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Activity of photon during wavelegnth duration

  1. Mar 16, 2014 #1
    (disregard my improvised science lingo)

    so like... a radio wave has a rather macroscopic wavelength. the photon is depicted as travelling back and forth in unison with the wavelength. im having trouble understanding why the photon cant hit you from the "side". if the photon is travelling a zig-zaged path (zig zags due to wavelength), then is it possible for the photon to actually hit you from the "side"? if you get hit by a radiowave when its coming back down from its wavelength, it has some velocity in a direction which the light isnt actually travelling. im thinking uncertainty principals somehow negate this? please help thanks
     
  2. jcsd
  3. Mar 16, 2014 #2

    jtbell

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    Staff: Mentor

    No, it doesn't do that. Where have you seen this depicted?
     
  4. Mar 16, 2014 #3
    im not sure. i did a google image search and couldnt find any depictions of such, which discourages me.

    thanks
     
  5. Mar 16, 2014 #4

    jtbell

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    Staff: Mentor

    The sinusoidal "pictures" that you usually see of electromagnetic waves are supposed to represent the behavior of classical electric and magnetic fields. They show the magnitude and direction of those fields at various points, at various times, not the motion of actual objects.

    The relationship between classical electric and magnetic fields on one hand, and quantum-electrodynamical photons on the other hand, is rather complex and subtle. Unless you know QED well, it's dangerous to try to connect the two.

    The safest way is via energy: classical electric and magnetic fields carry energy. A volume of space "filled" with electromagnetic radiation contains a certain amount of energy E, which we can calculate from classical electrodynamics in terms of the amplitudes of the electric and magnetic fields. Looking at this in terms of photons, each photon has energy hf. So if the radiation has a single frequency, then we can say the average number of photons in that volume is N = E / hf.
     
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