An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < aff con for inf mol spe uni > >>

Number of Results: 134 Search : form
  یکدیس، یکنواخت   
yekdis, yeknavâxt

Fr.: uniforme   

Without variations; identical, always the same in quality, degree, character, or manner.

uni- + → form.

Yekdis, from yek, → uni-, + dis, → form; yeknavâxt, literally "with one rhythm," from yek, → one, + navâxt "rhythm," from navâxtan, navâzidan "to play an instrument; to gratify," navâ "music, song, melody" (Mid.Pers. nw'c "to treat kindly, honour," niwag "music, melody;" Proto-Iranian *ni-uac-, from ni- "down; into," → ni- (PIE), + *uac- "to speak, treat kindly").

uniform circular motion
  جنبش ِ دایره‌ای ِ یکدیس، ~ ~ یکنواخت   
jonbeš-e dâyereyi-ye yekdis, ~ ~ yeknavâxt

Fr.: mouvement circulaire uniforme   

The motion of an object around a fixed point at a constant angular speed, and at constant radius.

uniform; → circular; → motion.

uniform field
  میدان ِ یکدیس، ~ ِ یکنواخت   
meydân-e yekdis, ~ yeknavâxt

Fr.: champ uniforme   

A field that at a given instant has the same value at all points within a specified region of interest.

uniform; field.

uniform magnetic field
  میدان ِ مغناتیسی ِ یکدیس   
meydân-e meqnâtisi-ye yekdis

Fr.: champ magnétique uniforme   

A → magnetic field whose direction does not change and whose strength is constant at every point.

uniform; → magnetic; → field.

uniform motion
  جنبش ِ یکدیس، ~ ِ یکنواخت   
jonbeš-e yekdis, ~ yeknavâxt

Fr.: mouvement uniforme   

Motion at a constant → velocity. The state of rest is a special case of uniform motion. → accelerated motion; → inertial motion.

uniform; motion.


Fr.: uniformitaire   

1) Of, characterized by, or conforming to → uniformity.
2) Of or relating to → uniformitarianism.

uniformity + -arian.


Fr.: uniformitarisme   

The doctrine whereby geologic processes (→ erosion, → deposition, → compaction, and → uplift) observed at Earth's surface now are the same that have shaped Earth's landscape over long periods of time in the past. The term uniformitarianism was first used in 1832 by William Whewell, to present an alternative explanation for the origin of the Earth. The prevailing view at that time was that the Earth was created through supernatural means and had been affected by a series of catastrophic events such as the biblical Flood. This theory is called → catastrophism. The ideas behind uniformitarianism originated with the work of Scottish geologist James Hutton. In 1785, Hutton presented at the meetings of the Royal Society of Edinburgh that the Earth had a long history and that this history could be interpreted in terms of processes currently observed. For example, he suggested that deep soil profiles were formed by the weathering of bedrock over thousands of years. He also suggested that supernatural theories were not needed to explain the geologic history of the Earth (

uniformitarian; → -ism.

  یکدیسواری، یکدیسیگی   
yekdisvâri, yekdisigi

Fr.: uniformité   

The state or quality of being uniform.

uniform; → -ity.

unitary transformation
  ترادیس ِ یکایی، ~ یکانی   
tarâdis-e yekâyi, ~ yekâni

Fr.: transformation unitaire   

A transformation whose reciprocal is equal to its Hermitian conjugate.

unitary; → transformation.

violent star formation
  دیسش ِ سورای ِ ستارگان   
diseše surâ-ye setâregân

Fr.: formation violente d'étoiles   

The concept of star formation pertaining to a variety of systems (OB associations, giant H II regions, H II galaxies, massive star clusters, etc.) that are believed to have formed large numbers of stars in a very short time.

violent; → star formation.


Fr.: forme d'onde   

A graphical representation of the shape of a wave for a given instant in time.

wave; → form.

waveform analysis
  آنالس ِ موجدیس   
ânâlas-e mowjdis

Fr.: analyse de forme d'onde   

The resolution of a complex waveform into a sum of simple periodic waves, usually by computer means.

waveform; → analysis.

Weizsacker formula
  دیسول ِ وایتسکر   
disul-e Weizsäcker

Fr.: formule de Weizsäcker   

A → semiempirical → equation which describes the → binding energy of the → atomic nucleus. It is essentially a nuclear mass formula that provides the total binding energy per → nucleon as the sum of five terms:
Eb = aVA - aSA2/3 - aCZ2/A1/3 - aA(N -Z)2/A + δ(A,Z),
where the terms in the right-hand side of this equation are called the volume term, surface term, Coulomb term, asymmetry term, and pairing term, respectively. A, Z, and N are the number of nucleons, → protons, and → neutrons, respectively (see, e.g., Alexi M. Frolov, 2013, Also called Bethe-Weizacker formula and → semiempirical binding energy formula.

Named after Carl Friedrich von Weizäcker (1912-2007), German physicist, who derived the formula in 1935, Z. für Physik 96, 431; → formula.

well-formed formula (wff)
  دیسول ِ خوش‌دیسه (wff)   
disul-e xošdisé (wff)

Fr.: formule bien formée (FBF)   

A string of → symbols from the alphabet of the → formal language that conforms to the grammar of the formal language. → closed wff, → open wff.

Wff, pronounced whiff; → well; → form; → formula.

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