Why does the sky seem blue when in reality space is black?
369937
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.
1057175
Blue sky is cause the the defraction of blue light in the atmosphere... at night there is no light to defract....
80014
The nitrogen and the oxygen molecules in the air have the right dimensions to scatter blue light, but other colors pass through with little problem. So this causes the sky to look blue. \n\n(whitish sunlight)-(blue light scattered)= (yellowish sunlight)\n\nAs the sun sets (or rises), the sunlight passes through more air, and more blue light gets scatted, so the sunlight looks closer to orange or red\n\n(whitish sunlight)-(even more blue light scattered)=(red or orange sunlight)
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.
86349
Blue is the color that is reflected from the atmosphere--alll over colors are absorbed...Light is divided into the colors of the spectrum and each color has it's own specific wavelength.....so the wavelength for "blue light" is reflected and not absorbed and that is why you see a blue sky.
917666
Why is the sky blue?\n\nhttp://math.ucr.edu/home/baez/physics/General/BlueSky/blue_sky.html\n\nhttp://www.sciencemadesimple.com/sky_blue.html\n\nGood luck.\n\nKevin, Liverpool, England.
4645
because of water vapor (in the air...gives it a blueish hue.  not much to due with physics... maybe chemistry.
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.
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.
178836
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.
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
1056723
The sky is blue due to the way that light is bent, it's called Rayleigh Scattering.  Sunlight is white and white light consists of all colors but when it hits our atmosphere the light is broken up into it's component colors by the particles in the atmosphere.  The shortest wavelengths don't make it through the particles but the blue light does - hence the sky appears blue when in fact it has no color ro it (it is after all, nothing but air and water).\n\nAs others have said - grass is green because of chlorophyll - the chemical in all plants and it just happens to be green.
71027
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
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.
311003
light is scattered by the suspended water droplets in the air. blue light is preferentially scattered down, thus the sky looks blue
191878
The sky is blue because of the ozone layer, which is blue. The ozone layer is blue because (have you ever tried to shine light through a triangular pyramind (glass)?) It filters everything but blue color...why? I don't know. Uh...I'm not sure, probably because they want to know more about female sex organs because girls have 2 and we have 1 ugly sex organ that's not exactly as attractive as girls. Not that I'm a pervert...only nerds are.
900269
there are defferent sphares of light.   White light comes from the sun and when it hits the atmospher it splits into different colors of the rainbow.  Blue being the fastest light is the only light that escapes the atmospher and that is what makes a blue sky.  Blue skies also mean clear skies.  now a red sky means lots of deferent types of air in the sky.  in the morning the sun is just starting to warm up the atmospher.  so you have a lot of defferent types of air going to get charged up.   Think of it like starting all the appliences  in your kitchen starting up but you don't know what they are gonna do.  basically you get speratic weather.  As apposed to a blue sky getting warmed up.  All it does is warm up the air.    \n \nhope this helps\n-David-