WHY THE SKY IS BLUE AND SUNSETS ARE RED

Sunlight is pure white.  The gas molecules of the air account for most of the scattering in the visible region of the spectrum, where the wavelength increases from violet to red.  The blue end is scattered more than the red end.  Some of this scattered light reaches Earth where we see it as blue skylight.  The other colors are present, but are surpressed by the dominant blue.  Thus the sky is more blue overhead and less near the horizon.   Why not violet (the shortest wavelength)?  The eye is more sensitive to blue, and the sunlight contains more blue light than violet light.

The scattering of sunlight by the atmospheric gases and small particles gives rise to red sunlight.
 
 
 
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