Kerr-Newman black hole 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. |
linewidth 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. |
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/r^{2}. 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. |
new now (#) Fr.: nouveau, neuf Of recent origin, production. 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) 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 Horizons 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 moon 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. |
newton 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 = 10^{5} → dynes. Named after Sir Isaac Newton (1642-1727), the English highly prominent physicist and mathematician. |
Newton constant pâyâ-ye Newton Fr.: constante de Newton Same as the → gravitational constant. |
Newton's color wheel 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's constant pâyâ-ye Newton Fr.: constante de Newton Same as the → gravitational constant. |
Newton's cradle 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's disk gerde-ye Newton Fr.: disque de Newton |
Newton's equation 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's first law of motion 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's law of cooling 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 - T_{s}), where T is the temperature of the object, T_{s} is that of its surroundings, t is time, and k is a constant, different for different bodies. |
Newton's law of gravitation 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 (m_{1}.m_{2})/r^{2}, where G is the → gravitational constant. → Newton; → law; → gravitation. |
Newton's laws of motion 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's method raveš-e Newton Fr.: méthode de Newton Same as the → Newton-Raphson method. |
Newton's rings 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. |