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Another speed of light: the function followed.

  1. Apr 21, 2006 #1
    We always consider light speed as v=lambda/T but for a moment let's suppose that light would travel all around the function, following the whole curve.
    In this case its speed would be at least doubled (should not be difficult to calculate it) and it will constantly change depending on the frequence.

    So i'm not talking about the speed of light as v=lambda/T but how much space light really travel on.
    if the classical rule is right, for absurde, it means that a photon, following the function (y=sen...etc) must absolutly maintain his horizzontal speed constant, so, this means, that in a wave the photon would accelerate a lot when the curve begins to be almost vertical, then when it returns almost orizzontal (the top or the bottom) it would decrease his speed relative to the horizontal travelling....and this is impossible for the standard theory (standard for me is hight school physics, what i am doing); as the bible says, c is constant.
    (i know i semplified about waves photons and functions...probably are the same thing)

    So should not be considered c speed as its entire track, the whole function followed?
    Last edited by a moderator: Apr 21, 2006
  2. jcsd
  3. Apr 21, 2006 #2


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    Gold Member

    I'm not really sure that I understand your question, but it appears that you think of light as photonic particles moving in a sinusoidal path like a snake. That isn't what the wave nature of EM is actually about. The wave function travels at a constant c. I'll have to leave it up to someone else to explain it in more detail. For now, just bear in mind that the photons themselves are not constantly shifting direction in order to follow a wavy path.
  4. Apr 25, 2006 #3

    Claude Bile

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    The sinusoidal variation in an EM wave is the variation in the electromagnetic field itself, not displacement as is the case with a wave on a string.

    Last edited: Apr 25, 2006
  5. Apr 25, 2006 #4


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    Staff: Mentor

    The sinusoidal graphs you usually see in connection with light describe the the electric or magnetic field, and have no connection whatsoever with position (in the direction perpendicular to the direction the wave is traveling).

    The vertical units of such a graph are volts/meter or newtons/coulomb (for electric field) or tesla (for magnetic field), not meters.
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