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:
“A man should not go where he cannot carry his whole sphere or society with him,Mnot bodily, the whole circle of his friends, but atmospherically. He should preserve in a new company the same attitude of mind and reality of relation, which his daily associates draw him to, else he is shorn of his best beams, and will be an orphan in the merriest club.”
—Ralph Waldo Emerson (18031882)
“A knowledge of the Globe and its various inhabitants, however slight ... has a kindred effect with that of seeing them as travellers, which never fails, in uncorrupted minds, to weaken local prejudices, and enlarge the sphere of benevolent feelings.”
—James Madison (17511836)
“Everything goes, everything comes back; eternally rolls the wheel of being. Everything dies, everything blossoms again; eternally runs the year of being. Everything breaks, everything is joined anew; eternally the same house of being is built. Everything parts, everything greets every other thing again; eternally the ring of being remains faithful to itself. In every Now, being begins; round every Here rolls the sphere There. The center is everywhere. Bent is the path of eternity.”
—Friedrich Nietzsche (18441900)