The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
All other sections in this Literature Study Guide are owned and copyrighted by BookRags, Inc.
In, the scattering of values in a distribution of data from an average value is called dispersion. The term dispersion generally means the spread of a series of values, usually about some central point such as the, also called the average, or the of the values. The measure of dispersion normally used is the, but the mean deviation and the mean difference are also used.
A well known example of what might be called physical dispersion is the refraction of light into its component colors when it passes through a material in which the velocity of the light waves varies with the wavelength. In a vacuum, light may be thought of as being composed of superimposed trains of light waves of many wavelengths. When light passes through some materials, like a glass prism, it is bent and spread out into its component colors because the different component wave trains travel at different speeds through the glass resulting in a spectrum. An example of such a spectrum in nature is the rainbow. When split into its colors, the light is said to be dispersed. Given appropriate media through which to send them, other wavelengths along the electromagnetic spectrum can be dispersed in a similar way. Each wave changes its length as it moves through the material, at each point having a length determined by the time of arrival of the waves traveling the point of origin.
As defined above, dispersion is the separation of a complex wave into components. The term is also applied to the property of an optical device or medium giving rise to the phenomenon, or the numerical value of this property.