Is the sky really blue or are we all color blind?
371401
The sky has no color. The color that you see depends on the reflections from the ocean and other bodies of water and the suns ability to cause a reflection on the water.
1048733
The sky is blue partly because air scatters short-wavelength light in preference to longer wavelengths. \nWhere 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\nso\n\nAn old weather predicting adage rhythmically states: \n\nRed sky at night, Sailors' delight.\nRed sky in morning, Sailors take warning. \n\nHumidity in the air is indicated by red skies at sunset-- red sky at night-- or, at sunrise-- red sky in morning. The forming raindrops scatter the short-wavelength blue light so that only the long-wavelength red light reaches the observer.
137401
Blue on a clear day.\nWhite if it is cloudy.\nRed on a cloudy sunset.\nBlack at night.
276006
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.
274364
the sky appears blue becuase that is the color of ozone (O3), the gas that surrounds the earth.
336150
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 !
646815
it's not actually, if you look at the ocean, from the top it is blue becaues it is reflecting the light from the sky.   if you are underwater, it looks blue because the blue light is dispersed the least, meaning that the blue light penetrates farther into the water than the other colors of light.
329750
uum... we're not green, the world's not blue, and we don't see only red. We see billions of colors. We see many more colors, the world's many more colors, and we are anywhere from orange (the oompa loompa's) to red (burned)to purple (bruised), to blue(choking), to green (again bruised) to brown (or black), to tan or peach (whites).\n\nSo I guess the answer to your question is we're not green, the world is not blue, and we don't only see red... oh and the world is not blue (for the second time)
764619
To start of with we must understand what light is. \n\nLight isnt just made up of 1 colour, it contains a number of different colours each of which has a different wavelength. Light is split up into the following colours with the first having the longest wavelenght and the last having the shortest. \n\nRed\nOrange\nYellow\nGreen\nBlue\nIndico\nViolet\n\nAn easy way to rememeber this is ROY G BIV (my year 12 geology teacher taught me that about 8 years ago)\n\nAs light moves through the atmosphere, most of the longer wavelengths are able to 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 in the atmosphere which is mainly nitrogen (78%) and oxygen (21%). The absorbed blue light is then scattered in all different directions. Since you see the blue light from everywhere overhead, the sky looks blue. \n\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\nYou didnt ask about sunsets, but what the heck :)\n\nWhat happens during sunsets is that as the sun begins to go down, the light must travel farther through the atmosphere before it gets to you. More of the light is reflected and scattered. As less light 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. \n\nThe second part of the your question is a lot easier. The sky is black simply  because of the lack of light from the sun going through the atmosphere. If there are no colours from the spectrum to get absorbed then the only thing that is left is the blackness of the sky.
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
20213
Why is the sky blue? why is the grass green? some things are just unexplainable...
92915
The sky appears blue due to the scattering of sunlight by dust particles in the air.\n\nSunlight is comprised of light in different wavelengths and can easily be split with a prism.  The dust particles in the air are of the right size that they scatter blue light preferentially.  As a result, we see the sky blue.\n\nThe sky is black at night simply because there isn't any blue light to be scattered.\n\nIncidentally, moonlight is yellow because that is the generally reflected colour off the moon's surface.  It is reflected light strongly in the yellow waveband. The yellow light is not affected by atmospheric scattering.
848010
when the sunlight enters the earth atmospere,,\nthe light gets split up into 7 colours,,\nbut the most defracted light is blue,,\nthus,,sky is observed as blue,,\n\none thing u have to keep it in ur mind,,\nthat there r no specific colours to any object in this world,,everything is white in colour in this world,,but,,due to some specific colours reflecting in our eye,,we can see those objects in those specific colours only,,\nthis is what xplains colour-blindness in humans,,,
389534
it is 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 \n 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
1107787
The word 'colorblind' really means 'abnormal color vision' ... in other words the vast majority of humans fall into a certain range of color vision, and 'colorblind' people fall outside that range.\n\nSo we all can't be 'colorblind' by definition of the word 'colorblind'.\n\nAnd words like 'blue' and 'orange' are just names we give to certain experiences.  There is no way to tell if two humans actually have a different personal experience when they look at the sky ... both will point at the sky and say 'blue' ... simply by definition of the word 'blue' as "the same color as the sky."\n\nAll we can tell is that most of us will point to a sky, and the sea, and to Italy's home uniform and say they are all the same color ... a color that we were taught in childhood is named 'blue.'\n\nIn other words, all we can tell is that most of us have the same color *categories*, regardless of whether we call it 'blue' or 'azul' or 'bleen.'
160687
Sky blue\n--------\n\nYou 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 more than 400 times so far here. \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.\n\nGrass Green\n-------------\n\nFrom the color of chlorophyll, the chemical that plants use to capture energy from sunlight. \n\nEarth Boring\n-------------\n\nIf the earth is boring, then what is not boring to you?
1015359
using simple physics\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\nthe grass is green because the other colors are absorbed and only green is reflected. Grass and most other plants are green because they contain a pigment known as chlorophyll.\n\nSun isn't really yellow. The color yellow is a purely human interpretation of a collection of radiation that hits the retinae of our eyes and gets processed by our visual cortex.