Sphere
A sphere (from Greek σφαῖρα — sphaira, "globe, ball") is a perfectly round geometrical object in three-dimensional space, such as the shape of a round ball. Like a circle, which is in two dimensions, a sphere is the set of points which are all the same distance r from a given point in space. This distance r is known as the "radius" of the sphere, and the given point is known as the center of the sphere. The maximum straight distance through the sphere is known as the "diameter". It passes through the center and is thus twice the radius.
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Famous quotes containing the word sphere:
“It is in the nature of allegory, as opposed to symbolism, to beg the question of absolute reality. The allegorist avails himself of a formal correspondence between “ideas” and “things,” both of which he assumes as given; he need not inquire whether either sphere is “real” or whether, in the final analysis, reality consists in their interaction.”
—Charles, Jr. Feidelson, U.S. educator, critic. Symbolism and American Literature, ch. 1, University of Chicago Press (1953)
“In the new science of the twenty-first century, not physical force but spiritual force will lead the way. Mental and spiritual gifts will be more in demand than gifts of a physical nature. Extrasensory perception will take precedence over sensory perception. And in this sphere woman will again predominate.”
—Elizabeth Gould Davis (b. 1910)
“For my part, I have no hesitation in saying that although the American woman never leaves her domestic sphere and is in some respects very dependent within it, nowhere does she enjoy a higher station . . . if anyone asks me what I think the chief cause of the extraordinary prosperity and growing power of this nation, I should answer that it is due to the superiority of their woman.”
—Alexis de Tocqueville (1805–1859)