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: 43 Search : motion
Newton's third law of motion
  سومین قانون ِ نیوتنی ِ جنبش   
sevomin qânun-e Newtoni-ye jonbeš (#)

Fr.: troisième loi newtonienne de mouvement   

In a system where no external forces are present, every action force is always opposed by an equal and opposite reaction.

Newton; → third; → law; → motion.

parallactic motion
  جنبش ِ دیدگشتی   
jonbeš-e didgašti

Fr.: mouvement parallactique   

The proper motion of a star due to the effect of the Sun's motion relative to the → local standard of rest.

parallactic; → motion.

peculiar motion
  جنبش ِ اَفد   
jonbeš-e afd

Fr.: mouvement particulier   

1) The true motion of a star with respect to the Local Standard of Rest. → proper motion.
2) The motion of a cosmological object other than the apparent recession caused by the expansion of the Universe.

peculiar; → motion.

periodic motion
  جنبش ِ دوره‌ای   
jonbeš-e dowreyi

Fr.: mouvement périodique   

Any motion that recurs in identical forms at equal intervals of time.

periodic; → motion.

perpetual motion
  جنبش ِ همیشگی   
jonbeš-e hamišegi

Fr.: mouvement perpétuel   

The motion of a hypothetical machine which, once set in motion, will go on for ever without any losses due to → friction or other forms of → dissipation of energy and without receiving any external energy.

perpetual; → motion.

Poinsot's motion
  جنبش ِ پویءنسو   
jonbeš-e Poinsot

Fr.: mouvement à la Poinsot   

The motion of a torque free rotating rigid body in space, in general whose angular velocity vector precesses regularly about the constant angular momentum factor.

After Louis Poinsot (1777-1859), French physicist and mathematician. He was the inventor of geometrical mechanics, showing how a system of forces acting on a rigid body could be resolved into a single force and a couple.

polar motion
  جنبش ِ قطبی   
jonbeš-e qotbi

Fr.: mouvement du pôle   

The irregularly varying motion of the Earth's pole of rotation with respect to the Earth's crust.

polar; → motion.

prograde motion
  جنبش ِ فرارو   
jonbeš-e farârow

Fr.: mouvement prograde   

A rotational or orbital movement that is the same as most bodies within a celestial system. In the solar system, the apparent eastward motion of a celestial body on the celestial sphere. Opposed to → retrograde motion. Same as → direct motion.

From → pro- "forward" + grade, from L. gradi "to go, step, walk;" → motion.

Jonbeš, → motion; farârow, from farâ- "forward," → pro-, + row present stem of raftan "to go, walk;" Mid.Pers. raftan, raw-, Proto-Iranian *rab/f- "to go; to attack."

promotion
  فرکشن   
farkašan

Fr.: promotion   

1) The act of promoting someone to a higher job, grade, or rank, or the fact of being so promoted.
2) Support or encouragement of the progress, growth, or acceptance of something.
3) An act, event, or offer that helps to increase interest in or demand for something (FreeDictionary.com).

Verbal noun of → promote.

Farkašan, literally "draw forward, pull up," from far-, variant of farâ-, → pro-, + kašan "drawing, pull," from kaš present stem of kašidan, → galaxy, + noun suffix -an.

proper motion
  جنبش ِ سره   
jonbeš-e saré

Fr.: mouvement propre   

The apparent motion of a star across the sky (not including a star's parallax), arising from the star's velocity through space with respect to the Sun. Proper motion is usually tabulated in star catalogs as changes in right ascension and declination per year or century. See also: → proper motion distance.

proper; → motion.

proper motion distance
  دورای ِ جنبش ِ سره   
durâ-ye jonbeš-e saré

Fr.: distance mouvement propre   

The distance derived from the → proper motion of an object. If an object has a known → transverse velocity  u, and has an observed angular motion of dθ/dt, then the proper motion distance is defined as: d = u/(dθ/dt).

proper; → motion; → distance

quasiperiodic motion
  جنبش ِ چونان-دوره‌ای   
jonbeš-e cunân-dowreyi

Fr.: mouvement quasipériodique   

In a dynamical system, a form of motion that is regular but never exactly repeating. Quasiperiodic motion appears when the system contains two or more incommensurate frequencies.

quasi-; → periodic; → motion.

radial motion
  جنبش ِ شعاعی   
jonbeš-e šo'â'i

Fr.: mouvement radial   

A motion away from or toward a central point or axis.

radial; → motion.

random thermal motion
  جنبش ِ گرمایی ِ کاتوره   
jonbeš-e garmâyi-ye kâturé

Fr.: mouvement thermique aléatoire   

The agitated motion of molecular, atomic, or → subatomic particles in all possible directions at any temperature, except at → absolute zero, where → thermal motion would cease.

random; → thermal; → motion.

retrograde motion
  جنبش ِ پسرو   
jonbeš-e pasrow

Fr.: mouvement rétrograde   

The orbital motion or rotation of a solar system body in a clockwise direction (East to West) when viewed from the north pole of the ecliptic. It is a motion opposed to the → direct motion of the great majority of solar system bodies.

retrograde; → motion.

rotational motion
  جنبش ِ چرخشی   
jonbeš-e charkheshi

Fr.: mouvement de rotation   

Of a → rigid body, a motion in which there are always two points of the body which remain motionless.

rotational; → motion.

simple harmonic motion
  جنبش ِ هماهنگ ِ ساده   
jonbeš-e hamâhang-e sâdé

Fr.: mouvement harmonique   

The motion of a body subjected to a restraining force which is directly proportional to the displacement from a fixed point in the line of motion. The equation of simple harmonic motion is given by x = A sin(ωt + θ0), where x is the body's displacement from equilibrium position, A is the → amplitude, or the magnitude of harmonic oscillations, ω is the → angular frequency, t is the time elapsed, and θ0 is the → initial phase angle.

simple; → harmonic; → motion.

space motion
  جنبش ِ فضایی   
jonbeš-e fazâyi

Fr.: mouvement spatial   

The velocity and direction of motion of a star or celestial object with respect to the Local Standard of Rest. Same as → peculiar velocity.

space; → motion.

superluminal motion
  جنبش ِ اَبَر-نوری   
jonbeš-e abar-nuri

Fr.: mouvement superluminal   

Apparent proper motion exceeding the velocity of light seen toward certain astronomical objects, such as the jets of radio galaxies and quasars. However, these jets are not actually moving at speeds in excess of the speed of light: the apparent superluminal motion is a projection effect caused by objects moving near the speed of light and at a small angle to the line of sight.

super-; luminal, from → lumen; → motion.

Jonbeš, → motion; abarsuper-; nur, → light.

tangential motion
  جنبش ِ سایانی   
jonbeš-e sâyâni

Fr.: mouvement tangentiel   

That component of a an object's motion which is perpendicular to the observer's → line of sight.

tangential; → motion.

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