An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

The force that takes part in an → electroweak interaction.

→ electroweak; → force.

The unified description of two of the four fundamental interactions of nature, → electromagnetism and the → weak interaction which would merge into a single force under conditions of extreme temperature (above 10¹⁶ degrees, 10² GeV) prevalent in the early history of the → Universe.

→ electroweak; → interaction.

A postulated type of star that could form toward the end of a → massive star's life, after → nuclear fusion has stopped in its → core, and before the star → collapses into a → black hole. In those → extreme conditions, when → temperature and → density inside the star are very high, → quarks could convert into → leptons. Hence huge amounts of energy can be released, much of which would be in the form of → neutrinos.

→ electroweak; → star.

The increase of dust grains to micron sizes in the interstellar environments due to various physical processes, for example mutual collisions and accumulation of ice mantles.

→ grain; → growth.

To increase by natural development, as any living organism or part by assimilation of nutriment; increase in size or substance (Dictionary.com).

From M.E. growen, O.E. growan; cf. Du. groeien, O.H.G. grouwan; PIE base *ghre- "to grow, become green," from which is also derived grass.

Ruyidan, rostan "to grow," from Mid.Pers. rôditan, rustan "to grow;" Av. raod- "to grow, sprout, shoot," with fra- "to grow up, shoot forth;" cf. Skt. ruh- "to grow, develop, ascend, climb," rohati "grows," rudh- "to grow, sprout, shoot," rodhati "grows."

The act or process, or a manner of growing; development; gradual increase. → curve of growth; → grain growth.

Ruyeš, verbal noun of → grow; rost, past stem of ruyidan, → grow, used as verbal noun.

A prism having angles of 30, 60, and 90°, which uses the same face for input and dispersed radiation. The beam is reflected at the face opposite to the 60° angle because it is coated to be highly reflecting. A beam entering at the → Brewster angle undergoes minimum deviation and hence maximum dispersion. Littrow prisms are used in laser cavities to fine tune lasers by selection of wavelength.

Joseph Johann Littrow (1781-1840), Austrian astronomer; → prism.

Electromagnetic radiation having wavelengths in the 1 to 300 mm range.

→ micro-; → wave.

Thermal radiation with a temperature of 2.73 K that is apparently uniformly distributed in the Universe. It is believed to be a redshifted remnant of the hot radiation that was in thermal equilibrium with matter during the first hundred thousand years after the Big Bang. Same as → cosmic microwave background (CMB) radiation.

→ microwave; → background; → radiation.

A type of electrically operated oven that cooks food very quickly using microwaves instead of heat.

→ microwave; → oven.

Electromagnetic radiation carried by → microwaves.

→ microwave; → radiation.

Of little breadth or → width.

M.E., from O.E. nearu; cf. O.S. naru "narrow," Du. naar "unpleasant;" akin to Ger. Narbe "scar," literally, "narrow mark."

Bârik, from Mid.Pers. bârîk "narrow," from O.Iranian *bāra-ya-ka-, from stem *bāra- "to cut;" cf. Av. bāra- "edge, blade," in tiži-bāra- "sharp-edged," from brī- "to cut, shave, shear;" cf. Skt. bhrī- "to hurt, injure," bhrinanti "they hurt;" O.C.S. briti "to shave;" PIE base *bhrē- "to cut, pierce."

Optics: Of a filter, same as → interference filter.
Radio.: Encompassing a small frequency range, typically less than 300 Hz.

→ narrow; → band.

Photometry using narrow-band filters to isolate a particular spectroscopic line or molecular band.

→ narrow band; → photometry.

The outer region of a → quasar or an → active galactic nucleus displaying narrow spectral lines. Also called Type II AGN. See also → obscuring torus.

→ narrow; → line; → region.

The forepart of a ship or boat; bow; opposite to stern or poop→ Puppis.

From M.Fr. proue, from Upper It. (Genoese) prua, from L. prora "prow," from Gk. proira, related to pro "before, forward," → pro-.

Farâl, from farâ "forward" (farâ raftan "to go forward, proceed," farâ rândan "to drive forward"), equivalent to → pro-, + relation suffix -âl, → -al. Compare farâl with prow "bow," Fr. la proue "prow, bow," from dialectal It. proa, prua, from L. prora "bow," from Gk. proira, related to pro "before, forward."

CCD detector: Series of pixels arranged along a line. → column

O.E. ræw "a row, line;" cf. Du. rij "row;" O.H.G. rihan "to thread," riga "line;" Ger. Reihe "row, line, series."

Raj "line, row," variants raž, rak, râk, rezg (Lori), ris, risé, radé, rasté, râsté, related to râst "right, true; just, upright, straight;" Mid.Pers. râst "true, straight, direct;" Soghdian rəšt "right;" O.Pers. rāsta- "straight, true," rās- "to be right, straight, true;" Av. rāz- "to direct, put in line, set," razan- "order;" cf. Skt. raj- "to direct, stretch," rjuyant- "walking straight;" Gk. orektos "stretched out;" L. regere "to lead straight, guide, rule," p.p. rectus "right, straight;" PIE base *reg- "move in a straight line," hence, "to direct, rule."

To propel something through the air in any way, especially by swinging the arm and releasing the object from the hand; → ejecter.

M.E. throwen, thrawen, "to twist, turn writhe" (cf. O.S. thraian, M.Du. dræyen, Du. draaien, O.H.G. draen, Ger. drehen "to turn, twist").

Andâxtan, andâz-, from Mid.Pers. handâxtan, handâz-; ultimately from Proto-Iranian *ham-tak-, from *ham- "together, with, same," → syn- + *tak- "to run, to flow;" cf. Av. tak- "to run, to flow," taciāp- "flowing water," tacinti (3pl.pers.act.) "to flow," tacar- "course," tacan "current, streaming;" Mod.Pers. tacidan, tâxtan, tâzidan "to run; to hasten; to assault," tajan name of a river (initially "flowing, streaming, stream"), tâzi "swift (greyhound)," tak "running, rush," from Mid.Pers. tâz-, tâxtan "to flow, to cause to walk," tc- "to flow, to walk," tag "running, attack," tâzig "swift, fast;" Khotanese ttajs- "to flow, to walk;" Skt. tak- to rush, to hurry," takti "runs;" O.Ir. tech- "to flow;" Lith. teketi "to walk, to flow;" O.C.S. tešti "to walk, to hurry;" Tokharian B cake "river;" PIE base *tek^w- "to run; to flow.

The sequence of all natural processes in which the → entropy increases. In other words, the fact that these processes all move in one direction in time and are → irreversible. The past is distinctly different from the future; things always grow older, never younger.

→ time; arrow, M.E. arewe, arwe, from O.E. arwan, earh "arrow," from P.Gmc. *arkhwo (cf. Goth. arhwanza), from PIE base *arku- "bow and/or arrow," source of Latin arcus, → arc.

Peykân "arrow," → Sagitta; zamân, → time.

A space telescope launched by NASA in 2001 which measures the temperature fluctuations in the → cosmic microwave background (CMB) radiation. It creates a full-sky map of the CMB, with a 13 arcminute resolution via multi-frequency observations. WMAP is the first mission to use a → Lagrangian point L2 as its permanent observing station at a distance of 1.5 million km. WMAP completed its prime two years of mission operations in September 2003 and is continuing in 2009 its observations for still several years to come. WMAP's measurements have played a considerable role in establishing the current standard model of cosmology. They are consistent with a Universe that is dominated by → dark energy, with negative pressure or a → cosmological constant. In this model, the age of the Universe is 13.73 ± 0.12 billion years. The current expansion rate of the Universe measured by the Hubble constant, is 70.5 ± 1.3 km·s^-1 Mpc^-1. The content of the Universe consists of 4.56% ± 0.15% ordinary → baryonic matter, 22.8% ± 1.3% → cold dark matter, and 72.6% ± 1.5% of → dark energy, that accelerates the → expansion of the Universe.

WMAP, short for Wilkinson Microwave Anisotropy Probe, in honor of David Todd Wilkinson (1935-2002), who had been a member of the mission's science team.