## 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:

**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**" ...

... 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 ...

... 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 ...

**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 ...

**Sphere**s

... 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

- (
*noun*): The apparent surface of the imaginary sphere on which celestial bodies appear to be projected.

Synonyms: celestial sphere, empyrean, firmament, heavens, vault of heaven, welkin

### 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)