light and the perception of color!”. White light is NOT the absence of all color! Black is NOT all of the colors all mixed together! (Remember second grade? When you ran out of black crayon and just scribbled all of the remaining colors together and got a muddy brownish gray at best? Uh-uh…never works.) Thus, I have taken it upon myself to enlighten the rest of us “just don’t know ANYTHING” grown-ups on the subject of color and the visible spectrum of light. Pay attention, class! This is Visible Light 101. All light consists of waves traveling in space. The length of the waves determines the color of the light. Each color of light has its’ own characteristic wavelength and what is visible to the human eye is termed the visible spectrum of light. It begins on one end with the color red and goes through the spectrum to the color violet. The entire spectrum consists of the following colors: red, orange, yellow, green, blue, indigo, and violet. White light consists of a mixture of many different wavelengths. Try this: use a prism to disperse white light from a source such as a light bulb or flashlight into its’ separate component (colors). The fact that we “see” a certain color at all is dependent on a couple of basic principles. First, ordinary colored light consists of a broad range of wavelengths covering a particular portion of the spectrum. When you isolate those wavelengths, by using a filter or a device that blocks the undesired wavelengths, you will see only the ones that are emitted when you view the light. A good example of this is a stop light… the green light emits the entire green portion of the spectrum plus a little of the neighboring yellow and blue regions. Other reasons for seeing only certain colors are attributed to the four properties of light know by the acronym RATS. R.A.T.S stands for reflection, absorption, transmission, and scattering. Each of t...
