Difference between revisions of "Spectrum"
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==Origin== | ==Origin== | ||
New Latin, from [[Latin]], [[appearance]] — more at specter | New Latin, from [[Latin]], [[appearance]] — more at specter | ||
| − | In [[Latin]] ''spectrum'' means "image" or "[[apparition]]", including the [[meaning]] "[[spectre]]". Spectral [[evidence]] is [[testimony]] about what was done by spectres of persons not present physically, or hearsay evidence about what [[ghosts]] or apparitions of [[Satan]] said. It was used to convict a number of persons of witchcraft at Salem, Massachusetts in the late 17th century. The word "spectrum" [Spektrum] was strictly used to designate a ghostly optical afterimage by [ | + | In [[Latin]] ''spectrum'' means "image" or "[[apparition]]", including the [[meaning]] "[[spectre]]". Spectral [[evidence]] is [[testimony]] about what was done by spectres of persons not present physically, or hearsay evidence about what [[ghosts]] or apparitions of [[Satan]] said. It was used to convict a number of persons of witchcraft at Salem, Massachusetts in the late 17th century. The word "spectrum" [Spektrum] was strictly used to designate a ghostly optical afterimage by [https://en.wikipedia.org/wiki/Goethe Goethe] in his ''[https://en.wikipedia.org/wiki/Theory_of_Colours_(book) Theory of Colors]'' and [https://en.wikipedia.org/wiki/Arthur_Schopenhauer Schopenhauer] in ''[https://en.wikipedia.org/wiki/On_Vision_and_Colors On Vision and Colors]''. |
| − | *[ | + | *[https://en.wikipedia.org/wiki/17th_century 1671] |
==Definitions== | ==Definitions== | ||
*1a : a [[continuum]] of [[color]] formed when a beam of white [[light]] is dispersed (as by passage through a prism) so that its component [[wavelengths]] are arranged in order | *1a : a [[continuum]] of [[color]] formed when a beam of white [[light]] is dispersed (as by passage through a prism) so that its component [[wavelengths]] are arranged in order | ||
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:c : a range of effectiveness against pathogenic organisms <an antibiotic with a broad spectrum> | :c : a range of effectiveness against pathogenic organisms <an antibiotic with a broad spectrum> | ||
==Description== | ==Description== | ||
| − | A '''spectrum''' (plural spectra or spectrums) is a condition that is not limited to a specific set of [[values]] but can vary infinitely within a [[continuum]]. The word was first used scientifically within the field of [[optics]] to describe the [[rainbow]] of [[colors]] in visible light when separated using a prism. As scientific understanding of light advanced, it came to apply to the entire [ | + | A '''spectrum''' (plural spectra or spectrums) is a condition that is not limited to a specific set of [[values]] but can vary infinitely within a [[continuum]]. The word was first used scientifically within the field of [[optics]] to describe the [[rainbow]] of [[colors]] in visible light when separated using a prism. As scientific understanding of light advanced, it came to apply to the entire [https://en.wikipedia.org/wiki/Electromagnetic_spectrum electromagnetic spectrum]. |
Spectrum has since been applied by [[analogy]] to topics outside of optics. Thus, one might talk about the spectrum of political [[opinion]], or the spectrum of activity of a [[drug]], or the [[autism]] spectrum. In these uses, values within a spectrum may not be associated with precisely quantifiable numbers or [[definitions]]. Such uses imply a broad range of conditions or [[behaviors]] grouped together and studied under a single title for ease of [[discussion]]. | Spectrum has since been applied by [[analogy]] to topics outside of optics. Thus, one might talk about the spectrum of political [[opinion]], or the spectrum of activity of a [[drug]], or the [[autism]] spectrum. In these uses, values within a spectrum may not be associated with precisely quantifiable numbers or [[definitions]]. Such uses imply a broad range of conditions or [[behaviors]] grouped together and studied under a single title for ease of [[discussion]]. | ||
Latest revision as of 02:37, 13 December 2020
Origin
New Latin, from Latin, appearance — more at specter In Latin spectrum means "image" or "apparition", including the meaning "spectre". Spectral evidence is testimony about what was done by spectres of persons not present physically, or hearsay evidence about what ghosts or apparitions of Satan said. It was used to convict a number of persons of witchcraft at Salem, Massachusetts in the late 17th century. The word "spectrum" [Spektrum] was strictly used to designate a ghostly optical afterimage by Goethe in his Theory of Colors and Schopenhauer in On Vision and Colors.
Definitions
- 1a : a continuum of color formed when a beam of white light is dispersed (as by passage through a prism) so that its component wavelengths are arranged in order
- b : any of various continua that resemble a color spectrum in consisting of an ordered arrangement by a particular characteristic (as frequency or energy): as (1) : electromagnetic spectrum (2) : radio spectrum (3) : the range of frequencies of sound waves (4) : mass spectrum
- c : the representation (as a plot) of a spectrum
- 2a : a continuous sequence or range <a wide spectrum of interests> <opposite ends of the political spectrum>
- b : kinds of organisms associated with a particular situation (as an environment)
- c : a range of effectiveness against pathogenic organisms <an antibiotic with a broad spectrum>
Description
A spectrum (plural spectra or spectrums) is a condition that is not limited to a specific set of values but can vary infinitely within a continuum. The word was first used scientifically within the field of optics to describe the rainbow of colors in visible light when separated using a prism. As scientific understanding of light advanced, it came to apply to the entire electromagnetic spectrum.
Spectrum has since been applied by analogy to topics outside of optics. Thus, one might talk about the spectrum of political opinion, or the spectrum of activity of a drug, or the autism spectrum. In these uses, values within a spectrum may not be associated with precisely quantifiable numbers or definitions. Such uses imply a broad range of conditions or behaviors grouped together and studied under a single title for ease of discussion.
In most modern usages of spectrum there is a unifying theme between extremes at either end. Some older usages of the word did not have a unifying theme, but they led to modern ones. Modern usages in mathematics did evolve from a unifying theme, but this may be difficult to recognize.
