An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < alk Car ele las par pro sup > >>

Number of Results: 128 Search : art
elementary particle
  ذره‌ی ِ بنیادین   
zarre-ye bonyâdin (#)

Fr.: particule élémentaire   

A particle which cannot be divided into other constituents. More specifically, a particle whose field appears in the fundamental field equations of the unified field theory of elementary particles, in particular in the Lagrangian. For example, the → electron, the → photon, and the → quark are elementary particles, whereas the proton and neutron are not. The elementary nature of a particle can be revised depending on new observations or theories. Also called → fundamental particle.

Elementary, M.E. elementare, from M.F. élémentaire, from L. elementarius, from → element + adj. suffix -arius; → particle.

Bonyâdin, from bonyâd "basis, foundation," variant of bonlâd, from bon "basis; root; foundation; bottom" → element + lâd "root; foundation; reason, cause; wall" + adj. suffix -in.

energetic solar particles
  ذره‌های ِ خورشیدی ِ کاروژمند   
zarrehâ-ye xoršidi-ye kâružmand

Fr.: particules solaires énergétiques   

Electrons and atomic nuclei ejected by solar flares, travelling with velocities amounting to a fraction of the velocity of light, and energies mostly in the range 1-100 million → electronvolts (eV), but occasionally as high as 15 billion eVs. Also known as solar → cosmic rays.

Energetic, from Gk. energetikos, from energe-, → energy, + -tikos a suffix, equivalent in meaning to → -ic, occurring in adjectives; → solar; → particle.

Zarrehâ plural of zarré, → particle; xoršidi, → solar; kâružmand from kâruž, → energy, + -mand possession suffix.

equilibrium partitioning
  پرکه‌بندی ِ ترازمند   
parkebandi-ye tarâzmand

Fr.: équilibre de partition   

A concept whereby chemical → concentrations among geological or environmental media are at equilibrium, and therefore the partitioning of metals in those media can be predicted based on → partition ratios.

equilibrium; → partitioning.

equipartition of energy
  هموگپرکش ِ کاروژ   
hamugparkeš-e kâruž

Fr.: équipartition de l'énergie   

1) General: Equal sharing of the → total energy among all → components of a → system.
2) In the → kinetic theory of gases, the → theorem according to which → molecules in → thermal equilibrium have the same average energy (1/2 kT) associated with each independent → degree of freedom of their motion.

equi-; → partition.

exchange particle
  ذره‌ی ِ گهولی   
zarre-ye gahuli

Fr.: particule d'échange   

In quantum field theory, a particle that transfers momentum and energy between interacting objects, and is said to mediate the interaction. All four of the fundamental forces involve the exchange of one or more particles. For example, photon is the exchange particle of the electromagnetic force.

exchange, → particle.


Fr.: exoterre   

An → exoplanet similar to Earth.

exo- + → earth.

finding chart
  نگاره‌ی ِ یابش   
negâre-ye yâbeš

Fr.: carte de champ   

A sketch or image used to recognize objects in the field of view of a telescope.

Finding, noun of → find; chart, from M.Fr. charte "card, map," from L. charta "leaf of paper, tablet," from Gk. khartes "layer of papyrus."

Negâre-ye yâbeš, from negâré, from negâr "picture, figure" (verb negârdan, negâštan "to paint"), from prefix ne- "down; into," → ni-, + gâr, from kar-, kardan "to do, to make" (Mid.Pers. kardan; O.Pers./Av. kar- "to do, make, build;" Av. kərənaoiti "he makes;" cf. Skt. kr- "to do, to make," krnoti "he makes, he does," karoti "he makes, he does," karma "act, deed;" PIE base kwer- "to do, to make"); yâbeš, verbal noun of yâftan, → find.

first quarter
  چارک ِ نخست   
cârak-e naxost

Fr.: premier quartier   

A → lunar phase that occurs in the middle of the interval between the → new Moon and the → full Moon, when half of the Moon's disk is illuminated. At first quarter, the Moon is situated at 90° east of the Sun.

first; → quarter.

first-order partial derivative
  واخنه‌ی ِ پاری ِ رایه‌ی ِ نخست   
vâxane-ye pâri-ye râye-ye naxost

Fr.: dérivée partielle du premier degré   

For a → function with several → variables, the derivative, done only once, with respect to one of the variables. For example ∂u/∂x for u = u(x,y).

first; → order; → partial; → derivative.

fundamental particle
  ذره‌ی ِ بنیادین   
zarre-ye bonyâdin (#)

Fr.: particule élémentaire   

Same as → elementary particle.

fundamental; → particle.

Hartle-Hawking initial state
  استات ِ آغازین ِ هارتل-هاؤکینگ   
estât-e âqâzin-e Hartle-Hawking

Fr.: état initial de Hartle-Hawking   

A proposal regarding the initial state of the → Universe prior to the → Planck era. This → no boundary hypothesis assumes an imaginary time in that epoch. In other words, there was no real time before the → Big Bang, and the Universe did not have a beginning. Moreover, this model treats the Universe like a quantum particle, in an attempt to encompass → quantum mechanics and → general relativity; and attributes a → wave function to the Universe. The wave function has a large value for our own Universe, but small, non-zero values for an infinite number of other possible, parallel Universes.

Hartle, J., Hawking, S., 1983, "Wave function of the Universe," Physical Review D 28; → initial; → state.

Hartley band
  باند ِ هارتلی   
bând-e Hartley

Fr.: bande de Hartley   

A band in the → absorption spectrum of → ozone (O3) extending in the → ultraviolet from 200 nm to 300 nm. It is stronger than the → Huggins band. See also: → Hartley band.

W. N. Hartley, J. Chem. Soc. 39, 111 (1881).

Hartmann test
  آزمون ِ هارتمان   
âzmun-e Hârtman (#)

Fr.: test de Hartmann   

A way of testing the quality of optical systems. In this method, incident rays from a point source are isolated by small holes in an opaque screen located close to the lens or mirror under test. Photographic plates are inserted into the beam within and beyond the focal region. The black dots on the exposed plates, which reveal differences of optical focus in the various zones of the lens or mirror, are analyzed to yield the objective's figure. → Shack-Hartmann wavefront sensor.

Named after the German astronomer Johannes Hartmann (1865-1936), who developed the method. → test.


Fr.: hartree   

A unit of energy used in atomic and molecular physics; symbol Ha or Eh. It is defined as: 1 Ha = mee4/(4ε02ħ), where me is the mass of electron, e its charge, ε0 the → permittivity of vacuum, and ħ → reduced Planck's constant. Its value is 2 → rydbergs, or 4.3597 x 10-18 → joule, or 27.213 → electron-volts.

Named for the British physicist and mathematician Douglas R. Hartree (1897-1958).

del (#)

Fr.: cœur   

1) A hollow muscular organ that pumps the blood through the circulatory system by rhythmic contraction and dilation. In vertebrates there may be up to four chambers (as in humans), with two atria and two ventricles.
2) The heart regarded as the centre of a person's thoughts and emotions, especially love or compassion (

M.E. herte, from O.E. heorte "heart breast, soul, spirit, will, desire; courage; mind, intellect;" cf. O.Saxon herta, O.Frisian herte, O.Norse hjarta, Du. hart, O.H.G. herza, Ger. Herz; cognate with Pers. del, as below; PIE root *kerd- "heart."

Del "heart" (Pashtu z'rrah, zyah; Baluci zirde "heart, mind, soul;" Kurd. zar; Sogd. žyâwar); Mid.Pers. dil; Av. zərəd-; cf. Skt. hrd-; Gk. kardia; L. cor "heart" (Fr. cœur; Sp. corazon, It. cuore); Russ. serdtse; Arm. sirt; E. heart, as above.


Fr.: donner, transmettre, communiquer   

1) To give, convey, or grant from or as if from a store.
2) To communicate the knowledge of; disclose.

M.E., from O.Fr. impartir, from L.L. impartire "to share in, divide with another, communicate," from assimilated form of → in- "into, in" + partire "to divide, → part."

Darpârdan, from dar-, → in-, + pâr, → part, Mid.Pers. pârag "part, portion; gift, offering;" Av. pāra- "debt," from par- "to remunerate, equalize; to condemn;" PIE *per- "to sell, hand over, distribute; to assign;" + -dan infinitive suffix.

inclination of Earth's equator
  درکیل ِ هموگار ِ زمین   
darkil-e hamugâr-e zamin

Fr.: inclinaison de l'équateur terrestre   

obliquity of the ecliptic.

inclination; → Earth; → equator.

inner Earth object (IEO)
  بر‌آخت ِ درونی ِ مدار ِ زمین   
barâxt-e daruni-ye madâr-e zamin

Fr.: objet interne à l'orbite terrestre   

A → near-Earth object whose → orbit lies always inside Earth's orbit.

inner; → Earth; → object.

integer partition
  پرکش ِ درسته   
parkeš:-e doroste

Fr.: partition des entiers   

An expression of an integer nas the sum of one or more positive integers. The number of different partitions of n is denoted p(n). This function is called the partition function. For example, p(5) = 7, because 5 can be partitioned as: 5 = 5 = 4 + 1 = 3 + 2 = 3 + 1 + 1 = 2 + 2 + 1 = 2 + 1 + 1 + 1 = 1 + 1 + 1 + 1 + 1.

partition; → integer.

Lagrangian particle
  ذره‌ی ِ لاگرانژی   
zarre-ye Lâgrânži

Fr.: particule lagrangienne   

Fluid mechanics: In the → Lagrangian method, a particle that moves as though it is an element of fluid. The particle concept is an approach to solving complicated fluid dynamics problems by tracking a large number of particles representing the fluid. The particle may be thought of as the location of the center of mass of the fluid element with one or more property values.

Lagrangian; → particle.

<< < alk Car ele las par pro sup > >>