What is sphere?

  • (noun): A three-dimensional closed surface such that every point on the surface is equidistant from the center.
    See also — Additional definitions below


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.

Read more about Sphere.

Some articles on sphere:

Marcus Theory - Outer Sphere Electron Transfer
... complexes, are tightly bound and constitute the "inner sphere" ... Reactions in which these participate are called inner sphere redox reactions ... The free solvent molecules constitute the "outer sphere" ...
Geotrekking - Navigation Equations - Trilateration
... Satellite position and pseudorange determines a sphere centered on the satellite with radius equal to the pseudorange ... is used to estimate 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
... Each vertex 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 dimensions (the kissing number) is 126 ...
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 ... 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 ...
Cubes in Relation To Spheres
... For every sphere there are multiple cuboids that may be inscribed within the sphere ... The largest cuboid which can be inscribed within a sphere is a cube ...

More definitions of "sphere":

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

Famous quotes containing the word sphere:

    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–?)

    Don’t feel guilty if you don’t immediately love your stepchildren as you do your own, or as much as you think you should. Everyone needs time to adjust to the new family, adults included. There is no such thing as an “instant parent.”
    Actually, no concrete object lies outside of the poetic sphere as long as the poet knows how to use the object properly.
    Johann Wolfgang Von Goethe (1749–1832)

    Thought dissolves the material universe by carrying the mind up into a sphere where all is plastic.
    Ralph Waldo Emerson (1803–1882)