An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < -sc Sag sam sat sca sca Sch sco sec sec sec sei sel sem sep sex Sha she sho sid sig sim sin Sir sky slo sno sod sol sol sol sol sou sou spa spe spe spe spe sph spi spo SS sta sta sta sta ste ste sto str str str sub sub suc sun sup sup sup sup sur swi syn Syr > >>

Number of Results: 1290
sidereal year
  سال ِ اختری   
sâl-e axtari (#)

Fr.: année sidérale   

The interval between two successive passages of the Sun, in its apparent → annual motion around the → celestial sphere, through a particular point relative to stars. It is equal to 365.256356 days for the J2000.0 epoch and is 20m 24.5s longer than the → tropical year.

sidereal; → year.

siderit (#)

Fr.: sidérite   

1) A mineral composed of iron carbonate, FeCO3, that is a valuable ore of → iron.
2) A category of → meteorites consisting mainly of → iron and → nickel, commonly referred to as Irons. There are 13 different chemical groups of siderites. These groups are defined based on the relative abundance of nickel, gallium, germanium, and iridium. Irons are also categorized by their structural type.

From Gk. sider- variant of sidero- before a vowel, from sideros "iron" + -ite a suffix with several senses, specifically some minerals or chemical compounds.

siderolit (#)

Fr.: sidérolithe, sidérolite   

The category of → meteorites commonly referred to as → stony-irons. The three classes of siderolites are → lodranites, → mesosiderites, and → pallasites.

From Gk. sidero-, from sideros "iron" + -lite a combining form used in the names of minerals.


Fr.: sidérophile   

Any → chemical element that prefers to combine with → iron rather than some other element.

From Gk. sidero-, from sideros "iron" + → -phile.

Âhandust, from âhan, → iron, + -dust, → -phile.


Fr.: sidérostat   

A mirror arrangement with clock drive that reflects light from a celestial body to a fixed position. → coelostat; → heliostat.

From L. sidero-, from sidus (genitive sideris) "star, constellation" + -stat prefix denoting something that stabilizes, keeps, fixes, from -stata, from Gk. -states "one that causes to stand," or statos "standing," from *sta- "to stand."

Axtardâštâr, from axtar, → star, + dâštâr "holder, maintainer," from dâštan "to hold, maintain; to have; to possess;" Mid.Pers. dâštan; O.Pers./Av. dar- "to hold, keep back, maintain, keep in mind;" cf. Skt. dhr-, dharma- "law;" Gk. thronos "elevated seat, throne;" L. firmus "firm, stable;" Lith. daryti "to make;" PIE base *dher- "to hold, support."

siemens (S)
siemens (#)

Fr.: siemens   

The SI unit of electrical conductance, equal to the reciprocal of the ohm and replacing the equivalent MKS unit.

Named for the German electrical engineer Werner von Siemens (1816-1892).

sieve of Eratosthenes
  غربال ِ اراتوستنس   
qarbâl-e Eratosthenes (#)

Fr.: crible d'Eratosthène   

A classical method of finding all → prime numbers up to any given number n. The method consists of listing all positive integers from 2 up to the given number and then deleting some of them sequentially in steps. For example, if we wish to find the primes less than or equal to 50, we proceed as follows. All integers from 2 to 50 are first written. The integers that are divisible by 2, other than 2, are crossed out from the list. Since 3 is the first integer greater than 2 that is not removed, all the integers divisible by 3, other than 3, are crossed out. We do the same with 5 and then 7. Since all composite integers ≤ 50 are divisible by 2, 3, 5, or 7 (i.e. ≤ √50), all the remaining integers not deleted are prime numbers: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, and 47.

M.E. sive, O.E. sife "sieve;" cf. M.Du. seve, Du. zeef, O.H.G. sib, Ger. Sieb, of unknown origin. Related to sift; → Eratosthenes experiment.

Qarbâl (variants qarbil, qarbir, qelber, qalbur, gerbâl), probably related to the PIE base *krei- "to sieve, separate;" cf. Gk. krinein "to separate, decide, judge," krisis "decision;" L. cribrum "sieve" (Fr. crible), cernere "to sift, separate;" O.E. hriddel "sieve;" O.Ir. criathar; O.Welsh cruitr "sieve." Pers. qarbâl loaned in Ar. as gharbala "to sift," itself loaned in It. garbellare; M.Fr. garbeler "to sift;" E. garble "to sift impurities from."

sievert (Sv)
sievert (#)

Fr.: sievert   

The SI unit for the dose equivalent of ionizing radiation. One sievert represents a dosage of 1 → joule per kg of tissue, absorbed from the ionizing radiation. The effect of radiation depends on its total amount of energy, the type of radiation, and the energy levels of particular particles. The dose equivalent in sieverts of radiation is the product of the absorbed dose in → gray (Gy)s and a dimensionless numeric factor, called the quality factor or relative biological effectiveness, dependent on the type of radiation. The sievert has replaced the → rem as the unit of dose equivalent. 1 rem = 10-2 Sv.

The unit honors the Swedish physicist Rolf Sievert (1898-1966), who worked over many years to measure and standardize the radiation doses used in cancer treatment.

did (#)

Fr.: visée   

The act or fact of seeing; field of vision. → line of sight.

M.E., from O.E. gesiht, gesihð "thing seen;" cf. Dan. sigte, Swed. sigt, M.Du. sicht, Du. zicht, O.H.G. siht, Ger. Sicht, Gesicht, related to → sign.

Did "sight, vision," past stem of didan "to see" (Mid.Pers. ditan "to see, regard, catch sight of, contemplate, experience;" O.Pers. dī- "to see;" Av. dā(y)- "to see," didāti "sees;" cf. Skt. dhī- "to perceive, think, ponder; thought, reflection, meditation," dādhye; Gk. dedorka "have seen").


Fr.: ligne de visée   

line of sight.

sight; → line.

  نشان، نشانه   
nešân, nešâné (#)

Fr.: signe   

1) A conventional or arbitrary mark, figure, or symbol used as an abbreviation for the word or words it represents. Related terms: → signal, → signature, → symbol, → index.
2) Math.: A plus sign or minus sign used as a symbol for indicating addition or subtraction; also a sign for indicating the positive or negative value of a quantity.
3) → sign of the zodiac.

M.E., from O.Fr. signe "sign, mark, signature," from L. signum "mark, token, indication, symbol," from PIE base *sekw- "to see."

Nešân "sign, mark," from Mid.Pers. nišân "sign, mark, omen," nišitan "to gaze, stare, look into," niš in marv.niš "taking omen, foretelling, or divining from birds," nišak "clear, evident," from Proto-Iranian *niiaš- "to show," from *ni- "down, below," → ni- (PIE), + *iaš- "to show, appear;" cf. Armenian loanword niš "sign, mark, spot," loaned also in Syriac as nyš "sign" (Cheung 2007).

sign of the zodiac
borj (#)

Fr.: signe du zodiaque   

One of the 12 constellations (in fact 13) making up the → zodiac.

sign; → zodiac.

Borj originally "tower," most probably related to Pers. borz "height, magnitude, greatness," boland "high," bâlâ "up, above, high, elevated, height," Laki dialect berg "hill, mountain;" Mid.Pers. burz "height," buland "high;" O.Pers. baršan- "height;" Av. barəz- "high, mount," barezan- "height;" cf. Skt. bhrant- "high;" L. fortis "strong" (Fr. and E. force); O.E. burg, burh "castle, fortified place," from P.Gmc. *burgs "fortress;" Ger. Burg "castle," Goth. baurgs "city," E. burg, borough, Fr. bourgeois, bourgeoisie, faubourg; PIE base *bhergh- "high." Borj may have been loaned into Ar. from Mid.Pers. The meaning extension of borj to its astronomical sense of zodiacal sign may have arisen from the conception of the zodiac as a barrier between heaven and Earth through which access was gained by means of twelve gates.


Fr.: signal   

1) Useful part of the received information that can be distinguished from noise.
2) Information transmitted by means of a modulated current or an electromagnetic wave and received by telephone, radio, television, etc.

M.E., from O.Fr. signal, from M.L. signale "a signal," from L.L. signalis (adj.) "used as a signal, pertaining to a sign," from L. signum "signal, sign."

Nešâl, from neš- base of nešân meaning → sign + -âl, → -al.

signal-to-noise ratio
  وابَر ِ نشال-به-نوفه   
vâbar-e nešâl-bé-nufé

Fr.: rapport signal sur bruit   

Concept used to quantify the effects of noise. It is the ratio of a signal to the standard deviation of the signal.

signal; → noise; → ratio.


Fr.: signature   

1) Physics, Chem.: A distinctive trace or sign that indicates the presence of a substance or the occurrence of a physical process or event.
2) Telecommunication: The complete set of electromagnetic and/or acoustic signals received, e.g., from an infrared source, a radio or radar transmitter, an aircraft, or a ship. Signatures may consist of analog or digital signals, or both, and may be analyzed to indicate the nature of their source and assist in its recognition.

M.Fr. signature, from M.L. signatura "sign," in classical L. "the matrix of a seal," from signatus, p.p. of signare "to mark, sign," → sign.

Nešânzad, literally "striking a mark, sign" (cf. angošt zadan "fingerprint"), from nešân, → sign, + zad past stem of zadan "to strike, beat; to do; to play an instrument" (Mid.Pers. zatan, žatan; O.Pers./Av. jan-, gan- "to strike, hit, smite, kill" (jantar- "smiter"); cf. Skt. han- "to strike, beat" (hantar- "smiter, killer"); Gk. theinein "to strike;" L. fendere "to strike, push;" Gmc. *gundjo "war, battle;" PIE *gwhen- "to strike, kill").


Fr.: significativité   

1) The state or quality of being significant; → meaning; importance.
2) Statistics: An estimated measure of the degree to which a result is not merely a matter of chance. See also → significance level, → significance testing.

From L. significantia "meaning, force, energy," from significans, present participle of significare, → signify.

Nešânâri, noun from nešânâr, → significant.

significance level
  تراز ِ نشاناری   
tarâz-e nešânâri

Fr.: niveau de significativité   

The level of → Type I error which one is willing to risk in a → test of significance. Also called level of significance.

significance; → level.

significance testing
  آزمون ِ نشاناری   
âzmun-e nešanâri

Fr.: test de significativité   

Statistics: A procedure that is used to decide whether to accept or reject the → null hypothesis or to determine whether observed samples differ significantly from expected results. Also called → test of significance and → rule of decision.

significance; → test.


Fr.: significatif   

1) Having a special or suggestive → meaning.
2) Statistics: Of or pertaining to a result that is not plausible to occur by chance.

From L. significant-, stem of significans, from significare, "to → signify."

Nešânâr, from nešân, → sign, + âr short form of âvar present stem of âvardan "to bring, adduce, cause, produce."

significant digit
  رقم ِ نشانار   
raqam-e nešânâr

Fr.: chiffre significatif   

The number of digits used to express a measured or calculated quantity. Rules for deciding the number of significant digits:
The leftmost digit which is not a zero is the most significant digit.
If the number does not have a decimal point, the rightmost digit which is not a zero is the least significant digit.
If the number does have a decimal point, the rightmost significant digit is the least significant digit, even if it's a zero.
Every digit between the least and most significant digits should be counted as a significant digit.

significant; → digit.

<< < -sc Sag sam sat sca sca Sch sco sec sec sec sei sel sem sep sex Sha she sho sid sig sim sin Sir sky slo sno sod sol sol sol sol sou sou spa spe spe spe spe sph spi spo SS sta sta sta sta ste ste sto str str str sub sub suc sun sup sup sup sup sur swi syn Syr > >>