Sphere (disambiguation)
A sphere is an object shaped like a ball and can also be used to refer to a sphere-like region or shell.
Sphere may also refer to:
In mathematics
Spherical surface, the boundary of a sphere (also known simply as sphere in mathematics)
Spherical volume, the region inside a sphere (also known as a ball in mathematics)
n-sphere, the set of points at fixed distance from a central point in n+1 dimensional space
In sociology
Public sphere, an area where individuals can discuss social problems
In astronomy
Celestial sphere, the astronomical description of the sky
Armillary sphere, a physical model of the celestial sphere
Celestial spheres or planetary spheres, refer to a geocentric model of the universe and the associated postulate of a "Musica Universalis" (Music of the Spheres)
Hill sphere, the spherical region around an astronomical body where the primary gravitational influence on an orbiting object is that body
Sphere of influence (astrodynamics), similar to the Hill sphere, but smaller, only about 60% of the radius