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Thread: Probably a dumb question....

  1. #1
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    Default Probably a dumb question....

    this is probably a really silly question, but someone asked me this today and i felt dumbfounded becasue i didnt know the answer...

    Does a White Light Laser beam have a wavelength? (a white beam).

    is the wavelength a sum of its combined wavelengths? im guessing, no.

  2. #2
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    Lightbulb

    Nope, it is the combination of n different wavelengths making white light. The only frquesncies present are the ones being combined. R/G/B, R/Y/G/B... depending on what lasers you are using. I think.
    Love, peace, and grease,

    allthat... aka: aaron@pangolin

  3. #3
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    That's about it. Every single wavelentgh of light is perceived by the human eye and brain as a fully saturated color; technically known as hue. White (looking) light can be synthesized by mixing a few lines that are spread out in the spectrum; ie: R G B. True white light is rare in man made divices that reproduce color; except for those fairly new full spectrum white light lasers. Those actually put out a broad spectrum of coherent light. Some how this seems like an oxymoron to me.

    James.
    Last edited by James Lehman; 08-04-2008 at 16:23.

  4. #4
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    Default

    thanks Gentlemen!

    makes sense.

    -Marc

  5. #5
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    Default

    When you think about it, the light you see from the sun is white, pass that through a prism, and you get alot of colours, not just white out.

  6. #6
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    Default

    Quote Originally Posted by Things View Post
    When you think about it, the light you see from the sun is white, pass that through a prism, and you get alot of colours, not just white out.
    I always thought it was yellow-ish. Thought-provoking..

  7. #7
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    Quote Originally Posted by platinum View Post
    I always thought it was yellow-ish. Thought-provoking..
    That is exactly why the sky is blue!

    The atmosphere absorbs HUGE amounts off the high end of the radiation from the Sun, hence it looks blue and the light that makes it through to the surface of the Earth looks yellow. White - blue = yellow!

    James.

  8. #8
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    Quote Originally Posted by James Lehman View Post
    That is exactly why the sky is blue!

    The atmosphere absorbs HUGE amounts off the high end of the radiation from the Sun, hence it looks blue and the light that makes it through to the surface of the Earth looks yellow. White - blue = yellow!

    James.
    Eureka! Thanks for the lesson.

  9. #9
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    Cool

    Quote Originally Posted by James Lehman View Post
    That is exactly why the sky is blue!
    The atmosphere absorbs HUGE amounts off the high end of the radiation from the Sun, hence it looks blue and the light that makes it through to the surface of the Earth looks yellow. White - blue = yellow!
    Technically the atmosphere *scatters* the blue light (google "Rayleigh scattering" if you're interested in the physics behind the process) rather than strictly absorbing or filtering it.

    However the end result is the same: the sky appears blue, and the sun appears yellow.

    Adam

  10. #10
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    Default

    .......unless you're on LSD.

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