What colour is an orange in the dark

Discussion in 'General Science & Technology' started by mick, Oct 21, 2001.

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  1. EndLightEnd This too shall pass. Registered Senior Member

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    What pitch is a violin in a vacuum?
     
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  3. jpappl Valued Senior Member

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    It's orange.

    Is it not orange if we shine an artificial light on it and make it purple. No, because that same light on a banana would affect it's color as well.

    In normal light it is orange to us. The color is it's own, just like a green apple is green.

    If a tree falls in a forest it does make a sound even if it was to far away from us to hear, a dog sitting next to you probably did.

    The orange is orange and the tree falling makes a sound we know this from experience.
     
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  5. Oli Heute der Enteteich... Registered Senior Member

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    No.

    Define "normal light".
    We call it "orange" because that's what shows under the light we're used to.
    If the sun gave out a different range of frequencies (and we'd evolved under that) what colour would we consider the orange to be?
    The colour is NOT the colour of the orange at all. It's a combination of the orange, the frequency of ambient EM radiation and our receptors.
     
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  7. Saquist Banned Banned

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    In the absense of light the color is black.
    It's composition doesn't change.
    It's presence doesn't change.

    It's still there...It's still an orange but it's color is unpercievable.

    But this sounds like a bad joke.
     
  8. Enmos Valued Senior Member

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    Isn't the color of something established using 'normal' light i.e. sunlight ?

    Hmm I beg to differ.
    Colors are defined by wavelength alone.
    Light with a wavelength of 700nm, for example, is defined as red light.
    And what wavelengths an object reflects is entirely based on what the object is made of.
     
  9. Enmos Valued Senior Member

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    Yes, it's imperceivable. Are you saying that if something is imperceivable, it doesn't exist ?
     
  10. Oli Heute der Enteteich... Registered Senior Member

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    I think I may have expressed that badly (going out with family soon and keeping an eye on a certain thread

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    ).
    Orange is a human term used for our experience of the "colour".
    If we'd evolved under a different sun what would be "normal" for us?
    Meh, it mad sense to me before I started typing

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    I'll go and have a couple of pints of Guinness, that way it'll either make more sense or I won't care either way.

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  11. Enmos Valued Senior Member

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    I think I see what you're saying, but I don't think it has much relevance though.
    Anyway, have a good time! And have one on the Dominion

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  12. jpappl Valued Senior Member

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    Oli,

    Exactly, and before we had artificial lights that we could create we had sunlight. And that is normal light IMO as a baseline.

    Artificial light affects all colors, ever put paint on a wall and it looked good with sunlight and then turn on an incandesent or flourescent bulb, it changes. Sometimes looks like crap.

    But it doesn't. If it did, it would be a different color or hue. Who came up with the color orange I don't know but it's orange. What if the sun were green ?

    In our perception it is orange correct. What color is a lime in our perception with the above. Green.
     
  13. jpappl Valued Senior Member

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    Because we can't see it, we might as well ask is there an orange there at all ?

    But the question is what color is an orange in the dark. Since by experience we know what color the orange is in the light, then unless we are suggesting that in the dark the orange itself changes it's color to blue for example, then it is still orange.

    Once the light reveals the orange we then say or there's an orange. And what color is the freaking "orange".
     
  14. Oli Heute der Enteteich... Registered Senior Member

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    You're missing the point: (or I'm looking too deeply).
    The colour "orange" is a confluence of our perception and the prevailing conditions: "orange" is the interaction between us and an orange - not necessarily a property of the orange itself.
     
  15. jpappl Valued Senior Member

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    I understand where you are coming from but I think on these types of questions we over think it.

    In the end, it doesn't matter what the cause of the orange being orange is, it just is. Even if the properties of the orange is debated as to what causes it to have it's color, we still see it as orange.

    So I wasn't disagreeing or discussing why it is orange just that it is.

    We could ask, what causes an orange to appear orange ?

    That would be different.
     
  16. ripleofdeath Registered Senior Member

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    nice one !

    colour is a state of material physics.
    just like pitch.

    problem is society has become soo egocentric that they fail to grasp such concepts.
     
  17. Fraggle Rocker Staff Member

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    I think this is the crux of the question. What defines the color of an object? Is it A) The color we would observe if it were in normal solar-spectrum light, or B) The color we actually observe in the current conditions? If A, then the orange is always orange, but if B, then it's color varies and it is currently black--or perhaps very dark grey, depending on what you meant by "in the dark."

    I tend to go with B. There are too many things on this planet--especially man-made things--that change in appearance depending on the spectrum of the ambient light. I was instructed to wear black pants to a Christmas choir performance, and my wife (women are ALWAYS right about colors) picked out a pair from my closet. When I got to the company cafeteria under its peculiar lighting, they turned greenish-brown. Artificial dyes can be phosphorescent, absorbing light of one frequency and "reflecting" it back in another.
    The customary definition of "the dark" is "a space with so little solar-spectrum light that only the rods in the eyes react to the light and send signals through the optic nerve." It is the cones that discern color. The rods present a monochrome image in which everything is shades of grey.

    Of course "in the dark" can also refer to an area that is literally without light. That didn't seem like the correct interpretation of the question in the O.P., since in absolute darkness we would not even know the orange was there.
     
  18. ripleofdeath Registered Senior Member

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    our perception does not change the physics principals at work to define the "orange" as "orange" in colour.

    just as much as one might define radioactive waste(etc) as being not there while it is killing you.

    colour may be a witnessable product of spectral analysis however it does not stop it from being what it is and does not change it from being what it is.

    thus observation is completely pure and the actual state has not changed.

    the orange is a poison to something that is poisoned by it.
    yet is is also defined as food to us.
    reasonable doubt as far as perceptive interpretation surely cant go past basic physics as we currently understand them ?
     
  19. bluesea50 Registered Member

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    it will be dark orange haha
     
  20. Enmos Valued Senior Member

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    I go with A, because it makes sense to establish an objects color in the presence of light of all wavelengths. Otherwise, what's the point ? You have to have a standard.
    Also, the chemical composition of the orange determines what wavelengths will be reflected off it. If you shine a light composed of just one color on it, the orange will not reflect all the wavelengths it normally could. So the colored light only lets us see one aspect of the oranges appearance. Only the molecules that reflect the used wavelength will now reflect light, so it's not the whole picture.
     
  21. EndLightEnd This too shall pass. Registered Senior Member

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    "Orange" is just a reference to a specific wavelength of light we perceive as the color orange. The spectrum of light hitting the object does not change this specific wavelength reference in any way.

    If we are assuming it is completely dark and there is no light, then there can be no color. Color cannot exist without light transmitting that information. Hence my "pitch in a vacuum" analogy, if there are no sound waves there is no pitch.
     
  22. Oli Heute der Enteteich... Registered Senior Member

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    So if there were to be no light there wouldn't be any colour?
    So orange isn't actually a property of the orange, it's only orange because light "says" it is?
     
  23. Fraggle Rocker Staff Member

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    I would go further and say it's only orange because it appears that way to us.

    Forty years ago, when many old-fashioned men still wore plain white shirts to work, manufacturers were adding phosphorescent dyes to laundry detergent. Under sunlight and fluorescent office lights the dyes would absorb certain frequencies and reflect them back as extra blue light. This was culturally perceived as extra cleanliness, since white shirts tend to turn slightly yellow over time after absorbing body oils. Some of the advertisements called this new color "whiter than white." One of the brands of detergent was even honestly named "Rinso Blue."

    Of course household incandescent lights did not provide the right spectrum so there was no phosphorescence and the shirts continued to look yellow.
     
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