Skat Bo said:
*Stares blankly at computer screen, waiting for a correct answer (Though ardvarks is close) *
Atmospheric Attraction (of) Aardvarks!
Yes!
I win!
(umm...I better be careful....sometimes you get what you wish for...and...umm...(I'm ashamed)....I was just now wishing that Rebecca Romajn would show up on my doorstep, naked, covered in caramel and fudge...)
(is that what I won?
)Kewl.
That was the prize originally....but then she showed up on my doorstep to be delivered to you...and...uh, she was 'lost in technical difficulties, so you get a free hotel pen from a motel Eight (Go over to pick it, but don't tell anyone - just pick it up and run - it's like a game 
)
Now, c'mere Rebecca...Where'd your shirt go...!!! Look at those!
)Now, c'mere Rebecca...Where'd your shirt go...!!! Look at those!
Lol, I must be tired because that whole muggle bit had me laughing harder than anything else today .
Atmospheric Attenuation is simple enough, though a big enough word to make you sound all intelligent.
Quite simply, the atmosphere is such that it blocks all frequencies of light (Which would be visible light *Color*) except one. This particular frequency is the one for the color blue - so the reason the sky is blue is because out of all the colors that come down at us, blue is the only one that can make it through.
.Atmospheric Attenuation is simple enough, though a big enough word to make you sound all intelligent.
Quite simply, the atmosphere is such that it blocks all frequencies of light (Which would be visible light *Color*) except one. This particular frequency is the one for the color blue - so the reason the sky is blue is because out of all the colors that come down at us, blue is the only one that can make it through.
That doesn't sound right. If the atmosphere blocked all frequencies but blue, then the sun would look blue (only the blue wavelengths of the sun's light would make it to our eyes - all the other wavelengths would be blocked).Skat Bo said:
Now if the light that was blocked was just reflected back into space, or absorbed, the sky would be black. In fact we wouldn't have colour vision at all - we would just see in monochrome (different intensities of the blue light). At the Earth's surface, there would only be one sort of light, and that would be blue.
ceptimus.
Stimpson J. Cat
Graduate Poster
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As Tez pointed out, it is scattering. Without scattering, the whole sky would be black, except where the sun is.
The scattering causes some of the light from the sun to be bounced around and redirected in the atmosphere. This results in light coming from the whole sky. Higher frequencies are scattered more by the air than lower ones. Since blue light is scattered more that the lower frequencies, the sky appears blue. It does not appear violet simply because the human eye is far more sensitive to blue light than to violet light.
At least, that is what my Mama always told me.
Dr. Stupid
The scattering causes some of the light from the sun to be bounced around and redirected in the atmosphere. This results in light coming from the whole sky. Higher frequencies are scattered more by the air than lower ones. Since blue light is scattered more that the lower frequencies, the sky appears blue. It does not appear violet simply because the human eye is far more sensitive to blue light than to violet light.
At least, that is what my Mama always told me.
Dr. Stupid
zer0vector
Scholar
- Joined
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- 89
My astro professor always said once you understand why the sky is blue, the natural followup is "Why isn't it purple?" Stimpy made a good point about the human eye not being as sensitive to violet light, but another good (and related reason) is that the sun doesn't put out much light in the violet. The sun is pretty close to a blackbody, and its frequency peak is in the yellow (thus the color we see it at), but the brightness drops off drastically away from the peak. Thus there just isn't enough violet light there to be scattered.
On an semi-related, evolutionary note, the reason the human eye isn't sensitive to violet light is because the sun doesn't emit much at those wavelengths.
On an semi-related, evolutionary note, the reason the human eye isn't sensitive to violet light is because the sun doesn't emit much at those wavelengths.
I thought our eyes had cones sensitive to three colour ranges, centered on red, green and blue. There is some overlap between the ranges of course.
I suppose what we call 'blue' activates the blue receptors, and the green ones a bit too.
What we call 'violet' must activate only the blue sensors and not the green.
So when we say we are seeing violet, our eyes are really seeing 'pure blue'!
ceptimus.
I suppose what we call 'blue' activates the blue receptors, and the green ones a bit too.
What we call 'violet' must activate only the blue sensors and not the green.
So when we say we are seeing violet, our eyes are really seeing 'pure blue'!
ceptimus.
zer0vector
Scholar
- Joined
- Jun 25, 2003
- Messages
- 89
Using Wien's law, which relates the temperature of a blackbody and the peak wavelength:
lamda = (0.0029 m K)/T
With T= 5800 K for the sun, lamda equals about 500 nm. This lies between the commonly defined green and yellow, known in highly scientific circles as yellow-green. My statement about the sun being yellow was slightly off, because I'd been too lazy to do the calculation.
lamda = (0.0029 m K)/T
With T= 5800 K for the sun, lamda equals about 500 nm. This lies between the commonly defined green and yellow, known in highly scientific circles as yellow-green. My statement about the sun being yellow was slightly off, because I'd been too lazy to do the calculation.
Stimpson J. Cat said:
I had thought that it was also because the scattering was so strong for the higher frequencies, the intensity from any particular direction was relatively very low. This explains why sunsets are red. Light has to pass through more atmosphere which leads to more scattering. Only reddish colours are transmitted with a significant intensity. Presumably, there is also a significant dependence of the absorption on wavelength and thickness.
Earthborn
Terrestrial Intelligence
Booh!
Very wise!
That's just an explanation of the mechanisms. God could have chosen any mechanism, to make the sky any colour he wants. It is not the ultimate answer 'why'.
The ultimate 'because' is: God likes blue. That's why He created it blue.Of course God likes many other colours too, so many other things are in other colours.
"So why didn't God make it in another colour?"
Well, if He did, you would be asking pretty much the same question, wouldn't you? He had to choose a colour for everything and He just happened to choose blue for the sky, and green for the plants, white for the clouds, red for roses, etcetera.
But he had to choose a specific colour for everything because if he didn't, everything would have looked the same muddled colour. And God does not like that.
The fact that things don't all have the same muddled colour makes it easier for us to recognize things too. If everything had a muddled colour, God had to give us something different than colour vision to make sense of the world, like echo-location like bats have. But than you would still ask a similar question: "Why does the sky not return an echo?", and the physicists on this board would give you a scientific explanation for that.
So the reason is that God had to chose one colour, he could have chosen anyone, it wouldn't have made much difference, but he chose blue.
"But why couldn't he made a different colour everyday?"
Because that would violate the number one rule in interface design: give the user the impression of stability.
You see, the world as we experience it is just the human-world interface. Deep down at the actual mechanisms of the world, things are a lot more fuzzy and chaotic, as the physisists on the forum will admit. So God had to create a userfriendly interface for the people he created, or else they would have had great difficulty interacting with the world. By presenting us with a stable looking world, we were able to do things with it that would be difficult if we had to consider all the unpredictable reactions that govern the world at low level.
A paranormal event is just when the world has a 'general protection fault'. Pretty stable so far!
However, to remind us what wonderfull colours the sky could have had, God created the rainbow, showing us pretty much every colour He likes.
He has noticed however that humans were very disappointed that the rainbow doesn't appear more often, so He created the omnipresent Compuserve Subscription CD. Whereever you go, you will be able to see it's wonderfull iridescent colours.
I hope that answers your question.
RSLancastr
www.StopSylvia.com
Alcoholics Anonymous?Skat Bo said:
American Airlines?
Armande Assanti?