Colours of Light by 2E2 Riesky

The colors are being produced when light passes through a prism and dispersion is the separation or splitting of white light into its separate colors.

The most famous example of dispersion is a rainbow, in which dispersion causes the spatial separation of a white light into components of different colors. However, dispersion is the most often explained for light waves, but it possibly occur for any kind of wave that interacts with a medium or passes through an inhomogeneous geometry. On the other hand dispersion also has an impact in my other circumstances.

Ordinary light (white light )is really a mixture of different colors. When a beam of white light passes through a glass prism, the light splits up into the colors you see is a rainbow. These colors are called the spectrum of white light.

The spectrum consists of seven colors: Red, Orange, Yellow, Green, Blue, Indigo and Violet or You can remember the order of the seven colors as a boy’s name: ROY G BIV. As these colors merge one into another gradually, it is difficult to say exactly where one colors ends and the next colors starts.

A rainbow is formed when sunlight (white light) passes through raindrops. These drops of water act as small prisms. The white light separates to form the colors of the spectrum.

Since white light consists of seven colors, we should be able to get white light again by combining the colors together. There are 2 ways:
By using a second prism
Spinning a color wheel
White light and light of other colors can be obtained by mixing just three colors – red, blue and green.

These colors are called the primary colors of light.

There are 2 basic ways colors can be mixed to make other colors. One is by combining color light. Mixing color light is called additive color mixing, because the combined colors are formed by the adding of light from 2 or more light sources together. Two or more lights added together will give more illumination than any of the lights by them selves.
If colored light is mixed together, the brightness of the colored lights are added together. This can be seen where the color illumination overlaps. The yellow mixed from red plus green will be brighter than either the red light or green light alone.

Likewise the color cyan is formed by adding green light and blue light. The cyan is also brighter than its two components.
green light + blue light = cyan
The same goes for the magenta and its mixture of red and blue.
red light + blue light = magenta
White light is formed where all three additive primary colors overlap. Since the white mixture results from the adding of all three color light sources, the white light mixture appears even brighter yet.

PRIMARY COLORS OF LIGHT
By varying the amount of the individual light sources, a full range of colors can be obtained. Television screens and PC monitors use the additive color process.


(http://en.wikipedia.org/wiki/Dispersion_(optics)
(http://home.att.net/~RTRUSCIO/COLORMX.htm)
Text book pg (128, 129 and 130)