An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



Number of Results: 15 Search : Newtonian
MOdified Newtonian Dynamics (MOND)
  توانیک ِ نیوتنی ِ واترزیده   
tavânik-e niyutoni-ye vâtarzidé

Fr.: dynamique newtonienne modifiée   

A modification of the Newton's law of gravitation below a critical acceleration of about 1.2 x 10-8 cm s-2, where the gravitational force scales as 1/r instead of 1/r2. Originally put forward to describe the rotation curves of galaxies with no need to assume any dark matter, MOND is now tested at larger cosmological scales (Milgrom, M. 1983, ApJ, 270, 365).

modify; → Newtonian dynamics.

Newtoni (#)

Fr.: newtonien   

Of or pertaining to Sir Isaac Newton or to his theories or discoveries.

Newtonian, from → Newton + -ian a suffix forming adjectives.

Newtonian approximation
  نزدینش ِ نیوتنی   
nazdineš-e Newtoni

Fr.: approximation newtonienne   

A particular solution of the → general relativity when the → gravitational mass is small. The → space-time is then approximated to the → Minkowski's and this leads to → Newtonian mechanics.

Newtonian; → approximation.

Newtonian constant of gravitation
  پایای ِ گرانش ِ نیوتن   
pâyâ-ye gerâneš-e Newton

Fr.: constante de la gravitation newtonienne   

Same as the → gravitational constant.

Newtonian; → constant; → gravitation.

Newtonian cosmology
  کیهان‌شناسی ِ نیوتنی   
keyhânšenâsi-ye Newtoni

Fr.: cosmologie newtonienne   

The use of → Newtonian mechanics to derive homogeneous and isotropic solutions of → Einstein's field equations, which represent models of expanding Universe. The Newtonian cosmology deviates from the prediction of → general relativity in the general case of anisotropic and inhomogeneous models.

Newtonian; → cosmology.

Newtonian fluid
  شاره‌ی ِ نیوتنی   
šârre-ye Newtoni

Fr.: fluide newtonien   

Any → fluid with a constant → viscosity at a given temperature regardless of the rate of → shear.

Newtonian; → fluid.

Newtonian focus
  کانون ِ نیوتن، ~ نیوتنی   
kânun-e Newton, ~ Newtoni

Fr.: foyer de Newton   

The focus obtained by diverting the converging light beam of a reflecting telescope to the side of the tube.

Newtonian; → focus.

Newtonian limit
  حد ِ نیوتنی   
hadd-e Newtoni

Fr.: limite newtonienne   

The limit attained by → general relativity when velocities are very smaller than the → speed of light or gravitational fields are weak. This limit corresponds to the transition between general relativity and the → Newtonian mechanics. See also → Newtonian approximation.

Newtonian; → limit.

Newtonian mechanics
  مکانیک ِ نیوتنی   
mekânik-e Newtoni (#)

Fr.: mécanique newtonienne   

A system of mechanics based on → Newton's law of gravitation and its derivatives. Same as → classical mechanics.

Newtonian; → mechanics.

Newtonian potential
  توند ِ نیوتنی   
tavand-e Newtoni

Fr.: potentiel newtonien   

A potential in a field of force obeying the inverse-square law such as → gravitational potential.

Newtonian; → potential.

Newtonian principle of relativity
  پروز ِ بازانیگی ِ نیوتن   
parvaz-e bâzânigi-ye Newton

Fr.: principe de relativité de Newton   

The Newton's equations of motion, if they hold in any → reference frame, they are valid also in any other reference frame moving with uniform velocity relative to the first.

Newtonian; → principle; → relativity.

Newtonian relativity
  بازانیگی ِ نیوتنی   
bâzânigi-ye Newtoni

Fr.: relativité newtonienne   

The laws of physics are unchanged under → Galilean transformation. This implies that no mechanical experiment can detect any intrinsic diff between two → inertial frames. Same as → Galilean relativity.

Newton; → relativity.

Newtonian telescope
  دوربین ِ نیوتن، تلسکوپ ِ ~   
durbin-e Newton, teleskop-e ~

Fr.: télescope de Newton, ~ newtonien   

A telescope with a concave paraboloidal objective mirror and a small plane mirror that reflects rays from the primary mirror laterally outside the tube where the image is viewed with an eyepiece.

Newtonian; → telescope.

post-Newtonian expansion
  گسترش ِ پسا-نیوتنی   
gostareš-e pasâ-Newtoni

Fr.: développement post-newtinien   

post-Newtonian formalism.

post-; → Newtonian; → expansion.

post-Newtonian formalism
  دیسه‌گرایی ِ پسا-نیوتنی   
disegerâyi-ye pasâ-Newtoni

Fr.: formalisme post-newtonien   

An approximate version of → general relativity that applies when the → gravitational field is → weak, and the matter → velocity is → small. Post-Newtonian formalism successfully describes the gravitational field of the solar system. It can also be applied to situations involving compact bodies with strong internal gravity, provided that the mutual gravity between bodies is weak. It also provides a foundation to calculate the → gravitational waves emitted by → compact binary star systems, as well as their orbital evolution under radiative losses. The formalism proceeds from the Newtonian description and then, step by step, adds correction terms that take into account the effects of general relativity. The correction terms are ordered in a systematic way (from the largest effects to the smallest ones), and the progression of ever smaller corrections is called the → post-Newtonian expansion.

post-; → Newtonian; → formalism.