a monopole. A photon is a distortion in the electromagnetic field.

As the magnetic field is part of an electromagnetic field, the photon quantizes it as well.
The monopole is certainly not the quantum of the magnetic field, if anything, you could call it a hypothetical magnetic charge.
A photon is the quantum of the electromagnetic field.
 
  • #25
Goldstone1 said:
And yet why deny they are particles as well?

What do you mean by deny? The solutions to the Maxwell equations are waves, they have nothing to do with particles.
 
  • #26
Polyrhythmic said:
What do you mean by deny? The solutions to the Maxwell equations are waves, they have nothing to do with particles.

I thought you were advocating that particles did not exist in Nature and that Maxwells Equations where absolute.
 
  • #27
Polyrhythmic said:
As the magnetic field is part of an electromagnetic field, the photon quantizes it as well.
The monopole is certainly not the quantum of the magnetic field, if anything, you could call it a hypothetical magnetic charge.
A photon is the quantum of the electromagnetic field.
Well, we both know it is argued from both sides.

You are right, as well as am I in saying it is possible the magnetic quantization is the magnetic monopole. I wasn't trying to insinuate that the photon is not a quantization itself... sorry.
 
  • #28
davenn said:
heresy, heresy I cry :wink:

so you don't agree with any of the Richard Feynman teachings and explanations ?

Dave

Before you bring Feynman into a discussion I think you should make sure that you understand just what he did say and didn't say. The 'squiggle' on a Feynman diagram in no way tells us that a particle goes from place to place, for example - can you find any evidence of his actually saying that it does?

There are a million miles between the separate ideas of quanta and particles.
 
  • #29
Goldstone1 said:
I thought you were advocating that particles did not exist in Nature and that Maxwells Equations where absolute.

I didn't, I just said that Maxwell's equations were the classical description of light.
 
  • #30
Goldstone1 said:
Well, we both know it is argued from both sides.

You are right, as well as am I in saying it is possible the magnetic quantization is the magnetic monopole. I wasn't trying to insinuate that the photon is not a quantization itself... sorry.

The magnetic monopole would play the same role as the electric charge, it would be a source for the magnetic field, not a quantization.
 
  • #31
Polyrhythmic said:
The magnetic monopole would play the same role as the electric charge, it would be a source for the magnetic field, not a quantization.

Why would it not be a quantization of the magnetic field, if it is itself, a particle?
 
  • #32
Goldstone1 said:
Why would it not be a quantization of the magnetic field, if it is itself, a particle?

For the same reason the electron is no quantization of the electric field. I think you're mistaken on what we mean by "quantization of the field". If we look at a traveling electromagnetic wave, quantum mechanically, energy is transferred in discrete packages. Those packages are what we call photons, quanta of the field. The charge would be merely the source.
 
  • #33
Goldstone1 said:
Why would it not be a quantization of the magnetic field, if it is itself, a particle?

But that is not quantization. If you allow for magnetic monopoles, just as we already allow for electric monopoles, then the magnetic field will still be continuous. The quantization of the field means that the energy is quantized. Since a monopole will produce a field of continuous magnitude, there is no quantization of the field.

EDIT: It appears I lost this one by a nose.
 
  • #34
Born2bwire said:
But that is not quantization. If you allow for magnetic monopoles, just as we already allow for electric monopoles, then the magnetic field will still be continuous. The quantization of the field means that the energy is quantized. Since a monopole will produce a field of continuous magnitude, there is no quantization of the field.

EDIT: It appears I lost this one by a nose.

Hah, gotcha! But I still think that a variety of explanations is beneficial, as long as they are not contradictory!
 
  • #35
Born2bwire said:
But that is not quantization. If you allow for magnetic monopoles, just as we already allow for electric monopoles, then the magnetic field will still be continuous. The quantization of the field means that the energy is quantized. Since a monopole will produce a field of continuous magnitude, there is no quantization of the field.

EDIT: It appears I lost this one by a nose.

It's ok, we all make mistakes. :P
 

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