An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 732
data model
  مدل ِ داده‌ها   
model-e dâde-hâ

Fr.: modèle de données   

An abstract entity that describes the structure of → database by including the formal description of the information system used in the database.

data; → model.

data number (DN)
  شمار ِ داده‌ها   
šomâr-e dâdehâ


Unit of the analog-to-digital conversion system of a CCD apparatus. For example a 16 bit system may use a maximum of 65536 DN. The acronym ADU, for analog-to-digital unit, is also used.

data; → number.

data processing
  داده آمایی   
dâdé âmâyi (#)

Fr.: traitement de données   

Systematic operations on data, such as handling, merging, sorting, and computing.

data; → processing.

data processor
  داده آما   
dâdé âmâ (#)

Fr.: processeur de donées   

A machine for handling data in → data processing.

data; → processor.

data reduction
  بازهازش ِ داده‌ها   
bâzhâzeš-e dâdehâ

Fr.: réduction de données   

The process of converting crude observational data into usable information for scientific interpretation, by correcting, rearranging, ordering, and simplifying.

data; → reduction.

data structure
  ساختار ِ داده‌ها   
sâxtâr-e dâdehâ

Fr.: structure de données   

A → method or → format for organizing and storing data. Any data structure is designed to organize data to suit a specific purpose so that it can be accessed and worked with in appropriate ways. In computer programming, a data structure may be selected or designed to store data for the purpose of working on it with various algorithms.

data; → structure.

  پایگاه ِ داده‌ها   
pâygâh-e dâdehâ (#)

Fr.: base de données   

A combined and coordinated set of data that supplies information for a specific purpose in a variety of forms.

data; → base.


Fr.: date   

A particular day, month, and year at which some event happened or will happen.

Date, from O.Fr. date, from M.L. data, from datus "given," p.p. of dare "to give, grant, offer," from PIE base *do- "to give" (cf. Pers. dâdan "to give," as below). The Roman convention of closing a document by writing "given" and the day and month (meaning "given to messenger") led to data becoming a term for "the time stated."

Gâhdâd, from gâh "time" (Mid.Pers. gâh, gâs "time;" O.Pers. gāθu-; Av. gātav-, gātu- "place, throne, spot;" cf. Skt. gâtu- "going, motion; free space for moving; place of abode;" PIE *gwem- "to go, come") + dâd "given," as in Latin; p.p. of dâdan "to give" (Mid.Pers. dâdan "to give," O.Pers./Av. dā- "to give, grant, yield," Av. dadāiti "he gives," Skt. dadáti "he gives," Gk. didomi "I give;" akin to L. data, as above); cf. Mid.Pers., Mod.Pers. dâd "year, age, period of life," Lori, Laki dâ(d) "age," homdâ "of equal age."
Note: In current Persian a single term, târix (تاریخ), is used for two different but related concepts: date and history. This may be confusing, → history (تاریخ).

senn yâbi (#)

Fr.: datation   

Use of appropriate techniques to estimate the age of geological specimens or astronomical objects such as meteorites.

Verbal noun of date, from O.Fr. date, from M.L. → data.

Sen yâbi, from Ar. sen "age" + yâbi verbal noun of yâftan, yâbidan "to find, discover; to obtain, acquire," Mid.Pers. ayâftan, ayâpênitan "to reach, attain," Manichean Mid.Pers. 'y'b "to attain," Parthian, Sogdian (+ *pati-) pty'b "to reach, obtain," Av. ap- "to reach, overtake," apayeiti "achieved, reached," Skt. âp- "to reach, gain," âpnoti "reaches, gains," Gk. hapto, haptomai "to touch, cling to, adhere to," L. apiscor "touch, reach;" PIE base *ap- "to take, reach."

  ۱) داده؛ ۲) داده‌بن؛ ۳) فرازبن   
1) dâdé (#); 2) dâdebon; 3) farâzbon

Fr.: donnée   

1) A single piece of information, as a fact, statistic, or code.
2) Any numerical or geometric quantity which serves as a reference or a base for measurement of other quantities.
3) Surveying: Any basis level (surface, line, or point) used as a reference in measuring elevations.

L. datum "given," neuter p.p. of dare "to give, offer," cf. Av. and O.Pers. dā- "to give, grant, yield," Av. dadāiti "he gives," Skt. dadáti "he gives," Gk. didomi "I give," PIE base *do- "to give."

Dâdé "given," p.p. of dâdan "to give," Mid.Pers. dâdan "to give," O.Pers./Av. dā- "to give, grant, yield," akin to L. data, as above.
Dâdebon, from dâdé "datum," + bon "basis, base," → element.
Farâzbon, from farâz "above, up, upon," → height, + bon "basis, base," as above.

doxtar (#)

Fr.: noyau fils   

A term used in → nuclear physics to denote a → nuclide produced by the → radioactive decay of a → parent nuclide.

From M.E. doughter, O.E. dohtor, from P.Gmc. *dochter (Ger. Tochter), from PIE *dhug(h)əter-; cf. Av. dugədar-, duγdar-, Mod.Pers. doxtar, Skt. duhitár-, Gk. thygater, Arm. dowstr, Lith. dukte.

Doxtar, from Mid.Pers. duxtar, duxt, O.Pers. *duxçi-, Av. dugədar-, duγdar-, cognate with daughter, as above.

daughter product
doxtar (#)

Fr.: noyau fils   

In → nuclear physics, same as → daughter.

daughter; → product.

Davisson-Germer experiment
  آزمایش ِ دیویسون-جرمر   
âzmâyeš-e Davisson-Germer

Fr.: expérience de Davisson-Germer   

The experiment carried out in 1927 that confirmed the → de Broglie hypothesis as to the → wave nature of the → electron. It showed that electrons scattering off crystals form a → diffraction pattern. The experimental setup consisted of a → nickle chloride → crystal as → target, an electron gun, and a → detector placed on a graduated circular scale. The intensity of the reflected electrons was measured as a function of angle and electron energy. The observations showed a strong intensity peak at a certain angle. The nickel crystal acted as a → diffraction grating. → Constructive interference occurred at a particular angle, where the peak intensity was observed in accord with → Bragg's law. Interestingly, the intent of the initial experiment was was not to confirm the de Broglie hypothesis. In fact, the discovery was made by accident.

Carried out by American physicists Clinton Davisson (1881-1958) and Lester Germer (1896-1971); → experiment.

  پگاه، سپیده دم، بامداد   
pegâh (#), sepidedam (#), bâmdâd (#)

Fr.: aube, point du jour, aurore   

The first daylight in the sky before sunrise, equivalent to morning astronomical → twilight; opposed to → dusk.

M.E. dawen (v.), from O.E. dagung, from dagian "to become day," from root of dægday.

Pegâh, from Mid.Pers. pa gâh, from pa "to; for; in; on; with; by; according to," O.Pers. upā, Av. upa "toward, with, on, in, in the time of" (cf. Skt. úpa "toward, together with, under, near to, on," Gk. hypo "under, below," L. sub "under," Ger. auf, E. up; PIE *upo "under, up from under, over") + gâh "time," O.Pers. gāθu-, Av. gātav-, gātu- "place, throne, spot" (Skt. gátu- "going, motion; free space for moving; place of abode," PIE *gwem- "to go, come").
Sepidedam, from sepidé "whitish; dawn," from sepid "white" (Mid.Pers. spêt, Av. spita- "white," Skt. śveta- "white," Lith. sviesti "to shine," svaityti "to brighten," P.Gmc. *khwitaz, O.E. hwit, E. white, Ger. weiss, PIE *kwintos/*kwindos "bright") + dam "moment, time; to blow, breathe; smoke" (Mod./Mid.Pers. damidan "to blow, breathe," Av. dāδmainya- "blowing up," Skt. dahm- "to blow," dhámati "blows," Gk. themeros "austere, dark-looking," Lith. dumti "to blow," PIE dhem-/dhemə- "to smoke, to blow").
Bâmdâd, from Mid.Pers. bâmdât, Av. bāmya- "the dawn," from bā- "to shine" (cf. Skt. bhā- "light, brightness," Gk. phainomai "to appear, shine, gleam," Arm. banam "to open, uncover," PIE *bhā- "to shine").

Dawn spacecraft
  فضاناو ِ داؤن   
fazânâv-e Dawn


NASA's mission to explore the two largest objects in the → asteroid belt, the asteroid Vesta and the → dawarf planet Ceres, gathering data relating to their composition, internal structure, density and shape. Launched in September 2007, Dawn entered the orbit of → Vesta in July 2011 and spent 16 months there before leaving for → Ceres. It entered Ceres orbit on March 6, 2015. The Dawn spacecraft is made of aluminium and graphite composite, it has a dry mass of 747.1 kg and a mass of 1217.7 kg when fully fuelled prior to launch. The spacecraft is a box-shaped design measuring 1.64m × 1.27m × 1.77m.

dawn; → spacecraft.

ruz (#)

Fr.: jour   

The length of time it takes Earth (or a planet) to rotate once on its axis relative to some external reference. The day is measured in several ways, depending on this reference, → sidereal day; → solar day; → mean solar day.

M.E., from O.E. dæg (cf. Ger. Tag, Swedish and Danish dag "day"), from PIE base *dhegh- "to burn." Not related to L. dies "day" (from *dyeu- "to shine," → diurnal), but rather to Av. dag- "to burn," dažaiti "burns," Mod.Pers. dâq "hot," Skt. dah- "to burn," dáhati, Gk. tephra "ash," L. fovere "to boil," Albanian djeg "to burn," Russ. žeč' "to burn," Lith. dagas "hot season," degti "to burn," O.Prus. dagis "summer."

Ruz "day," from Mid.Pers. rôc, O.Pers. raucah-, Av. raocah- "light, luminous; daylight," Skt. roka- "brightness, light," cognate with Gk. leukos "white, clear," L. lux "light" (also lumen, luna), PIE base *leuk- "light, brightness". The Persian words rowšan "bright, clear," foruq "light," and afruxtan "to light, kindle" also belong to this family, as well as the E. light, Ger. Licht, and Fr. lumière.

daylight meteor
  شهاب ِ روز   
šahâb-e ruz

Fr.: météore de jour   

A → meteor detected using → radar techniques during daylight or when skies are cloudy.

day; → light; → meteor.

daylight saving time
  وخت ِ نور‌اندوزی، وقت ِ ~   
vaxt-e nur anduzi, vaqt-e ~

Fr.: heure d'été   

A system of adjusting the official local time in some countries in order to provide a better match between the hours of daylight and the active hours of work and school. The "saved" daylight is spent on evening activities which get more daylight, rather than being "wasted" while people sleep past dawn. Although known also as summer time, it includes the spring season and nearly half of autumn.

day; → light; saving, from save, from O.Fr. sauver, from L.L. salvare "to secure," from L. salvus "safe," PIE *solwos, from base *sol- "whole" (cf. O.Pers. haruva-, Av. haurva- "whole, intact," Mod.Pers. har "every, all; any," Skt. sarva- "whole, entire," Gk. holos "whole"); → time.

Vaxt, written vaqtوقت but pronounced vaxtوخت, is a Pers. word meaning "portion (of time)". Its variants and related words in Mod./Mid.Pers. are: baxt "what is alloted, fate, fortune," baxš "portion, part, division," baxšidan, baxtan "to divide, distribute, grant," Av. base bag- "to attribute, allot, distribute," baxš- "to apportion, divide, give to," baxta- "what is alloted (luck, fortune)," baxədra- "part, portion," baγa- "master, god," O.Pers. bāji- "tribute, tax," cf. Skt. bhaj- "to share, divide, distribute, apportion," bhájati "divides," bhakta- "alloted; occupied with; a share; food or a meal, time of eating?," Gk. phagein "to eat (to have a share of food)"; PIE base *bhag- "to share out, apportion."
anduzi, verbal noun of anduxtan "to save; acquire, gather," from Mid.Pers. handôxtan, handôz- "to gain, acquire, amass," from *ham-tuj-, from ham- "together," → com- + *tuj- "to save, gather, (re)pay," cf. Skt. tuj- "to promote, be strong, move quickly."

ruzhangâm (#)

Fr.: temps de jour   

The time interval when the Sun is above the horizon for a given position.

day; → time.

Ruzhangâm, from ruzday + hangâm "time, hour, season," Mid.Pers. hangâm "time, epoch, season," Av. ham-gam- "to meet together," from ham- "together," → com- + gam- "to come; to go," jamaiti "goes," O.Pers. gam- "to come; to go," Mod.Pers. âmadan "to come," Skt. gamati "goes," Gk. bainein "to go, walk, step," L. venire "to come," Tocharian A käm- "to come," O.H.G. queman "to come," E. come; PIE root *gwem- "to go, come."

DB gap
gâf-e DB

Fr.: lacune DB   

The observed absence of helium white dwarfs with temperatures between 45,000 and 27,000 K. A possible explanation lies in the chemical evolution of white dwarfs. Four processes can change the structure of a white dwarf: gravitational settling, interstellar medium accretion, mass loss, and subsurface convective mixing.

DB white dwarf; → gap.

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