An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 471 Search : ity
relativity theory
  نگره‌ی ِ بازانیگی   
negare-ye bâzânigi

Fr.: théorie de la relativité   

The → theory of relativity.

theory; → relativity.

reliability
  استیگانی   
ostigâni

Fr.: fiabilité   

1) The state or quality of being reliable.
2) A statement of the error or precision.

reliable; → -ity.

repulsive gravity
  گرانی ِ وازننده   
gerâni-ye vâzanadé

Fr.: gravité répulsive   

In → general relativity, the gravity resulting from a → negative pressure. See also → cosmological constant.

repulsive; → gravity.

resistivity
  بر‌ایست‌مندی   
baristmandi

Fr.: resistivité   

A property of a → conductor which is defined as the ratio of the → electric intensity (E) to the → current density (J): ρ = E/J. The greater the resistivity, the greater the intensity needed to establish a given current density, or the smaller the current density for a given intensity. A "perfect" conductor would have zero resistivity, and a "perfect" → insulator an infinite resistivity.

From → resistive + → -ity.

responsibility
  پاسخداری   
pâsoxdâri

Fr.: responsabilité   

1) The state or fact of being responsible, answerable, or accountable for something within one's power, control, or management.
2) An instance of being responsible.
3) A person or thing for which one is responsible (Dictionary.com).

responsible; → -ity.

responsivity
  پاسخندگی   
pâsoxandegi

Fr.: responsivité   

A performance criterion for an electronic detector, the ratio of the detector's electrical output to its optical input.

responsive; → -ity.

rigidity
  سخت‌پایی   
saxtpâyi

Fr.: rigidité   

1) The quality or state of being → rigid. See also → modulus of rigidity.
2) → magnetic rigidity.

rigid + → -ity.

Rosseland mean opacity
  کدری ِ میانگین ِ روسلاند   
kederi-ye miyângin-e Rosseland

Fr.: opacité moyenne de Rosseland   

The → opacity of a gas of given composition, temperature, and density averaged over the various wavelengths of the radiation being absorbed and scattered. The radiation is assumed to be in → thermal equilibrium with the gas, and hence have a → blackbody spectrum. Since → monochromatic opacity in stellar plasma has a complex frequency dependence, the Rosseland mean opacity facilitates the analysis. Denoted κR, it is defined by: 1/κR = (π/4σT3) ∫(1/kν) (∂B/∂T)νdν, summed from 0 to ∞, where σ is the → Stefan-Boltzmann constant, T temperature, B(T,ν) the → Planck function, and kν monochromatic opacity (See Rogers, F.J., Iglesias, C. A. Radiative atomic Rosseland mean opacity tables, 1992, ApJS 79, 507).

Named after Svein Rosseland (1894-1985), a Norwegian astrophysicist, who obtained the expression in 1924; → mean; → opacity.

rotational velocity
  تندای ِ چرخشی   
tondâ-ye catxeši

Fr.: vitesse de rotation   

The velocity of a → rotational motion; same as → angular velocity.

rotational; → velocity.

scalability
  مرپل-پذیری   
marpel-paziri

Fr.: scalibilité, extension graduelle, évolutivité, facteur d'échelle, extensibilité   

The ability of something, especially a computer system, to adapt to increased demands.

scalable; → -ity.

scalar density
  چگالی ِ مرپلی   
cagâli-ye marpeli

Fr.: densité scalaire   

A → tensor density of → order 0.

scalar; → density.

Schwarzschild singularity
  تکینی ِ شو‌آرتسشیلد   
takini-ye Schwarzschild

Fr.: singularité de Schwarzschild   

A region of infinite → space-time curvature postulated to lie within a → black hole.

Schwarzschild black hole; → singularity.

scientificity
  دانشیگی   
dânešigi

Fr.: scientificité   

The quality of the practices and theories that aim at establishing reproducible regularities in phenomena by using experimental method and providing a clearly formulated description.

scientific + → -ity.

secular instability
  ناپایداری ِ دیریاز   
nâpâydâri-ye diryâz

Fr.: instabilité séculaire   

Instability caused by a slow dissipation of energy.

secular; → instability.

secular stability
  پایداری ِ دیریاز   
pâydâri-ye diryâz

Fr.: stabilité séculaire   

1) The condition in which the equilibrium configuration of a system is stable over long periods of time.
2) The condition of a star when it is stable against arbitrary adiabatic perturbations.

secular; → stability.

security
  زیلگی   
zilegi

Fr.: sécurité   

1) Freedom from care, anxiety, or doubt; well-founded confidence.
2) Something that secures or makes safe; protection; defense.
3) A department or organization responsible for protection or safety (Dictionary.com).

secure; → -ity.

self-gravity
  خود-گرانی   
xod-gerâni

Fr.: auto-gravité   

The → gravitational attraction of a system of masses, such of a planet, that allows the system to be held together by their mutual gravity. Self-gravity between atoms allows a → star to hold together, despite tremendous temperature and pressure. Similarly, to be considered a → planet, a body must have enough mass so that its self-gravity pulls it into a near-spherical shape.

self-; → gravity.

self-similarity
  خودهمانندی   
xod-hamânadi

Fr.: auto-similarité   

The property of being → self-similar.

self-; → similarity.

sensibility
  حسّ-پذیری   
hess-paziri

Fr.: sensibilité   

1) Capacity for sensation or feeling; responsiveness to sensory stimuli.
2) Physics: The realignment of a magnetic compass pointer along a magnetic field line after the pointer has been deflected.

sensible; → -ity.

sensitivity
  حسّ‌مندی   
hessmandi

Fr.: sensibilité   

1) The required brightness for an object in order to be detected by an observing instrument. A highly sensitive telescope can detect dim objects, while a telescope with low sensitivity can detect only bright ones.
2) Of a radio receiver or similar device, the minimum input signal required to produce a specified output signal having a specified signal-to-noise ratio.

State noun from → sensitive.

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