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    Kinds of radiation received at the top of the atmosphere and at the ground

Downloaded from Wikipedia, March 31, 2009.
Note - this is not an original scientific resource.

The sunlight that enters the top of our atmosphere is centered on the visible part of the electromagnetic spectrum. Since living things developed on an Earth that is bathed in this kind of radiation, it is no wonder that eyes are receptive to this part of the electromagnetic spectrum.

Note that the sunlight that actually makes it to the ground isn't the same. It's missing some components that have been absorbed by substances in the atmosphere.

On a related note - solar (photovoltaic) cells that depend on capturing the Sun's energy are optimized to capture as much of the available spectrum as possible.

Also, radio waves happen to pass freely through the Earth's atmosphere so even ground-based telescopes can "see" radio waves from distant galaxies.