why is the sky blue?

Answer 1

The atmosphere is the mixture of gas molecules and other materials surrounding the earth. It is made mostly of the gases nitrogen (78%), and oxygen (21%). Argon gas and water (in the form of vapor, droplets and ice crystals) are the next most common things. There are also small amounts of other gases, plus many small solid particles, like dust, soot and ashes, pollen, and salt from the oceans.

The blue color of the sky is due to Rayleigh scattering. As light moves through the atmosphere, most of the longer wavelengths pass straight through. Little of the red, orange and yellow light is affected by the air.

However, much of the shorter wavelength light is absorbed by the gas molecules. The absorbed blue light is then radiated in different directions. It gets scattered all around the sky. Whichever direction you look, some of this scattered blue light reaches you. Since you see the blue light from everywhere overhead, the sky looks blue.

As you look closer to the horizon, the sky appears much paler in color. To reach you, the scattered blue light must pass through more air. Some of it gets scattered away again in other directions. Less blue light reaches your eyes. The color of the sky near the horizon appears paler or white.

Answer 2

OK, FORGET AAAAALLLLLLL Of The Other "Answers" if you would suspend your disbelief for just one moment, THEN, and only then will you see the ACTUAL Truth!

You see, ALL of these other answers here on Yahoo Answers, and on Wiki, and Google, Bing, and just about everywhere else, if you take close notice at the actual answers, you will just see that they are all the same answers about some sort of refraction and color of the oxygen science thingy type thing...all FAAAAR too Shmancy if you ask me!!! LOL!

The only REAL TRUTH (only for those actually seeking the real truth) is that the Sky is Blue is because water looks blue! Period!

Now, because we have a tried & very well tested Firmament (dome) over the top of our beautiful round, flat disk that we like to call home, and directly over the top of the Firmament, there is a very thick layer of water of which contain the Sun & the Moon, both of equal size, about 32km in diameter, it is that very water which makes the Sun & Moon & other so-called "planets" in our night sky look as if they are either inside or directly behind the very properties of water, and it is this same water which ALSO makes the sky look beautifully light blue in the Daytime!

END OF STORY!!

Answer 3

The sky isn't necessarily blue, as the only truly existent colors are black and white. [Black being no color, white being all.] Color is an optical illusion, therefore, the blue of the sky is this, too.

The light of the sun hits reflective objects below, plus passes through clouds. In doing this, the light hits the sky, and, as light is white, AKA all colors, it takes the material of the air and transforms it into blue. The sky, or air's, whatever you want to call it, material or whatever it's called in this reference, is, what one might say, "coded" for that specific color it is.

Remember that this is my own words; I'm making a theory out of all the things I already know and just guessed about. Don't take this too seriously.

Answer 4

A clear cloudless day-time sky is blue because molecules in the air scatter blue light from the sun more than they scatter red light. When we look towards the sun at sunset, we see red and orange colours because the blue light has been scattered out and away from the line of sight.

Answer 5

oxygen is clear. If oxygen was blue then at night the sky should stay blue. And the sun should shine blue. the sky is not blue from any type of atom in the sky. Nobody have not explain or found the truth yet. But I have

Answer 6

So many answers are overloaded with science stuff because they came from teachers trying to teach you the science of refraction. That's silly and it confuses more than it answers the question. The simple reason is that oxygen is blue. I've seen a flask of liquid oxygen and sure enough it is blue. Liquid nitrogen which makes up about 3/4 of the rest of the air is clear. Of course you need a lot of oxygen in front of you to see the blue. When you're looking up you're looking through about 0.21*14.7 = 3 pounds of the stuff. So why is it blue? For the same reason leaves are green and cherries are red. Because it absorbs other colors more strongly.

Answer 7

Blue light is scattered in all directions by the tiny molecules of air in Earth's atmosphere. Blue is scattered more than other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time.

Answer 8

This question has been asked over 5000 times, and I've prepared a simple answer, without too much science:

The correct answer is that the blue light is scattered by the air molecules in the atmosphere (referred to as Rayleigh scattering). The blue wavelength is scattered more, because the scatteing effect increases with the inverse of the fourth power of the incident wavelength.

OK, but I've known science graduates who don't understand what this means.
Here's my attempt at an answer without too much physics:

I think most people know that sunlight is made up of light of several different wavelengths, and can be split up into the colours of the rainbow. Blue light has the shorter wavelength, and red the longest wavelength.

When sunlight hits the molecules in the atmosphere, the light strikes the molecules and is absorbed, causing the molecules to vibrate and give off, or 're-emit' the light. It's not the same as reflection, but the effect is similar. The molecules in the air are much smaller than the wavelength of visible light, but because the blue wavelength is shorter and more energetic, it reacts much more with the air molecules than the red and yellow wavelengths; which tend to pass straight through.

Because the blue radiation is re-emitted from the air molecules in all directions ('scattered'), it seems to us looking from the ground that the blue light is coming from everywhere; hence the sky seems blue.

Near sunset, because of the low angle of the sunlight, we see more of the red and yellow wavelendth passing straight through, hence the colours of the setting sun.

BTW: The sky isn't blue because of a reflection of the sea; its the other way round, although the blue colour of the sea is mostly caused by the water molecules scattering the blue light, in a similar way. This effect is even stronger with ice; which results in the intense blue colour we see if we look down a crevasse in a glacier, or down a hole in the snow made by a ski stock..

For a complete, scientific explqanation, look up 'blue sky' in Wikipedia.

Answer 9

reflects water

Answer 10

Because of the ocean

Answer 11

Hope this helps!