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Propagation of light

  1. Dec 31, 2009 #1
    light doesn't cotain any charge then how it fluctulate the electric and magnetic field in vacumn or medium.
  2. jcsd
  3. Dec 31, 2009 #2


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    Staff: Mentor

    According to Maxwell's equations, an electric field can be produced either by electric charge or by a changing magnetic field; and a magnetic field can be produced either by electric current (moving charges) or by a changing electric field. In an electromagnetic wave the continually changing electric and magnetic fields keep each other going.
  4. Jan 1, 2010 #3
    But for the electric or magnetic field a charge is needed.
    But in vacumn in the absence of charge how light propagate as there is no question of electric or magnetic field in absence of charge.
  5. Jan 1, 2010 #4

    Vanadium 50

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    Please reread jtbell's message. You can create an electric field either with an electric charge or a changing magnetic field.
  6. Jan 1, 2010 #5


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    Light doesn't "fluctuate the electric and magnetic field", light is the fluctuations in the electro-magnetic field.
  7. Jan 1, 2010 #6

    Andy Resnick

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    google "polarizibility", "susceptibility", "induced dipole moment", etc.
  8. Jan 1, 2010 #7
    sorry andy i didn't get u.
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