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:
“If today there is a proper American sphere of influence it is this fragile sphere called earth upon which all men live and share a common fatea sphere where our influence must be for peace and justice.”
—Hubert H. Humphrey (19111978)
“Wherever the State touches the personal life of the infant, the child, the youth, or the aged, helpless, defective in mind, body or moral nature, there the State enters womans peculiar sphere, her sphere of motherly succor and training, her sphere of sympathetic and self-sacrificing ministration to individual lives.”
—Anna Garlin Spencer (18511931)