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.
Immediately following in time, order, place, and so on.
M.E., from O.E. next, nehst, niehsta, nyhsta "nearest, closest," superlative of neah "nigh" + superlative suffix. Cognate with Du. naast "next," O.H.G. nahisto "neighbor," Ger. nächst "next."
Pasin, from pas "after; behind;" → back-.
Fr.: NGC 1275
A → Seyfert galaxy, which is the central, dominant member of the large and relatively nearby → Perseus cluster of galaxies. A powerful source of X-rays and radio emission, NGC 1275 accretes matter (→ accretion) as intercluster material falls into it, ultimately feeding a → supermassive black hole (SMBH) at the galaxy's core. NGC 1275, hosts a narrow-line radio source, Perseus A (3C 84), which interacts with the intracluster gas through its jets and bipolar outflows.
NGC, → New General Catalogue.
Fr.: NGC 346
A prominent → star cluster, and the ionizing core of giant → H II region → N66 in the → Small Magellanic Cloud galaxy. NGC 346 hosts the largest sample of young, → massive stars in the whole SMC, containing 33 → O-type stars among which 11 are of type O6.5 or earlier. This is young massive star cluster with an estimated age of about 3 million years.
346, a serial number in the → New General Catalogue.
Fr.: NGC 3603
The most massive and luminous visible → starburst region in the Galaxy. This is our local → giant H II region lying at a distance of about 6-7 kpc in the → Carina arm (→ right ascension = 11h, → declination = -61°). Its central starburst cluster hosts the largest known concentration of extremely young, mostly unevolved → high-mass stars in the Galaxy. With an age of only 1-2 Myr for its most massive stars, NGC 3603 is one of the youngest starburst clusters known. It has about 40 known → O stars and → W-R stars, producing a → Lyman continuum flux of 1051 s-1, about 100 times the ionizing power of the Orion → Trapezium cluster. The OB stars contribute to more than 2000 → solar masses to the cluster mass. With a bolometric luminosity over 107→ solar luminosities, NGC 3603 has about 10% of the luminosity of → 30 Doradus and looks in many respects very similar to its core, → R136. A total mass of 7,000 solar masses is measured in the inner 1 pc from the cluster center, whereas the → low-mass stars extend out to at least 5 pc. The mass segregated core of the cluster, with 105 solar masses per pc3, displays the highest local stellar density outside the Galactic Center region. The spectral analysis of the W-R like massive component in the cluster core (→ HD 97950) suggests a → metallicity close or equal to solar (See, e.g., Melena et al. 2008, AJ 135, 878, and references therein).
3603, a serial number in the → New General Catalogue.
ne-, ni- (#)
PIE prefix *ni- "down, below."
E. nether is from this PIE root; M.E. nethere, O.E. neothera, nithera "down, downward, below, beneath" (cf. O.S. nithar, O.N. niðr, O.Fris. nither, Du. neder, Ger. nieder); akin to Pers. ne-, ni-, as below.
Mod.Pers. ne-, ni- "down, below" (as in negâh "look, watch," nešastan "to sit down," nehoftan "to conceal," nehâdan "to place, put," nemudan "to display," nefrin "curse," etc.); Mid.Pers. ni-, O.Pers. preposition and verbal prefix ni- "down;" Av. nī- "down, in, into;" cf. Skt. ni- "down," nitaram "downward;" Gk. neiothen "from below;" E. nether, as above.
Metallic chemical element belonging to the iron group; symbol Ni. Atomic number 28; atomic weight 58.69; melting point about 1,453°C; boiling point about 2,732°C. It was discovered by the Swedish metallurgist Axel-Fredrik Cronstedt (1722-1765) in 1751.
Nickel, from shortening of Swedish kopparnickel "copper-colored ore," from which it was first obtained, a half-translation of Ger. Kupfernickel, literally "copper demon," from Kupfer "copper" + Nickel "demon, rascal" (from Nikolaus; cf. E. Old Nick "the devil;" the ore so called by miners because it looked like copper but yielded none.
manšur-e Nicol (#)
Fr.: prisme de Nicol
Optical device constructed from a crystal of calcite, used for obtaining plane polarized light.
Named after John Pringle Nicol (1804-1859), British physicist; → prism.
M.E., from O.E. niht (O.H.G. naht, Du., Ger. Nacht, O.N. natt, Goth. nahts), from PIE *nok(w)t- "night;" cf. Gk. nuks; L. nox (Fr. nuit; Sp. noche); Skt. nákt-; Av. *naxtar- "night," upa.naxtar- "adjoining the night" (Kurd. Soriani nûtak (?) "sheer darkness"); Lith. naktis; Russ. noch'.
Šab, from Mid.Pers. šab, šap "night;" O.Pers. xšap- "night;" Av. xšapan-, xšafn-, xšap- "night;" cf. Skt. ksáp- "night;" PIE base *k(w)sep- "night."
Fr.: assistant de nuit
A specialized technician in an observatory who is in charge of functioning a telescope and helping visiting astronomers during their observation run.
From → night + assistant; M.E. assistent, from L. assistent-, stem of assistens, pr.p. of assistere "assist, stand by," from → ad- "to" + sistere "take a stand, cause to stand," cognate with Pers. istâdan "to stand," → histogram.
Dastyâr "assistant," from dast "hand" (Mid.Pers. dast; O.Pers. dasta-; Av. zasta-; cf. Skt. hásta-; Gk. kheir; L. praesto "at hand;" Arm. jern "hand;" Lith. pa-žastis "arm-pit;" PIE *ghes-to-) + yâr "helper; companion" (Mid.Pers. hayyâr "helper," hayyârêh "help, aid, assistance," Proto-Iranian *adyāva-bara-, cf. Av. aidū- "helpful, useful").
Fr.: luminescence nocturne
Same as → airglow.
Nihal (β Leporis)
A yellow star of visual magnitude 2.84, the second brightest in the constellation → Lepus. It is a giant of → spectral type G5, lying some 159 light-years away. Nihal is double, with a companion, 2.5 seconds of arc apart.
From Ar. an-nihal (
M.E., from O.E. nigen, nigan, nigon, akin to M.Du. neghen, Du. negen, O.H.G. niun, Ger. neun, Goth. niun "nine," Pers. noh, as below; from PIE *newn "nine."
Noh, from Mid.Pers. nô; Av. nava; cognate with Skt. nava-; Gk. ennea; L. novem.
Gaseous chemical element; symbol N. Nitrogen is the most abundant constituent of dry air. It comprises 78.09% (by volume). → Atomic number 7; → atomic weight 14.0067; → melting point -209.86°C; → boiling point -195.8°C. Nitrogen is a colorless, odorless, tasteless diatomic gas. It was discovered by the Scottish physician and chemist Daniel Rutherford in 1772.
From Fr. nitrogène, coined 1790 by Fr. chemist Jean Antoine Chaptal (1756-1832), from combining form of Gk. nitron "sodium carbonate" + Fr. gène "producing."
Azot, loan from Fr. azote, from Gk. azotos "lifeless," from negation prefix → a- + zotos "vital."