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Electrical and magnetic fields are spherical right?

  1. Aug 24, 2012 #1
    When i think of electromagnetic waves i think of a fast moving sphere of expanding or contracting fields,either magnetic or electrical depending on where its at in its cycle. So i guess im picturing a single photon as a sphere. Is this a correct visualization?(i doubt it). If so, how does a sphere of electricity become perpendicular to sphere of magnetism? Haha
     
  2. jcsd
  3. Aug 24, 2012 #2
    It is most convenient to think of electromagnetic fields as arrows (as they are vector fields). So at every point in space there is an arrow of a certain length and direction.

    When thinking of waves these arrows are perpendicular. To make a planewave just pick a crest and draw an arrow at that point (the field is greatest in this point) then draw arrows next to it in the direction the wave is moving that gradually (depending on the frequancy/wavelength of the wave) become smaller, then zero and then bigger in the opposite direction then you get something like this: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/imgel2/emwavec.gif

    There is also something like a spherical wave. In this case you still draw the arrows in much the same way but now froming a sphere like this: http://www.phy.uct.ac.za/demonline/virtual/images/23_Radiation3D.JPG [Broken]
    this last image is one wavefront.
     
    Last edited by a moderator: May 6, 2017
  4. Aug 24, 2012 #3

    Drakkith

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    Staff: Mentor

    I wouldn't try to "visualize" a photon. I visualize the EM wave as a whole and only use the concept of the photon to explain the interaction between the wave and anything else. To me this is the only thing that makes sense, as photons are most assuredly not little spheres that bounce off of stuff or anything like that.
     
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