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Fluid appearing colorless when poured

  1. Jan 23, 2008 #1
    I apologise if this seems like a random question, but I can't seem to explain it...

    In these pictures, why is it, that at some points during the descent of the colored fluid, that it appears colorless:


    I thought it to be some kind of scattering effect, but to be honest, I haven't reached a decent conclusion...

    Any help would be appreciated,
    Last edited: Jan 23, 2008
  2. jcsd
  3. Jan 23, 2008 #2


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    Soda fountains have nozzles which release mostly carbonated water (which is bubbly and appears white) along with a few thin jets of colored syrup along the sides. The bulk of the liquid appears white, with only two thin stripes of color along the sides.

    Some fountains also pulse the amount of syrup released by the nozzle. During some periods, nothing but carbonated water is being released.

    The coloration effects have nothing to do with light or scattering or anything else -- the carbonated water and syrup are just not yet thoroughly mixed. If you pour pre-mixed Coke out of a bottle, it looks like Coke.

    - Warren
  4. Jan 24, 2008 #3

    Andy Resnick

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    Soda has a color becasue it selectively absorbs different wavelengths. The less soda there is, the less absorption that can occur and so the intensity of color is decreased. Let a drop of soda spread on glass or a mirrored surface and it will also appear colorless.
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