Concentric

With concentric ( from the Latin con, "with" and centrum, "center ", so "with a [ single ] center " ) is called something symmetrical about a common center Ruled. Concentric are geometric figures, if they have the same focus.

Concentric circles

Of concentric circles is when several circles one and the same center but different radii, such as at a target or waves that propagate starting from a stone thrown into the water ( see picture). Concentric circles are - often combined with the spiral - one of the earliest known human ornaments at all.

During the Bronze Age, there are concentric circles, which are interpreted as a sun symbol, for example, in the petroglyphs on Carschenna and on the sun chariot of Trundholm. In late antiquity, specifically Christian imagery of the circular halo (Latin Nimbus ) symbolizes the divinity and a sacred personality, while the concentric circles represent the hierarchies of the Christian kingdom of heaven.

Concentric spheres are - by analogy - multiple balls at the same center with different radii.

Concentric squares

From concentric squares is when several squares have the same center but different side lengths. This creates a three-dimensional effect of depth.

Concentric squares often form test patterns as a basis for testing and quality assurance of cameras, lenses or electro-optical systems. In the modern nonrepresentational art can be found in the works of Vera Molnar (* 1924).

Concentric muscle contraction

From a concentric muscle contraction occurs when a muscle shortens forcibly, so for example, lifting a weight or accelerate an object. Here, the muscle performs physical work.

In contrast to the muscle contraction is concentric to the eccentric muscle contraction in a muscle is extended to its resistance, so, for example, a weight settling or movement slows down. This physical work is done on the muscle ( negative work of the muscle ).