MOdified Newtonian Dynamics (MOND)
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).
Of or pertaining to Sir Isaac Newton or to his theories or discoveries.
Newtonian, from → Newton + -ian a suffix forming adjectives.
Fr.: approximation newtonienne
Newtonian constant of gravitation
pâyâ-ye gerâneš-e Newton
Fr.: constante de la gravitation newtonienne
Same as the → gravitational constant.
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.
Fr.: fluide newtonien
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.
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.
mekânik-e Newtoni (#)
Fr.: mécanique newtonienne
Fr.: potentiel newtonien
A potential in a field of force obeying the inverse-square law such as → gravitational potential.
Newtonian principle of relativity
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.
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.
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.
Fr.: développement post-newtinien
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.