Table of Contents
I – Blue Sky, Red Sunset, White Clouds 1.1 Why do we have Blue Sky?
1.2 Why is the Sunset Red? 1.3 Why is Clouds White?
II – Conclusion
III - References
SUMMARY
Not all colors are the result of subtraction and addition of light. Some colors like the blue sky result from the selective scattering of the colors of light by particles in the atmosphere. The color scattered by the particles depends on the size of the particles themselves.
BLUE SKY Violet is scattered more than blue; our eyes are not very sensitive to violet. The scattered blue light predominates, so we see the sky as blue. The Color of the sky varies with the conditions of the atmosphere. On days when the atmosphere contains water vapor, particles of dust, and others bigger than nitrogen and oxygen, the sky appears less blue compared to clear dry days.
Why do we have Blue Sky? 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.
RED SUNSET The sky around the setting sun may take on many colors. The most spectacular shows occur when the air contains many small particles of dust or water. These particles reflect light in all directions. Then, as some of the light heads towards you, different amounts of the shorter wavelength colors are scattered out. You see the longer wavelengths, and the sky appears red, pink or orange.
Why is the Sunset Red? As the sun begins to set, the
References: http://answers.wikia.com/wiki/Blue_sky_red_sunset_and_white_clouds http://www.sciencemadesimple.com/sky_blue.html http://wiki.answers.com/Q/Why_are_clouds_white Science and Technology Physics textbook