ThirstyFish

The sky is blue. Well, have you ever thought why the sky is blue? How about why blue is blue? Although ancient scientists have tried to explain why we see colors, it was not until Isaac Newton that light was identified as the source of colors. Light is the portion of electromagnetic radiation that is visible to the human eye. We see colors by distinguishing the various wavelengths of light in the retina of our eyes. Our eyes are sensitive to the peak wavelengths (energies) of radiation produced by our sun. Blue light has more energy than red light and green light falls somewhere in between.

The blue color of the sky is due to a phenomenon called Rayleigh scattering. While most of the longer wavelengths of light, such as reds and oranges pass through the atmosphere, shorter wavelengths of light are absorbed by the gas molecules in the air and scattered in all directions. During the day, the peak (average) energy of this scattered light is blue, and during sunsets, it peaks in the reds and oranges.

To enjoy a sunset, you don't have to know any of this. The photograph of the sunset above, is nothing but a few pixels of light reaching your eyes from your monitor.

Song of the Day: Fidayda - Ithikon Akmeotaton (2006)