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Why water is colourless

  1. Dec 19, 2014 #1
    Here is the link which explains this.But i don't think it is right because according to the explanation given water should be black not colourless.http://kinooze.com/2012/09/09/why-is-water-colourless/I think water reflects light which is not in our visible range,right?
     
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  3. Dec 19, 2014 #2

    DrClaude

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  4. Dec 19, 2014 #3
  5. Dec 19, 2014 #4

    DrClaude

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    Water is transparent.

    Water can have a colour, or rather a slight tint, but I don't want to go into the details. Look at other threads in PF, such as https://www.physicsforums.com/threads/why-water-blue.133850/
     
  6. Dec 19, 2014 #5

    davenn

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    Exactly !

    its is noted that purified (distilled) water will have a slight blue tint to it

    that last statement on the linked page is just so wrong .....
    if all the colours were absorbed then yes, it would be black

    Dave
     
  7. Dec 19, 2014 #6
    Ok can you please tell me if white color reflects infrared light also?
     
  8. Dec 19, 2014 #7

    Orodruin

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    What your eye sees as white is a combination of light of wavelengths across the spectrum.
     
  9. Dec 19, 2014 #8

    davenn

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    IT does to a better degree than say black

    feel the difference in temperature between a white and a black painted car that is in the sun
     
  10. Dec 19, 2014 #9
    So the object which is reflecting most nearly all of the wavelength of visible spectrum (i.e white color object)will reflect infrared light also.right?
     
  11. Dec 19, 2014 #10

    DrClaude

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    First, infrared is a big part of the electromagnetic spectrum, so there is not a single thing as infrared light. As davenn said, in general withe things will also show greater reflection of IR radiation, especially in the near IR. But you could, at least in principle, have a material that is white but still absorbs all IR radiation.
     
  12. Dec 19, 2014 #11

    davenn

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    great response :)
     
  13. Dec 19, 2014 #12
    But white color object would reflect IR better than any other colored object say red or blue,is it right?
     
  14. Dec 19, 2014 #13

    Orodruin

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    You cannot say this a priori. The color of an object is (mainly) based on its interaction with light in the visible range.

    The main part of the Sun's light is in the visible spectrum, which black absorbs and thus becomes warmer. You cannot draw a conclusion about the IR properties solely based on this, you would need a source mainly active in the IR spectrum.
     
  15. Dec 19, 2014 #14

    DrClaude

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    If its blue, probably, but if it is red, absolutely not! It is already reflecting in the red part of the spectrum, so it is probably also reflecting in the near IR.
     
  16. Dec 19, 2014 #15

    davenn

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    True and I didn't :)

    DrClaude expanded on the theme well :)

     
  17. Dec 19, 2014 #16
  18. Dec 19, 2014 #17

    Orodruin

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    If you ask him to feel a black and white car in the Sun, this seems to imply that this is an argument for white reflecting more of the IR. It is an argument for white reflecting more visible light.

    I agree DrClaude wrote it nicely.
     
  19. Dec 19, 2014 #18
  20. Dec 19, 2014 #19

    Orodruin

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  21. Dec 19, 2014 #20

    DaveC426913

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    No, this is not true. White is reflecting all colours, including red.

    A red object is as likely to reflect infra-red frequencies as a white object. It's all in the specifics of the pigment.
     
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