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: 558
true Sun
  خورشید ِ راستین   
xoršid-e râstin

Fr.: Soleil vrai   

The Sun as seen in the sky, also referred to as the → apparent Sun; in opposition to → mean Sun.

true; → Sun.

Trumpler 14
  ترامپلر ۱۴   
Trumpler 14

Fr.: Trumpler 14   

A young → massive star cluster in the → Carina Nebula, lying about 10 arcmin to the north-west of → Trumpler 16. It comprises several → O-type stars. In particular, its core contains at least three very early O-type stars; → HD 93129.

From a catalog by Robert J. Trumpler (1886-1956), the Swiss-American astronomer who studied the → open clusters at Lick Observatory (1930). He was the first to produce a definite evidence of the existence of → interstellar reddening, due to → absorption, and to estimate its magnitude.

Trumpler 16
  ترامپلر ۱۶   
Trumpler 16

Fr.: Trumpler 16   

A → massive star, and the most populous cluster of the → Carina Nebula. It contains several → O-type stars and three known → Wolf-Rayet stars in addition to the famous → LBV star → Eta Carinae. Trumpler 16 is probably older than → Trumpler 14.

Trumpler 14.

truncate
  کل کردن   
kol kardan

Fr.: tronquer   

To shorten by cutting off a part.
Math.: 1) To shorten a number by dropping a digit or digits; e.g. to shorten 3.438 to 3.4.
2) To remove portions of solids falling outside a set of symmetrically placed planes.

From L. truncatus "cut off," p.p. of truncare "to maim, cut off," from truncus "mutilated, cut off."

Kol kardan "to cut off the end of; to dock a tail," from kol "docked, short," variants in a large number of dialects: kola, kalta, kel, kelma, koc, kall, kor, kul in Gilaki, Tâleši, Lori, Malâyeri, Hamedâni, Qâeni, and others, cf. Av. kaurvô- "bald, docked," kaurvôduma- "with a bald tail," kaurvôgaoša- "with bald ears;" cf. Gk. kol(os) "docked" (kolouros "dock-tailed;" L. colurus) + kardan "to do, to make" (Mid.Pers. kardan, O.Pers./Av. kar- "to do, make, build," Av. kərənaoiti "makes," cf. Skt. kr- "to do, to make," krnoti "makes," karma "act, deed;" PIE base kwer- "to do, to make").

truncation
  کل‌کرد، کل‌شد   
kolkard, kolšod

Fr.: troncature   

The act or process of truncating, as → disk truncation.

Verbal noun from → truncate.

truth
  راستینی   
râstini (#)

Fr.: vérité   

1) The quality of being true, genuine, actual, or factual.
2) Something that is → true as opposed to → false.
3) Logic: The correct corresponding of a → proposition with a → fact. See also → truth value, → partial truth.

M.E. treuthe; O.E. trêowth "faith, faithfulness, fidelity; quality of being true," from triewe, treowe "faithful," → tue, with suffix *-itho-th.

Noun from râstin, → true, + noun suffix -i.

truth function
  کریای ِ راستینی   
karyâ-ye râstini

Fr.: fonction de vérité   

A → total function from → truth values to truth values (a sequence of truth values).

truth; → function.

truth table
  جدول ِ راستینی   
jadval-e râstini

Fr.: table de vérité   

A table with columns and rows that lists the resultant → truth value of the given → sentences for each of the possible combinations of truth values to the simple sentences out of which the given sentences are constructed.

truth; → value.

truth value
  ارزش ِ راستینی   
arzeš-e râstini

Fr.: valeur de vérité   

The quality of a logical → proposition (or a formal → symbol) which describes the relation of a proposition to → truth. The traditional → formal logic admits only two contradictory values, → true or → false. In → symbolic logic, more specifically in → polyvalent logics, other truth values are used (such as possible, impossible, undetermined, probable, random, etc.).

truth; → value.

tsunami
  تسونامی   
tsunami (#)

Fr.: tsunami   

A huge wave, caused by undersea earthquakes, volcanic eruptions, or, more rarely, by asteroid or meteoroid impact (as in the case of the K-T extinction).

From Japanese tsunami, from tsu "harbor" + nami "waves."

tube
  لوله   
lulé (#)

Fr.: tube   

1) A long hollow cylinder of metal, glass, rubber, or other material used to transport or contain liquids or gases.
2) An electronic device in which electrons operate in a gas or in vacuo inside a closed envelope.

M.E., from M.Fr. tube, from L. tubus "tube, pipe," of unknown origin.

Lulé "tube, pipe; roll," dialectal Lori, Laki lil, Laki lul "wanderer;" Hamadâni lul "spiral, coil."

tube of flow
  لوله‌ی ِ تچان   
lule-ye tacân

Fr.: tube d'écoulement   

Same as → flow tube.

tube; → tube.

tube of flux
  لوله‌ی ِ شار   
lule-ye šâr

Fr.: tube de flux   

Bundles of lines of electrical intensity into which the vector field of electrical force can be divided. Same as tube of force, field tube.

tube; → flux.

Tucana
  توکان   
Tukân (#)

Fr.: Toucan   

The Toucan. A constellation of the southern hemisphere, at approximately 0h right ascension, -65° declination, represented as a toucan, a brightly colored South American bird with a very large, thick bill. Tucana contains the second most prominent → globular cluster in the sky, 47 Tucanae, and the → Small Magellanic Cloud. Abbreviation: Tuc; genitive: Tucanae. The constellation was one of twelve created by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman Houtman between 1595 and 1597, and it first appeared in Johann Bayer's Uranometria of 1603.

From Fr., from Portugese tucano, from tucan (onomatopoeia) in the language spoken by the Tupi Indians in Brazil.

Tully-Fisher relation
  بازانش ِ تولی-فیشر   
bâzâneš-e Tully-Fisher

Fr.: relation Tully-Fisher   

An observed correlation between the luminosity of a spiral galaxy and its rate of rotation (measured from its 21 cm hydrogen line). This means that more luminous galaxies have stars that are moving faster. Knowing the rotational velocity of a spiral galaxy, this relation provides its absolute magnitude and then its distance. → Faber-Jackson relation.

Named after R. B. Tully and J. R. Fisher who first derived this relationship (1977, A&A 54, 661); → relation.

tungsten
  تنگستن   
tangestan (#)

Fr.: tungstène   

A very hard, silver-white to steel-gray metal with a body-centered cubic crystalline structure; symbol W. Atomic number 74; atomic weight 183.85; melting point about 3,410°C; boiling point 5,660°C; specific gravity 19.3 at 20°C. The chemical element was discovered by the Swedish chemist Carl-Wilhelm Scheele in 1781. Tungsten metal was first isolated by the Spanish chemists Don Fausto d'Elhuyar and his brother Don Juan Jose d'Elhuyar in 1783.

The name derives from the Swedish ng sten "heavy stone". The chemical symbol, W, is derived from the Ger. wolfram, which was found with tin and interfered with the smelting of tin.

Tunguska event
  رویداد ِ تونگوسکا   
ruydâd-e Tunguska (#)

Fr.: événement de la Toungouska   

The violent impact of a comet or meteorite in the Tunguska region of Siberia on 30 June 1908. The object exploded in the atmosphere before touching the ground at an estimated height of 5-10 km. Observers reported seeing a fireball as bright as the Sun. The explosion caused a shock wave that shook buildings and caused damage, though there was no loss of human life. The first expedition to the remote area of the explosion took place in 1927. An estimated 80 million trees covering more than 2,150 square km were flattened. The energy of the explosion is estimated to have been equivalent to that of about 15 → megatons of TNT , a thousand times more powerful than the atomic bomb dropped on Hiroshima in 1945.

From the name of the central Siberian region, Russ. Podkamennaya (Lower Stony) Tunguska River, today Krasnoyarsk Krai; → event.

tunnel effect
  اُسکر ِ تونل   
oskar-e tunel

Fr.: effet tunnel   

A phenomenon in quantum mechanics whereby a particle can penetrate and cross a potential barrier whose energy is greater than the particle's energy. The tunnel effect, forbidden in classical mechanics, is a direct consequence of the wave nature of material particles. Also called tunneling

M.E. tonel, from M.Fr. tonele, tonnelle "funnel-shaped net," feminine of tonnel,diminutive of tonne "tun, cask for liquids." Sense of "tube, pipe" developed in Eng. and led to sense of "underground passage."

Oskar, → effect; tunel, from Fr. tunnel, as above.

turbid
  تار   
târ (#)

Fr.: turbide   

Having sediment or foreign particles stirred up or suspended; obscured, muddy, such as turbid water.

From L. turbidus "muddy, full of confusion," from turbare "to confuse, disturb," from turba "turmoil, crowd," probably from Gk. tyrbe "turmoil;" cf. Pers. târ "dark, obscure, cloudy," Laki tur "balk, refractory, restive."

Târ "obscure, dark," variant târik "dark;" Mid.Pers. târig "dark," târ "darkness;" Av. taθra- "darkness," taθrya- "dark;" cf. Skt. támisrâ- "darkness, dark night," L. tenebrae "darkness;" Hittite taš(u)uant- "blind;" O.H.G. demar "twilight."

turbidity
  تاری   
târi (#)

Fr.: turbidité   

1) Meteo.: A measure of vertical extinction of solar radiation in the atmosphere. Turbidity is directly related to aerosol concentrations in the tropospheric and stratospheric layers. → visibility.
2) The cloudiness or haziness of a fluid caused by individual particles (suspended solids) that are generally invisible to the naked eye, similar to smoke in air.

turbid; → -ity.

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