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

Not → fuzzy. → nonfuzzy set.

→ non-; → fuzzy.

A set that obeys the rules of → classical logic, a → crisp set, as contrasted with a → fuzzy set.

→ nonfuzzy; → set.

A mechanical system with constraints on their velocity that are not derivable from position constraints. Nonholonomic systems arise, for instance, in mechanical systems that have rolling contact (for example, the rolling of wheels without slipping) or certain kinds of sliding contact (such as the sliding of skates). They are a remarkable generalization of classical Lagrangian and Hamiltonian systems in which one allows position constraints only.

→ non-; → holonomic; → system.

Not homogeneous. → nonhomogeneous linear differential equation.

→ non-; → homogeneous.

A → linear differential equation if Q(x)≠ 0 on interval I.

→ nonhomogeneous; → linear; → differential; → equation.

The quality of an atom that has neither lost nor gained any electrons.

→ non-; → ionized.

Not a linear function of the relevant variables.
Containing a variable with an exponent other than one; opposite of → linear.

→ non-; → linear.

An electronic device whose output is not directly proportional to its input. For example, in a → diode the current is a nonlinear function of the voltage; its voltage-current characteristics do not obey → Ohm's law.

→ nonlinear; → device.

Same as → chaos.

→ nonlinear; → dynamics.

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.

A system in which small changes can result in large effects, and large changes in small effects.

→ nonlinear; → system.

The property, condition, or state of being → nonlinear.

→ non-; → linearity.

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."

Word or language having no meaning. → absurd.

→ non- + → sense.

Jafang "nonsense, futile."

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.

A → square matrix that is not a → singular matrix.

→ non-; → singular; → matrix.

See also → non-thermal.

→ non-; → thermal.

Same as → suprathermal escape.

→ non-; → thermal; → escape.

Fluid mechanics: Having no → viscosity. Same as → inviscid.

From → non- + → viscous.

The time of day when the Sun crosses the observer's meridian and is at its highest point above the horizon. At this point, the Sun lies due south of an observer in the northern hemisphere and due north of an observer in the southern hemisphere.

M.E. none; O.E. non, from L. nona hora "ninth hour" of daylight by Roman reckoning, about 3 p.m.

Nimruz, from nim "mid-, half" (Mid.Pers. nêm, nêmag "half;" Av. naēma- "half;" cf. Sk. néma- "half") + ruz→ day.