Why is the sky blue??
476620
The sky is blue because it would be ugly red....JK. The sky is blue because of all the mixes of gases in the atmosphere.  ;)
928427
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. \n\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. \n\nSOURCES:\nhttp://www.sciencemadesimple.com/sky_blu...\n\nThe Earth's sky is blue because the air molecules (largely nitrogen and oxygen) are much smaller than the wavelength of light. When light encounters particles much smaller than its wavelength, the scattered intensity is inversely proportional to the 4'th power of the wavelength. This is called "Rayleigh scattering," and it means that half the wavelength is scattered with 2**4 = 16 times more intensity.\nThat's why the sky appears blue: the blue light is scattered some 16 times more strongly than the red light. Rayleigh scattering is also the reason why the setting Sun appears red: the blue light has been scattered away from the direct sunlight.\n\nThus, if the atmosphere of another planet is composed of a transparent gas or gases whose molecules are much smaller than the wavelength of light, we would, in general, also expect the sky on that planet to have a blue color.\n\nIf you want another color of the sky, you need bigger particles in the air. You need something bigger than molecules in the air--dust.\n\nDust particles can be many times larger than air molecules but still small enough to not fall out to the ground. If the dust particles are much larger than the wavelength of light, the scattered light will be neutral in color (i.e., white or gray)---this also happens in clouds here on Earth, which consist of water droplets. If the dust particles are of approximately the same size as the wavelength of light, the situation gets complex, and all sorts of interesting scattering phenomena may happen. This happens here on Earth from time to time, particularly in desert areas, where the sky may appear white, brown, or some other color. Dust is also responsible for the pinkish sky on Mars, as seen in the photographs returned from the Viking landers.\n\nIf the atmosphere contains lots of dust, the direct light from the Sun or Moon may occasionally get some quite unusual color. Sometimes, green and blue moons have been reported. These phenomena are quite rare though---they happen only "once in a blue moon...." :) The dust responsible for these unusual color phenomena is most often volcanic in origin. When El Chicon erupted in 1982, this caused unusually strongly colored sunsets in equatorial areas for more than one year. The much bigger volcanic explosion at Krakatoa, some 110 years ago,\ncaused green and blue moons worldwide for a few years.\n\nOne possible exception to the above discussion is if the clouds on the planet are composed of a strongly colored chemical. This might occur on Jupiter, where the clouds are thought to contain sulfur, phosphorus, and/or various organic chemicals.\n\nIt's also worth pointing out that the light of the planet's primary is\nquite insignificant. Our eyes are highly adaptable to the dominating illumination and perceive it as "white," within a quite wide range of possible colors. During daytime, we perceive the light from the Sun (6000 K) as white, and at night we perceive the light from our incandescent lamps (2800 K, like a late, cool M star) as white
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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.
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.
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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!\n\nThe light from the Sun looks white. But it is really made up of all the colors of the rainbow. \nA prism is a specially shaped crystal. When white light shines through a prism, the light is separated into all its colors. \n\nIf 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! \n\nLike 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. \nAll light travels in a straight line unless something gets in the way to--\n\n\nreflect it (like a mirror) \n\nbend it (like a prism) \n\nor scatter it (like molecules of the gases in the atmosphere) \n\nSunlight 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.\nCloser 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.\n\nWhat Makes a Red Sunset?\n\nAs the Sun gets lower in the sky, its light is passing through more of the atmosphere to reach you. Even more of the blue light is scattered, allowing the reds and yellows to pass straight through to your eyes\nSometimes the whole western sky seems to glow. The sky appears red because larger particles of dust, pollution, and water vapor in the atmosphere reflect and scatter more of the reds and yellows\n\nWhy Does Scattering Matter?\n\nHow much of the Sun's light gets bounced around in Earth's atmosphere and how much gets reflected back into space? How much light gets soaked up by land and water, asphalt freeways and sunburned surfers? How much light do water and clouds reflect back into space? And why do we care? \nSunlight carries the energy that heats Earth and powers all life on Earth. Our climate is affected by how sunlight is scattered by forests, deserts, snow- and ice-covered surfaces, different types of clouds, smoke from forest fires, and other pollutants in the air. \n\nMISR (for Multi-angle Imaging SpectroRadiometer) is one of five instruments onboard the Terra satellite. MISR has nine separate cameras that take pictures of Earth's atmosphere and surface from different angles as the Terra satellite passes over a region during its orbit
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The sky is air.  Air is transparent, mostly.  However, air does slightly bend very high frequencies of visible light.  These frequencies include purple and blue.  This makes the sky appear blue.\n\nWhen the Sun is near the horizon at sunrise and sunset, its light is passing through much more air (about 4000 miles' worth, instead of the overhead air that is about 50 miles thick), and much more light is bent out.  This is why the sky turns red.
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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.
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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. \n\nThe atmosphere is the mixture of gas molecules and other materials surrounding the earth. It is made mostly of the gases nitrogen and oxygen. 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.
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it's all about water\nwater in the atmosphere is like a beam splitter to the light, and at the angle we're at to the beams of light, the sky looks blue
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first of all, to Paranoid Princess:\n\nwhoa, whoa WHOA.  just a minute.  the sky is not blue because there's liquid oxygen in the upper atmosphere.  that's just retarded and you shouldn't go presenting bizzare mis-truths as fact when they *aren't* fact.\n\nhere is a profile of temperatures at various altitudes:\nhttp://www.windows.ucar.edu/tour/link=/earth/images/profile_jpg_image.html\nas you can clearly see the lowest temperature is about -100C.  oxygen liquefies at -182C at normal pressures (reference: http://www.ucc.ie/ucc/depts/chem/dolchem/html/elem/elem008.html ), and even lower temperatures at the low pressures in the upper atmosphere.  PLEASE don't present some bizarre fiction as truth to someone who isn't well-informed enough to know that you're simply fabricating nonsense from thin air.  if you have simply been misled by someone else, at least try to do a marginal amount of research before answering a question on something you don't know much about.\n\nthat said, to the original asker:\n\nthe sky is blue because of a phenomenon called "rayleigh scattering", which occurs because the molecules of air (mostly N2 and O2) happen to be the right size to scatter blue light in all directions.  some of this blue light reaches your eye after being re-scattered again by a second molecule, sometimes all the way across the sky.  \n\nthis is also why the sky turns red at sunset - at low angles, the sunlight has to travel a longer distance through the atmosphere, and by the time it reaches your eye, a lot of the blue light has already been scattered away, leaving yellow orange and red.  (i have yet to hear any explanation of why the sky doesn't turn green between daytime and sunset, though.  still tryin' to figure that one out.)\n\nanyway here are some home/school experiments designed to illustrate rayleigh scattering:\nhttp://www.physics.brown.edu/physics/demopages/Demo/optics/demo/6f4010.htm\nhttp://www.chaosscience.org.uk/dem/public_html/article.php?story=20050222224622239\nhttp://teachers.web.cern.ch/teachers/archiv/HST2002/smallexp/krug/Rayleigh.htm\nhttp://bulldog2.redlands.edu/facultyfolder/deweerd/research/scattering-AJP.pdf\nhttp://www.ktca.org/newtons/9/sky.html\n\nalso, a nice page illustrating rayleigh scattering:\nhttp://hyperphysics.phy-astr.gsu.edu/hbase/atmos/blusky.html\nand a slightly more advanced version:\nhttp://world.std.com/~mmcirvin/bluesky.html
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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.
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Why is the sky blue: Discussion \nTransmitted light (from the sun, light bulbs, fire, etc) is made up of a spectrum of colors. The longest wavelengths of light are on the red end of the spectrum and the shortest wavelengths are on the blue/violet end of the spectrum.\nWhen transmitted light such as sunlight enters our atmosphere it collides with the oxygen and nitrogen atoms. The color with the shorter wavelength is scattered more by this collision. Because violet and blue are the shortest wavelengths the sky appears to be violet / blue. But because our eyes are more sensitive to blue light than they are violet light, we perceive the sky as blue.\nOur eyes contain thousand of rods and cones, which are the receptors for light. Whenever one of the 3 Stooges pokes you in the eye you see a giant blue spot. This is because the blue receptors have been activated. Blue is one of the primary colors and thus more easily activated and seen by our eyes.
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largely, for the same reason the sky is blue.  the amount that light is scattered is proportional to its frequency to the fourth power.  thus, blue light is scattered most strongly, and the sky appears blue.  at sunset (and sunrise), we're looking directly at the sun, and all the blue light has been scattered away.  other colors (yellow and green, mainly) are absorbed by the water vapor in the air.  the orange and red, being the smallest visible frequencies, are what come through the strongest.
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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
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Well.........\n\nThe 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.
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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.
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Why is the sky blue ?  Why is the sun yellow ? That is a very logical question guy please, lemme see um cause maybe JUST MAYBE if we do it standing up like you guys, how do I put this umm not a pretty picture right ?  so duh !