# REDIRECT Reciprocity ( electromagnetism )

Reciprocity is closely related to the concept of Hermitian operators from linear algebra, applied to electromagnetism.

Reciprocity is useful in optics, which ( apart from quantum effects ) can be expressed in terms of classical electromagnetism, but also in terms of radiometry.

* Brady Ivan, Kinship Reciprocity in the Ellice Islands, Journal of Polynesian Society 81: 3 ( 1972 ), 290-316

* cancellation of the Canadian-American Reciprocity Treaty ( a free trade policy whereby products were allowed into United States without taxes or tariffs starting in 1854 ), which was then considered to be beneficial for Canada, in 1865 by the United States, partly as a revenge against Great Britain for unofficial support of the South in the American Civil War

* Reciprocity ( Canadian politics ), used to describe the concept of free trade with the United States of America

* Reciprocity ( photography ), the relationship between the intensity of the light and duration of the exposure that result in identical exposure

* Reciprocity ( Fringe ), a 2011 episode of the television series Fringe

* Reciprocity ( cultural anthropology ), way of defining people's informal exchange of goods and labour

* Reciprocity ( evolution ), mechanisms for the evolution of cooperation

* Reciprocity ( international relations ), principle that favours, benefits, or penalties that are granted by one state to the citizens or legal entities of another, should be returned in kind

* Reciprocity ( social and political philosophy ), concept of reciprocity as in-kind positive or negative responses for the actions of others

* Reciprocity ( social psychology ), in-kind positively or negatively connotated responses of individuals towards the actions of others

* Reciprocity ( engineering ), used in the analysis of structures and to resolve complex load conditions

* Reciprocity ( network theory ), theorem about transfer function of passive networks

* Reciprocity theorem ( disambiguation ), several unrelated results

* Reciprocity ( projective geometry ), a collineation from a projective space onto its dual space, taking points to hyperplanes ( and vice versa ) and preserving incidence

* Berg, Dickhaut, McCabe ( 1995 ): " Trust, Reciprocity and Social History ," Games and Economic Behavior 10 ( 1995 ), p122-42

* Dufwenberg and Kirchsteiger ( 2000 ), “ Reciprocity and wage undercutting ,” European Economic Review 44, ( 2000 ), p1069-1078

* Fehr, Gächter, Kirchsteiger ( 1997 ), “ Reciprocity as a Contract Enforcement Device ”, Econometrica, 65 ( 4 ) ( July 1997 ), p833-60

( 1986 ), “ Reciprocity in international relations ”, in International Organisation, Vol. 40, No. 1.

Reciprocity as a form of social obligation calling for future acts kindness can be seen in the Japanese word for thank you, " sumimasen ," which means " this will not end " It is also presented in the Bulgarian word for thank you " Благо-даря " ( blago-dariya ), which means " Good I'll Give ".

Menier was the author of several works on fiscal and economic questions, notably L ' impôt sur le capital ( 1872 ), La Réforme fiscale ( 1872 ), Economie rurale ( 1875 ), L ' Avenir économique ( 1875-1878 ), Atlas de la production de la richesse ( 1878 ) and, published in the English language by G. P. Putnam's Sons, New York City in 1878, France And The United States: Their Present Commercial Relations Considered With Reference to a Treaty of Reciprocity ( downloadable )

See also Reciprocity ( mathematics ) for unrelated reciprocity theorems, and Reciprocity ( disambiguation ) for more general usages of the term.

Reciprocity is also a basic lemma that is used to prove other theorems about electromagnetic systems, such as the symmetry of the impedance matrix and scattering matrix, symmetries of Green's functions for use in boundary-element and transfer-matrix computational methods, as well as orthogonality properties of harmonic modes in waveguide systems ( as an alternative to proving those properties directly from the symmetries of the eigen-operators ).

There he was an alternate member of the Committee for Reciprocity Information, which took care of technical work relating to trade agreements under the Reciprocal Trade Agreement Act and doing preparatory work for the International Trade Organization.

* Chirality ( electromagnetism ), an electromagnetic propagation in chiral media

Conversely, one might expect that inertial motions, once identified by observing the actual motions of bodies and making allowances for the external forces ( such as electromagnetism or friction ), can be used to define the geometry of space, as well as a time coordinate.

In modern geometry, the extra fifth dimension can be understood to be the circle group U ( 1 ), as electromagnetism can essentially be formulated as a gauge theory on a fiber bundle, the circle bundle, with gauge group U ( 1 ).

* Null ( radio ), a concept in electromagnetism

File: H. C. Ørsted ( C. A. Jensen ). jpg | Hans Christian Ørsted ( 1777 – 1851 ): discovered that electric currents create magnetic fields ( an important aspect of electromagnetism ), shaped advances in science in the late 19th century, namesake of the oersted ( Oe ) ( the cgs unit of magnetic H-field strength )

Quarks are the only elementary particles in the Standard Model of particle physics to experience all four fundamental interactions, also known as fundamental forces ( electromagnetism, gravitation, strong interaction, and weak interaction ), as well as the only known particles whose electric charges are not integer multiples of the elementary charge.

Two physical phenomena which are described by classical fields are Newtonian gravitation, described by Newtonian gravitational field g ( x, t ), and classical electromagnetism, described by the electric and magnetic fields E ( x, t ) and B ( x, t ).

Despite the nomenclature, the " field " under study is the gravitational potential, φ, rather than the gravitational field, g. Similarly, when classical field theory is used to study electromagnetism, the " field " of interest is the electromagnetic four-potential ( V / c, A ), rather than the electric and magnetic fields E and B.

After 1915, when Albert Einstein published the theory of gravity ( general relativity ), the search for a unified field theory combining gravity with electromagnetism started again with renewed intensity.

In the twentieth century, the search for a unifying theory was interrupted by the discovery of the strong and weak nuclear forces ( or interactions ), which differ both from gravity and from electromagnetism.

Named for Hans Christian Ørsted ( often rendered Oersted in English ; 14 August 1777 – 9 March 1851 ), a Danish physicist and chemist who discovered that electric currents create magnetic fields, an important aspect of electromagnetism.

Unlike quarks however, leptons are not subject to the strong interaction, but they are subject to the other three fundamental interactions: gravitation, electromagnetism ( excluding neutrinos, which are electrically neutral ), and the weak interaction.

* Permeability ( electromagnetism ), the degree of magnetization of a material in response to a magnetic field

* Electromagnetic therapy ( alternative medicine ), the unscientific use of electromagnetism in alternative medicine

It is named after the physicist Hans Christian Ørsted ( 1777 – 1851 ), who discovered electromagnetism ( 1820 ) and was the first to isolate aluminium ( 1825 ).

A significant part of this larger enterprise is the quest for a theory of quantum gravity, which would unify the classical theory of general relativity and the Standard Model, which explains the other three basic forces in physics ( electromagnetism, the strong interaction, and the weak interaction ), and provides a palette of fundamental particles upon which all four forces act.

Core subjects required for graduation with a TAMS diploma are biology, chemistry, physics ( mechanics and electromagnetism ), mathematics ( precalculus and calculus ), English literature, US history, and political science.

In special relativity, electromagnetism and wave theory, the d ' Alembert operator ( represented by a box: ), also called the d ' Alembertian or the wave operator, is the Laplace operator of Minkowski space.

The original choice of G in the physics of electromagnetism was U ( 1 ), which is commutative.

The term electromagnetic propulsion ( EMP ) can be described by its individual components: electromagnetic-using electricity to create a magnetic field ( electromagnetism ), and propulsion-the process of propelling something.

In 1962, Universitetets Kemiske Laboratorium moved to its present location in the H. C. Ørsted Institute ( HCØ ), named after Hans Christian Ørsted who discovered electromagnetism in 1820.

The four Maxwell's equations ( including the Maxwell – Faraday equation ), along with the Lorentz force law, are a sufficient foundation to derive everything in classical electromagnetism.