Divergence

(redirected from divergency)
Also found in: Dictionary, Thesaurus, Medical, Financial, Wikipedia.

divergence

[də′vər·jəns]
(electronics)
The spreading of a cathode-ray stream due to repulsion of like charges (electrons).
(fluid mechanics)
The ratio of the area of any section of fluid emerging from a nozzle to the area of the throat of the nozzle.
(mathematics)
For a vector-valued function, the sum of the diagonal entries of the Jacobian matrix; it is the scalar product of the del operator and the vector.
(meteorology)
The two-dimensional horizontal divergence of the velocity field.
(nucleonics)
In a nuclear reactor, the condition wherein the number of neutrons produced increases in each succeeding generation.
(oceanography)
A horizontal flow of water, in different directions, from a common center or zone.
(physics)
The spreading apart of a beam of particles of light.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Divergence

 

in biology, the divergence of characters of organisms in the process of evolution.

The concept of divergence was proposed by C. Darwin to explain the appearance of diverse varieties of cultivated plants, breeds of domestic animals, and biological species in nature. In artificial selection divergence within each group of cultivated plants and domestic animals depends on the needs of man. Darwin used the principle of divergence to explain species formation in nature. If a species has a broad distribution and adapts to various ecological conditions, divergence takes place. Divergence is expressed in the appearance of differences in populations that were originally similar and is caused by the inevitably slightly different direction of natural selection in various parts of a species’ range. Divergence leads to the appearance of organisms that vary in structure and function; this in turn assures more complete use of environmental conditions, since, according to Darwin, the greatest “sum of life” is realized by the broadest variety of structures. Divergence is supported by the struggle for existence: usually even slightly specialized forms have selective advantages, which brings about more rapid extinction of intermediate forms and development of various types of isolation. The principle of divergence also explains the process of formation of larger (supraspecies) systematic groups and the rise of gaps between them.

A. V. IABLOKOV


Divergence

 

[of a vector field a(M) at a point (x, y, z)], the scalar quantity

div a = σPx + σQy + σRR/σZ

where P, Q, and R are components of the vector a. The divergence is the limit of the ratio of the flux of a vector field through a closed surface surrounding the given point, to the volume delimited by it when the surface contracts toward the point. Divergence plays an important role in the applications of mathematics to physics. For example, if the vector field a(M) is considered to be a velocity field in a steady flow of an incompressible fluid, then div a at a point designates the intensity of the source (div a > 0) or of the flow (div a < 0) located at this point, or the absence of source and flow (div a = 0). The properties of divergence are:

div (a + b) = div a + div b

div (φa) = φ div a + a grad φ div rot a =0

div grad φ = Δφ

where Δ is a Laplace operator.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

divergence

divergenceclick for a larger image
Directional divergence or divergence due to diffluent flow.
i. A static instability due to the aerodynamic loads which deform the control surface or body being greater than the elastic restoring forces.
ii. A situation in which a control application by the pilot results in uncommanded and/or undesirable behavior of the aircraft that is unintended by the pilot, such as a steepening spiral descent, spin, pitch-up, etc. Divergence may result in severe deformation or even breakup of the aircraft.
iii. A condition that exists when the distribution of winds within a given area results in a net horizontal flow of air outward from the region.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved

digital divergence

(1) See technology gap.

(2) Using digital technologies, the capability of creating infinite product variations that were far more difficult by mechanical methods. See Long Tail and digital convergence.
Copyright © 1981-2019 by The Computer Language Company Inc. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.
References in periodicals archive ?
In the small modulation amplitude limit, the wave equation becomes a Mathieu equation, and one has to face divergency problems in the numerical evaluation of these functions.
The case of divergency also occurs in the ridge curve extracted by the cost function scheme at a later stage.
They also discussed the relevant thermodynamic properties and deduced the vanishing temperature in the extreme configuration and thus eliminated the unfavorable divergency of the Hawking radiation.
This property means that the evaporation of black holes behaves well; that is, it has no divergency due to the appearance of the minimal length [7].
Due to the case-2 coherence factor describing the quasiparticle excitations in a superconductor, the conductivity only smoothly increases for [omega] > 2[DELTA]/[??], despite the divergency in the density of states right above and below the gap [46].
Also, according to Table 2, the lower bound of horizon radius and the first divergence point ([mathematical expression not reproducible]) will increase by increasing [beta] (the nonlinearity parameter), whereas the second point of divergency remains steady over this change.
Second, modifying the linear Maxwell theory to the nonlinear electrodynamics theory can eliminate the problem of divergency in electromagnetic field and leads to finite self-energy and finite electric potential at the origin.
In other words, considering the LNE and ENE branches, we could remove the lower bound divergency of electromagnetic field.