# An Etymological Dictionary of Astronomy and AstrophysicsEnglish-French-Persian

## فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

### M. Heydari-Malayeri    -    Paris Observatory

Homepage

Number of Results: 12948 Search : far
 relative error   ایرنگ ِ بازانی   irang-e bâzâniFr.: erreur relative   The → absolute error divided by the true value x, that is: Δx/x. The result may be expressed as a percentile and is useful when we want to determine the error relative to the value of the exact quantity.→ relative; → error. relative frequency   بسامد ِ بازانی   basâmad-e bâzâniFr.: fréquence relative   Statistics: The number of the occurrences of an event divided by the number of observations.→ relative; → frequency. relative humidity   نم ِ بازانی   nam-e bâzâniFr.: humidité relative   The amount of moisture in the air compared to what the air can "hold" at that temperature. It is given by the ratio of the partial pressure of water vapor in the mixture to the saturated vapor pressure of water at a specific temperature.→ relative; → humidity. relative invariant   ناورتای ِ بازانی   nâvartâ-ye bâzâniFr.: invariant relatif   A → relative tensor of order zero.→ relative; → invariant. relative permeability   تراوایی ِ بازانی   tarâvâyi-ye bâzâniFr.: perméabilité relative   → relative; → permeability. relative refractive index   دیشن ِ شکستی ِ بازانی   dišan-e šekasti-ye bâzâniFr.: indice de réfraction relatif   The ratio of the sine of the angle of incidence to the sine of the angle of refraction for a ray passing out of one of the media into the other.→ relative; → refractive; → index. relative sunspot number   شمار ِ بازانی ِ هورلک   šomâr-e bâzâni-ye hurlakFr.: nombre relatif de taches solaires   Same as → Wolf number and → sunspot number.→ relative; → sunspot; → number. relative tensor   تانسور ِ بازانی   tânsor-e bâzâniFr.: tenseur relatif   A generalized tensor concept that is characterized by a → Jacobian matrix of transformation raised to a power called → weight of a tensor density. In practice, only relative tensors of weight 1 or -1 are used. The product of a relative tensor of weight -1 by another tensor of weight 1 is an → absolute tensor. Same as → tensor density.→ relative; → tensor. relative vector   بردار ِ بازانی   bordâr-e bâzâniFr.: vecteur relatif   A → relative tensor of → order  → one.→ relative; → vector. relative velocity   تندای ِ بازانی   tondâ-ye bâzâniFr.: vitesse relative   For two objects A and B, the velocity which B, supposing itself at rest, assigns to A.→ relative; → velocity. relatively   بازانی‌وار، بازانانه   bâzânivâr, bâzânânéFr.: relativement   In a relative manner; in relation to something else.From → relative + -ly "-vâr, -âné." relativism   بازانی‌باوری   bâzâni-bâvariFr.: relativisme   The belief that truth is relative and may vary from individual to individual, from group to group, or from time to time, having no objective standard.From → relative + -ism a suffix used in the formation of nouns denoting action or practice, state or condition, principles, doctrines, etc.Bâzâni-bâvari, from bâzâni, → relative, + bâvari, from bâvar "belief" (Mid.Pers. wâbar "beleif;" Proto-Iranian *uar- "to choose; to convince; to believe;" cf. Av. var- "to choose; to convince" varəna-, varana- "conviction, faith;" O.Pers. v(a)r- "to choose; to convince;" Skt. vr- "to choose," vara- "choosing"). relativist   بازانی‌باور   bâzâni-bâvarFr.: relativiste   An adherent or advocate of relativism.From → relative + -ist a suffix of nouns.Adj. from → relativism. relativistic   بازانیگی‌مند، بازانیگی‌ور   bâzânigimand, bâzânivarFr.: relativiste   1) Physics: Relating to the → relativity theory. 2) Philosophy: Involving or characterized by → relativism. See also: → non-relativistic, → relativistic aberration, → relativistic Doppler effect, → relativistic effect, → relativistic mass, → relativistic particle, → relativistic precession, → relativistic quantum mechanics, → relativistic redshift, → relativistic speed, → relativistic spin precession, → relativistic velocity, → ultrarelativistic, → ultrarelativistic gas.From → relativist + → -ic. relativistic aberration   بیراهش ِ بازانیگی‌مند   birâheš-e bâzânigimandFr.: aberration relativiste   The aberration of light for an object moving with → relativistic speed. In contrast to the classical case, the → Lorentz transformation between the → rest frame of the observer and that of the object must be used. Relativistic aberration is expressed by the equation: cos φ' = (cos φ - )/(1 - cos φ.v/c), where φ is the classical → aberration angle, v the speed of the Earth, and c the → speed of light. It can also be expressed as: tan φ' = -(c/v)(1 - v2/c)1/2. relativistic Doppler effect   اُسکر ِ دوپلر ِ بازانیگی‌مند   oskar-e Doppler-e bâzânigimandFr.: effet Doppler relativiste   The Doppler effect when the relative motion of the source and the observer is comparable to the speed of light. In that case the classical Doppler formula should be corrected for effects of the special theory of relativity (Lorentz transformation). relativistic effect   اسکر ِ بازانیگی‌مند   oskar-e bâzânigimandFr.: effet relativiste   A physical phenomenon described only by the theories of → special relativity or → general relativity.→ relativistic; → effect. relativistic mass   جرم ِ بازانیگی‌مند   jerm-e bâzânigimandFr.: masse relativiste   In → special relativity, the mass that is assigned to a body in motion. Einstein demonstrated that the velocity of the observer has an effect on the way inertial mass is measured. The relativistic mass is expressed by mt = m0 / [1 - (v/c)2]1/2, where m0 is the → rest mass, v is the velocity, and c the → velocity of light. The experimental evidence for this phenomenon is observed in the mass of high-speed electrons accelerated by magnetic fields. This formula shows that it is impossible for a mass to be accelerated to the velocity of light in a vacuum.→ relativistic; → mass. relativistic particle   ذرّه‌ی ِ بازانیگی‌مند   zarre-ye bâzânigimandFr.: particule relativiste   A particle which has a speed comparable to the velocity of light.→ relativistic; → particle. relativistic precession   پیشایان ِ بازانیگی‌مند   pišâyân-e bâzânigimandFr.: précession relativiste   A → general relativistic phenomenon in which the line joining the → apsides of an orbit gradually rotates in a → prograde direction. Also called the → orbital precession and → perihelion precession. Although the general relativistic precession of Mercury's orbit is extremely small, the similar precession observed in the orbit of the → binary pulsar PSR B1913+16 amounts to 4.23 degrees per year, i.e. 36,000 times greater than the → advance of perihelion of Mercury.