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

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 712
rift
  چاک، گسل‌دره   
câk, gosal-darré

Fr.: rift; fissure, crevasse   

1) General: a gap or break made by splitting, cleaving, etc.; fissure; cleft.
2) Geology: A narrow cleft, fissure, or other opening in rock, made by cracking or splitting.
3) Geology: An elongated trough in the Earth's crust bounded by → faults.

M.E., from a Scandinavian source; cf. Dan., Norw. rift "a cleft."

1) Câk "fissure, rupture, cleft, crack," related to caqidan "to drive a nail, strike together, fix a spike;" caxidan "to quarrel, strive;" diatectal Shughni cuγ, Roshani coγ "breaking, tearing, ripping up;" Malâyeri ceqidan "cracking of a cold porcelain bowl when receiving hot water;" Yazghulami cok-, coxt "to pound, to stamp;" Wakhi cuk-, cukt "to strike;" Ossetic cædyn "to shake, strike iron;" Lori cok "a mark fixed to separate two grounds;" Sogd. cax "to battel, fight;" Mid.Pers. (prefixed) pacên "copy" (see also Cheung 2007). Gosal-darré, from gosal, → fault, + darré, → valley.

rift valley
  گسل‌دره   
gosal-darré

Fr.: fossé d'effondrement, ~ tectonique   

A long, narrow valley formed by the lowering of land between two → faults. Also called → graben.

rift; → valley.

Rigel (β Ori)
  رجل   
Rejl (#)

Fr.: Rigel   

The brightest star in the constellation → Orion (visual magnitude 0.18). A → blue supergiant of type B8 Iab with an initial mass of 17 solar masses, Rigel is 773 light-years away, and actually shines with the light of 40,000 Suns. It is accompanied by a fairly bright, seventh magnitude companion nine seconds of arc apart. The companion is itself double, the components much fainter and much less massive → main sequence stars of type B.

Rigel "foot," short for Ar. rijl al-jauza' (رجل‌الجوزاء) "the foot of jauza'." The latter word means "the manifest one," initially "black sheep with white middle." The Gk. figure was translated as such because of its conspicuousness among other constellations.

Rejl, from Ar., as above.

Rigel Kentaurus
  پای ِ کنتاؤروس   
Pâ-ye Kentawros

Fr.: Rigil Kentaurus   

Same as the star → Alpha Centauri.

From Ar. Rijl al-Qanturis "foot of Centaurus," from rijl "foot," + Qanturis Arabicized → Centaurus.

Pâ-ye Kantawros, "foot of Centaurus," from , → foot, + Kentawros, → Centaurus.

right
  ۱) راست؛ ۲) درست؛ ۳) راشن   
1) râst (#); 2) dorost; 3) râšan

Fr.: droit   

1a) Straight, free from curves, angles, or irregularities. → right ascension.
1b) Opposite of → left. → right-hand rule, → right-hand screw rule.
2) In accordance with fact, reason, or truth; correct or true.
3) Something that a person is or should be morally or legally allowed to have, get, or do (Merriam-Webster).

M.E.; O.E. reht, riht; cf. O.H.G. reht, Ger. recht, O.N. rettr, Goth. raihts; P.Gmc. *rekhtaz, cognate with Pers. râst, as below.

1) Râst "right, true; just, upright, straight;" Mid.Pers. râst "true, straight, direct;" Soghdian rəšt "right;" O.Pers. rāsta- "straight, true," rās- "to be right, straight, true;" Av. rāz- "to direct, put in line, set," razan- "order;" related to Mid.Pers. rây-, râyênitan "to arrange;" Mod.Pers. raj "line, row," variants raž, rak, râk, rezg (Lori), radé, râdé "line, rule, row," rasté, râsté "row, a market with regular ranges of shops;" ris, risé "straight;" cf. Skt. raj- "to direct, stretch," rjuyant- "walking straight;" Gk. orektos "stretched out;" L. regere "to lead straight, guide, rule," p.p. rectus "right, straight;" PIE base *reg- "move in a straight line," hence, "to direct, rule;"
2) Dorost "correct, whole, complete, healthy," → integral.
3) Râšan, related to râst, as above; cf. Mid.Pers. Rašn "Justice deity; calendar 18th day;" Av. rašnu- "the Zoroastrian Justice deity, orientation."

right angle
  زاویه‌ی ِ راست   
zâviye-ye râst

Fr.: angle droit   

An angle of 90°.

right; → angle.

right ascension
  راست‌افراز   
râst afrâz (#)

Fr.: ascension droite   

A coordinate in the → equatorial system measured from the → vernal equinox eastward to the point where the object → hour circle intersects the → celestial equator. Right ascension (symbol α) is expressed in hours, minutes, and seconds. See also: → declination.

right; ascension, M.E. ascencioun, from O.Fr., from L. ascendere "to climb up," from → ad- "to" + scandere "to climb."

Râst, → right; afrâz present stem of afrâzidan, afrâštan "to raise, exalt, extole," from Mid.Pers. abrâstan, abrâz- "to lift, raise," from ab-, from O.Pers./Av. abiy-/aiwi- "to, upon, against;" cf. Skt. abhi-, Gk. amphi- + râst "straight, direct, true;" from O.Pers. rāsta- "straight, true," rās- "to be right, straight, true;" Av. rāz- "to direct, put in line, set," razan- "order;" cf. Skt. raj- "to direct, stretch," rjuyant- "walking straight;" Gk. orektos "stretched out;" L. regere "to lead straight, guide, rule," p.p. rectus "right, straight;" Ger. recht; E. right; PIE base *reg- "move in a straight line," hence, "to direct, rule."

right triangle
  سه‌بر ِ راست   
sebar-e râst (#)

Fr.: triangle droit   

A triangle one of whose angles is a → right angle.

right; → triangle.

right-hand rule
  رزن ِ دست ِ راست   
razan-e dast-e râst

Fr.: règle de la main droite   

See → Fleming's rules.

right; → hand; → rule.

right-hand screw rule
  رزن ِ پیچ ِ راست‌گرد   
razan-e pic-e rast-gard

Fr.: règle de la vis droite   

A rule that gives the direction of the resultant vector in a → vector product: A x B = C. It is the direction of advance of a right-hand screw whose axis, held perpendicular to the plane of A and B, is rotated in the same sense that rotates the first-named vector (A) into the second-named vector B through the smaller angle.

right; → hand; → screw; → rule.

right-handed
  راستال، راستدست   
râstâl, râstdast (#)

Fr.: droitier   

Using the right hand with greater skill or ease than the left.

right; → hand + -ed.

Râstâl, from râst, → right, + -al-al. Râstdast, with dast, → hand.

rigid
  سخت‌پای   
saxtpây (#)

Fr.: rigide   

1) General: Stiff or unyielding; inflexible, strict, severe.
2) Physics: → rigid body; → rigidity.

From L. rigidus "hard, stiff, rough," from rigere "to be stiff;" related to L. frigus "cold," Gk. rhigos "frost, cold."

Saxtpây, from saxt, → hard, + pây present stem of pâyidan "to stand firm, to be constant, steady, fixed;" Mid.Pers. pâyitan, pâtan, pây- "to protect; wait, stand," Sogdian p'y "to protect, watch over;" O.Pers./Av. pâ(y)- "to protect, keep" pâtar- "protector, watcher," cf. Skt. pâ- "to protect, keep," pâti "protects;" Gk. poimen "shepherd," poma "lid, cover;" L. pastor "shepherd," panis "bread;" PIE base *pa- "to protect, guard, pasture, feed."

rigid body
  جسم ِ سخت‌پای   
jesm-e saxtpây

Fr.: corps rigide   

Mechanics: A system of many particles whose positions relative to one another remain fixed.

rigid; → body.

rigidity
  سخت‌پایی   
saxtpâyi

Fr.: rigidité   

1) The quality or state of being → rigid. See also → modulus of rigidity.
2) → magnetic rigidity.

rigid + → -ity.

Rigil Kentaurus (α Centauri)
  پای ِ کنتاؤروس   
pâ-ye Kentâwros

Fr.: Alpha du Centaure   

Another name of → Alpha Centauri.

Rigel, from Ar. rijl (رجل) "foot;" Kentaurus, → Centaurus.

"foot, step" (from Mid.Pers. pâd, pây; Av. pad- "foot;" cf. Skt. pat; Gk. pos, genitive podos; L. pes, genitive pedis; P.Gmc. *fot; E. foot; Ger. Fuss; Fr. pied; PIE *pod-/*ped-); KentâwrosCentaurus.

rigorous
  فرسخت   
farsaxt (#)

Fr.: rigoureux   

1) Severely exact or accurate; precise.
2) Logic, Math.: Logically valid. See also: → accurate, → exact, → precise.

M.E., from M.L. rigorosus, from rigor "stiffness, rigor," from rigere "to be stiff."

Farsaxt, from far- intensive prefix "much, abundant; elegantly" (Mid.Pers. fra- "forward, before; much; around;" O.Pers. fra- "forward, forth;" Av. frā, fərā-, fra- "forward, forth; excessive;" cf. Skt. prá- "before; forward, in fron;" Gk. pro "before, in front of;" L. pro "on behalf of, in place of, before, for;" PIE *pro-) + saxt "hard, strong, firm, secure, solid, vehement, intense" (Mid.Pers. saxt "hard, strong, severe;" Av. sak- "to understand or know a thing, to mark;" cf. Skt. śakta- "able, strong," śaknoti "he is strong," śiksati "he learns").

rigorous selection rule
  رزن ِ گزینش ِ فرسخت   
razan-e gozineš-e farsaxt

Fr.: règle de sélection rigoureuse   

A → selection rule obeyed by → discrete transitions. Among them are: rigorous selection rules for → electric dipole transitions (→ permitted) requiring: 1) ΔJ must be 0 or ± 1 with J = 0 ↔ 0 forbidden. 2) ΔMJ = 0, ± 1. 3) → Parity change, i.e. even ↔ odd.

rigorous; → selection; → rule.

rille
  ریل   
ril

Fr.:   

A long, narrow, straight or sinuous trench or valley with steep walls and roughly parallel sides on the surface of the Moon.

From Ger. Rille "a small rivulet or brook."

Borrowed from E., as above.

rim
  لبه   
labé (#)

Fr.: bord   

The outer edge, border, margin, or brink of something, especially of a circular object.

M.E., from O.E. -rima (in compounds, as in særima "seashore"); cognate with O.Norse rimi "raised strip of land, ridge"

Labé "limb, edge," from lab "lip;" Mid.Pers. lap; cognate with L. labium, E. lip; Ger. Lefze.

rima
  ریما   
rimâ

Fr.: rima   

A long fissure on the surface of a planet or Moon; plural form rimae.

From L. rima "fissure, slit."

Loan from E., as above.

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