Why is the sky blue if outerspace is black?
344653
First off why is the sky any color at all and not black?\nThe answer -- the presence of the atmosphere -- oxygen molecules absorb energy and release at pretty much a random angle(Rayleigh scattering). So the light from the sun is "diffused" around the atmosphere and when it reaches our eyes it come in from all directions -- creating the colored sky effect.\n\nNow on to the 2nd question why is the sky specifically blue. Blue is high energy color(it is created by high frequency waves) so it does not spread as much as other colors. In fact the sky is not uniform blue -- Come out of your house on a clear sunny day and you will see that the sky is the bluest directly above your head but it gets more and more white as you look toward horizon. This means that blue light diffuses the least creating blue appearance around the sun -- but as you look further from the sun more colors are visible creating the white effect. \nThe Sky may also be seen in weird colors like red and orange when the sun is at the sharp angle with the atmosphere(dusk and dawn).
1089706
When 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.\n\nIt is because blue light from the sun strikes the air molecules and scatters and our eyes perceive it as blue.\n\nBlue in sunlight collides with air molecules and our eyes see it as blue.
388504
because of tyndall effect as the blue clour as a longer wave length in the spectrum of colours it gets scaterd more in the sky \n\n\nmxwltan\n6 minutes ago\n\n\n\nThe Earth's sky is blue because the air molecules (largely nitrogen\nand oxygen) are much smaller than the wavelength of light. When light\nencounters particles much smaller than its wavelength, the scattered\nintensity is inversely proportional to the 4'th power of the\nwavelength. This is called "Rayleigh scattering," and it means that\nhalf 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\ntimes more strongly than the red light. Rayleigh scattering is also\nthe reason why the setting Sun appears red: the blue light has been\nscattered away from the direct sunlight.\n\nThus, if the atmosphere of another planet is composed of a transparent\ngas or gases whose molecules are much smaller than the wavelength of\nlight, we would, in general, also expect the sky on that planet to\nhave a blue color.\n\nIf you want another color of the sky, you need bigger particles in the\nair. You need something bigger than molecules in the air---dust.\n\nDust particles can be many times larger than air molecules but still\nsmall enough to not fall out to the ground. If the dust particles are\nmuch larger than the wavelength of light, the scattered light will be\nneutral in color (i.e., white or gray)---this also happens in clouds\nhere on Earth, which consist of water droplets. If the dust particles\nare of approximately the same size as the wavelength of light, the\nsituation gets complex, and all sorts of interesting scattering\nphenomena may happen. This happens here on Earth from time to time,\nparticularly in desert areas, where the sky may appear white, brown,\nor some other color. Dust is also responsible for the pinkish sky on\nMars, as seen in the photographs returned from the Viking landers.\n\nIf the atmosphere contains lots of dust, the direct light from the Sun\nor Moon may occasionally get some quite unusual color. Sometimes,\ngreen and blue moons have been reported. These phenomena are quite\nrare though---they happen only "once in a blue moon...." :) The dust\nresponsible for these unusual color phenomena is most often volcanic\nin origin. When El Chicon erupted in 1982, this caused unusually\nstrongly colored sunsets in equatorial areas for more than one year.\nThe 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\nplanet are composed of a strongly colored chemical. This might occur\non Jupiter, where the clouds are thought to contain sulfur, phosphorus,\nand/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\nillumination and perceive it as "white," within a quite wide range of\npossible colors. During daytime, we perceive the light from the Sun\n(6000 K) as white, and at night we perceive the light from our\nincandescent lamps (2800 K, like a late, cool M star) as white. Only\nif we put these two lights side-by-side, at comparable intensities,\nwill we perceive a clear color difference.\n\nIf the Sun was a hot star (say of spectral type B), it's likely we\nstill would perceive its light as "white" and the sky's color as blue
629153
The sky is what people back in the day called what they saw above them because they didnt know what it was..\n\nnow that we know, we know that what we see as blue sky is just refraction of light, and when there is no light ( night ) we just see things out in the universe that reflect light(moon) or emit light ( stars ) \n\nso the sky doesnt really exist, what it is is gases that refract sunlight during the day, and let you see through at night
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
31576
The Earth's sky is blue because the air molecules (largely nitrogen\nand oxygen) are much smaller than the wavelength of light. When light\nencounters particles much smaller than its wavelength, the scattered\nintensity is inversely proportional to the 4'th power of the\nwavelength. This is called "Rayleigh scattering," and it means that\nhalf 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\ntimes more strongly than the red light. Rayleigh scattering is also\nthe reason why the setting Sun appears red: the blue light has been\nscattered away from the direct sunlight.\n\nThus, if the atmosphere of another planet is composed of a transparent\ngas or gases whose molecules are much smaller than the wavelength of\nlight, we would, in general, also expect the sky on that planet to\nhave a blue color.\n\nIf you want another color of the sky, you need bigger particles in the\nair. You need something bigger than molecules in the air---dust.\n\nDust particles can be many times larger than air molecules but still\nsmall enough to not fall out to the ground. If the dust particles are\nmuch larger than the wavelength of light, the scattered light will be\nneutral in color (i.e., white or gray)---this also happens in clouds\nhere on Earth, which consist of water droplets. If the dust particles\nare of approximately the same size as the wavelength of light, the\nsituation gets complex, and all sorts of interesting scattering\nphenomena may happen. This happens here on Earth from time to time,\nparticularly in desert areas, where the sky may appear white, brown,\nor some other color. Dust is also responsible for the pinkish sky on\nMars, as seen in the photographs returned from the Viking landers.\n\nIf the atmosphere contains lots of dust, the direct light from the Sun\nor Moon may occasionally get some quite unusual color. Sometimes,\ngreen and blue moons have been reported. These phenomena are quite\nrare though---they happen only "once in a blue moon...." :) The dust\nresponsible for these unusual color phenomena is most often volcanic\nin origin. When El Chicon erupted in 1982, this caused unusually\nstrongly colored sunsets in equatorial areas for more than one year.\nThe 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\nplanet are composed of a strongly colored chemical. This might occur\non Jupiter, where the clouds are thought to contain sulfur, phosphorus,\nand/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\nillumination and perceive it as "white," within a quite wide range of\npossible colors. During daytime, we perceive the light from the Sun\n(6000 K) as white, and at night we perceive the light from our\nincandescent lamps (2800 K, like a late, cool M star) as white. Only\nif we put these two lights side-by-side, at comparable intensities,\nwill we perceive a clear color difference.\n\nIf the Sun was a hot star (say of spectral type B), it's likely we\nstill would perceive its light as "white" and the sky's color as blue
66724
Rayleight Scattering.\n\nThe blue color of the sky is caused by the scattering of sunlight off the molecules of the atmosphere. This scattering, called Rayleigh scattering, is more effective at short wavelengths (the blue end of the visible spectrum). Therefore the light scattered down to the earth at a large angle with respect to the direction of the sun's light is predominantly in the blue end of the spectrum.
617565
The water particles,mixed in the air ( sky ), are responsible for this.The sunlight is refracted by those water molecules and thus we see the colour of the sky as blue.As you may remember,in the rainbow colours,Blue comes just after Violet and Indigo which are not that prominent as Blue. \nThus we see the sky blue.
262627
It is.  It's just very dark blue so it looks black.  I'm sure you'll agree that even a "very bright" moon is a lot darker than the sun.  I took a picture at night for fifteen seconds at 1600 ISO on a hazy night and the sky came out blue.  I think the bright points (stars) add contrast to the sky that make it look dark so the haze evened the sky out.
249388
One of the most common questions on YA!\n\nA 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.\n\nSee the link below for full details.
378185
Particles in the air refract the white light of the sun into the spectrum.  The sky is blue because blue gets through the easiest.
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)
989881
The main reason light from the sky is blue is Rayleigh scattering (named after Lord Rayleigh), which is the scattering of light, or other electromagnetic radiation, by particles much smaller than the wavelength of the light. It occurs when light travels in transparent solids and liquids, but is most prominently seen in gases.
838471
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
24151
Everyone else is wrong. This has nothing to do with water. The sky is blue because as the light waves pass trhough the air they collide with molecules, effectively scattering the blue wavelenghts of light. This is demonstated by the fact that the sky at lower angles appears more blue, because there is more air that the light must travel through.
680880
We see the blue sky because of Rayleigh scattering.  Short wavelengths (blue light) are scattered more than long wavelengths (red light).\n\nAs the sun dips below the horizon, it doesn't get dark immediately.  We still see some light, this is twilight.  At night, even though sunlight is scattered, it doesn't scatter all the way around the globe.  Hence you eventually observe a black sky.
43825
When the sun is directly overhead, the sunlight has to only pass through a few miles worth of thick atmosphere.  But when the sun is close to the horizon (at sunrise or sunset) the light goes a much longer distance through the atmosphere.  This causes attenuation of the shorter wavelengths (blue - this is why the sky is blue at other times of the day) leaving only the longer wavelengths like orange and red to reach us.  Having clouds in the sky and a variety of other atmospheric effects also contributes to the play of colors.