An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



Number of Results: 15 Search : edge
absorbing wedge
  گُوه‌ی ِ درشمنده   
gove-ye daršamandé

Fr.: coin absorbant   

Optics: A strip or annulus of material, such as glass or film, whose density increases progressively from one end to the other. The function of the wedge is to weaken the light beam in an optical system.

Verbal adj. from → absorb; → wedge.


Fr.: reconnaître   

1) To admit to be real or true; recognize the existence, truth, or fact of.
2) To recognize the authority, validity, or claims of.
3) To show or express appreciation or gratitude for (

A blend of M.E aknow "admit or show one's knowledge" (from O.E. oncnawan "understand") and M.E. knowlechen "to admit."

Âdânidan, from âdân, from prefix â- + dân present stem of dânestan, → know; cf. Sogd. âzân, azân "to acknowledge, to confess," from prefixed zân, variant of dân.

directed edge
  لبه‌ی ِ سودار   
labe-ye sudâr

Fr.: graphe orienté   

In → graph theory, an edge where endpoints are distinguished; one is the head and the other is the tail. A directed edge is specified as an ordered pair of → vertices, u, v and is denoted by (u, v) or uv.

directed; → edge.


Fr.: dragage, remontée   

A process by which the nucleosynthesis products inside a star are drawn to upper layers of the star. → first dredge-up; → second dredge-up; → third dredge-up.

From M.E. (Scots) dreg-, O.E. draeg- (in drægnet "dragnet"), akin to dragan "to draw" + up.

Birunkašid, past stem of birun kašidan, from birun "out, the outside" (Mid.Pers. bêron, from "outside, out, away" + rôn "side, direction," Av. ravan- "(course of a) river") + kašidan "to draw," Mid.Pers. kašitan, Av. karš- "to draw," Skt. kars-, kársati "to pull, drag, plough," Gk. pelo, pelomai "to be busy, to bustle."

  ۱) لبه؛ ۲) تیغه   
1) labé (#); 2) tiqé (#)

Fr.: 1) bord; 2) tranchant, fil   

1) A line or border at which a surface terminates.
2) The thin, sharp side of the blade of a cutting instrument or weapon (
3) In → graph theory, any line in a → graph that joins two distinct → nodes. Any pair of → vertices.

M.E. egge; O.E. ecg "corner, edge;" cf. Ger. Eck "corner;" PIE base *ak- "sharp, pointed" (cf. L. acies; Gk. akis "point").

1) Labé "limb, edge," from lab "lip;" Mid.Pers. lap; cognate with L. labium; E. lip; Ger. Lefze.
2) Tiqé "blade of a knife or sword," from tiq "blade," tiz "sharp," variants tig, tež, tej, tij; Mid.Pers. tigr, têz, têž "sharp," O.Pers. tigra- "pointed," tigra.xauda- "pointed helmet (epithet of Scythians);" Av. tiγra- "pointed," tiγray- "arrow," tiži.arštay- "with the pointed spear," cf. Skt. tikta- "sharp, pungent, bitter," tejas- "sharpness, edge, point or top of a flame;" PIE base *st(e)ig- "to stick; pointed." Cognates in other IE languages: Gk. stizein "to prick, puncture," stigma "mark made by a pointed instrument," L. in-stigare "to goad," O.H.G. stehhan, Ger. stechen "to stab, prick," Du. stecken, O.E. sticca "rod, twig, spoon," E. stick.

edge-on galaxy
  کهکشان ِ پهلونما   
kahkašân-e pahlunemâ

Fr.: galaxie vue par la tranche   

A → spiral galaxy oriented edge-on to our view. → face-on galaxy.

edge; on, from O.E. on, variant of an "in, on, into" (cf. Du. aan; Ger. an; Goth. ana "on, upon"), from PIE base *ano "on" (cf. Av. ana "on;" Gk. ana "on, upon;" L. an-); → galaxy.

Kahkašân, → galaxy; pahlunemâ "showing the side," from pahlu, → side, + nemâ, from nemudan "to show, display," → display.

first dredge-up
  برونکشید ِ نخست   
borunkašid-e naxost

Fr.: premier dragage   

The → dredge-up occurring after core hydrogen burning as the core contracts before helium burning ignites (on the ascending giant branch). The hydrogen envelope becomes convective and this convective zone penetrates deep into the core dredging up material that has been processed by the central nuclear reactions. As a result the abundances of helium and nitrogen are boosted.

first; → dredge-up.

Foucault knife-edge test
  آزمون ِ کارد ِ فوکو   
âzmun-e kârd-e Foucault

Fr.: contrôle par foucaultage   

A method used to test the → image quality of → mirrors and → lenses. The test is performed by moving a knife edge laterally into the → image of a small → point source. The → eye, or a → camera, is placed immediately behind the knife edge, and the → exit pupil of the system is observed.

Named after the French physicist Léon Foucault (1819-1868), who invented the method; → knife; → edge; → test.

knife-edge test
  آزمون ِ کارد   
âzmun-e kârd (#)

Fr.: contrôle par foucaultage   

The same as → Foucault knife-edge test.

knife; → edge; → test.

šenâxt (#)

Fr.: connaissance   

1) All the information, facts, truths, and principles learned throughout time.
2) Acquaintance with facts, truths, or principles, as from study or investigation.

M.E. cnawlece, from O.E. cnawan, cf. O.H.G. bi-chnaan, ir-chnaan "to know;" cognate with Pers. šenâxt, as below.

Šenâxt, past stem of šenâxtan, šenâsidan "to know, discern, distinguish, be acquainted with;" Mid.Pers. šnâxtan, šnâs- "to know, recognize," dânestan "to know;" O.Pers./Av. xšnā- "to know, learn, come to know, recognize;" cf. Skt. jñā- "to recognize, know," jānāti "he knows;" Gk. gignoskein "to know, think, judge;" L. gnoscere, noscere "to come to know" (Fr. connaître; Sp. conocer); O.E. cnawan; E. know; Rus. znat "to know;" PIE base *gno- "to know."

Rindler wedge
  گوه‌ی ِ ریندلر   
gove-ye Rindler

Fr.: coin de Rindler   

A portion of the → space-time described by → Rindler coordinates.

Rindler coordinates; → wedge.

second dredge-up
  برونکشید ِ دوم   
borunkašid-e dovom

Fr.: deuxième dragage   

A → dredge-up process that occurs after core helium burning, in which the convective envelope penetrates much more deeply, pushing hydrogen burning shell into close proximity with the helium burning shell (→ first dredge-up). This arrangement is unstable and leads to burning pulses. The reason is that the hydrogen shell burns out until there is enough helium for the helium combustion to occur and all the helium is rapidly burnt. Afterward the hydrogen shell again burns outward and the process repeats.

second; → dredge-up.

third dredge-up
  برونکشید ِ سوم   
borunkešid-e sevom

Fr.: troisième dragage   

A → dredge-up process that occurs in the stellar interior during He shell burning, as in → asymptotic giant branch (AGB) stars. These stars consist of a degenerate carbon-oxygen core, surrounded by a helium-rich region, above which lies a hydrogen-rich convective envelope. Following thermal pulses of the helium-burning shell, the convective envelope moves inward in mass, penetrating the hydrogen-exhausted regions. This is known as third dredge-up. As convection moves inward, nuclear processed materials are carried to the surface.

third; → dredge-up.

  گو ِه   
gové (#)

Fr.: coin   

A glass prism of very small angle used as an optical element to divert the path of a beam of light for a particular purpose. → absorbing wedge.

M.E. wegge; O.E. wecg "a wedge," cf. M.Du. wegge, Du. wig, O.H.G. weggi "wedge," Ger. Weck "wedge-shaped bread roll."

Gové "wedge;" Av. vada- "wedge," xvaδa- "deadly weapon;" cf. Skt. vadhá- "killer, deadly weapon," vadh- "to slay, kill;" Gk. othein "to push" (root of → osmosis).

wedge photometer
  نورسنج ِ گُوه‌ای   
nursanj-e gove-yi

Fr.: photomètre à coin   

A photometer in which an → absorbing wedge is inserted in the brighter of two beams until the flux densities of the two light sources are equal.

wedge; → photometer.