Occurring in nature; not artificially prepared. → nature.
Adj. of → nature.
Fr.: fréquence naturelle
Any frequency of small-amplitude oscillation for a system with a position of stable equilibrium and in the absence of external forces. In other words, the frequency of → free oscillation. Also called characteristic frequency.
Fr.: histoire naturelle
The → sciences, as → botany, → mineralogy, or → zoology, dealing with the study of all objects in → nature: used especially in reference to the beginnings of these sciences in former times (Dictionary.com).
Fr.: langage naturel
natural line broadening
pahneš-e zâstâri-ye xatt
Fr.: élargissement naturel de raie
The broadening of any spectral line due to the fact that excited levels have mean lives, which, by virtue of the uncertainty principle, implies a spread in the energy values.
Fr.: logarithme naturel
The logarithm in which the → base is the → irrational number e = 2.718281828.... Also called → Napierian logarithm. The natural logarithm is denoted ln, an abbreviation of logarithmus naturalis. Natural logarithms are related to → common logarithms through: ln x = (1/M) log x, with M = (1/ln 10) ≅ 0.434294.
Fr.: nombre naturel
Either a member of the set of positive integers 1, 2, 3, ..., or the set of non-negative integers 0, 1, 2, 3, ... There seems to be no general agreement about whether to include 0 in the set of natural numbers.
Fr.: période naturelle
Of a body or system, the period of → free oscillation.
Fr.: résonance naturelle
A resonance such that the period of the driving force is the same as the natural period of the system.
Fr.: satellite naturel
Fr.: science naturelle
A science that deals with matter, energy, their interrelations and transformations, In other words, natural sciences are concerned with physical processes observable in nature. They can be divided into physical and biological sciences.
Fr.: unités naturelles
Physical units of measurement defined in terms of universal physical constants in such a manner that some chosen physical constants (e.g. the speed of light, Planck's constant, Boltzmann's constant, etc.) are equal to unity. The use of natural units allows these constants to be omitted from mathematical equations, leading to simpler calculations.
Fr.: uranium naturel
Uranium as found in nature. It contains 0.7% uranium-235, 99.3% uranium-238, and a trace of uranium-234 by weight.
1) Of, pertaining to, or being above or beyond what is natural; unexplainable by natural;