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Difference between black and transparent object

  1. Dec 24, 2014 #1
    Difference between transparent and black object?I mean black object is black because 1-it absorbs all the wavelengths of light OR 2-because it doesn't reflect any wavelength of light
    If first one is the reason then alright but if second one then transparent object should also be black as it does not reflect(reflects only 5%)it all transmit (about 95%)
     
    Last edited: Dec 24, 2014
  2. jcsd
  3. Dec 24, 2014 #2

    Matterwave

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    Black objects don't transmit light either, they absorb light. That's why you can't see through them. :)
     
  4. Dec 24, 2014 #3
    Why black objects are black?Because of reason 1 in my original post?Not because of reason 2?
     
  5. Dec 24, 2014 #4

    ehild

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    If you look at a transparent object, you see not only the light reflected from it, but also the light coming from behind and transmitted by the object.
     
  6. Dec 24, 2014 #5
    Till now i have been told that we only see color of objects depending upon what wavelength they reflect ,do the color of the object also depends on the wavelength which is transmitted?
     
  7. Dec 24, 2014 #6

    ehild

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    Yes. The colour of transparent objects is more the colour of the transmitted light than the reflected one. But it depends also, how you look at them. What colours you see if you look through your sunglasses? And how do they look like in reflected light?
     
  8. Dec 24, 2014 #7
    Water is colorless ,why?Is it transparent?
     
  9. Dec 24, 2014 #8

    sophiecentaur

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    It can be described as transparent but, in reality, even a thin layer of water does absorb some of the of light (some wavelengths more than others) , which you can detect if you go diving in ('clear') water of more than 10m or so. The Red end of the (visible) spectrum is absorbed more than the Blue end and objects will look generally 'bluer'. your brain does its best to compensate for this but, in the end, you just seem to see things in 'monochrome'.
    As it happens, UV is absorbed too. The absorption / frequency characteristic is complicated with various peaks and troughs (See this wiki link) because of the way the water molecules interact with various frequencies of WM waves.
     
  10. Dec 25, 2014 #9

    NascentOxygen

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    A very thin gold leaf, viewed in reflected light, appears golden because it reflects the yellows and reds especially well. But if you hold it up against a bright light, it appears green. Being very thin it allows some light to pass through, and this transmitted light is white minus the colours it reflects on the other side.
     
  11. Dec 25, 2014 #10

    CWatters

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    Yes. Objects can be transparent to some wavelengths and not others. A red filter (eg for stage lighting) allows red light through and absorbs other colours. The result is that only red light illuminates the stage. If you look at the filter with a white light behind it only red light arrives at the eye so it looks red.

    The plastic on a TV remote control is opaque to visible light but it is transparent to invisible infra red light so it can control the TV. The plastic is usually back but could be any colour. So it can be transparent to Infra Red, opaque to visible light but reflect any or all visible light.
     
  12. Dec 26, 2014 #11

    sophiecentaur

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    Very thin lays of very transparent materials can produce very intense colours by reflecting some wavelengths and transmitting others. There is (virtually) no absorption of energy within the layers all the light is either reflected or transmitted. (Interference Filters)
    Examples: Bird Feathers, Butterfly wings, Dichroic halogen lamps, which do not use pigments or dyes. Most familiar example is the bright colours from oil films on puddles of rainwater. Notice the colours are not 'rainbow-like' but very striking and unusual.
     
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