Concentricity
With concentric (from latin con , "with" and centrum , "center" ie "with a [single] center") refers to something symmetrical about a common center Arranged. Geometric figures are concentric if they have the same center of gravity .
Concentric circles
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One speaks of concentric circles when several circles have the same center point but different radii , as is the case with a target or with waves that spread out from a stone thrown into the water (see picture). Concentric circles are - often combined with the spiral - one of the oldest ornaments ever to have been handed down by humans .
During the Bronze Age, there are concentric circles that are interpreted as a sun symbol, e.g. B. in the rock carvings on Carschenna and on the sun chariot of Trundholm , or structurally as henge and stone circles ( Gunnerkeld , Yellowmead Down ) etc. In late antique , especially Christian imagery, the circular halo ( Latin nimbus ) symbolizes divinity and a holy personality, while the concentric circles depict the hierarchies of the Christian kingdom of heaven.
Concentric spheres are - analogously - several spheres around the same center point, with different radii.
Concentric squares
Concentric squares are used when several squares have the same center point but different side lengths. This creates a spatial depth effect.
Concentric squares often form test patterns as the basis for testing and quality assurance of cameras, lenses or electro-optical systems. In modern non-representational art they can be found in the works of Vera Molnár (* 1924).
Concentric muscle contraction
A concentric muscle contraction is when a muscle shortens when force is exerted, for example lifting a weight or accelerating an object. The muscle does physical work .
In contrast to concentric muscle contraction, there is eccentric muscle contraction , in which a muscle is lengthened against its resistance, for example, putting down a weight or braking a movement. This involves doing physical work on the muscle (negative work of the muscle).
military
A concentric attack or concentric fire is an attack from all directions or from different sides on a common target.
