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Wavelength of light

  1. Jul 15, 2004 #1
    Hey guys,

    I've started a thread in usenet sci.physics.relativity


    but the answers given there didn't really satisfy me, so I'm back here.

    I couldn't get people there to confirm that wavelength shortens as frequency increases when light source approaches lab frame, and that we could prove the change in wavelength by examining diffraction through a slit. Am I wrong? Why hesitate to confirm that wavelength shortens, I don't understand.

    I'm thinking maybe wavelength has two components, one from electic and one from magnetic fields, and diffraction is due to the component perpendicular to light's direction, and the shortened wavelength is the other component. Wild guess, eh? I'm afraid to ask this on usenet.

    On the other hand, I know that light isn't considered an electromagnetic wave anymore. There is wave/particle duality. I know light is considered as a probability wave and it collapses when detected, or something like that. But then, I'm confused, can we really talk about a wavelength associated with light or is it a leftover from the days of electromagnetic theory of light?

    Now, you know I'm not the crackpot I used to be. But, this is theory development, and I'd like to throw in an idea. Instead of saying light explores all possible paths, maybe we could say a photon is a peak, and according to fourier transform, carries all possible frequencies. A single photon then can interact with itself after passing through two slits, because some of the frequency components would be filtered. Wavelength of light then would be the distance between two consecutive peaks (a single photon would not have a wavelength). Yeah, probably a stupid idea, and of course I haven't thought how to explain other light phenomena with this. And it is too simple so someone must have thought of it before. I'd appreciate if anyone knows a website that discusses this. Thanks.
  2. jcsd
  3. Jul 15, 2004 #2
    not sure if a "wavelength" applies to light anymore or not, i haven't kept up with the current descriptions, but last i heard lead me to believe that the photon does exist as a particle, and exhibits the characteristics of a wave, not in a standing wave sense with peaks and troughs but more of a compression wave, where frequency would be the number of photons intercepted by an observer in a second.

    as such, doppler effects of photons would be easy to imagine, changing the spacing of the photons (but not the actual speed of the photons) as an object approaches or recedes, by virtue of emitting them closer or farther than would be if the object was stationary.

    also in this model a photon by itself would carry no wavelength or frequency on its own, color can only be defined as multitudes of photons and their progression intervals
  4. Jul 15, 2004 #3
    well actually to clarify, wavelength and frequency would be the same thing in the above description, the distance between consecutive photons would also be the frequency... well... not if you're moving towards the light source... but that's another theory altogether i think
  5. Jul 16, 2004 #4
    The wave/particle duality you mention is so named because experiments done on light give evidence to both of then.
    We are still not completely sure whether light is a wave or particle allthough many scientists can argue strongly for both cases. if you can supply good evidence for your theories and apply them to all circumstances then you might be right.
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