Page 116 - The Creation Of The Universe

114 THE CREATION OF THE UNIVERSE

Ultraviolet Visible light Infrared

Intensity of
solar
radiation

0.2 0.4 0.8 1.5
wavelengths (microns)
Nearly all of the Sun's radiation is restricted to a narrow band of wavelengths ranging from 0.3
to 1.50 microns. This band encompasses near ultraviolet, visible, and infrared light.

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though it occupies less than 1/10 of the whole electromagnetic spectrum.
In his famous article "Life and Light", which appeared in Scientific
American, the renowned physicist George Wald considered this matter and
wrote "the radiation that is useful in prompting orderly chemical reactions
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comprises the great bulk of that of our sun." That the Sun should radiate
light so exactly right for life is indeed an important example of Creation.
Is the rest of the light the Sun radiates good for anything?

When we look at this part of the light we see that a large part of solar
radiation falling outside the range of visible light is in the section of the
spectrum called "near infrared". This begins where visible light ends and
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again occupies a very small part of the total spectrum–less than 1/10 .
Is infrared light good for anything? Yes, but this time it's no use to look
around because you can't see it with the naked eye. However you can eas-
ily feel it: the warmth you feel on your face when you look up on a bright