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Light and color question

  1. Dec 2, 2014 #1
    If the color black absorbs all colors and reflects none and the color red absorbs all colors but reflects the color red and the color white is made up of all colors no absorption and all reflection how come the color white is not a mirror?
     
  2. jcsd
  3. Dec 2, 2014 #2

    Danger

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    For one thing, the reflected light is scattered in all directions and is therefore incapable of conveying an image.
     
  4. Dec 2, 2014 #3

    DaveC426913

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    As Danger says:

    specularjavafigure1.jpg
     
  5. Dec 2, 2014 #4
    So when we see the color white we are seeing all colors reflected in a chaotic ( diffused ) manner with no one color dominating on both the absorbtion and reflection sides of the coin?
     
  6. Dec 2, 2014 #5
    In the picture of diffuse reflection you show an uneven surface but what about a smooth surface like a white car bumper?
     
  7. Dec 2, 2014 #6

    Drakkith

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    Car bumpers are not smooth when you get down to nanometer sized scales. In addition, light is partially penetrating the material a small ways before being reflected back out, which can cause scattering and other effects.
     
  8. Dec 3, 2014 #7

    A.T.

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    You can have a smooth, but mostly transparent layer, which causes some specular reflection at the surface. But most light penetrates the surface and gets diffused below it.
     
  9. Dec 3, 2014 #8

    Danger

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    Also, there are a lot of different "whites". Not all frequencies are reflected equally by most of them.
     
  10. Dec 3, 2014 #9

    NascentOxygen

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    It's interesting just how good a "mirror" some polished black flat surfaces are, such as the plastic case/cabinet of electronic gear.
     
  11. Dec 4, 2014 #10
    Since we're talking about light and color, I've always wondered: what would a fourth primary color look like? If our eyes could see far enough beyond infrared or ultraviolet would a fourth primary color likely show up?
     
  12. Dec 4, 2014 #11

    Danger

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    I think that it's purely a matter of semantics. Insects see ultraviolet, but I don't think that it's considered a "primary colour" even to them. There's some kind of shrimp or something that has about 9 different types of cones in its eyes. I have no idea what it "sees".
     
  13. Dec 4, 2014 #12

    DaveC426913

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    Why don't you ask them? They're called tetrachromats - people with a fourth colour detector in their eyes.
     
    Last edited: Dec 4, 2014
  14. Dec 4, 2014 #13

    DaveC426913

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    (It's not quite as awesome as it sounds. They don't really see new colours, but they can distinguish far finer gradients between existing colours than the rest of us can - mostly in the blue-green range.)
     
  15. Dec 4, 2014 #14

    Danger

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    That area drives me nuts! I never know what to call something anywhere near the transition point. One of my favourite colours is teal. I know exactly what it looks like, but I have absolutely no idea as to whether it's blue or green. I see it as both at the same time.
     
  16. Dec 4, 2014 #15
    Blue? Green? Frequencies may be absolute; but I thought color is not, in other words each of us is genetically unique and perceive light in different ways
     
  17. Dec 4, 2014 #16

    Danger

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    We all, if in normal health, perceive it the same way from a physical standpoint. How our brains interpret it might very well be unique to each individual. There is really no way to know. That would require telepathy, so as to "see" through someone else's eyes. Something red to me might very well be "seen" by you as what I think of as yellow. I just go by what I'm told they are.
    That's why I always refer to my Pantone swatch kit when doing graphics. (Well, that and the fact that what shows on a monitor isn't what comes out on the printer.)
     
    Last edited: Dec 4, 2014
  18. Dec 4, 2014 #17
    What I meant to say is that while we all receive the same light, we do not perceive it the same way in as much as each of us may have different number of retinal cones of the various types... And then there are Colo blind people
     
  19. Dec 4, 2014 #18

    Bandersnatch

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    It's these guys:
    170px-Mantis_shrimp_from_front.jpg
    12 types of colour recognition photoreceptors. Sees polarization. Single eye depth perception. The coolest animal on the planet.
    http://en.wikipedia.org/wiki/Mantis_shrimp
     
  20. Dec 4, 2014 #19

    DaveC426913

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    Different ways yes, but not more ways. Tetrachromats can distinguish finer differences than others.

    One woman, who had not known she was special, recounts stories where she would see people wearing clothes that they thought matched, but to her, it was obvious that they clashed - different shades of blue-green that no one else seemed to see.
     
  21. Dec 4, 2014 #20

    Danger

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    That's the little bugger that I meant, alright! I've never seen that article before. They're even more impressive than I thought. (And frightening, given that I'm deathly allergic to shrimp... :D)
     
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