Sfäärilised

Sfäärilised is Estonian adjective describing objects, surfaces or shapes that have the form of a sphere or are closely approximating a sphere. The term is used across disciplines to indicate spherical geometry and symmetry, in contrast with other closed surfaces such as ellipsoids or cylinders. It is derived from the noun sfäär, meaning sphere, and is commonly attached to nouns to denote spherical characteristics, for example sfääriline pind or sfäärilised koordinaadid.

In geometry, a perfect sphere is the set of all points at a fixed distance, called the radius, from a central point. Thus a sfääriline pind refers to a spherical surface, while sfääriline keha denotes a solid sphere. Spherical coordinates, often described in Estonian as sfäärilised koordinaadid, express positions using a radius and two angles, rather than Cartesian x, y and z.

The term is also used to describe approximate shapes in science and engineering. Many natural and manufactured objects are treated as sfäärilised for modelling purposes when their shape is close to a sphere, such as droplets, bubbles or some celestial bodies. In Earth sciences, the planet is commonly modeled as an oblate spheroid rather than a perfect sphere to account for equatorial bulge.

In practical contexts, sfäärilised forms are valued for their symmetry and uniform curvature, which simplify mathematical treatment and visual rendering in computer graphics and design. The concept also informs discussions of surface tension, optics and acoustics, where spherical or near-spherical geometries influence behavior and performance.