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: 86 Search : rem
extreme mass ratio inspiral (EMRI)
  فروپیچه با وابر ِ استوم ِ جرم   
forupicé bâ vâbar-e ostom-e jerm

Fr.: orbite plongeante d'un trou noir binaire, au rapport de masse extrême   

A compact stellar remnant (e.g., a → white dwarf, → neutron star, or → black hole) that undergoes → inspiral into a much more massive object (→ supermassive black hole found → galactic centers). EMRIs are potential sources of low-frequency → gravitational waves. Predictions of the EMRI event rates span a wide range, from ~ 10-9 to 10-6 yr-1 per galaxy (Merritt et al. 2011, Physical Review D 84, 044024). See also → resonant relaxation.

extreme; → mass; → ratio; → inspiral.

extreme ultraviolet (EUV)
  فرابنفش ِ استوم   
farâbanafš-e ostom

Fr.: ultraviolet extrême   

A part of the ultraviolet radiation with wavelengths between 50 and 300 Angstöms.

extreme; → ultraviolet.

extremely metal-poor star (EMPS)
  ستاره‌ی ِ اُستومانه کم‌فلز   
stâre-ye ostomâné kamfelez

Fr.: étoile extrêmement pauvre en métaux   

A star with an iron abundance [Fe/H] < -3 found in a → galactic halo. These stars, whose → metallicity is typically less than one thousandth of the solar value, are believed to have formed shortly after the → Big Bang, 13.7 billion years ago. The number of such stars depends on the primordial → initial mass function. If the IMF were steep, there could, in principle, be a lot of EMPSs formed at high → redshifts. Thus many of them could have ended up in the halos of galaxies. See also → Population III star.

extreme; → metal; → poor; → star.

extremophile
  استومدوست   
ostomdust

Fr.: extrêmophile   

A → microorganism with the ability to thrive in extreme environmental conditions that would kill other species. These conditions include high temperatures, very low temperatures, high pressures, high levels of radiation, and high concentrations of salt in water.

extreme; → -phile.

extremum
  استومه   
ostomé

Fr.: extrémum   

A maximum or minimum value of a function in a specified interval.

From L. extremus, → extreme.

Ostomé, from ostom, → extreme + noun suffix , from Mid.Pers. -ag.

Fermat's last theorem
  واپسین فربین ِ فرما   
vâpasin farbin-e Fermat

Fr.: dernier théorème de Fermat   

In → number theory, the statement that for all → integers, the equation xn + yn = zn has no solution in → positive integer. After 358 years of effort by mathematicians to prove the theorem, a complete proof was found by Andrew Wiles in 1995.

Fermat's principle; → last; → theorem.

Fourier theorem
  فربین ِ فوریه   
farbin-e Fourier

Fr.: théorème de Fourier   

Any finite periodic motion may be analyzed into components, each of which is a simple harmonic motion of definite and determinable amplitudes and phase.

Fourier analysis; → theorem.

Gauss's theorem
  فربین ِ گاؤس   
farbin-e Gauss

Fr.: théorème de Gauss   

The total normal induction over any closed surface drawn in an electric field is equal to 4π times the total charge of electricity inside the closed surface. Gauss's theorem applies also to other vector fields such as magnetic, gravitational, and fluid velocity fields. The theorem can more generally be stated as: the total flux of a vector field through a closed surface is equal to the volume → integral of the vector taken over the enclosed volume. Also known as → divergence theorem, Ostrogradsky's theorem, and Gauss-Ostrogradsky theorem.

gauss; → theorem.

Helmholtz's theorem
  فربین ِ هلمهولتس   
farbin-e Helmholtz

Fr.: théorème de Helmholtz   

A → decomposition theorem, whereby a continuous → vector field, F, can be broken down into the sum of a → gradient and a → curl term: F = -∇φ + ∇ xA, where φ is called the → scalar potential and A the → vector potential.

Helmholtz free energy; → theorem.

increment
  فزایه   
fazâyé

Fr.: incrément   

The amount by which a varying quantity increases between two of its stages. In → calculus, the Greek letter Δ (delta) is used to denote an increment; e.g. Δx is an increment of x, contrasted to → decrement.

Increment, from L. incrementum "growth, increase," from stem of increscere "to grow in or upon" from → in- "in" + crescere "to grow."

Fazâyé, from fazâ shortened present stem of afzudan "to add, increase" (Mid.Pers. abzudan "to increase, grow;" O.Pers. abijav- "to increase, add to, promote," from abi-, aiby- "in addition to; to; against" + root jav- "press forward;" Av. gav- "to hasten, drive;" Skt. jav- "to press forward, impel quickly, excite," javate "hastens") + -y- euphonic infix + noun/nuance suffix.

inverse bremsstrahlung
  لگام-تابش ِ وارون   
legâm-tâbeš-e vârun

Fr.: Bremsstrahlung inverse   

The absorption of a photon by an electron in a strong electric field. → bremsstrahlung.

inverse; → bremsstrahlung.

Larmor's theorem
  فربین ِ لارمور   
farbin-e Larmor

Fr.: théorème de Larmor   

If a system of → charged particles, all having the same ratio of charge to mass (q/m), acted on by their mutual forces, and by a central force toward a common center, is subject in addition to a weak uniform magnetic field (B), its possible motions will be the same as the motions it could perform without the magnetic field, superposed upon a slow → precession of the entire system about the center of force with angular velocity ω = -(q/2mc)B.

Larmor frequency; → theorem.

Liouville's theorem
  فربین ِ لیوویل   
farbin-e Liouville

Fr.: théorème de Liouville   

A key theorem in statistical mechanics of classical systems which states that the motion of phase-space points defined by Hamilton's equations conserves phase-space volume.

After Joseph Liouville (1809-1882), a French mathematician; → theorem.

magnetic bremsstrahlung
  لگام-تابش ِ مغناتیسی   
legâm-tâbeš-e meqâtisi

Fr.: rayonnement de freinage magnétique   

Same as → synchrotron radiation.

magnetic; → bremsstrahlung.

major premise
  پیشپایه‌ی ِ مهین   
pišpâye-ye mehin

Fr.: prémisse majeur   

Logic: In a → categorical syllogism, the premise containing the → major term.

major; → premisse.

mean value theorem
  فربین ِ ارزش ِ میانگین   
farbin-e arzeš-e miyângin

Fr.: théorème des accroissements finis   

1) If f(x) is a continuous function on the interval from a to b, then:
f(x) dx = f(c)(b - a) (summed from a to b) for at least one point in that interval.
2) More generally, If f(x) and g(x) are continuous functions on the interval from a to b and g(x)≥ 0, then:
f(x)g(x) dx = f(c) ∫ g(x) dx (both integrals summed from a to b).

mean; → value; → theorem.

measurement
  اندازه‌گیری   
andâzegiri (#)

Fr.: mesure   

1) The act of measuring; a measured quantity.
2) The determination of the magnitude or amount of a quantity by comparison (direct or indirect) with the prototype standards of the system of units employed (IEEE Standard Dictionary of Electrical and Electronics Terms). → absolute measurement, → measurement uncertainty, → Roemer's measurement.

Verbal noun of → measure.

measurement uncertainty
  ناتاشتیگی ِ اندازه‌گیری   
nâtâštigi-ye andâzegiri

Fr.: incertitude de mesure   

The interval within which lies the actually measured value of a physical quantity and the true value of the same physical quantity.

measurement; uncertainty, from negation prefix un- + → certainty.

minor premise
  پیشپایه‌ی ِ کهین   
pišpâye-ye kehin

Fr.: prémisse mineur   

Logic: In a → categorical syllogism, the premise containing the → minor term.

major; → premisse.

Nernst heat theorem
  فربین ِ گرمای ِ نرنست   
farbin-e garmâ-ye Nernst

Fr.: théorème de Nernst   

The entropy change for chemical reactions involving crystalline solid is zero at the absolute zero of temperature. Also known as the third law of thermodynamics.

Nernst effect; → heat; → theorem.

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