What is 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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Some articles on sphere:

Marcus Theory - Outer Sphere Electron Transfer
... in complexes, are tightly bound and constitute the "inner sphere" ... Reactions in which these participate are called inner sphere redox reactions ... solvent molecules constitute the "outer sphere" ...
Cubes in Relation To Spheres
... For every sphere there are multiple cuboids that may be inscribed within the sphere ... largest cuboid which can be inscribed within a sphere is a cube ...
Geotrekking - Navigation Equations - Trilateration
... position and pseudorange determines a sphere centered on the satellite with radius equal to the pseudorange ... receiver position based on the intersection of three sphere surfaces so determined ... In the usual case of two intersections of three sphere surfaces, the point nearest the surface of the sphere corresponding to the fourth satellite is chosen ...
1 33 Honeycomb - Kissing Number
... of this polytope corresponds to the center of a 6-sphere in a moderately dense sphere packing, in which each sphere is tangent to 70 others the best known for 7 ...
Kline Sphere Characterization
... In mathematics, a Kline sphere characterization, named after John Robert Kline, is a topological characterization of a two-dimensional sphere in terms of what sort of subset separates it ... A simple closed curve in a two-dimensional sphere (for instance, its equator) separates the sphere into two pieces upon removal ... If one removes a pair of points from a sphere, however, the remainder is connected ...

More definitions of "sphere":

  • (noun): A particular aspect of life or activity.
    Synonyms: sector
  • (noun): Any spherically shaped artifact.
  • (noun): The geographical area in which one nation is very influential.
    Synonyms: sphere of influence
  • (noun): A solid figure bounded by a spherical surface (including the space it encloses).
  • (noun): A particular environment or walk of life.
    Example: "His social sphere is limited"
    Synonyms: domain, area, orbit, field, arena
  • (noun): A three-dimensional closed surface such that every point on the surface is equidistant from the center.

Famous quotes containing the word sphere:

    I count him a great man who inhabits a higher sphere of thought, into which other men rise with labor and difficulty; he has but to open his eyes to see things in a true light, and in large relations; whilst they must make painful corrections, and keep a vigilant eye on many sources of error.
    Ralph Waldo Emerson (1803–1882)

    No person can be considered as possessing a good education without religion. A good education is that which prepares us for our future sphere of action and makes us contented with that situation in life in which God, in his infinite mercy, has seen fit to place us, to be perfectly resigned to our lot in life, whatever it may be.
    Ann Plato (1820–?)

    Every person is responsible for all the good within the scope of his abilities, and for no more, and none can tell whose sphere is the largest.
    Gail Hamilton (1833–1896)