Sky

[Prophet Peer]

Y is the sky blu.

N y it darker the further up into space u go?

sorry if simple questions. Just dunno.

[Freethinker]

Hi Prophet. Welcome to our discussions. Yes the question is simple, but the answer can be very complex. Depending on how far into it you wish to go.

 

First, "color", such as the color blue, is a figment of our imagination. It doesn't exist in nature. Color" is a function of how our brains interpret information from our visual system. Chemical reactions caused by photons hitting our eyes cause electrical signals that are passed to the brain. Our "conscious mind" presents a picture to us which we interpret as, amoung other things, colors.

 

Energy is contained in what we call the electromagnetic (EM) spectrum. This includes other information such as radio and TV signals and now wifi network connections. The electromagnetic spectrum covers an extremely wide range of frequencies (how many oscillations in a period of time). EM in a narrow band of frequencies, as stated above, is picked up in our eyes and we call it "light". When the EM contains a wide range of frequencies, we see "white light", such as from the sun or light bulbs. When the light consists of a specific or vary narrow band of frequencies, we see it as individual colors.

 

Certain materials can filter (either reflect or absorb) the wideband white light into these narrow bands. A car may have chemicals (paint pigments) that reflect specific frequencies and we "see" a blue or red car and absorb all the rest. Or a piece of plastic or glass may be tinted to only allow certain frequencies/ colors to come thru. It absorbs the rest.

 

The sky, our atmosphere, has a certain density of specific gasses and molecules. And is a specific distance from the surface of the earth. This combination of matter and it's mass has specific filtering properties. The sun generates white light. The sky allows some colors to pass thru without my filtering. It blocks/ reflects some frequencies completely. For a specific band of frequencies/ colors, it scatters the energy/ photons. The scattering of these photons cause a "glow" from the energy being scattered/ absorbed. The frequency/ color this happens at is "blue".

 

If you watch the sun rise or set however, because the sun's light has to pass thru more atmosphere, the frequency absorbed/ scattered has a longer wavelength/ lower frequency. This relates more to the color red.

[deamonstar]

a very detailed explanation, Freethinker.

Prophet Peer, our atmosphere could also be thought of simply as a large prism. at certain angles that the suns light passes through, the light is split into different colors. when the sun is high overhead, we see the shorter wavelenght EM (light) as blue. and so with the light passing through the atmosphere at a shallower angle near sunrise or sunset as the longer wavelength of red.

as to why it appears to get darker as you approach the boundry of space... the less atmosphere that there is, the less readily that the light can be scattered as with the "prism effect" so colors are less appearant until there is no more atmosphere when we see blackness (or it can be said that there is nothing to reflect, absorb, filter or scatter the suns light which is actually there in more than abundance (unless, of course, you happen to be in the earth's shadow (the night side). in which case there is no light to be reflected, absorbed, filtered or scattered)).

[wepe]

Peer, dont listen to freethinker, he is only going to confuse you more. he thinks color doesnt exist.

dont listen to any of that i already know, you confused, so was I. The reason why our sky is blue, is because when the light from the sun reaches our atmosphere (sky) it

is bent, or distorted by all of the particles in the atmosphere (sky), like oxygen, carbon minoxide, polution, like car exost, and all of that stuff. when the sun is low in the horizon

the sky is that reddish color because the light has to pass through sooo much more atmosphere because of that low angle, its not over head like in mid-day, so it has to pass through so much more. Now, there is something called an electromagnetic spectrum, its also known as the 'light spectrum'. its basically all the different colors of light. A rainbow is a good example of the visible light spectrum, its sun light comming into the atmosphere passing through all the particles in our sky, but what makes it that wide aray of colors, is because theres moisture in the air (water), and when light passes throught water it shows all the colors,

alot like on the pink floyd t-shirt, where is shows white light passing through a prism and comming out the other end as a rainbow. thats an example of our atmosphere and sun light, the light passes throught and comes out as a different color, because its bent. There is more to the light spectrum than the eye can see, like UV light, gamma rays, and inferred light.

[Freethinker]

Originally posted by: wepe

Peer, dont listen to freethinker, he is only going to confuse you more. he thinks color doesnt exist.

...when light passes throught water it shows all the colors, alot like on the pink floyd t-shirt,

Your right. How foolish of me! Of course a "pink floyd t-shirt" is so much more accurate of an explanation!

 

Is a white or black T shirt more accurate?

 

What about different sizes? Does a Small have fewer colors than an XXL?

 

IS a 100% cotton shirt more or less accurate than one with some polyester in it?

 

"Color vision

 

It is important to note that we do not see color but the interaction of information being supplied from rods (black/white) and cones (red/green or blue/yellow opponent process). The information is sent to the primary visual cortex where different cells respond to inputs of different color. How much stimulation and where defines the reported psychological perception of color. Millions of lighting and color levels can be recognized. It is likely that the red you see does not generate the same psychological experience of redness for another person."

 

http://encyclopedia.thefreedictionary.com/color%20vision

 

"Color in Astronomical Images

 

color, and its perception by humans, is subjective because of its interpretation by the brain... In some sense, our perception of colors can even be considered an "illusion"... To quote from Oliver Sacks, clinical neurologist, in his book An Anthropologist on Mars, these illusions "demonstrated a neurological truth - that colors are not 'out there in the world', nor (as classical theory held) an automatic correlate of wavelength, but rather, are constructed by the brain."

 

http://www.astropix.com/HTML/I_ASTROP/I14/I14.HTM

 

Strictly speaking, the colors that you see are not in the emitting substances, or even in the light that they reflect because color is a *physiological* experience and therefore dependent on the individual viewing the object. Color is in your head. So an apple *appears* red, the setting Sun *appears* orangish-red, and so on. (Paul Hewitt, Conceptual Physics)

[Uncle Martin]

I agree completely with FT's above post. Color DOES NOT EXIST! It is all our perception. There is way too much info if you just do a google search for me to elaborate more. Now you have to say don't believe FT and Unc, I dare you.....

[wepe]

ahaha are you serious, well explain to me, the visual spectrum? please, explain to me the other types of light and how they differ in there wave lengths. stop smoking pot and hanging out with your older sister. and Unc, is a google search the best you can do?

[wepe]

color is not something that is there just because thats the way we want to precieve it.

[wepe]

Its what the "pink floyd t-shirt" was representing, i was trying not to approach it with dynamics, just keeping it simple, for him to understand.

[wepe]

"First, "color", such as the color blue, is a figment of our imagination. It doesn't exist in nature. Color" is a function of how our brains interpret information from our visual system. Chemical reactions caused by photons hitting our eyes cause electrical signals that are passed to the brain. Our "conscious mind" presents a picture to us which we interpret as, amoung other things, colors."

 

What are you talking about? what is this? none of this makes sense at all

[Tim_Lou]

sorry, wepe, yes color doesnt exist...

 

imagine some whatever animals are able to see TV singles, the long waves.... that means long waves is a type of color to that animal...

 

would we say long wave is a color? no... color doesnt exist.

[wepe]

Wow, its not even a scientific argument anymore. Due to how you put it, its just how one goes about defining the word color. QUOTE “would we say long wave is a color? no... color doesnt exist.” Look, im not saying that color exists as a massive object. I don’t get how you people can say color isn’t there ”existing” when everything we look at reflects back with color.

[Freethinker]

Originally posted by: wepe

Wow, its not even a scientific argument anymore.

Well, you couldn't handle the scientific ones, so Tim tried something different.

I don’t get how you people can say color isn’t there ”existing” when everything we look at reflects back with color.

1) not everything REFLECTS, some things are light sources.

 

2) Not everything "reflects back with color". Somethings are neutral, NO color.

 

3) NOTHING has color until it passes thru the human visual system and creates an image in our consciousness. Color is all in our mind. (Back to square one)

[Tim_Lou]

definition from website: http://www.dictionary.com

 

"ex·ist ( P ) Pronunciation Key (g-zst)

intr.v. ex·ist·ed, ex·ist·ing, ex·ists

To have actual being; be real.

To have life; live: one of the worst actors that ever existed.

To live at a minimal level; subsist: barely enough income on which to exist.

To continue to be; persist: old customs that still exist in rural areas.

To be present under certain circumstances or in a specified place; occur: “Wealth and poverty exist in every demographic category” (Thomas G. Exter). "

 

maybe you wanna check out reality in the other group....long time ago though...

(dont mean any offend)

[wepe]

QUOTE : "Well, you couldn't handle the scientific ones"

 

Lets refrane from comments like that one just because they dont serve any purpose

[IrishEyes]

Lets refrane from comments like that one just because they dont serve any purpose

 

Everyone needs to take a deep breath, ok?

 

wepe, while I agree that the comment you quoted from Freethinker ("Well, you couldn't handle the scientific ones") was far from necessary, I hope that you can understand why he made it. He seems rather frustrated that you are having a difficult time comprehending what he is trying to explain. Sometimes the explanations that we may get do not seem to make a whole lot of sense because we have never been given the correct information. I urge you to take a step back from the conversation and let the information that Freethinker and Tim have given you settle into your head for a bit. Do some research into what they are saying. If you disagree with them still, do a Google and try to prove that what they are saying is incorrect. I think that, after you have thought about what they have presented, anc studied/researched what they have given you, you will understand that while the presentation of the information could have been made in a different way, the information itself is still very valid.

 

Freethinker, while your sarcasm is very often the thing that keeps discussions interesting, I hope that by re-reading this you will also see how wepe was offended by your comment. Your posts would have been just as effective without that little jab.

[IrishEyes]

ahaha are you serious, well explain to me, the visual spectrum? please, explain to me the other types of light and how they differ in there wave lengths. stop smoking pot and hanging out with your older sister. and Unc, is a google search the best you can do?

 

While I'm in this thread...

 

wepe, I must not have read this as close as I should have. Your comments are also highly uncalled for, and much more offensive than what Freethinker said. Leave it alone after the questions and you'll be ok. But if you continue to make remarks like the one quoted here about ANY of our members, you'll need to find a new place to ask your questions. And FYI, Uncle Martin was more than correct in telling you to go to Google. No, it's not 'the best he can do', but he is not your 10th grade science teacher, and therefore not responsible for explaining everything to you. You are posting in a science forum. If you don't understand something, PLEASE ask. But don't expect people to explain everything when the information is readily available by typing a question into a search engine. You are responsible for using your brain. Don't expect anyone else to do it for you.

 

Freethinker, thank you for showing restraint and not tearing into wepe after the 'pot-smoking' comment. You displayed much more self-control than I gave you credit for, forgive me?