why is the sky blue???

Answer 1

"A 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."

LOTS more info on the page.

Answer 2

Cool - It is due to Tyndall Effect ...

The term Tyndall effect is usually applied to the effect of light scattering on particles in colloid systems, such as suspensions or emulsions. It is named after the Irish scientist John Tyndall. The Tyndall effect is used to tell the difference between the different types of mixtures namely solution, colloid and suspension. For example, the Tyndall effect is noticeable when car headlamps are used in fog. The light with shorter wavelengths scatter better, thus the color of scattered light has a bluish tint. This is also the reason as to why the sky looks blue - the light from the sun is scattered and we see the blue light because it scatters better.

This effect occurs because short wavelengths of light towards the blue end of the spectrum hit the air molecules in the earth's atmosphere and are reflected down to the earth's surface. Longer wavelengths towards the red end of the spectrum are not affected by the particles and pass on through the earth's atmosphere. This causes blue light to be reflected down to the earth's surface which makes the sky appear blue.

Answer 3

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. 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. Simply put, the human visual system is not good at detecting violet light when other wavelengths are present, and so the sky appears blue rather than violet.

Answer 4

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.

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.

Answer 5

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.

Answer 6

A 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


The white light from the sun is a mixture of all colours of the rainbow. This was demonstrated by Isaac Newton, who used a prism to separate the different colours and so form a spectrum. The colours of light are distinguished by their different wavelengths. The visible part of the spectrum ranges from red light with a wavelength of about 720 nm, to violet with a wavelength of about 380 nm, with orange, yellow, green, blue and indigo between. The three different types of colour receptors in the retina of the human eye respond most strongly to red, green and blue wavelengths, giving us our colour vision.

Answer 7

Becuase it's made up of alot of Oxygen molecules and Nitrogen molecules, when light goes through the molecules it acts kindof like a crystal and bends the light so that only certain wavelenghts get through, different wavelenths appear the the human eyes as different colours, in this case that colour happens to be blue.

Answer 8

The sky appears blue due to the blackness of outer space and the light from our sun.

Answer 9

water particles in the sky split the light as it enters our atmosphere, and at the angle we are from the sun, only the blue light is visible, it is also why the sky changes colors at dawn and dusk, different angle, different colors

Answer 10

Reflction of the large Sea,as there is no sky.