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Thread: What color is the sun?

  1. #51
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    Quote Originally Posted by The_Doctor View Post
    Science falls back too readily on its models, especially when looking at what it thinks is old territory.
    I concour and believe that some physics assumptions will be turned on their head at some point, maybe when the LHC starts churning out data?
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  2. #52
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    I wouldn't call our brains bad at color perception. They simply adapt to the environment, which is a good thing. Unless you're in color science...

    Now on a more serious note, I'd argue that if we had perfect eyes and wanted to assign a hue to the sun it should be red or orange, not yellow. Why? Well, look at the solar spectrum. There's about twice as many red photons as green photons.

  3. #53
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    If a laser projector had 100mW of red and 50mW of green, would that be red as well?

  4. #54
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    What color is a white piece of paper?



    --John

  5. #55
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    Quote Originally Posted by Xytrell View Post
    If a laser projector had 100mW of red and 50mW of green, would that be red as well?
    To perfect (ideal) eyes, the hue would be more to the red, yes. By ideal I mean that the response is directly proportional to the incident photon flux. Since in that particular case there's about 2.5 times as many red photons as green photons I would argue that it should be a lot more to the red.

    Human eyes are of course far from ideal. We are quite poor at seeing red light and we are merely trichromatic.

    Quote Originally Posted by wolfblue View Post
    What color is a white piece of paper?



    --John
    Objection, leading question! Besides, paper usually contains whitener (a compound with blue fluorescence), effectively making it an active optical component. It changes the spectrum of the reflected light!

  6. #56
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    Quote Originally Posted by tocket View Post
    Objection, leading question! Besides, paper usually contains whitener (a compound with blue fluorescence), effectively making it an active optical component. It changes the spectrum of the reflected light!
    And its a easy matter to find whitener with your 405nm diode. Paper(and my socks) would look a little yellow without it. Just the nature of the plant fiber( maybe paper is made from yellow pine

    But what color is white styrofoam?

    --John

  7. #57
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    Nobody?

    Styrofoam is the same color as the light that strikes it.

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  8. #58
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    Styrofoam can also be black and yellow, if it's on fire.

  9. #59
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    Stars don't have "a" colour. They emit EM radiation due to a number of processes involving several elements' emission and absorption characteristics. They can be more one wavelength than another by merit of overlapping power spectra, but the atmosphere distorts that big-time, and our eyes are far from having a flat response across the visible region. (And the sun is most certainly not a black body!)


  10. #60
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    Quote Originally Posted by smokeAndMirrors View Post
    Stars don't have "a" colour. They emit EM radiation due to a number of processes involving several elements' emission and absorption characteristics. They can be more one wavelength than another by merit of overlapping power spectra, but the atmosphere distorts that big-time, and our eyes are far from having a flat response across the visible region. (And the sun is most certainly not a black body!)


    The same can be said for a red lightbulb, or a green lightbulb etc etc.

    The nitty gritty of this topic here, is really about what we perceive as white, which as it happens; is almost any dominating colour that we're enveloped with for long enough, our brains just have to set a white balance..

    Ian
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    Doc's website

    The Health and Safety Act 1971

    Recklessly interfering with Darwin’s natural selection process, thereby extending the life cycle of dim-witted ignorami; thus perpetuating and magnifying the danger to us all, by enabling them to breed and walk amongst us, our children and loved ones.





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