An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

1) A line or border at which a surface terminates.
2) The thin, sharp side of the blade of a cutting instrument or weapon (Dictionary.com).
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.

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.

To modify or prepare for publication or public presentation by checking, improving, cutting, rearranging, etc.

Back formation from editor or from Fr. éditer, or from L. editus, p.p. of edere "bring forth, produce," from → ex- "out," + -dere, combining form of dare "to give," → datum.

Virâstan, from Mid.Pers. virâstan "to arrange, prepare, restore," from prefix vi- "apart, away from, out" (Av. vi-; O.Pers. viy- "apart, away;" cf. Skt. vi- "apart, asunder, away, out;" L. vitare "to avoid, turn aside") + râstan "to arrange, to set in order," → coordinate.

1) The act or process of editing.
2) A version of anything, printed or not, presented to the public.

Verbal noun of → edit.

1) A person who edits material for publication or public presentation.
2) A computer program that enables creating and editing text files.

Agent noun of → edit.

1) An article in a newspaper or other periodical or on a website presenting the opinion of the publisher, writer, or editor.
2) A statement broadcast on radio or television that presents the opinion of the owner, manager, or the like, of the program, station, or channel (Dictionary.com).

→ editor + -i- + → -al.

To give knowledge or develop the faculties and powers of somebody by teaching. instruction.

From L. educatus, p.p. of educare "bring up, rear, educate," from → ex- "out" + ducere "to lead."

Farhixtan, "educate," literally "drawing forward, pulling up;" from far- perfection prefix, → pro-, + hanjidan "to draw," → culture.

The act or process of educating.
The knowledge or abilities gained through being educated.

Verbal noun of → educate.

1) Something brought about by a → cause or agent; a result.
2) A scientific law, hypothesis, or phenomenon, such as the → Compton effect, → Coriolis effect, → Doppler effect, → diamond ring effect, → photoelectric effect, and so on.

From O.Fr. effect, from L. effectus "accomplishment, performance," from stem of efficere "to work out, accomplish," from → ex- "out" + facere "to do, to make," from PIE base *dhe- "to put, to do;" cf. Mod.Pers. dâdan "to give," Mid.Pers. dâdan "to give," O.Pers./Av. dā- "to give, grant, yield," dadāiti "he gives;" Skt. dadáti "he gives," Gk. didomi "I give," tithenai "to put, set, place;" L. dare "to give, offer;" Rus. delat "to do;" O.H.G. tuon, Ger. tun, O.E. don "to do."

Oskar, from os-, → ex-, + kar-, kardan "to do, make;" Mid.Pers. kardan; O.Pers./Av. kar- "to do, make, build," Av. kərənaoiti "he makes;" cf. Skt. kr- "to do, to make," krnoti "he makes, he does," karoti "he makes, he does," karma "act, deed;" PIE base k^wer- "to do, to make."

Actually in operation or in force; concrete; real.

M.E., from L. effectivus "practical," from effect(us), p.p. of efficere, → effect + -ivus "-ive."

Oskarmand, from oskar, → effect + -mand possession suffix.

Of an antenna, the ratio of the extracted power by the antenna to the power per unit area (power density) in the incident wave.

→ effective; → aperture.

The effective value of the → Eddington parameter in a non-homogeneous system (porous opacity).

→ effective; → Eddington limit; → parameter.

The focal length of an imaging system, which consists of several lenses or mirrors.

→ effective; → focal length.

In a → rotating star, the sum of the → gravity and the → centrifugal acceleration. The effective gravity is a function of the rotation velocity (Ω) and the → colatitude (θ). At the pole (θ = 0°) and the equator (θ = 90°) the effective gravity is radial. See also → total gravity.

→ effective; → gravity.

Of a galaxy, the distance from its center within which half of the total luminosity is included.

→ effective; → radius.

A measure of the surface temperature of a star derived from the total emitted energy, assuming that the star is a → blackbody emitter (→ Stefan-Boltzmann law, → Planck's radiation law). See also → brightness temperature; → color temperature.

→ effective; → temperature.

The degree to which goals are achieved and the extent to which posed problems are solved. Compare → efficiency.

→ effective; → -ness.

Power or capacity to produce a desired effect; → effectiveness.

From L. efficacia "efficacy, efficiency," from efficax "powerful, effectual, efficient," from stem of efficere "accomplish," → effect.

Oskarmandi, → effectiveness.

1) The state or quality of being efficient; competence. Compare → effectiveness.
Of a machine, engine, or device, the ratio of the physical quantity which may be stored, transferred, or transformed to the total input quantity.

L efficientia, from efficient-, → effect, + -ia "-y," an E. suffix of adjectives.

Kârâyi, from kârâ "efficient," from kâr, → work + â present stem of âmadan "to come," from Av. ay- "to go, to come," aēiti "goes," O.Pers. aitiy "goes," Skt. e- "to come near," eti "arrival," Gk. eimi "I go," L. eo "I go," Tokharian AB i-; PIE *ei- "to go, to walk."

Outward flow of a → liquid. Something that → flows out.

L. effluxus, p.p. of effluere "to flow out," from → ex- "out" + fluere "to flow," → flux.

Zošâr, from zo- "out of, from," → ex-, + šâr, → flux.