Image:Hypersphere_coord.PNG|right|frame|Stereographic projection of the hypersphere's parallels (red), meridians (blue) and hypermeridians (green). Due to conformal property of Stereographic projection, the curves intersect each other orthogonally (in the yellow points) as in 4D. All curves are circles: the curves that intersect <0,0,0,1> have infinite radius (= straight line). In mathematics, a 3-sphere is a higher-dimensional analogue of a sphere. It consists of the set of points equidistant from a fixed central point in 4-dimensional Euclidean space. Just as an ordinary sphere (or 2-sphere) is a two dimensional surface that forms the boundary of a ball in three dimensions, a 3-sphere is an object with three dimensions that forms the boundary of a ball in four dimensions. A 3-sphere is an example of a 3-manifold. A 3-sphere is also called a hypersphere, although the term hypersphere can in general describe any n-sphere for n ≥ 3.

[Last contributor : Jemebius , Content under LGPL licence]