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Magnetic field is made of virtual photons?

  1. Oct 23, 2006 #1


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    magnetic field is made of photons?!?!?

    i've been researching photons and i discovered on
    http://http://van.physics.uiuc.edu/qa/listing.php?id=414" [Broken]
    http://en.wikipedia.org/wiki/Photon" [Broken]

    both resources state that all mangetic fields are made of photons. soooooo, this brings up a lot of questions... first, why (when im in the presence of a mangetic field) dont i see light? (because light is mad of photons):cry:
    im sure if i get a simple understanding of this concept, it will probably rule out most of my questions, so i'll wait for a reply to continue.

    SO WHAT ARE PHOTONS MADE OF? -obviously they're charged (hence mangetic fields)
    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. Oct 24, 2006 #2
    Photons aren't "particles" in the sense that they're made of anything. You seem to have a somewhat naive understanding of what a photon is, so I'd recommend reading a little more about them from credible sources before moving on.
  4. Oct 24, 2006 #3


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    The photons in a magnetic or electric field that doesn't transport energy from one place to another are virtual photons, not real ones. Some people consider virtual photons to be simply a name for a mathematical construct that pops up in calculations in quantum electrodynamics. Others consider them to have some degree of "reality" but not as much as real photons.

    And even real photons are pretty strange things. Don't think of them as little tiny balls flying around!
  5. Oct 24, 2006 #4

    Meir Achuz

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    "both resources state that all mangetic fields are made of photons"
    I couldn't get to the first website. The Wikipedia was confusing as usual, but I didn't see that it said "all magnetic fields are made of photons".
    A static magnetic field is not made of photons. EM waves are quantized in packets called photons.
  6. Nov 26, 2006 #5
    Then is a static magnetic field made of virtual photons?
  7. Nov 27, 2006 #6

    Meir Achuz

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    No. That simple answer was too short for the forum.
  8. Dec 15, 2006 #7
    If Photons are light waves and you’re able you reflect them with a mirror, and some are saying magnetic waves are virtual photons so can you reflect magnetic waves.

    And how could you reflect a magnetic wave “flux”, is it possible, a mirror will probably not work.
  9. Dec 18, 2006 #8
    A static magnetic field being made of virtual photons is too simple and short for the forum, if not the particle part of a light wave, would it be more appropriate to call it a potentional wave of photons?
  10. Dec 18, 2006 #9
    Can you tell me, what must I do to be able to reflect magnetic wave from a permanent magnet?
  11. Jan 27, 2007 #10
    I would think that you must spin the magnetic within reach of a coil of wire. I do not believe you will be reflecting the complete wave but just parts of all the waves in the field, or am I just trying to over simplify.
  12. Jan 27, 2007 #11
    I would think that you must spin the magnetic within reach of a coil of wire. I do not believe you will be reflecting the complete wave but just parts of all the waves in the field, or am I just trying to over simplify.
  13. Jan 28, 2007 #12
    I’ve got no idea, I would really be nice if somebody knows how to built a camera to see magnetic waves just like you can see IR light with a video cam after you take the IR filter out.

    Or maybe just add a magnetic filter :-)
  14. Jan 28, 2007 #13

    Meir Achuz

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    I don't know how this concept of "magnetic waves" got started here.
    To be a wave in the usual sense requires a specific combination of both electric and magnetic fields. There is no purely magnetic wave.
  15. Jan 28, 2007 #14
    There's some confusion about the nature of electromagnetic fields here. The electromagnetic field is mediated by the photon as part of the standard model. Changing electromagnetic fields are propagated by real photons that we can detect. Charged particles exchange virtual photons presenting the behavior of an electrostatic field. See here for a discussion of deriving Coulomb's law from virtual photon exchanges. Charged particles in motion similarly account for magnetic fields.
    For more information, see texts on quantum electrodynamics (QED), ie., https://www.amazon.com/Photons-Atom...ef=sr_1_2/102-2413551-3632907?ie=UTF8&s=books.
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  16. Jan 28, 2007 #15
    Didn't we have this discussion a month a go? Oh well, here is my take now:

    If we take a look at Maxwell's Equations, what do we get? We get something like this if we digest them in a semi-mathematical manner:

    1. Electrical Flux through a closed surface = net charge inside closed surface / constant

    2. Magnetic field through a closed surface = 0

    3. Circulation of electrical flux around a curve = d(magnetic field through the surface that the curve, on the left side, encloses)/dt
    Note(d/dt is just the rate of change of the value in ())

    4. Constant times the circulation of magnetic flux around a curve = d(electric field through the surface that the curve, on the left side, encloses)/dt + flux of electric current through the surface /constant.

    #1 tells us that if we have a charged particle, we have an electric field.
    #2 tells us that we can't have a static magnetic field (no monopole)
    #3 tells us that the change of the magnetic flux, creates electric flux
    #4 tells us that the change of the electric flux creates magnetic flux and a current also creates an electric flux.

    Because the current is made of moving charged particles, it has electric fields associated with it (see #1) and therefore #4 is a restatment of #2: Magnetic fields are ALWAYS associated with moving electric fields. And what do you get when you have an electric wave and a magnetic wave. Yea! Photons!

    Of course you have photons associated with magnetic fields. Of course the energy is carried by the photons. What else would it be? Little green men?

    A magnetic field is a mathematic construct to describe what we are seeing when the associated photons are at low frequency. In other words, the photons are big enough to study with our instruments. At higher frequencies (like visible light), the magnetic field can't be teased out by itself because the photons are too small, but we would be able to pick out the magnetic field in photons in the same manner if our instruments were small enough (I think!)
  17. Feb 2, 2007 #16


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    That's very nice, Interested Learner. A question -
    the electric field from a point charge extends
    to infinity in the absence of other charges. How is the electric field in a photon confined to a smaller region ?
  18. Feb 2, 2007 #17
    An electric field is an abstact concept. It is model to describe what we observe at a macroscopic level. It is really not fundamental in any sense.

    While a photon is something that is fundamental in the sense that it is an actual particle. It is what mediates the forces in electromagnetic fields. Electromagnetic fields are made up of photons. So the field is what we see at a macroscopic level with our instruments (at least at low frequency), but photons are what we get when we drill down and look at what is really going on.

    And don't take that stuff about electric fields extending to infinity too seriously. It is a model. Nothing else. Of course in real life, charged particles don't exist in isolation and we haven't checked to see if the field of that nonexistant isolated particle really does extend to infinity. (Since it is nonexistant, that would be difficult even if we could get out to infinity [which we can't] to measure the field).
  19. Feb 3, 2007 #18


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    Thank you, IL. I have seen exactly the opposite view expressed, but I lean towards
    the photon, which seems to have a lot of experimental support now.
  20. Feb 3, 2007 #19
    Why is it not fundamental ?

    What do you mean by "actual particle" ? A particle like an electron ?

    Forces IN EM fields ? What is that supposed to mean ? Can you give me an example of a force IN an EM field ?

    No, photons are the force carriers of the EM INTERACTION. They mediate all forces between electrically charged particles, magnetic dipoles, quadropoles etc etc etc...So all the "EM stuff"

    Really ? So how come i detect and E field at the metal high k interface in a MOSFET transistor. When i study such an interface, i study a crystallographic cell. This cell contains maybe 30 atoms (which is far from being macroscopic, no ?) and still i can detect an E field if i plot the electrostatic potential.

    No, we already discussed this "E field is made up of photons stuff" and the picture is not that clear-cut. You should certainly not be making any conclusions from such a vague model.
    How can you be so sure of that ?

    Last edited: Feb 3, 2007
  21. Feb 4, 2007 #20
    Thanks Marlan. When I read the question, the first impression was to send you an email to try to ask you to answer it. That is what I should have done. I did my best but it was obviously short of good. I am after all just an engineer and not a phyisicist. Or maybe I should just ignored the question and stopped when I was winning....

    But still, I am going to blow back a bit, not to say you are wrong (you seldom are wrong), but for my own education. I will start at the top.

    1) Bad use of the word fundamental. I really didn't know what to say. I have a gut level feeling for fields from the math, but it is sort of hard to put that into English.... I guess I was trying to say what the difference is between a field and a photon. My take on a field is that it is a mathematical model (of vectors) of something that we can measure at a macroscopic level. It really isn't what is going on at the lowest level. I think? Oh well...

    2) A force would be on a charged particle. You place a charge particle in a field and there is a force exerted on it. Right? I mean F = q1 E? Right? It is a photon that mediates that Force. Right?

    3) You are right about the bad use of English again. Saying that fields are made up of photon stuff is not accurate. I was kind of struggling for words. What is actually going on? I just do the math and it comes out right. I don't really know what a field really is beyond the mathematical models I use. Does anyone?

    4) Of course, I didn't mean that fields don't exist at high frequency. What I mean is that we normally use fields to describe what we see at low frequency and optics at high frequency. It is the old wave particle duality thing. When the "particles" are large we study them as fields and when they are small they study them as particles. It is a practical thing that has nothing to do with reality.

    5) Ok, an isolated charged particle might exist somewhere in the universe. However, what I meant was a charged particle that we could experimentally study. Our bodies and our tools are full of particles. There is no way we could get close enough to study an isolated particle without affecting the particle. In that sense, an isolated particle is a mathematical model. They really don't exist in a practical sense.

    I guess I try to make it simple so the person reading the answer can understand. But I can't get it right. How come what is so clear and beautiful in the math comes out so rotton in the English?
    Last edited: Feb 4, 2007
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