An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 153 Search : ten

Fr.: persistance   

The act or fact of persisting; the quality of being persistent.

Verbal noun from → persist.


Fr.: persistant   

Persisting, especially in spite of opposition, obstacles, discouragement, etc.; persevering (

Adjective from → persist.


Fr.: potentiel   

1) A latent ability that may or may not be developed; possibility.
2) Physics: The → work required to → move a unit positive → charge, unit magnetic pole, or an amount of → mass respectively from → infinity (i.e. a place infinitely distant from the causes of the field) to a designated point. Gravitational potential is always negative, but the electric or magnetic potentials may be positive or negative.
3) (adj.) Capable of being or becoming, as opposed to → actual.
See also:
chemical potential, → electric scalar potential, → electromagnetic potential, → equipotential surface, → excitation potential, → gravitational potential energy, → ionization potential, → kinetic potential, → magnetic vector potential, → potential barrier, → potential density, → potential difference, → potential energy, → potential energy curve, → potential field, → potential gradient, → potential well, → potentiality, → retarded potential, → scalar potential, → thermodynamic potential, → Yukawa potential.

From L.L. potentialis "potential," from L. potentia "power," potis "powerful, able, capable;" cognate with Av. paiti- "lord, husband;" Mod.Pers. -bad (sepah-bad "general, commander of an army"); Skt. páti- "master, husband;" Gk. posis "husband;" Lith. patis "husband."

Tavand, from tav- + -vand. The first component tav- is the stem of tavân "power, strength," tavânestan "to be powerful, able;" variants tâv, tâb, (dialects) tew "power;" Mid.Pers. tuwan "power, might;" O.Pers. tav- "to have power, to be strong, to be able," tauman- "power, strength," tunuvant- "powerful;" Av. tauu- (tu-) "to be able, strong," tavah- "power," təviši- "strength" (Mod.Pers. tuš "power, ability"); Skt. tavi- "to be strong, to have authority," tavas-, tavisa- "strong, energetic," tavisi- "power, strength;" Gk. taus, saos "healthy;" L. tumere "to be swollen;" PIE *teu- "to swell, be strong." The second component -vand a suffix of adjectives and agent nouns, → actual.
Note: Tavand used as both noun and adjective, such as honarmand (n.) and mard-e honarmand (adj.).

potential barrier
  ورغه‌ی ِ توند   
varqeye tavand

Fr.: barrière de potentiel   

Region in a field of force in which the potential is such that a particle, which is subject to the field, encounters opposition to its passage.

potential; → barrier.

potential density
  چگالی ِ توند   
cagâli-ye tavand

Fr.: densité potentielle   

Of a fluid parcel at pressure P, the density that it would acquire if adiabatically brought to a reference pressure.

potential; → density.

potential difference
  دگرسانی ِ توند   
degarsâni-ye tavand

Fr.: différence de potentiel   

Between two points, the work done in taking the unit test object from one point to the other. Potential is a scalar quantity.

potential; → difference.

potential energy
  کاروژ ِ توند   
kâruž-e tavand

Fr.: énergie potentielle   

Of a system, the work done in changing the system from some standard configuration to its present state. Thus, if a body of mass m is raised vertically through a height h, the work done, mgh, is the increase in potential energy.

potential; → energy.

potential energy curve
  خم ِ کاروژ ِ توند   
xam-e kâruž-e tavand

Fr.: courbe de l'energie potentielle   

A plot that displays the → potential energy of a moving body as a function of its position. It is explained by the → conservation of energy and the conversion of potential energy into → kinetic energy and vice versa.

potential; → energy; → curve.

potential field
  میدان ِ توند   
meydân-e tavand

Fr.: champ de potentiel   

A field that has a → potential. A continuous → vector fieldA in a domain D is a potential field in D if and only if its → work around every closed curve C contained in D is zero: ∫A.ds = 0. Examples include the → gravitational field and the → electrostatic field.

potential; → field.

potential gradient
  زینه‌ی ِ توند   
zine-ye tavand

Fr.: gradient de potentiel   

At a point, the rate of change of potential V, with distance x, measured in the direction in which the variation is a maximum. The intensity F of the field is proportional to the potential gradient, but is oppositely directed: F = -dV/dx.

potential; → gradient.

potential well
  چاه ِ توند   
câh-e tavand

Fr.: puit de potentiel   

Region in a → field of force in which the potential decreases abruptly, and in the surrounding region of which the potential is larger.

potential; → well.


Fr.: potentialité   

1) The state or quality of being potential. Something potential.
2) According to Aristotle, what has the possibility of having → form, in contrast to → actuality; the power to effect change.

potential + → -ity.


Fr.: potentiellement   

With a possibility of becoming actual; possibly.

potential; → -ly.

potentially hazardous asteroid (PHA)
  سیارک ِ توندانه آپه‌ناک   
seyyârak-e tavandâné âpenâk

Fr.: astéroïde potentiellement dangereux   

An asteroid that could make a threatening close approach to the Earth. In technical terms a PHA is defined as having an → absolute magnitude of 22 or brighter and an → Earth Minimum Orbit Intersection Distance (MOID) of less than 0.05 → astronomical unit or 7.5 million km.

potentially; → hazardous; → asteroid.


Fr.: potentiomètre   

An instrument for measuring electrical quantities by balancing an unknown potential difference against a known potential difference.

From potenti(al), → potential + -o + → -meter.

Prutenic Tables
  زیج ِ پروسی   
zij-e Prusi

Fr.: Tables pruténiques   

A set of astronomical tables (→ ephemeris) created in 1551 by Erasmus Reinhold (1511-1553), professor of astronomy at Wittenberg, indicating the positions of the Sun, the Moon, and the planets on the basis of the → Copernican model of heliocentric solar system. They superseded the → Alfonsine Tables, but since circular orbits were used, they were no more accurate than those tables. They were themselves replaced by the → Rudolphine Tables.

From original L. title Tabulae prutenicae "Prussian Tables," such named because Albert I, Duke of Prussia, supported Reinhold and financed the printing; → table; → zij.

radiant intensity
  درتنویی ِ تابشی   
dartanuyi-ye tâbeši

Fr.: intensité de rayonnement   

A measure of the amount of radiation emitted from a point expressed as the radiant flux per unit solid angle leaving this source.

radiant; → intensity.

relative tensor
  تانسور ِ بازانی   
tânsor-e bâzâni

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.

relative; → tensor.

retarded potential
  توند ِ دیررس   
tavand-e dirras

Fr.: potentiel retardé   

The → electromagnetic potential at an instant in time and a point in space as a function of the charges and currents that existed at earlier times.

Retarded, adj. of → retard; → potential.

Ricci tensor
  تانسور ِ ریتچی   
tânsor-e Ricci

Fr.: tenseur de Ricci   

A → rank 2, → symmetric tensor Rμν that is a contraction of the → Riemann curvature tensor Rλμνλ. More specifically, Rμν ≡ Σ (λ) Rλμνκ = Rλμνκ. Closely related to the Ricci tensor is the → Einstein tensor, which plays an important role in the theory of → general relativity.

Named after the Italian mathematician Gregorio Ricci-Curbastro (1853-1925); → tensor.

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