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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1201-1274
Arab astronomer and mathematician who established an observatory at Maragheh (now in Azerbaijan) under the patronage of the Mongol conqueror Hulagu Khan. Al-Tusi designed a number of instruments for the observatory, which became a center of scientific learning in Muslim Central Asia. There al-Tusi prepared the Ilkhanic Tables, which contained 12 years worth of astronomical observations. He also developed new hypotheses on the movement of planets, ideas some scholars consider the most important contributions to the understanding of cosmology between the time of Ptolemy (second century A.D.) and that of Nicolaus Copernicus (1473-1543).