Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Why are clouds white?

  1. Dec 16, 2012 #1
    In one place I read that since the particles are big they reflect white light as is. But in another I read that they are made up of water droplets of varying sizes so,

    small droplets: make blue
    medium droplets: make green
    larger droplets: make red

    ...and together they combine to make a white cloud. Which one is correct?

    And also, under Raman effect it's given that in Rayleigh scattering the scattered light is the same as that of the incident light. But how. The sky is blue. This is because blue light is scattered. But the incident light is white? Or do they mean that the scattered light's wavelength does not change?
    Last edited: Dec 16, 2012
  2. jcsd
  3. Dec 16, 2012 #2


    User Avatar
    Staff Emeritus
    Science Advisor

    I've only read that water droplets are larger than the wavelengths of visible light and therefore reflect or scatter all of it equally.
  4. Dec 16, 2012 #3
    diffuse reflection off water droplets.
  5. Dec 16, 2012 #4
    May I join in along a sideline.

    Clouds consist of water droplets. What holds the cloud up in the air?
  6. Dec 16, 2012 #5
  7. Dec 16, 2012 #6
    Thanks Charmar.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook