The sky....?

Question

Why is it blue?

Answer 1

To quote Lucy of "Peanuts" fame------Because it isn't purple.

Answer 2

its the same reason a sunset is red.

according to zeke's yin-yang model of the universe, a photon is an infinitely small particle or 2 spinning, or orbiting in 11 (more or less) dimensions.

if a photon is spinning more slowly, it is said to have a lower frequency. in the case of the photons we call light, red photons have a slower rotation than blue.

each individual photon of light has an extremely small chance fo striking the electrons of a dust particle in the sky. because blue light photons are spinning faster, they have more opportunities to collide, and therefore a greater number of them will be diverted in the process we call SCATTERING.

not all blue light is scattered, but enough that, against the blackness of space, we see a blue sky. This is the same reason we percieve blue eyes in people with very low percentages of melanen in their irises.

Photons of red light, at the other end of the spectrum, have the lowest probability of being scattered since they orbit more slowly, so are the most likely to survive a very long trip through a dusty atmosphere, so sunsets take on a reddish appearance.

Answer 3

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?

Normalized typical human cone responses (and the rod response) to monochromatic spectral stimuliBecause 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

There is a greater tendency for molecules of nitrogen and oxygen to absorb all the other colors. In fact, liquid oxygen is a pale blue color for the same reason.

Answer 5

Why is the sky blue?

http://math.ucr.edu/home/baez/physics/General/BlueSky/blue_sky.html

http://www.sciencemadesimple.com/sky_blue.html

Good luck.

Kevin, Liverpool, England.

Answer 6

It is due to refraction of light from water droplets. Of the visible light, blue light is scattered the most and we then see the sky as blue.

Answer 7

It is actually due to the refraction of the atmosphere in total, which very little is made up of water vapor. It is mostly nitrogen and oxygen.

Answer 8

Because of the earth's atmosphere