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

How come when h2o drops on my computer screen I see

  1. Jul 30, 2011 #1
    I hope this topic belongs here, after all this is about color and color is described through quantum mechanics.

    How come when water molecules drop on my computer screen I see a variety of colors (kind of like a rainbow), and those colors change depending on the angle I am observing it [itex]\vartheta[/itex]. The colors seems to repeat every couple degrees.
  2. jcsd
  3. Jul 30, 2011 #2


    User Avatar

    Classical optics is pretty sufficient to give an answer :devil:

    Your screen is composed of red-green-blue dots spaced by 0.1mm or so.
    Now - an excercise in classical optics - compute how it looks if viewed through a droplet: transparent, but n>1, sphere of a diameter comparable to the pixel spacing?

    And behave! Don't sneeze on your screen!

    (I used to open cans with beer just by computer screen in old times, when all screen pixels were amber...)
    Last edited: Jul 30, 2011
  4. Jul 30, 2011 #3


    User Avatar

    Staff: Mentor

    Hence this thread has been moved to the classical physics forum.
  5. Jul 30, 2011 #4
    My screen is composed of red-green-blue dots? I want a more fundamental answer than that.

    And if they are composed of red-green-blue dots then how do I get all of these colors? Spaced by .1mm or so? Something seriously isn't making sense to me. :(

    lmao, actually I have this stupid persistent water damage on my roof from the neighbors above me :(.

    Amber? :confused:
  6. Jul 31, 2011 #5


    User Avatar


    Take a simple (high-school level) excercise on geometrical optics: find what you see through helf-sphere (or full sphere) of glass or water if you look at the pattern of coloured dots.

    First computer monitors were green. In 1980's amber ones become popular - they were nicer to eyes if you had to work long time with them. Even as a student I liked comfort, so I managed to get one of the first amber VT-220 on my desk :tongue2:
  7. Jul 31, 2011 #6
    Oh thank you.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook