An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < Ker New XMM > >>

Number of Results: 41 Search : new
Kerr-Newman black hole
  سیه‌چال ِ کر-نیومن   
siyah câl-e Kerr-Newman

Fr.: trou noir de Kerr-Newman   

A rotating charged black hole. Compare with the → Kerr black hole and the → Reissner-Nordstrom black hole.

Named after Roy P. Kerr and Ezra T. Newman (1929-) who in 1963 independently found this solution to Einstein's → field equations; → black; → hole.

  خط-پهنا، پهنای ِ خط   
xatt-pahnâ (#), pahnâ-ye xatt (#)

Fr.: largeur de raie   

1) The range of frequencies or wavelengths over which radiations are absorbed or emitted in a transition between a specific pair of atomic energy levels. The full width is determined between half-power points of the line.
2) In a laser, the range of frequencies over which most of the beam energy is distributed.

line; → width.

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.

now (#)

Fr.: nouveau, neuf   

Of recent origin, production.
Of a kind now existing or appearing for the first time. → new moon; → New General Catalogue (NGC).

O.E. neowe, niowe, niwe; cf. Du. nieuw, Ger. neu, Dan., Swed. ny; cognate with Pers. now, as below, L. novus "new, recent, fresh" (Fr. nouveau, neuf), from PIE *neu- "new, young."

Now, from Mid.Pers. nôg "new, fresh;" Av. nauua- "new, fresh;" cf. Skt. náva- "new, fresh, young;" Gk. neos "new, young;" L. novus, as above, cognate with E. new, as above.

New General Catalogue (NGC)
  کاتالوگ ِ هروین ِ نو   
kâtâlog-e harvin-e now

Fr.: New General Catalogue   

A catalogue of 7,840 non-stellar objects compiled by J. L. E. Dreyer and published in 1888. A further 1,529 objects were listed in a supplement that appeared seven years later, called the → Index Catalogue (IC). The Second Index Catalogue of 1908 extended the supplementary list to 5,386 objects.

new; → general; → catalog

New Horizons
  نیو هورایزنز   
New Horizons

Fr.: New Horizons   

A space mission by → NASA whose main goal is to study the → dwarf planet Pluto and it satellites. New Horizons was launched on January 19, 2006; it swung past → Jupiter for a → gravity assist and scientific studies in February 2007, and conducted a six-month-long reconnaissance → flyby study of → Pluto and its moons in summer 2015, culminating with Pluto closest approach on July 14, 2015. It flew 12,500 km above the surface of Pluto, making it the first spacecraft to explore the dwarf planet. Its science payload includes seven instruments: Ralph (visible and infrared imager/spectrometer), Alice (ultraviolet imaging spectrometer), REX (Radio Science EXperiment), LORRI (Long Range Reconnaissance Imager), SWAP (Solar Wind Around Pluto), PEPSSI: (Pluto Energetic Particle Spectrometer Science Investigation), and SDC: (Student Dust Counter). As part of an extended mission, New Horizons has maneuvered for a flyby of → Kuiper belt object 2014 MU69, expected to take place on January 1, 2019, when it is 43.4 → astronomical units (AU) from the Sun.

new; → horizon.

new moon
  نوماه، ماه ِ نو، اندرماه   
nowmâh (#), mâh-e now (#), andarmâh (#)

Fr.: nouvelle lune   

The Moon's phase when it is at the same celestial longitude as the Sun and thus totally un-illuminated as seen from Earth.

new; → moon.

newton (#)

Fr.: newton   

The unit of force in the SI system of units. 1 newton (N) is defined as the force required to give a mass of 1 kilogram an acceleration of 1 m s-2. 1 N = 105  → dynes.

Named after Sir Isaac Newton (1642-1727), the English highly prominent physicist and mathematician.

Newton constant
  پایای ِ نیوتن   
pâyâ-ye Newton

Fr.: constante de Newton   

Same as the → gravitational constant.

Newton; → constant.

Newton's color wheel
  چرخ ِ رنگ ِ نیوتن   
carx-e rang-e Newton

Fr.: disque de Newton   

The arrangement of the seven colors of the rainbow on a disk. When the disk rotates very fast, the eye cannot distinguish between individual colors and the disk is perceived as white. This apparatus demonstrates the discovery made by Newton (Opticks, 1704) that light is composed of seven colors.

Newton; → color; → wheel.

Newton's constant
  پایای ِ نیوتون   
pâyâ-ye Newton

Fr.: constante de Newton   

Same as the → gravitational constant.

Newton; → constant.

Newton's cradle
  گهواره‌ی ِ نیوتون   
gahvâre-ye Newton

Fr.: pendule de Newton   

A device consisting of a series of equal → pendulums in a row used to demonstrate the laws of → conservation of momentum and → conservation of energy.

Newton; → cradle.

Newton's disk
  گرده‌ی ِ نیوتن   
gerde-ye Newton

Fr.: disque de Newton   

Newton's color wheel.

Newton; → disk.

Newton's equation
  هموگش ِ نیوتن   
hamugeš-e Newton

Fr.: équation de Newton   

In → geometric optics, an expression relating the → focal lengths of an → optical system (f and f') and the object x and image x' distances measured from the respective focal points. Thus, ff' = xx'. Same as Newton's formula.

Newton; → equation.

Newton's first law of motion
  نخستین قانون ِ نیوتنی ِ جنبش   
naxostin qânun-e Newtoni-ye jonbeš (#)

Fr.: première loi newtonienne de mouvement   

A body continues in its state of constant velocity (which may be zero) unless it is acted upon by an external force.

Newton; → first; → law; → motion.

Newton's law of cooling
  قانون ِ سردش ِ نیوتن   
qânun-e sardeš-e Newton

Fr.: loi de refroidissement de Newton   

An approximate empirical relation between the rate of → heat transfer to or from an object and the temperature difference between the object and its surrounding environment. When the temperature difference is not too large: dT/dt = -k(T - Ts), where T is the temperature of the object, Ts is that of its surroundings, t is time, and k is a constant, different for different bodies.

Newton; → law; → cooling.

Newton's law of gravitation
  قانون ِ گرانش ِ نیوتن   
qânun-e gerâneš-e Newton

Fr.: loi newtonienne de la gravitation   

The universal law which states that the force of attraction between any two bodies is proportional to the product of their masses and inversely proportional to the square of the distance between them: F = G (m1.m2)/r2, where G is the → gravitational constant.

Newton; → law; → gravitation.

Newton's laws of motion
  قانونهای ِ جنبش ِ نیوتون   
qânunhâ-ye jonbeš-e Newton

Fr.: lois de mouvement de Newton   

The three fundamental laws which are the basis of → Newtonian mechanics. They were stated in Newton's Principia (1687). → Newton's first law, → Newton's second law , → Newton's third law.

Newton; → law; → motion.

Newton's method
  روش ِ نیوتن   
raveš-e Newton

Fr.: méthode de Newton   

Same as the → Newton-Raphson method.

Newton; → method.

Newton's rings
  حلقه‌های ِ نیوتن   
halqehâ-ye Newton (#)

Fr.: anneaux de Newton   

Colored circular → fringes formed when light beams reflected from two polished, adjacent surfaces, placed together with a thin film of air between them, interfere. → interference.

Newton; → ring.

<< < Ker New XMM > >>