An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 1026
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 &jbsp;$nrsp;
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 knowj potgndial difference.

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

tavân (#)

Fr.: puissance, pouvoir   

1) Physics: The → rate of doing → work on transferring → energy, as expressed in ergs/sec, watts, etc. Same as → mechanical power.
2) Math.: An → exponent to which a given quantity is raised. The expression xn is therefore known as "x to the n-th power."

M.E. pouer(e), poer(e), from O.Fr. povoir, noun use of the infinitive in O.Fr., "to be able," from V.L. *potere, from L. potis "powerful, able, capable;" cognate with Av. paiti- "lord, husband;" Mod.Pers. -bad (sepah-bad "general, commander of an army"); Skt. pái- "master, husband;" Gk. posis "husband;" Lith. patis "husband."

Tavân "power, strength," tavânestan "to be powerful, able;" Mid.Pers. tuwan "power, might," from O.Pers./Av. base tav- "to have power, to be strong, to be able," Av. tavah- "power," təviši- "strength," Mod.Pers. tuš, tâb "power, ability," O.Pers. tauman- "power, strength," tunuvant- "powerful," Skt. tu- "to be strong, to have authority," tavas-, tavisa- "strong, energetic," tavisi- "power, strength."

power function
  کریای ِ توانی   
karyâ-ye tavâni

Fr.: fonction de puissance   

A function of the form f(x) = xn, where n is a → real number.

power; → function.

power law
  قانون ِ توانی   
qânun-e tavâni (#)

Fr.: loi de puissance   

A mathematical relationship between two quantities expressed by a → power function.

power; → law.

power series
  سری ِ توانی   
seri-ye tavâni (#)

Fr.: série de puissance   

A series in which the terms contain regularly increasing powers of a variable. In general, a0 + a1x + a2x2 + ... + anxn, where a0, a1, etc. are constants.

power; → series.

power spectral density
  چگالی ِ بینابی ِ توان   
cagâli-ye binâbi-ye tavân

Fr.: densité spectrale de puissance   

Same as → spectral density.

power; → spectral; → density.

power spectrum
  بیناب ِ توانی   
binâb-e tavâni (#)

Fr.: spectre de puissance   

The plot that gives the portion of a signal's power falling within given frequency bins. The most common way of generating a power spectrum is by using a discrete Fourier transform.

power; → spectrum.

power-law distribution
  واباژش با قانون ِ توانی   
vâbâžeš bâ qânun-e tavâni

Fr.: distribution en loi de puissance   

For a → random variable X, any → distribution which has the form: P(X ≥ x) = (k/x)α, where x is a value in the range defined for X, k > 0 is a parameter termed location parameter, and α > 0 is the → slope parameter.

power; → law; → distribution.

power-law elliptical galaxy
  کهکشان ِ بیضی‌گون با قانون ِ توانی   
kahkešân-e beyzigun bâ qânun-e tavâni

Fr.: galaxie elliptique en loi de puissance   

An → elliptical galaxy whose → surface brightness can be approximated by a single → power law at small radii (r ≤ 10-20''). More modern interpretations have emphasized that these profiles can be better understood as the inward continuation of the galaxy's overall → Sersic profile, usually modified by an additional, nuclear-scale stellar component (S. P. Rusli et al., 2013, AJ 146, 160).

power; → law; → galaxy.

Poynting vector
  بردار ِ پوینتینگ   
bordâr-e Poynting

Fr.: vecteur de Poynting   

The amount of electromagnetic energy flowing through unit area, perpendicular to the direction of energy propagation, per unit time, given by (c/2 π)[E x H]. → Poynting's theorem.

Poynting's theorem; → vector.

<< < -ph pal par par par par pas Pau pen per per per per Per per pha Pho pho pho pho Pia Pis Pla pla pla pla Ple Pog pol pol pol pol pop pos pot Poy pre pre pre pre pri pri pro pro pro pro pro pro pro pub pul pyr > >>