spectrum
(noun) a broad range of related objects or values or qualities or ideas or activities
spectrum
(noun) an ordered array of the components of an emission or wave
Source: WordNet® 3.1
spectrum (plural spectra or spectrums)
A range; a continuous, infinite, one-dimensional set, possibly bounded by extremes.
Specifically, a range of colours representing light (electromagnetic radiation) of contiguous frequencies; hence electromagnetic spectrum, visible spectrum, ultraviolet spectrum, etc. [from later 17th c.]
(psychology, education) The autism spectrum.
(chemistry) The pattern of absorption or emission of radiation produced by a substance when subjected to energy (radiation, heat, electricity, etc.).
(mathematics, linear algebra) The set of eigenvalues of a matrix.
(mathematics, functional analysis) Of a bounded linear operator A, the set of scalar values λ such that the operator A—λI, where I denotes the identity operator, does not have a bounded inverse; intended as a generalisation of the linear algebra sense.
(abstract algebra, algebraic geometry) The set, denoted Spec(R), of all prime ideals of a given ring R, commonly augmented with a Zariski topology and considered as a topological space.
Hyponym: Stone space
(obsolete) Specter, apparition. [from early 17th c.]
The image of something seen that persists after the eyes are closed.
• cepstrum, crumpets
Source: Wiktionary
Spec"trum, n.; pl. Spectra. Etym: [L. See Specter.]
1. An apparition; a specter. [Obs.]
2. (Opt.) (a) The several colored and other rays of which light is composed, separated by the refraction of a prism or other means, and observed or studied either as spread out on a screen, by direct vision, by photography, or otherwise. See Illust. of Light, and Spectroscope. (b) A luminous appearance, or an image seen after the eye has been exposed to an intense light or a strongly illuminated object. When the object is colored, the image appears of the complementary color, as a green image seen after viewing a red wafer lying on white paper. Called also ocular spectrum. Absorption spectrum, the spectrum of light which has passed through a medium capable of absorbing a portion of the rays. It is characterized by dark spaces, bands, or lines.
– Chemical spectrum, a spectrum of rays considered solely with reference to their chemical effects, as in photography. These, in the usual photogrophic methods, have their maximum influence at and beyond the violet rays, but are not limited to this region.
– Chromatic spectrum, the visible colored rays of the solar spectrum, exhibiting the seven principal colors in their order, and covering the central and larger portion of the space of the whole spectrum.
– Continous spectrum, a spectrum not broken by bands or lines, but having the colors shaded into each other continously, as that from an incandescent solid or liquid, or a gas under high pressure.
– Diffraction spectrum, a spectrum produced by diffraction, as by a grating.
– Gaseous spectrum, the spectrum of an incandesoent gas or vapor, under moderate, or especially under very low, pressure. It is characterized by bright bands or lines.
– Normal spectrum, a representation of a spectrum arranged upon conventional plan adopted as standard, especially a spectrum in which the colors are spaced proportionally to their wave lengths, as when formed by a diffraction grating.
– Ocular spectrum. See Spectrum, 2 (b), above.
– Prismatic spectrum, a spectrum produced by means of a prism.
– Solar spectrum, the spectrum of solar light, especially as thrown upon a screen in a darkened room. It is characterized by numerous dark lines called Fraunhofer lines.
– Spectrum analysis, chemical analysis effected by comparison of the different relative positions and qualities of the fixed lines of spectra produced by flames in which different substances are burned or evaporated, each substance having its own characteristic system of lines.
– Thermal spectrum, a spectrum of rays considered solely with reference to their heating effect, especially of those rays which produce no luminous phenomena.
Source: Webster’s Unabridged Dictionary 1913 Edition
24 November 2024
(noun) a person (usually but not necessarily a woman) who is thoroughly disliked; “she said her son thought Hillary was a bitch”
The word “coffee” entered the English language in 1582 via the Dutch “koffie,” borrowed from the Ottoman Turkish “kahve,” borrowed in turn from the Arabic “qahwah.” The Arabic word qahwah was traditionally held to refer to a type of wine.
