An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < B r bac Bal Bar Bar Bay bed Bes bi- bif bin bin bio bit bla bli blu Boh Bol Bos bou bra bri bro buo > >>

Number of Results: 491
Bose-Einstein distribution
  واباژش ِ بوز-اینشتین   
vâbâžeš-e Bose-Einstein

Fr.: distribution de Bose-Einstein   

For a → population of independent → bosons, a function that specifies the number of particles in each of the allowed → energy states.

boson; → Einstein; → distribution.

Bose-Einstein statistics
  آمار ِ بوز-اینشتین   
âmâr-e Bose-Einstein (#)

Fr.: statistique de Bose-Einstein   

Same as → Bose-Einstein distribution.

boson; → Einstein; → statistics.

boson (#)

Fr.: boson   

Any of a class of particles (such as the → photon, → pion, or → alpha particle) that have zero or integral → spin and do not obey the → Pauli exclusion principle. The energy distribution of bosons is described by → Bose-Einstein statistics. See also: → gauge boson, → Higgs boson, → W boson, → Z boson, → intermediate boson.

Boson, in honor of the Indian-American physicist Satyendra Nath Bose (1894-1974).

giyâhšenâsi (#)

Fr.: botanique   

The branch of → biology that deals with → plants.

From botanic, from Fr. botanique, M.L. botanicus, from Gk. botanikos "of herbs," from botane "herb, grass, pasture."

Giyâhšenâsi, from giyâh, → plant, + šenâsi, → -logy.

Botein (δ Ari)
Boteyn (#)

Fr.: Botein   

A dim, red star in the constellation → Aries; a → giant of → spectral type K2 III at a distance of 168 light-years.

Botein, from Ar. Al-Butain "the little belly."

Boteyn, from Ar. Al-Butain.

botri (#)

Fr.: bouteille   

A portable vessel for liquids, typically cylindrical and often of glass or plastic with a narrow neck that can be closed. → magnetic bottle, → Leyden jar.

From O.Fr. bo(u)teille, from L.L. butticula diminutive of L. buttis "a cask."

Botri, loan from Fr. bouteille or E. bottle, as above.

  ته، پایین   
tah (#), pâyin (#)

Fr.: bas, fond   

1) The lowest or deepest part of anything, as distinguished from the → top. The under or lower side; underside. → bottom-up structure formation.
2) → bottom quark.

M.E. botme; O.E. botm, bodan "ground, soil, lowest part" (cf. O.Fris. boden "soil," O.N. botn, O.H.G. bodam, Ger. Boden "ground, earth, soil"), akin to Pers. bon "basis; root; foundation; bottom;" Mid.Pers. bun "root; foundation; beginning;" Av. būna- "base, depth" (Skt. bundha-, budhná- "base, bottom," Pali bunda- "root of tree;" Gk. pythmen "foundation;" L. fundus "bottom, piece of land, farm," O.Ir. bond "sole of the foot").

Tah "bottom; end" (Mid.Pers. tah "bottom." The origin of this term is not clear. It may be related to PIE *tenegos "water bottom;" cf. Gk. tenagos "bottom, swamp," Latvian tigas, from *tingas, from *tenegos "depth").
Pâyin "bottom, below; at the foot of," from pâ(y) "foot; step" (Mid.Pers. pâd, pây; Av. pad- "foot;" cf. Skt. pat; Gk. pos, genitive podos; L. pes, genitive pedis (Fr. pied); P.Gmc. *fot (E. foot; Ger. Fuss); PIE *pod-/*ped-); + -in a relation suffix.

bottom-up structure formation
  دیسش ِ ساختار از پایین به بالا   
diseš-e sâxtâr az pâyin bé bâlâ

Fr.: formation des structures du bas vers le haut   

A → structure formation scenario in which small galaxies form first, and larger structures are then formed in due course. Contrary to → top-down structure formation.

bottom; → up; → structure; → formation; → galaxy.

  ۱) بندیده؛ ۲) کران   
1) bandidé; 2) karân

Fr.: lié; lien   

1) (adj.) Tied, confined by bonds. → bound cluster, → bound charge, → bound system.
2) (n) a boundary; a limit.

1) p.p. of → bind. 2) → boundary.

bound charge
  بارِ بندیده   
bâr-e bandidé

Fr.: charge liée   

Any electric charge which is bound to an atom or molecule, in contrast to free charge, such as metallic conduction electrons, which is not. Also known as → polarization charge.

bound; → charge.

bound cluster
  خوشه‌ی ِ بندیده   
xuše-ye bandidé

Fr.: amas lié   

A cluster of astronomical objects, such as stars or galaxies, held together by their mutual gravitational attraction. → bound system.

Bound, p.p. of → bind; → cluster.

Xušé, → cluster; bandidé p.p. of bandidan, → bind.

bound occurrence
  رخداد ِ بندیده   
roxdâd-e bandidé

Fr.: occurrence liée   

Any → occurrence of a → variable  x in an x-bound part of a → wff.

bound; → occurrence.

bound orbit
  مدار ِ بندیده   
madâr-e bandidé

Fr.: orbite liée   

The orbit described by an object around a central gravitational force in a system whose total energy is negative. An elliptical orbit.

Bound, p.p. of → bind; → orbit.

Madâr, → orbit; bandidé, p.p. of bandidan, → bind.

bound system
  راژمان ِ بندیده   
râžmân-e bandidé

Fr.: système lié   

A system composed of several material bodies the total energy of which (the sum of kinetic and potential energies) is negative, e.g. a → bound cluster.

Bound, p.p. of → bind; → system.

Aâžmân, → system; bandidé p.p. of bandidan, → bind.

bound-bound transition
  گذرش ِ بندیده-بندیده   
gozareš-e bandidé-bandidé

Fr.: transition liée-liée   

A transition between two energy levels of an electron bound to a nucleus. The electron remains tied to the nucleus before and after the transition. → bound-free transition; → free-free emission.

Bound, p.p. of → bind; → transition.

bound-free transition
  گذرش ِ بندیده-آزاد   
gozareš-e bandidé-âzâd

Fr.: transition liée-libre   

A transition in which a bound electron is liberated. → free-bound emission; → free-free emission.

Bound, p.p. of → bind; → free.

karân (#)

Fr.: limite, bord   

1) General: Something that indicates a border or limit; the border or limit so indicated.
2) Thermodynamics: A conceptual closed surface useful in separating and distinguishing a system from its surroundings.
3) Math.: In topology, the boundary of a subset S of a topological space X is the set of points which can be approached both from S and from the outside of S.
4) Electronics: An area of meeting of P-type and N-type → semiconductor materials where the → donor and → acceptor concentrations are equal.

From Fr., from O.Fr. bodne, from M.L. bodina, butina "boundary, boundary marker."

Karân, karâné, kenâr from Mid.Pers. karânag, Av. karana- "boundary."

boundary conditions
  بوتارها‌ی ِ کران، ~ کرانی   
butârhâ-ye karân, ~ karâni

Fr.: conditions à la limite   

1) Math: Restriction on the limits of applicability of an equation. In a differential equation, conditions that allow to fix the constant of integration and reach a unique solution. The number of boundary conditions necessary to determine a solution matches the order of the equation.
2) Physics: Conditions needed to determine the evolution of a system, given the physical laws.

boundary; → condition.

boundary effect
  اسکر ِ کران   
oskar-e karân

Fr.: effet de bords   

An effect that forbids or invalidate locally the use of an idealized model of a system in which one or several of its dimensions are supposed to be infinite.

boundary; → effect.

boundary layer
  لایه‌ی ِ کرانی   
lâye-ye karâni

Fr.: couche limite   

A layer of fluid that is formed wherever a fluid flows past a solid surface and the effects of → viscosity are important. The boundary level forms because as the fluid moves past the object, the molecules which are in direct contact with the surface stick to the surface. The molecules just above the surface are slowed down in their collisions with the molecules sticking to the surface. These molecules in turn slow down the flow just above them, but less effectively. This creates a thin layer of fluid near the surface in which the velocity changes from zero at the surface to the free stream value away from the surface. The boundary layer may be either → laminar or → turbulent in character, depending on the value of the → Reynolds number. The concept of boundary level was first put forward by Ludwig Prandlt (1875-1953) in 1904.

boundary; → layer.

<< < B r bac Bal Bar Bar Bay bed Bes bi- bif bin bin bio bit bla bli blu Boh Bol Bos bou bra bri bro buo > >>