very simple question...why does clear sky always have blue colour?
916826
"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.\n\nHowever, 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. "
804432
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. \n\nHowever, 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. \nOn Earth, the sun appears yellow. If you were out in space, or on the moon, the sun would look white. In space, there is no atmosphere to scatter the sun's light. On Earth, some of the shorter wavelength light (the blues and violets) are removed from the direct rays of the sun by scattering. The remaining colors together appear yellow. \n\nAs the sun begins to set, the light must travel farther through the atmosphere before it gets to you. More of the light is reflected and scattered. As less reaches you directly, the sun appears less bright. The color of the sun itself appears to change, first to orange and then to red. This is because even more of the short wavelength blues and greens are now scattered. Only the longer wavelengths are left in the direct beam that reaches your eyes.
844556
Yes! Of course here in the UK it is not always 'blue' below the clouds! \n\nThe reason for the sky being blue is that 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. \n\nHowever, 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. \n\nTo get a fuller explanation (if you can bear it!) see the link below.\n\nGood question!\n\nx
953737
The answer to part one is "green", and the answer to the second part is "green".\n\nThat is why the sky actually appears blue at noon (blue light is more scattered) and red at sunset (red light is less scattered).
387628
not really true, the sky is blue because of the light waves produced by the sun, although it is believed that the sky is blue because it is reflected off the ocean, it is not necessarily true. The sky is blue because the water vapor molecules inside the air is breaking up the combined light "white light" into different frequencies of the light red being the strongest and penetrate through the water vapor, blue and violet being the weakest gets reflected back into the sky, if you noticed when you're on a plane at first at low altitudes the sky is blue, as you get higher the sky turns violet cool isnt it ^^...yes im a 10th grader but you don't need to know that
369741
The sky is blue to us beause of Rayleigh scattering.  From outer space, you don't have that atmosphere effect, so it's black.
580957
When the light from the sun hits the earth some of the light (The higher frequency or blue light) gets trapped or rather scattered by the smaller molecules in the atmosphere.  This scattering makes the sky blue because these particles reflect this blue light.\nAt night the light we are seeing is  the light of  the sun reflected off of the moon and it is much less intense.
271347
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. \n\nHowever, 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. \nAs 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.
59243
The light during the day comes from our star, the sun. The sunlight has to travel through air to get to us. The sunlight looks white, but it has many colors in it (for example, a prism or a rainbow breaks the sunlight into its colors so we can see them). \n\nSome of the blue part of the sunlight cannot go through the air without getting bounced around first by the air, and so it makes it look like the blue is coming from the air in the sky instead of the sun. That is why the sky looks blue.
327311
it is not a stupid question. mankind has woried over it for centuries. it is because blue is scattered the most and so u see it more. the scattering mechanism is called rayleigh scattering and it increases at lower wavelengths. the scattering is because of dust particles in the atmosphere.
463892
There is no such as the "real" color of the sky. The reason the sky is blue during the day is because the color of the light that the sun shines is white. And as you may know, white is the presence of all color and black is the absence of color.\n\nSo, the white light that the sun emits contains every possible color of light.  Now, each color of light has a different wave length depending on where it is on the color spectrum.  Red light has the longest wave length and blue/violet light have the shortest.  And since blue light has the shortest wave length, you see more of it's waves.\n\n\nsorry... that's the best i can explain it
1120862
There is a very, very detailed answer to this at the source below, but in a nutshell (and I quote): "The sky is blue because it is scattering blue light from the sun."\n\nAnd NO: The sky is not blue because of reflections from the oceans. As the source below says, if that were true, then the sky would be more blue out in the middle of the ocean and less blue when you are far inland. But it's equally blue at both locations.
1057175
Blue sky is cause the the defraction of blue light in the atmosphere... at night there is no light to defract....
576573
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.\n\nScattering 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.\n\nIndividual 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.
19151
Hey there Jenna!\n\nThe sky is blue on Earth.. why?  This is because of an effect called "Rayleigh scattering".  If you would like to learn more about Raleigh Scattering, I know a pretty neat site: http://www.sciencemadesimple.com/sky_blue.html\n\nHave a great day! :O)
123521
This is actually a much more complicated question than it appears. Of course, the ocean is not ALWAYS blue, but it is often blue. It is different shades of blue at different times. It appears that the ocean's color is a combination of at least 3 processes:\n\n1. reflection (from the blue sky above)\n2. absorption (of other colors)\n3. scattering (of the blue part of the spectrum by suspended particles in the water, or by the water itself). \n\nOne source I found said the scattering was because of the dissolved oxygen but I find that hard to believe. Another said that the scattering was mainly due to Raman scattering. That might be true.  \n\nThe blue of the sky is mainly because of scattering by oxygen and nitrogen (Rayleigh-Tyndall scattering) except at sunrise and sunset, when the ozone apparently absorbs much of the redder and orange colored light, leaving the sky overhead a dark blue. \n\nThe glass of water is too small a quantity to view the blue color.
117362
One meaning to this is that you did not check the archive of previously asked questions before you posted your question about the sky's color. This has been asked and answered almost 400 times so far here (see link below). \n\nHowever, the reason the sky appears blue (at least most of the daylight hours) is that the atmosphere is mostly oxygen and nitrogen, which are just the right size molecules to scatter the blue light, but let the other colors pass unimpeded. \n\nSo when you take the blue away from the mostly white sunlight, you get sorta yellow sunlight. \n\nAs the sun sets, the sunlight passes through more air, and more blue is scattered away, leaving the sunlight even less blue, that is, more orange. \n\nAs the sun sets even farther, even more blue is scattered away, and the sunlight appears red.