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2007-01-22 18:39:43 · 14 answers · asked by garima j 1 in Science & Mathematics Earth Sciences & Geology

14 answers

In sense Dave's answer is correct.
Our atmosphere is transparent but not completely transparent(like window pane). 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(in the light spectrun Blue and violet have longer wavelengths). 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. 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.

Blue sky from scattered light

As 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.

2007-01-22 18:54:37 · answer #1 · answered by Vikas 3 · 0 0

WHY IS THE SKY BLUE?

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.

However, 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.

Blue sky from scattered light

As 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.

2007-01-23 02:54:20 · answer #2 · answered by michael aguila 2 · 1 0

The sky is blue because molecules in the air scatter blue light from the sun.

2007-01-23 02:47:13 · answer #3 · answered by Anonymous · 0 1

The sky is blue partly because air scatters short-wavelength light in preference to longer wavelengths. Combined, these effects scatter (bend away in all directions) some short, blue light waves while allowing almost all longer, red light waves to pass straight through. When we look toward a part of the sky not near the sun, the blue color we see is blue light waves scattered down toward us from the white sunlight passing through the air overhead. Near sunrise and sunset, most of the light we see comes in nearly tangent to the Earth's surface, so that 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.

Scattering 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.

Why is the sky blue instead of violet?
Because of the strong wavelength dependence (inverse fourth power) of light scattering according to Raleigh's Law, one would expect that the sky would appear more violet than blue, the former having a shorter wavelength than the latter. There is a simple physiological explanation for this apparent conundrum. Simply put, the human eye cannot detect violet light in presence of light with longer wavelengths. There is a reason for this. It turns out that the human eye's high resolution color-detection system is made of proteins and chromophores (which together make up photoreceptor cells or "Cone" structures in the eye's fovea) that are sensitive to different wavelengths in the visible spectrum (400 nm–700 nm). In fact, there are three major protein-chromophore sensors that have peak sensitivities to yellowish-green (564 nm), bluish-green (534 nm), and blue-violet (420 nm) light. The brain uses the different responses of these chromophores to interpret the spectrum of the light that reaches the retina.

When one experimentally plots the sensitivity curves for the three color sensors (identified here as long (L), middle (M), and short (S) wavelength), three roughly "bell-curve" distributions are seen to overlap one another and cover the visible spectrum. We depend on this overlap for color sensing to detect the entire spectrum of visible light. For example, monochromatic violet light at 400 nm mostly stimulates the S receptors, but also slightly stimulates the L and M receptors, with the L receptor having the stronger response. This combination of stimuli is interpreted by the brain as violet. Monochromatic blue light, on the other hand, stimulates the M receptor more than the L receptor. Skylight is not monochromatic; it contains a mixture of light covering much of the spectrum. The combination of strong violet light with weaker blue and even weaker green and yellow strongly stimulates the S receptor, and stimulates the M receptor more than the L receptor. As a result, this mixture of wavelengths is perceived by the brain as blue rather than violet.

You could get more information from the link below...

2007-01-23 04:07:42 · answer #4 · answered by catzpaw 6 · 0 0

THis one got answered all right. i just want to inform the dorks that the sky is not blue because of the water. Dorks you are!
The water appears blue because the sky reflects in the water. See: color of sky -->color of water
color of water-/-> color of sky. Got that?!
By the way, which was first: chicken or egg?

2007-01-23 06:34:11 · answer #5 · answered by Anonymous · 0 0

sun emits white light and when the light falls on our atmosphere it splits into the seven colours of rainbow.during day time the sun is close to earth and the colour with shorter wavelength is scattered on the atmosphere that is blue.During evening time the colour with longer wavelength gets scattered that is red. that is the reason evening sky is red or orange in colour.

2007-01-23 14:17:46 · answer #6 · answered by Anonymous · 0 0

sky is blue because blue has less wavelength and so more energy. So it spreads higher than any other colour

2007-01-23 13:40:13 · answer #7 · answered by great sanz 1 · 0 0

The sky is blue because it reflects of the sea. Blue on a calm day, Grey and dark on a stormy day. Hope this is helpfull!

2007-01-23 02:49:21 · answer #8 · answered by animal_crazy_sam 3 · 0 2

I think the ozone reflects blue light from the sun

2007-01-23 07:24:28 · answer #9 · answered by Anonymous · 0 0

if you look it up you will find that the blue is dirt in our atmosphere ,if there was no dirt the sky would be black and you could see the stars..thank god for the atmosphere its the thin layer that protects our lives.. a tiny safety shield from destruction..

2007-01-23 02:50:17 · answer #10 · answered by Anonymous · 0 1

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