Fr.: instabilité non-linéaire
The instability of a physical or mathematical system that arises from the nonlinear nature of relevant variables and their interactions within the system.
→ nonlinear; → instability.
Fr.: système non-linéaire
A system in which small changes can result in large effects, and large changes in small effects.
The property, condition, or state of being → nonlinear.
setâre-ye hamiše penhân (#)
A star that is never seen above the horizon from a given position. These stars are located between the celestial pole and a diurnal circle with an angular distance larger than the altitude of the pole.
Nonrising, from → non- + rising adj. of → rise; → star.
Setâré, → star; hamiše penhân, literally "always hidden," coined by Biruni (A.D. 973-1050) in his at-Tafhim, from hamišé "always" (Mid.Pers. hamêšag "always") + penhân "hidden."
Fr.: non sense
Word or language having no meaning. → absurd.
Jafang "nonsense, futile."
setâre-ye hamiše peydâ (#)
A star that is always seen above the horizon from a given position. These stars are located between the celestial pole and a diurnal circle with an angular distance smaller than the altitude of the pole. Same as → circumpolar star.
Nonsetting, from → non- + setting adj. of → set; → star.
Setâré, → star; hamiše peydâ literally "always visible," coined by Biruni (A.D. 973-1050) in his at-Tafhim, from hamišé "always," → perpetual, + peydâ, → visible.
Fr.: matrice non singulière
A → square matrix that is not a → singular matrix.
Fr.: non thermique
See also → non-thermal.
Fr.: échappement non thermique
Same as → suprathermal escape.
Fr.: non visqueux
Fluid mechanics: Having no → viscosity. Same as → inviscid.
Nyquist-Shannon sampling theorem
farbin-e nemunân-giri-ye Nyquist-Shannon
Fr.: théorème d'échantillonnage de Nyquist-Shannon
The minimum number of resolution elements required to properly sample a signal, such as a star image, without causing erroneous effects known as aliasing. For electronic imaging, this number is generally taken as 2 pixels across the seeing disk diameter at the half intensity points. Also called → Shannon's sampling theorem and → sampling theorem.
Named after Harry Nyquist (1889-1976), a Swedish-born American physicist, who made important contributions to information theory, and Claude Elwood Shannon (1916-2001), an American mathematician and pioneer of information theory; → theorem.
1) An occurrence, circumstance, or fact, in matter or spirit, which can be perceived
by human senses. → physical phenomenon.
From L.L. phÃ¦nomenon, from Gk. phainomenon "that which appears or is seen," from phainesthai "to appear," passive of phainein "to bring to light; to show," from PIE base *bhhā- "to shine;" cf. Skt. bhāati "shines, glitters;" Av. bā- "to shine, appear, seem," bāmya- "light, luminous, bright," bānu- "light, ray;" Mid.Pers. bâm "beam of light, splendor," bâmik "brilliant," bâmdâd "morning, dawn."
Padidé, noun from padid "manifest, evident, conspicuous, in sight," variant padidâr, from Mid.Pers. pad didâr "visible," from pad "to, at, for, in," evolved to bé "to; for; in; on; with; by" in Mod.Pers. (O.Pers. paity; Av. paiti "to, toward, in, at;" cf. Skt. práti, Gk. poti) + did past stem of didan "to see, regard, catch sight of, contemplate, experience" (O.Pers. dī- "to see;" Av. dā(y)- "to see," didāti "sees;" cf. Skt. dhī- "to perceive, think, ponder; thought, reflection, meditation," dādhye; Gk. dedorka "have seen").
A quantum of vibrational or acoustic energy in a crystal lattice, being the analog of a photon of electromagnetic energy.
padide-ye fiziki (#)
Fr.: phénomène physique
A natural → phenomenon that can be explained by → physical laws.
→ physical; → phenomenon.
principle of non-contradiction
Fr.: principe de non-contradiction
The third principle of → formal logic introduced in Aristotle's theory of the → syllogism: No statement can be both → true and → false at the same time. Also called → law of non-contradiction.
→ principle; → non-; → contradiction.
Fr.: réaction pycnonucléaire
A nuclear reaction that takes place at high densities and relatively low temperatures. Pycnonuclear reactions are almost temperature independent and occur even at zero temperature. These reactions are extremely slow at densities typical for normal stars but intensify with increasing density. For example, carbon burns into heavier elements at densities over 1010 g cm-3.
Pycnonuclear, from pycno- a combining form meaning "dense, thick," from Gk. pyknos "dense, solid" + → nuclear; → reaction.
Vâžireš, → reaction; cagâl-hasteyi, from cagâl, → dense, + hasteyi, → nuclear.
Fr.: entropie de Shannon
Claude Elwood Shannon (1916-2001), an American mathematician and pioneer of → information theory; → entropy.
Shannon's sampling theorem
farbin-e nemunân-giri-ye Shannon
Fr.: théorème d'échantillonnage de Shannon
Same as → sampling theorem.
→ Shannon entropy; → sampling; → theorem.
Fr.: étoile super-canonique
A star whose mass exceeds the → canonical upper limit of the stellar → initial mass function (Kroupa et al. 2012, arXiv:1112.3340).
Grammar: A word having the same or nearly the same meaning as another in the language. Opposite of → antonym.
From L. synonymum, from Gk. synonymon "word having the same sense as another," from synonymos "having the same name as, synonymous," from → syn- "together, same" + onyma, → name.