An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 602
laxti (#)

Fr.: inertie   

Tendency of a body to preserve its state of rest or uniform motion in a straight line.

Inertia, from L. inertia "un-skillfulness, idleness," from iners (gen. inertis) "unskilled, inactive;" → inert.

Laxti "sluggishness, inertia."

inertia ellipsoid
  بیضی‌وار ِ لختی   
beyzivâr-e laxti

Fr.: ellipsoïde d'inertie   

An ellipsoid used in describing the motion of a rotating rigid body. It is stationary with respect to the rotating body, and is determined by the body's moments of inertia.

ellipsoid; → inertia.

  لختی‌ناک، لختی‌مند   
laxtinâk, laxtimand

Fr.: inertiel, d'inertie   

Of or relating to inertia.

From → inertia + → -al.

Laxt, adj. of laxti, → inertia

inertial force
  نیروی ِ لختی‌ناک، ~ لختی‌مند   
niru-ye laxtinâk, ~ laxtimand

Fr.: force inertielle   

A force arising from the → acceleration of an observer's → frame of reference.

inertial; → force.

inertial frame
  چارچوب ِ لختی‌ناک، ~ لختی‌مند   
cârcub-e laxtinâk, ~ laxtimand

Fr.: référentiel galiléen   

inertial reference frame.

inertial; → frame.

inertial mass
  جرم ِ لختی‌ناک، ~ لختی‌مند   
jerm-e laxtinâk, ~ laxtimand

Fr.: masse inertielle   

The mass of a body as determined from the acceleration of the body when it is subjected to a force that is not due to gravity.

inertial; → mass.

inertial motion
  جنبش ِ لختی‌ناک، ~ لختی‌مند   
jonbeš-e laxtinâk, ~ laxtimand

Fr.: mouvement inertiel   

Motion free of any force, with constant velocity.

inertial; → motion.

inertial oscillation
  نوش ِ لختی‌ناک، ~ لختی‌مند   
naveš-e laxtinâk, ~ laxtimand

Fr.: oscillation inertielle   

1) A periodic motion of a particle that moves, free from external forces, over the surface of a rotating sphere, such the Earth. Inertial oscillations result from the → Coriolis force. For example, a hockey puck launched on a big enough lake in the northern hemisphere would turn to the right (east) and eventually loop back to nearly the initial point (actually west of that point). The time it takes for the huckey puck to return can be computed with the → Coriolis frequency.
2) Meteo.: An anticyclonic (clockwise) rotation in the northern hemisphere, with the Coriolis force providing the → centripetal acceleration with period of 2π/f, where f is the Coriolis frequency. The opposite should occur in the southern hemisphere.

inertial; → oscillation.

inertial reference frame
  چارچوب ِ بازبرد ِ لختی‌ناک، ~ ~ لختی‌مند   
cârcub-e bâzbord-e laxtinâk, ~ ~ laxtimand

Fr.: référentiel galiléen   

A → reference frame or coordinate system in which there are no accelerations, only zero or uniform motion in a straight line. According to the special theory of relativity, it is impossible to distinguish between such frames by means of any internal measurement.

inertial; → reference; → frame.


Fr.: chute vers le centre   

The fall of matter toward the center of a region of gravitational influence.

Infall, from → in- + → fall.

Darun-oft, from darun- "in, into; within" (Mid.Pers. andarôn "inside," from andar, → inter-, + rôn "side, direction;" Av. ravan- "(course of a) river") + oft, → fall.


Fr.: inférence   

1) The act or process of deriving logical conclusions from premises known or assumed to be true.
2) Something that is inferred.

From M.L. inferentia, from inferre, from → in- "in" + ferre "to carry, bear," cognate with Pers. bordan "to carry, bear," as below.

Darbord (on the models of daryâft "perception" and peybord "understanding, finding;" see also bâzbord, → reference), from dar-, → in-, + bord past stem of bordan "to carry, bear;" (Mid.Pers. burdan; O.Pers./Av. bar- "to bear, carry," Av. barəθre "to bear (infinitive);" Skt. bharati "he carries;" Gk. pherein; L. fero "to carry;" PIE base *bher- "to carry").

zirin (#)

Fr.: inférieure   

Lower in place or position; closer to the bottom or base.
Astro.: → inferior conjunction; → inferior culmination; → inferior planet.

From L. inferior "lower," comp. form of inferus (adj.) "that is below or beneath," from infra "below" (→ infrared), cognate with Pers. zir, as below.

Zirin, adj. from zir "below, down," Mid.Pers. azêr "below, under," êr "below, down; low, under," adar "low;" Av. aδara- (adj.), aδairi- (prep.) "below;" cf. Skt. ádhara- "lower;" L. infra (adv., prep.) "below, underneath, beneath," inferus "lower;" O.E. under "under, among"); PIE base *ndher.

inferior conjunction
  هم‌ایستان ِ زیرین   
hamistân-e zirin

Fr.: conjonction inférieure   

The conjunction of an inferior planet with the Sun when the planet is between the Sun and the Earth. → superior conjunction.

inferior; → conjunction.

inferior culmination
  بالست ِ زیرین   
bâlest-e zirin

Fr.: culmination inférieure   

The meridian transit of a star between the celestial pole and the north point of the horizon. Same as → lower culmination. → superior culmination.

inferior; → culmination.

inferior planet
  سیاره‌ی ِ زیرین   
sayyâre-ye zirin (#)

Fr.: planète inférieure   

A planet that orbits between the Earth and the Sun. Mercury and Venus are the only two inferior planets in the Solar System.

inferior; → planète.

bikarân (#)

Fr.: infini   

Unlimited or unmeasurable in extent of space, duration of time, etc.
Math.: Not finite; an infinite quantity or magnitude; large beyond bound.
Of a set, having elements that can be put into one-to-one correspondence with a subset that is not the given set.

in- + → finite.

infinite population
  پرینش ِ بیکران   
porineš-e bikarân

Fr.: population infinie   

A → statistical population consisting of individuals or items which either possesses the infinite property through some limiting process or is non-enumerable. For example, the population of all → real numbers between 0 and 1 and the population of all → integers are examples of infinite population. In case of random sampling with replacement, any population is always infinite.

infinite; → population.

infinite series
  سری ِ بیکران   
seri-ye bikarân (#)

Fr.: série infinie   

A series with infinitely many terms, in other words a series that has no last term, such as 1 + 1/4 + 1/9 + 1/16 + · · · + 1/n2 + ... . The idea of infinite series is familiar from decimal expansions, for instance the expansion π = 3.14159265358979... can be written as π = 3 + 1/10 + 4/102 + 1/103 + 5/104 + 9/105 + 2/106 + 6/107 + 5/108 + 3/109 + 5/1010 + 8/1011 + ... , so π is an "infinite sum" of fractions. See also → finite series.

infinite; → series.

infinite set
  هنگرد ِ بیکران   
hangard-e bikarân

Fr.: ensemble infini   

A set which can be put in a one-to-one correspondence with part of itself.

infinite; → set.


Fr.: infinitésimal   

General: Indefinitely or exceedingly small.
Math.: A variable that approaches zero as a limit. A quantity decreasing indefinitely without actually becoming zero.

Infinitesimal, coined by Ger. philosopher and mathematician Baron Gottfried Wilhelm von Leibniz (1646-1716) from N.L. infinitesim(us) "infinite in rank," from infinit(us), → infinite, + -esimus suffix of ordinal numerals + → -al.

Bikarânxord, from bikarân "unbounded, unlimited, infinite," from bi- "without" + karân "boundary, side, end" (variants karâné, kenâr, from Mid.Pers. karân, karânak, kenâr "edge, limit, boundary," Av. karana- "side, boundary, end") + xord "minute, little, small" (from Mid.Pers. xvart, xôrt "small, insignificant;" Av. ādra- "weak, dependent;" Skt. ādhrá- "small, weak, poor," nādh "to be oppressed;" Gk. nothros "sluggish;" PIE base *nhdhro-).

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