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.
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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.
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1625-1698
Danish physician and mathematician remembered for discovering double refraction (1669). Bartholin noticed that the transparent crystal Iceland spar (calcite) produced double images of objects viewed through it. He assumed light transmitted through the crystal was being refracted through different angles so as to produce two light rays. Christiaan Huygens explained certain aspects of double refraction with his wave theory of light but full understanding awaited the work of Etienne Malus, on polarization (1809), and Augustin Fresnel (1817).