sphärische

Sphärische refers to something relating to or resembling a sphere. In geometry, spherical describes figures or concepts associated with spheres. For instance, spherical geometry is a non-Euclidean geometry that studies the properties of figures on the surface of a sphere. Unlike Euclidean geometry, where parallel lines never meet, in spherical geometry, any two "great circles" (the largest possible circles on the surface of a sphere) will intersect at two antipodal points. This means there are no parallel lines in spherical geometry.

The term "spherical" is also used in physics and astronomy. Spherical coordinates are a system for specifying points in three-dimensional space using three numbers: a radial distance from the origin and two angles indicating the direction. This system is particularly useful for describing phenomena that exhibit spherical symmetry, such as the distribution of stars in a galaxy or the behavior of waves emanating from a point source. In optics, a spherical lens is one with a curved surface that is a segment of a sphere. These are common in eyeglasses and cameras, although they can introduce optical aberrations like spherical aberration, where light rays passing through different parts of the lens are focused at slightly different points. The concept of sphericity is fundamental to understanding many natural phenomena and is applied across various scientific disciplines.