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: 14 Search : zero
absolute zero
  صفر ِ ا َوَست   
sefr-e avast

Fr.: zéro absolu   

The → zero point of the → Kelvin scale of → temperature; the theoretical point at which all molecular activity ceases, -273.16 °C.

absolute; → zero.

non-zero
  نا-صفر   
nâ-sefr

Fr.: non zéro, non nul   

Not equal to zero.

non-; → zero.

non-zero polynomial
  بلنامین ِ نا-صفر   
bolnâmin-e nâ-sefr

Fr.: polynôme non nul   

A → polynomial that at least has one non-zero → coefficient. See also → zero polynomial.

non-zero; → polynomial.

zero
  صفر   
sefr (#)

Fr.: zéro   

1) The cardinal number of a class that has no members.
2) The only integer that is neither negative nor positive.
3) The → identity element for addition.

From Fr. zéro, from It. zero, from M.L. zephirum, from Ar. sifr (صفر) "cipher," translation of Skt. śūnya "empty place, void, naught." The rules governing the use of zero appeared for the first time in the Indian mathematician Brahmagupta's book Brahmasputha Siddhanta "The Opening of the Universe," written in 628.

zero age horizontal branch star (ZAHB)
  ستاره‌ی ِ شاخه‌ی ِ افقی با سن ِ صفر   
setâre-ye šâxe-ye ofoqi bâ senn-e sefr

Fr.: étoile de la branche horizontale d'âge zéro   

A star that has arrived on the → horizontal branch after leaving the → red giant branch. It begins → helium burning in its core.

zero; → age; → horizontal; → branch; → star.

zero age main sequence (ZAMS)
  رشته‌ی ِ فریست با سن ِ صفر   
rešte-ye farist bâ senn-e sefr

Fr.: séquence principale d'âge zéro   

The position on the → Hertzsprung-Russell diagram for newborn stars which have just started → hydrogen burning in their cores. The ZAMS forms the lower luminosity boundary of of the → main sequence strip. See also → terminal age main sequence (TAMS).

zero; → age; → main sequence.

zero matrix
  ماتریس ِ صفر   
mâtris-e zefr

Fr.: matrice nulle   

Same as → null matrix.

zero; → matrix.

zero method
  روش ِ صفر   
raveš-e sefr

Fr.: méthode de zéro   

same as → null method.

zero; → method.

zero point
  نقطه‌ی ِ صفر   
noqte-ye sefr

Fr.: point zéro   

1) General: A starting point for making a measurement.
2) A basic parameter on which a → photometric system relies and must be determined each night. The zero points of → magnitudes and color indices (→ color index) depend on atmospheric transparency that varies from night to night.

zero; → point.

zero point energy
  کاروژ ِ نقطه‌ی ِ صفر   
kâruž-e noqte-ye sefr

Fr.: énergie du point zéro, point zéro   

The lowest possible energy that a → quantum mechanical system may possess. It is the energy of the → ground state of the system. The term "zero point" refers to the observed fact that → vacuum fluctuations persist at → absolute zero temperature. Same as → vacuum energy.

zero; → point; → energy.

zero polynomial
  بلنامین ِ صفر   
bolnâmin-e sefr

Fr.: polynôme nul   

A → polynomial whose → coefficients are all zero. See also → non-zero polynomial.

zero; → polynomial.

zero suppression
  نهاوش ِ صفر   
nehâveš-e sefr

Fr.: suppression de zéro   

The removal of non-significant zeroes from a number. For example, replacing 531.2300 by 531.23.

zero; → suppression.

zero-velocity surface
  رویه‌ی ِ تندای ِ صفر   
ruye-ye tondâ-ye sefr

Fr.: surface de vitesse nulle   

In the → restricted three-body problem, a surface which limits the region of space in which a small body can move. In the expression for the → Jacobi integral, the left side value is always positive or nul; hence the particle motion is confined to the region where U ≤ CJ. The surface that limits this region, defined by U = CJ, is called the zero-velocity surface.

zero; → velocity; → surface.

zeroth law of thermodynamics
  قانون ِ صفرُم ِ گرماتوانیک   
qânun-e sefrom-e garmâtavânik

Fr.: loi zéro de la thermodynamique   

Two objects that are in → thermal equilibrium with a third object will be in thermal equilibrium with each other.

zero; → law; → thermodynamics.