White light is a form of energy and all forms of energy can be measured in weight. One ounce of heat energy will melt about two million tons of rock to white hot lava. And every second, the sun pours forth about four million tons of electromagnetic energy. Just a small fraction of this energy is white light.
The radiant energy of the sun pulses along in millions of different wave lengths, all traveling at about 186,000 miles a second. Each pulse of energy has a crest and a trough and a wave length is the distance from crest to crest. The assorted wave ler4hs in the sun's total. electromagnetic energy vary from fractions of a millimeter to many miles.
White light is a blend of many short wave lengths. When bunt by a glass prism, these different wave lengths reveal themselves as the rainbow colors of the spectrum of white light. The shortest wave lengths are the violet rays, the longest are the red rays. E^.ch wave length is a little longer from violet, through indigo, blue, green, yellow, orange to red.
The wave lengths of white light are usually measured by the Angstrom unit, which is one hundred millionth part of a little centimeter. And the entire range of the wave lengths blended together in white light ranges from about 4,000 to 8,000 Angstroms. It takes about 130 red wave lengths and about 260 violet wave lengths to equal the thickness of a sheet of paper.
There are invisible longer and shorter wave lengths in the sun's electromagnetic energy and white light is but a tiny fraction of the total picture.
Longer rays which become heat measure up to more than a million Angstroms. Ultraviolet wave lengths are shorter than those of white light.
When we speak about white light, we are being very human. For though these are the wave lengths by which we see things, other creatures may be unable to see all these wave lengths and perhaps see others which we cannot see. Bugs, for example, keep away from. a yellow light because they cannot see the wave lengths in this range. Certain night prowling mammals seem unable to see the red wave lengths of light. A pit viper may be able to sense the longer infrared rays which are beyond our vision.
There are an infinite number of different wave lengths blended together in the form of energy we call white light. The red wave lengths, for example, range from 6,300 to 7,800 Angstrom unit.. The blue violet colors range from 3,800 to almost 5,000 Angstroms.