concerning the earth's atmosphere-why is the sky blue?

Question

it's a clear sunny day.

Answer 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.

Answer 2

Light coming from the sun is what's called "white light" White light contains all the colors of the rainbow. When it enters Earth's atmosphere this light is separated into its individual colors by chemical elements in the atmosphere and scattered across the sky. Nitrogen is the most abundant element in our atmosphere, and that element scatters the color blue across our sky more than the other colors. In space, there is no atmosphere to separate colors from the white light and space looks black.

Answer 3

Go to http://www.jmccsci.com listen to the shows on your Real player, especially the Janurary 18th broadcast, but start with February, he is really a great professor, this might interest you! He is not a copycat, his name is James McCanney. This may not answer your question, but I have found that the sky isn't "blue" like it used to be. Perhaps due to the evaporation of the oceans & lakes, & ice caps. Please listen & read at this webpage!