An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < -me mac mag mag mag mag mai Mal mar mas mas mat Max mea mec Mei Mer Mes met met met mic mid mil min mir mJy mod mol Mon moo Mou mul mul mys > >>

Number of Results: 683
mirror testing
  آزمون ِ آینه   
âzmun-e âyené (#)

Fr.: test d'un miroir   

The observation and measurement of the flatness of a mirror surface. The process generally is done before coating so as not to damage the delicate coated surface. For coated and curved surfaces, non-contact methods are often employed, generally using interference techniques.

mirror; → test.

Mirzam (β Canis Majoris)
Merzam (#)

Fr.: Mirzam   

The fourth brightest star in the constellation → Canis Major. It is a B1 → giant of magnitude 2.0 lying about 500 → light-years away. Mirzam is one of the brightest of the → Beta Cephei variable stars.

From Ar. al-Mirzam (المرزم) "subordinate," which according to the Persian astronomer Biruni (A.D. 973-1048) was a general name for a relatively fainter star lying beside a much brighter one, in this case → Sirius. Some sources have related the name of this star to Ar. al-Murzim (المرزم) "the roarer." They claim that this name refers to the fact that the star is situated to the east of Sirius and thus "announces, heralds" imminent rising of Sirius. However, this interpretation does not seem tenable since the meaning "announcing" is far-fetched, and moreover the angular distance between Sirius and Mirzam being small, they actually rise together.


Fr.: mésalignement   

Deviation of the chain of → optical components from the optimum → alignment in an instrument which leads to → loss of → light and poor → image.

From mis- a prefix meaning "ill, mistaken, wrong, wrongly" + → alignment.

Dožxateš, from dož-, → dys-, + (â)xateš, → alignment.

mušak (#)

Fr.: missile   

An object or weapon for throwing, hurling, or shooting. → ballistic missile.

From Fr. missile, from L. missile "weapon that can be thrown," from missus, p.p. of mittere "to send."

Mušak, literally "little mouse," or "mouse like," from a firework explosive that was likened to a mouse, from muš, → mouse, + -ak diminutive or similarity suffix.

missing mass
  جرم ِ گم‌شده   
jerm-e gomšodé (#)

Fr.: masse manquante   

The unseen mass whose gravitational influence is needed to account for the way galaxies rotate, and also to bind clusters of galaxies together. It is thought to consist, in part, of giant halos of dark matter that surround the visible portions of galaxies, and similar material that invisibly occupies the intergalactic voids. Same as → hidden mass; → dark matter.

Missing, from miss "to fail to be present," from M.E. missen, O.E. missan; cf. O.Fris. missa, M.Du. missen, Ger. missen "to miss, fail;" → mass.

Jerm, → mass; gomšodé "lost, missing," from gom "missing, lost" + šodé p.p. of šodan "to become" (from Mid.Pers. šudan, šaw- "to go;" Av. šiyav-, š(ii)auu- "to move, go," šiyavati "goes," šyaoθna- "activity; action; doing, working;" O.Pers. šiyav- "to go forth, set," ašiyavam "I set forth;" cf. Skt. cyu- "to move to and fro, shake about; to stir," cyávate "stirs himself, goes;" Gk. kinein "to move;" Goth. haitan "call, be called;" O.E. hatan "command, call;" PIE base *kei- "to move to and fro").

missing satellites problem (MSP)
  پراسه‌ی ِ بنده‌وارهای ِ گم‌شده   
parâse-ye bandevârhâ-ye gomšodé

Fr.: problème des satellites manquants   

The observed underabundance, by one or two orders of magnitude, of → dwarf galaxies orbiting → spiral galaxies compared to their number predicted by the standard model. The → cold dark matter (CDM) model predicts that dwarf galaxies are the building blocks of large galaxies like the Milky Way and should largely outnumber them. Dwarf galaxies form first, they merge into bigger and bigger galaxies, and galaxies into groups of galaxies. The dark matter halos, however, are very dense, and dwarf halos are not destroyed in the merging, resulting in their large predicted number, in numerical simulations.

Probably first dealt with in an article entitled "Where Are the Missing Galactic Satellites?" (Lypin et al. 1999, ApJ 522, 82); → missing mass; → satellite; → problem.


Fr.: mission   

An operation designed to carry out the goals of a specific program, such as a a space flight or voyage.

Mission, from L. missionem (nominative missio) "act of sending," from mittere "to send," of unknown origin.

Gosilân, from gosil, variant gosi "sending away, dismission;" Mid.Pers. wisé "to despatch" (Parthian Mid.Pers. wsys- "to despatch;" Buddhist Mid.Pers. wsydy "to despatch;" Sogdian 'ns'yd- "to exhort"), from Proto-Iranian *vi-sid- "to despatch, send off," from prefix vi- "apart, away, out," + *sid- "to call" + -ân nuance suffix.


Fr.: brume   

A very thin fog consisting of an aggregate of microscopic water droplets or wet hygroscopic particles (of diameter not less than 0.5 mm), in which the visibility at the earth's surface is greater than 1 km.

O.E. mist "dimness, mist," from P.Gmc. *mikhstaz (cf. M.L.G. mist, Icelandic mistur), from PIE *migh-/*meigh-; cf. Pers. miq "fog, mist;" Gk. omikhle, O.C.S. migla, Skt. megha- "cloud, mist." → nebula.

Nezm "mist, fog," variants nezu, nezvâ "mist," nam "moisture, humidity;" Av. napta- "moist," nabās-câ- "cloud," nabah- "sky;" cf. Skt. nábhas- "moisture, cloud, mist;" Gk. nephos "cloud, mass of clouds," nephele "cloud;" L. nebula "mist," nimbus "rainstorm, rain cloud;" O.H.G. nebul; Ger. Nebel "fog;" O.E. nifol "dark;" from PIE *nebh- "cloud, vapor, fog, moist, sky."


Fr.: mittaine   

A → glove that leaves the lower ends of the fingers bare, especially a long one made of lace or other fancy material and worn by women ( → mitten.


Dastpuš, from dast, → hand, + puš present stem of pušidan "to cover, to put on," → envelope.


Fr.: moufle   

A hand covering enclosing the four fingers together and the thumb separately ( → glove, → mitt.

M.E. miteyn, from M.Fr., O.Fr. mitaine, from from O.Fr. mite "mitten," and from M.L. mitta.

Dasmtuž, literally "hand-shoe" (Ger. Handschuh, "glove," literally "hand-shoe"), from dast, → hand, + Muž, variant of Pers. muzé "shoe," Mid.Pers. môg "shoe, boot;" cf. Pers. paymôz- / paymôxtan "to dress;" Av. (+ pati-paitišmaoc- "to shoe;" Proto-Ir. *(h)mauc-? "to dress, clothe" (Cheung 2007).

âmixtan (#)

Fr.: mélanger   

To combine (substances, elements, things) into one mass, collection, or assemblage, generally with a thorough blending of the constituents.

From M.E. myxte, from O.Fr. mixte, from L. mixtus, p.p. of miscere "to mix;" cognate with Pers. âmixtan, âmiz-, as below; from PIE *meik- "to mix."

Âmixtan, âmizidan "to mix," from Mid.Pers. âmêz-, âmêxtan (Proto-Iranian *āmis- ,*āmiz-; PIE *meik- "to mix"); cf. Av. mayas- "to mix;" Skt. miks- "to mix, mingle," miśr- "to mix, blend, combine;" Gk. misgein "to mix, mingle;" L. miscere (p.p. mixtus) "to mix;" O.C.S. meso, mesiti "to mix," Rus. meshat, Lith. maisau "to mix, mingle."

mixed merger
  تشک ِ آمیخته   
tašk-e âmixté

Fr.: fusion mixte   

A merger that takes place when a → gas-poor galaxy collides with a → gas-rich galaxy.

Past-participle of → mix; → merger.


Fr.: mélangeur   

In the → superheterodyne technique, the electronic component that lowers the frequency of the input signal and combines it with the signal coming from the → local oscillator to produce the → intermediate frequency signal. The lowered frequency, when amplified, has little chance to escape back into the antenna and produce feedback. Moreover, it is easier to make efficient amplifiers, filters, and other components for lower frequencies.

Agent noun from → mix.

âmizeš (#)

Fr.: mélange   

1) General: The process or result of irregular fluctuations in fluid motions on all scales from the molecular to large eddies.
2) Stellar interior: A process whereby → angular momentum and chemical species are transported from layer to layer within a star. The main mixing processes include: → convection, → overshooting, → rotation, → turbulence. The extent to which the interiors of stars are mixed strongly influences their evolution, age, chemical content, and the relationship between their internal and surface abundances.

Verbal noun of → mix.

mixing length
  درازای ِ آمیزش   
derâzâ-ye âmizeš

Fr.: longueur de mélange   

In a → turbulent flow, the average distance traveled by a → convective cell before it dissolves into its surroundings and deposits its energy. The mixing length is of the order of the → pressure scale height (HP), l = αHP, where α is the → mixing length parameter. See also → mixing length theory.

mixing; → length.

mixing length parameter
  پارامون ِ درازای ِ آمیزش   
pârâmun-e derâzâ-ye âmizeš

Fr.: paramètre de la longueur de mémange   

In the → mixing length theory, a parameter, α, that relates the → mixing length, l, to the → pressure scale height: α = l/HP. It is usually supposed that α is of order unity. Changes in α correspond to variations in the efficiency of the → convection, hence the transfer of heat.

mixing; → length; → parameter.

mixing length theory (MLT)
  نگره‌ی ِ درازای ِ آمیزش   
negare-ye derâzâ-ye âmizeš

Fr.: théorie de la longueur de mélange   

A theory dealing with heat transport by → turbulence which includes an elementary treatment of → convection. The central idea is that an unbalanced → buoyancy force drives a → convective cell to move through a distance, called the → mixing length, before the cell dissolves and joins the ambient medium. In this theory an adjustable → mixing length parameter  α is used. The theory, originally due to L. Prandtl (1925), was first applied to the Sun by L. Biermann (1932, Z. Astrophys. 5, 117).

mixing; → length; → theory.

mixing ratio
  وابر ِ آمیزش   
vâbar-e âmizeš

Fr.:rapport de mélange   

Mass of water vapor per mass of dry air; expressed as grams per kilogram. → humidity

mixing; → ratio.

âmizé (#)

Fr.: mixture   

An aggregate of two or more substances that are not chemically combined with each other.

M.E., from L. mixtura "a mixing," from mixtus, → mix.

Âmizé, from âmiz present stem of âmixtan, → mix.

Mizar (ζ Ursae Majoris)
Me'zar (#)

Fr.: Mizar   

A star of visual magnitude 2.3 in the constellation → Ursa Major, which is the second star from the end of the → Big Dipper's handle. It forms a naked-eye double with → Alcor, lying at an angular separation of about 12 minutes of arc. Mizar is resolved into a 14''.4 → binary star (denoted A and B) with a probable period of thousands of years. Mizar A is a nearly equal-mass, → double-lined spectroscopic binary with period 20.54 days and → eccentricity of 0.53. The two components of Mizar A (denoted Aa and Ab) are both about 35 times as luminous as the Sun, and revolve around each other in about 20 days. Similarly, Mizar B is a → spectroscopic binary with a period of 175.57 days and an eccentricity of 0.46. Recent results suggest that Alcor is actually a binary and apparently → gravitationally bound to the Mizar system. This would make the Mizar-Alcor system a probable → sextuplet, lying at about 78 → light-years from Sun and the second closest such multiple known, after → Castor (Mamajek et al., 2010, AJ 139, 919).

Mizar, from Ar. al-Mi'zar (المءزر) "loin cloth, apron, veil."

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