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

Same as → mirror blank.

→ mirror; → disk.

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.

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.

A prefix meaning "ill, mistaken, wrong, wrongly"

M.E., from O.E. mis-, cognate with M.Du. misse-, O.H.G. missa-, Ger. miss-, perhaps literally "in a changed manner," and with a root sense of "difference, change" and thus possibly from PIE root *mei- "to change;" cf. Av. miθo- "perverted," Skt. methati "changes, alternates, joins;" L. mutare "to change."

Dož-, → dys-.

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

→ mis-; → alignment.

1) Fail to hit, reach, or come into contact with (something aimed at); to fail to do something.
2) Pass by without touching.
3) Feel or notice the loss or absence of.

M.E. missen, O.E. missan "fail to hit, miss (a mark); fail in what was aimed at," akin to Du. missen, Ger. missen "to miss, fail," from PIE *mei- "to change, go, move."

Napidan, literally "fail attain, reach, or find," from negation suffix na-, → not, + Av. ap- "to reach, attain;" cf. Mid./Mod.Pers. (+abi-) yâftan "to obtain, to find;" Proto-Ir. *Hap/f- "to reach, attain;" PIE *H₁ep- "to take, seize, grab;" cf. L. apiscor "to reach, to get" (Cheung 2007).

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.

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"); napide, p.p. of napidan, → miss.

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.

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.

Spell a word wrongly.

→ mis-; → spell.

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."

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 (Dictionary.com). → mitten.

→ mitten.

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

A hand covering enclosing the four fingers together and the thumb separately (Dictionary.com). → 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).

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."

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

Past-participle of → mix; → merger.

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.

1) General: The process or result of irregular fluctuations in fluid motions on all scales from the molecular to large eddies.
2) Relating to → stellar interior, → mixing process.

Verbal noun of → mix.

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 (H_P), l = αH_P, where α is the → mixing length parameter. See also → mixing length theory.

→ mixing; → length.

In the → mixing length theory, a parameter, α, that relates the → mixing length, l, to the → pressure scale height: α = l/H_P. 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.