why is the sky blue?

Answer 1

Everyone's gonna say "reflection of the ocean". NO! The sun gives off all types of light in the spectrum, and surprisingly to most people it gives off a LOT of "blue" light. Now our atmosphere absorbs a lot of this blue light making it appear blue.

Answer 2

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 3

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 4

The sky is blue partly because air scatters short-wavelength light in preference to longer wavelengths. Where the sunlight is nearly tangent to the Earth's surface, the light's path through the atmosphere is so long that much of the blue and even yellow light is scattered out, leaving the sun rays and the clouds it illuminates red, at sunrise and sunset.

Scattering and absorption are major causes of the attenuation of radiation by the atmosphere. Scattering varies as a function of the ratio of the particle diameter to the wavelength of the radiation. When this ratio is less than about one-tenth, Rayleigh scattering occurs in which the scattering coefficient varies inversely as the fourth power of the wavelength. At larger values of the ratio of particle diameter to wavelength, the scattering varies in a complex fashion described, for spherical particles, by the Mie theory; at a ratio of the order of 10, the laws of geometric optics begin to apply.

Individual gas molecules are too small to scatter light effectively. However, in a gas, the molecules move more or less independently of each-other, unlike in liquids and solids where the density is determined the molecule's sizes. So the densities of gases, such as pure air, are subject to statistical fluctuations. Significant fluctuations are much more common on a small scale. It is mainly these density fluctuations on a small (tens of nanometers) scale that cause the sky to be blue.

Answer 5

A similar question was asked a few weeks ago. I will give you the same answer briefly: " It is not always blue. Have you not ever seen a grey sky?" By the way soon winter will come and the blue sky will be more rare most parts of the world!

Answer 6

Because of the way light scatters off molecules in the atmosphere. During the middle of the day, the angle of incidence of light is directly above and as such a beam of light will travel trough the least amount of air to get to the earth's surface. During this time gas molecules will absorb this light and re-emit it as a bluish colour. These remited light particles don't have to pass through much air (dust/particles) and so they generally don't get too scattered so what you see are those blue light rays.

If you look towards to horizon (rather than straight up) you will see it's much paler and less blue (more whitish). What happens here is that the light is actually travelling through more air (more particles that can scatter light) to get to you. (draw two circles one inside the other, draw a line at 90degrees to the circle and one at 45, and measure how much of each line is within the two circles - to 90'deg will be shorter). Anyway, since it passes through a lot more dust/particles it gets scattered more and more and what actually happens is that you see less and less of that blue light. When you look above you see all of it.

During a sunset, the sun is line with the horizon so all the light coming to you is taking a longer route through the air. The blue light is still made but it gets scattered a heck of a lot. The red's and the oranges don't get absorbed and aren't scattered as much so that's why we see red and orange. When there is a huge volcanic eruption in the world, billions of tonnes of ash get thrown into the atmosphere. When this happens an icredible amount of scattering (of the blue rays) take place and this leads to incredible sunsets, very deep red.

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. If shorter wavelengths are scattered most strongly, then there is a puzzle as to why the sky does not appear violet, the colour with the shortest visible wavelength. The spectrum of light emission from the sun is not constant at all wavelengths, and additionally is absorbed by the high atmosphere, so there is less violet in the light. Our eyes are also less sensitive to violet. That's part of the answer; yet a rainbow shows that there remains a significant amount of visible light coloured indigo and violet beyond the blue. The rest of the answer to this puzzle lies in the way our vision works. We have three types of colour receptors, or cones, in our retina. They are called red, blue and green because they respond most strongly to light at those wavelengths. As they are stimulated in different proportions, our visual system constructs the colours we see.

Answer 8

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 9

Why is the sky blue? This question has been asked for nearly 1 000 times here in Y!Q&A. Check out this link showing search results for the same question or related to it: http://answers.yahoo.com/search/search_result;_ylt=AmTfvfPTfrRC7.BrpnDXq5Hzy6IX?p=why+is+the+sky+blue%3F+

Answer 10

Because the sky changes depending on mood!