Fr.: équation de champ
In a physical theory, an equation that describe how a fundamental force interacts with matter. Einstein's equations of → general relativity are called field equations since they describe the → gravitational field. Similarly, → Maxwell's equations describe the electromagnetic field.
Fr.: galaxie de champ
A galaxy that lies in the direction of a → cluster of galaxies, but is not a member of the cluster. Field galaxies are rare, less than about 5% of all galaxies.
field horizontal branch star
setâre-ye šâxe-ye ofoqi-ye meydâni
Fr.: étoile de la branche horizontal du champ
A → horizontal branch star with high velocity.
Fr.: lentille de champ
A lens placed at or near the focal plane of a telescope to create an image of the primary mirror inside the instrument.
Fr.: objet de champ
An astronomical object that is seen in the direction of a group but not physically belonging to the group. → field galaxy.
field of force
meydân-e niru (#)
Fr.: champ de force
field of view
meydân-e did (#)
Fr.: champ de vue
The entire angular expanse of the sky viewed by an optical instrument.
Fr.: rotation de champ
The effect of the Earth's rotation on the position of the image formed on the → focal plane of a telescope during long exposures. In the case of → equatorial mounting, the image remains fixed, whereas it turns continuously with an → altazimuth mounting. In the latter case the image motion must be compensated by an appropriate mechanism, → field rotator.
Fr.: rotateur de champ
A device used on a telescope to correct for the → field rotation while tracking an object.
Fr.: étoile de champ
A star that does not belong to a stellar cluster, but happens to be adjacent to it.
Fr.: diaphragme de champ
A diaphragm located at an image plane of an optical system that determines the size and shape of the image. → aperture stop.
Fr.: théorie des champs
1) A theory which uses the concept of → field
to describe physical phenomena. It consists of two types:
→ classical field theory
and → quantum field theory.
The precise curve required on the surface of an optical element, especially the mirror of a reflecting telescope.
From O.Fr. figure, from L. figura "a shape, form."
Šekl from Ar. šakl "figure."
Figuring, noun of → figure.
Šekldahi, "giving form," from šekl, → figure + dahi, a verbal noun of dâdan "to give," from Mid.Pers. dâdan "to give," O.Pers./Av. dā- "to give, grant, yield," dadāiti "he gives;" cf. Skt. dadáti "he gives," Gk. didomi "I give," tithenai "to put, set, place;" L. dare "to give, offer;" facere "to do, to make;" Rus. delat "to do;" O.H.G. tuon, Ger. tun, O.E. don "to do." PIE base *dhe- "to put, to do."
1) A long tongue of a relatively cold matter (10,000 K),
suspended in the → solar corona (2 million K). Filaments
seem dark in the Hα light when they are seen projected on the
solar disk; at the limb they look as what they actually are:
From Mod.L. filamentum, from L.L. filare "to spin, draw out in a long line," from L. filum "thread," from PIE base *gwhi- "thread, tendon;" cf. Gk. bios "bow;" Skt. jiyā- "bow-string;" Av. jiiā- "bow-string;" Mod.Pers. zeh "string, bow-string" (dialectal Qomi zij "mason's cord"); Arm. jil "string, line;" Lith. gijà "thread;" Russ. žica "thread."
Rešté "thread, line, file," from reštan, ristan "to spin;" Mid.Pers. 'rws- "to turn to," abrešom "silk;" Sogdian rwyšt "spun;" Av. uruuaēs- "to twist, turn;" Proto-Iranian *uris- "to turn, spin."
Fr.: nébuleuse filamentaire
A nebula, generally ionized, consisting of filament-like structures of gas, such as the Veil Nebula (NGC 6960) or the supernova remnant IC 443.
Fr.: micromètre filaire
An instrument used with a telescope for accurately measuring small angular separations between two celestial bodies (as between binary stars). The instrument consists of two parallel fine wires with one wire being fixed and the other movable by means of a finely threaded screw.
Kehsanj, → micrometer; zehi adj. of zeh "string, bow-string;" Mid.Pers. zih "bow-string," zig "string; astronomical table" (loaned into Ar. as zij); Av. jiiā- "bow-string;" cf. Skt. jiyā- "bow-string;" Gk. bios "bow;" L. filum "thread;" Arm. jil "string, line;" Lith. gijà "thread;" Russ. žica "thread;" PIE base *gwhi- "thread, tendon."
In computer science, a collection of related data or program records stored on a support.
From M.E. filen, from M.F. filer "to string documents on a thread," O.F. filer "to wind or spin thread," from L.L. filare "to spin, draw out in a long line," from L. filum "thread," from PIE base *gwhi- "thread, tendon;" cf. Gk. bios "bow;" Skt. jiyā- "bow-string;" Av. jiiā- "bow-string;" Mod.Pers. zeh "bow-string;" Arm. jil "string, line," Lith. gijà "thread;" Russ. žica "thread."
Parvandé "file," initially "a bundle, roll, truss (of clothes)," from Mid.Pers. parwastan, parwand- "to surround, enclose, contain, comprise," from par-, variants far-, par-, pirâ- "around, about" (Mid.Pers. pêrâ; O.Pers. pariy "around, about," Av. pairi "around, over;" Skt. pari; Indo-Iranian *pari- "around;" PIE base *per- "through, across, beyond;" cf. Gk. peri "around, about, beyond;" L. per "through") + vand-/band- stem of vastan/bastan "to bind, shut;" O.Pers./Av. band- "to bind, fetter," banda- "band, tie" (cf. Skt. bandh- "to bind, tie, fasten;" PIE *bhendh- "to bind;" Ger. binden; E. bind).
Fr.: facteur de remplissage
Of a molecular cloud or a nebula, the ratio of the volumes filled with matter to the total volume of the cloud.
1) General: A device for separating the constituents of a system according to
a physical property. In particular, a device for removing solid matter suspended
in a liquid by forcing the suspension through a material which retains the solid
matter while allowing the liquid to pass.
From M.L. filtrum "felt," which was used to strain impurities from liquid, from W.Gmc. *filtiz.
Pâlâyé, from pâlây present stem of pâludan "to filter, purify;" Mid.Pers. pâludan, pâlây- "to strain, filter, purify," from Proto-Iranian *pari-harz-, from prefix *pari- "around," → peri-, + harz- "to let go, release;" cf. Av. pairi.harəz- "to filter," from pairi- "around, over" (cf. Skt. pari; Gk. peri "around, about, beyond;" L. per "through;" PIE base *per- "through, across, beyond") + harəz- "to release" (especially water, liquid; cf. Chorasmian pžy- "to purify, filter;" Arm. (loanword) parzel "to filter, purify;"