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

## فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

### M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 732
 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. relativistic quantum mechanics   کو‌آنتوم مکانیک ِ بازانیگی‌مند   kuântom mekânik-e bâzânigimandFr.: mécanique quantique relativiste   A quantum theory that incorporates special relativity, for example, → quantum electrodynamics. relativistic redshift   سرخ‌کیب ِ بازانیگی‌مند   sorx kib-e bâzânigimandFr.: décalage vers le rouge relativiste   A redshift caused by the → relativistic Doppler effect. → gravitational redshift.→ relativistic; → redshift. relativistic speed   تندی ِ بازانیگی‌مند   tondi-ye bâzânigimandFr.: vitesse relativiste   Same as → relativistic velocity.→ relativistic; → speed. relativistic spin precession   پیشایان ِ آسه‌ی ِ چرخش ِ بازانیگی‌مند   pišâyân-e âse-ye carxeš-e bâzânigi-mandFr.: précession de l'axe de rotation relativiste   The change in the direction of the → rotation axis of a → pulsar in a → binary pulsar. In such a system, → geodetic precession leads to a relativistic → spin-orbit coupling, analogous of → spin-orbit coupling in atomic physics. In consequence, the pulsar spin precesses about the total → angular momentum, changing the relative → orientation of the pulsar toward Earth (Damour & Ruffini, 1974). As a result, the angle between the pulsar → rotation axis and our → line of sight changes with time, so that different portions of the emission beam can be observed leading to changes in the measured pulse profile. In extreme cases, the precession may even move the beam out of our line of sight and the pulsar may disappear as predicted for PSR 1913+16 for the year 2025.→ relativistic; → spin; → precession. relativistic velocity   تندای ِ بازانیگی‌مند   tondâ-ye bâzânigimandFr.: vitesse relativiste   The velocity of a body when it is a significant fraction of the → speed of light.→ relativistic; → velocity. relativity   بازانیگی   bâzânigiFr.: relativité   General: The state or fact of being relative. Physics: 1) Short for the → Galilean relativity. 2) Short for the → relativity theory of Einstein.Relativity, from → relative + → -ity. relativity of simultaneity   بازانیگی ِ همزمانی   bâzânigi-ye hamzamâniFr.: relatitivité de simultanéité   A basic concept of → special relativity whereby → events that are simultaneous in one → reference frame are not simultaneous in another reference frame moving with respect to the first.→ relativity; → simultaneity.