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The Chetek Alert staff is adding a column to its regular lineup: Why is the Sky Blue? If you've ever wondered about something or found yourself pondering a simple question that poses a mystery but don't have the time to research answers, The Alert can help.
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Anyone can submit questions about any topic or subject, big or small, local or national, useful or useless. The Alert staff will then complete the needed research and print answers for questions deemed worthy.
Questions can be e-mailed to chetekalert@citypapers.com, faxed to 924-4122, called in at 924-4118 or dropped in the drop box outside the office. Names and phone numbers can be included with the submission, but are not mandatory.
The Chetek Alert reserves the right to choose which questions are researched and published.
Why is the sky blue?
Although the sun's light seems to be purely white, it consists of all colors, each with different wavelengths. Red light has a long wavelength and blue has the shortest. When the light passes through the atmosphere, the light is scattered by the air molecules. Blue light is scattered more than other colors because of the smaller wavelength. Because blue light is scattered more, the sky appear to be blue most of the time.
The sunlight from the horizons and lower in the sky has passed through more air molecules before reaching our eyes, thus it has more time to scatter and rescatter, which mixes the color wavelengths back together, making the sky appear lighter blue or white.
When the sun sets or rises, its light passes through even more molecules, which allows the red and yellow wavelengths to pass through while the blues are scattered. The sky appears red because the large dust particles, pollution and water vapor reflect the yellow and red wavelengths, making their presence more known.
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©The Chetek Alert 2010
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fern hansen |
Jun, 12 2009 |
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HOW NICE
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