why is the sky blue?

Answer 1

It was Einstein who answered this question. It has to do with the way sunlight is scattered by the molecules in the atmosphere. Blue light scatters more than red (Tyndall effect also known as Rayleigh scattering), so more blue light reaches our eye.

There is an excellent description at the website listed below (look at the cartoon and it will be pretty clear).

It is not a reflection from the ocean. And it isn't just water molecules that cause the effect.

Aloha

Answer 2

The sky appears blue during the cloudless day because the molecules in the air scatter this wavelength of light more than red light. At sunset, all the blue light was scattered out, so we see the sky orange/pink/reddish.

Actually, the light from the sun is white, as it is all the colours together, according to what Isaac Newton discovered using a prism to separate the colours of the sun light. He then formed a spectrum, each colour having its own wavelength, red's being 720 nanometers (nm) and violet's 380 nm. In between, there are all the colours of the rainbow.
The colours we perceive most easily are green, red and blue.

In 1859, a scientist called John Tyndall discovered that when the light passes through a fluid (with particules in suspension), the shorter wavelenghts are scattered more strongly. You may also have heard of this under the name of Rayleigh scattering. This name has been given because this man showed that the factor of blue light scattering to red light scattering is (700/400) to the power of 4, which is about 10.

Now, you may wonder why, in this case, the sky is not violet, as this is the shortest visible wavelength. Actually, the sun light is poorer in violet, and this wavelength is absorbed in the atmosphere. Also, our retina is less sensitive to violet than to blue, so we do not the sky as it is really. We see it in a light blue colour, but really, it is more violet.

Answer 3

It is easy to see that the sky is blue. Have you ever wondered why? A lot of other smart people have, too. And it took a long time to figure it out!
The light from the Sun looks white. But it is really made up of all the colors of the rainbow. A prism is a specially shaped crystal. When white light shines through a prism, the light is separated into all its colors.
If you visited The Land of the Magic Windows, you learned that the light you see is just one tiny bit of all the kinds of light energy beaming around the Universe--and around you!
Like energy passing through the ocean, light energy travels in waves, too. Some light travels in short, "choppy" waves. Other light travels in long, lazy waves. Blue light waves are shorter than red light waves. All light travels in a straight line unless something gets in the way to--


reflect it (like a mirror)

bend it (like a prism)

or scatter it (like molecules of the gases in the atmosphere)

Sunlight reaches Earth's atmosphere and is scattered in all directions by all the gases and particles in the air. 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.Closer to the horizon, the sky fades to a lighter blue or white. The sunlight reaching us from low in the sky has passed through even more air than the sunlight reaching us from overhead. As the sunlight has passed through all this air, the air molecules have scattered and rescattered the blue light many times in many directions. Also, the surface of Earth has reflected and scattered the light. All this scattering mixes the colors together again so we see more white and less blue.

and if u want pics go to
http://spaceplace.nasa.gov/en/kids/misrsky/misr_sky.shtml

Answer 4

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 5

Its to do with scattering and wavelength of various colors in the light.
Light travels through space in a straight line as long as nothing disturbs it. As light moves through the earth's atmosphere, it continues to go straight until it bumps into a bit of dust or a gas molecule. Then what happens to the light depends on its wave length and the size of the thing it hits.

Dust particles and water droplets are much larger than the wavelength of visible light.
When light hits these large particles, it gets reflected, or bounced off, in different directions. The different colors of light are all reflected by the particle in the same way. The reflected light appears white because it still contains all of the same colors.

Gas molecules are smaller than the wavelength of visible light. If light bumps into them, it acts differently.
When light hits a gas molecule, some of it may get absorbed.

After awhile, the molecule radiates (releases, or gives off) the light in a different direction. The color that is radiated is the same color that was absorbed.
The different colors of light are affected differently. All of the colors can be absorbed. But the higher frequencies (blues) are absorbed more often than the lower frequencies (reds). This process is called Rayleigh scattering

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.

Answer 6

It is because blue light is scattered more by molecules in the sky (e.g. oxygen and nitrogen). The sun produces rays of white light. White light is made up of Red, Orange, Yellow, Green, Blue, Indigo and Violet - the colours of the spectrum. For some reason which is probably very technical (it's to do with the wavelengths of light), blue light reacts more with the molecules and particles in our atmosphere and it is "scattered" most. At sunset when the sky is red/orange, this is caused because the blue light rays have been scattered so much that they have been worn out and so we start to see the other colours - red/orange/yellow because they have not been scattered as much as the blue.

It is NOT a reflection of the sea!!

Answer 7

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.

The white light from the sun is a mixture of all colours of the rainbow. This was demonstrated by Isaac Newton, who used a prism to separate the different colours and so form a spectrum. The colours of light are distinguished by their different wavelengths. The visible part of the spectrum ranges from red light with a wavelength of about 720 nm, to violet with a wavelength of about 380 nm, with orange, yellow, green, blue and indigo between. The three different types of colour receptors in the retina of the human eye respond most strongly to red, green and blue wavelengths, giving us our colour vision.

Answer 8

It has something to do with the distance of the UV rays. A lot of colors can only go so far in the universe, we get ours from the sun I believe. But the only one strong enough to make it here is blue, so the sky is always the shade of blue.

Answer 9

define blue! blue could be green and red could be yellow, and if you really thought about your qustion the sky is every colour you can think of sun sets clouds night time

Answer 10

It is blue because of the ozone layer. The ozone layer is a mixture of 3 oxigen atoms that´s why it gets a light blue color