Subject:
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Re: Why the sky is blue (was: Re: Libertarian SPAM (Propaganda))
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Newsgroups:
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lugnet.off-topic.debate
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Date:
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Tue, 19 Jun 2001 21:26:31 GMT
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Viewed:
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1505 times
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In lugnet.off-topic.debate, Jeff Jardine writes:
> In lugnet.off-topic.debate, Shiri Dori writes:
> >
> > Yep... the molecules in the atmosphere are the ones causing the sky's blue
> > appearance. That's also why the sun appears yellow on the background of the
> > sky (blue and yellow are complementary/opposite on the RGB scale, which is
> > what our eyes use). In outer space, in near-vacuum, nothing reflects the
> > light; the sky is black and the sun is white.
>
> Well... the colour of the Sun will be subjective to how each individual
> perceives colour, but it's peak output definitely lies in the range
> that most people would call yellow. It is a whitish-yellow, because the Sun
> also radiates at all other wavelengths.
>
> The Sun (and stars and other celestial objects) really do have colour. If you
> look at the night sky, all the little points of light look white. If you
> stare long enough, Betelgeuse (which is cooler than the Sun) will appear red
> and Sirius (which is hotter than the Sun) will look blueish.
>
>
> > As for ocean and lake water - they are blue because of the sky's reflection.
> > Not the other way around (NOT the sky is blue because water reflects in it).
> > Water in itself, if you look at a cup inside your house, is entirely clear.
>
> Ah, but if you look at a cup full of air, it also appears clear. It just
> takes a whole lot of air (or water) before it will look blue, because
> very little of the blue light passing through the air (or water) is scattered.
>
> If you look at a lake or the ocean on a completely grey day, it will still
> appear blue.
Art 101: large bodies of water take on the color of the sky. If the sky is
gray, the water is gray, not blue. Lemme see....
http://www.enchantedlearning.com/subjects/astronomy/planets/earth/Oceans.shtml
Scroll down a bit - they even use the gray sky/gray water in the example.
Bruce
(Arrrrrrrrrrrrrgh! I've become anal-retentive! Auuuuuuuuughhhhhh!)
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Message has 1 Reply:
 | | Re: Why the sky is blue
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| (...) That is misinformation! Water DOES have an intrinsic blue colour: (URL) Learning" indeed! However, I must apologise for my earlier starement that the bluish tinge of water is due to scattering. It is due to selective absorption (there's the (...) (23 years ago, 20-Jun-01, to lugnet.off-topic.debate)
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