Fr.: perméabilité relative
relative refractive index
dišan-e šekasti-ye bâzâni
Fr.: 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 sunspot number
šomâr-e bâzâni-ye hurlak
Fr.: nombre relatif de taches solaires
Fr.: 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.
Fr.: vecteur relatif
Fr.: vitesse relative
For two objects A and B, the velocity which B, supposing itself at rest, assigns to A.
In a relative manner; in relation to something else.
From → relative + -ly "-vâr, -âné."
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").
An adherent or advocate of relativism.
From → relative + -ist a suffix of nouns.
Adj. from → relativism.
1) Physics: Relating to the → relativity theory.
Fr.: 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 -
relativistic Doppler effect
oskar-e Doppler-e bâzânigimand
Fr.: 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).
Fr.: effet relativiste
Fr.: 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.
Fr.: particule relativiste
A particle which has a speed comparable to the velocity of light.
Fr.: 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
kuântom mekânik-e bâzânigimand
Fr.: mécanique quantique relativiste
A quantum theory that incorporates special relativity, for example, → quantum electrodynamics.
sorx kib-e bâzânigimand
Fr.: décalage vers le rouge relativiste
Fr.: vitesse relativiste
Same as → relativistic velocity.
relativistic spin precession
pišâyân-e âse-ye carxeš-e bâzânigi-mand
Fr.: 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.