Word meaning of spectrum

From Wikipedia, the free encyclopedia

A spectrum (plural spectra or spectrums)^[1] is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors in visible light after passing through a prism. As scientific understanding of light advanced, it came to apply to the entire electromagnetic spectrum. It thereby became a mapping of a range of magnitudes (wavelengths) to a range of qualities, which are the perceived «colors of the rainbow» and other properties which correspond to wavelengths that lie outside of the visible light spectrum.

Spectrum has since been applied by analogy to topics outside 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. Nonscientific uses of the term spectrum are sometimes misleading. For instance, a single left–right spectrum of political opinion does not capture the full range of people’s political beliefs. Political scientists use a variety of biaxial and multiaxial systems to more accurately characterize political opinion.

In most modern usages of spectrum there is a unifying theme between the extremes at either end. This was not always true in older usage.

Etymology[edit]

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.

The prefix «spectro-» is used to form words relating to spectra. For example, a spectrometer is a device used to record spectra and spectroscopy is the use of a spectrometer for chemical analysis.

Physical sciences[edit]

Biological science[edit]

Antibiotic spectrum of activity is a component of antibiotic classification. A broad-spectrum antibiotic is active against a wide range of bacteria,^[4] whereas a narrow-spectrum antibiotic is effective against specific families of bacteria.^[5] An example of a commonly used broad-spectrum antibiotic is ampicillin.^[5] An example of a narrow spectrum antibiotic is Dicloxacillin, which acts on beta-lactamase-producing Gram-positive bacteria such as Staphylococcus aureus.^[6]

In psychiatry, the spectrum approach uses the term spectrum to describe a range of linked conditions, sometimes also extending to include singular symptoms and traits. For example, the autism spectrum describes a range of conditions classified as neurodevelopmental disorders.

Mathematics[edit]

In mathematics, the spectrum of a matrix is the multiset of the eigenvalues of the matrix.

In functional analysis, the concept of the spectrum of a bounded operator is a generalization of the eigenvalue concept for matrices.

In algebraic topology, a spectrum is an object representing a generalized cohomology theory.

[edit]

In social science, economic spectrum is used to indicate the range of social class along some indicator of wealth or income. In political science, the term political spectrum refers to a system of classifying political positions in one or more dimensions, for example in a range including right wing and left wing.

References[edit]

English[edit]

Etymology[edit]

From Latin spectrum (“appearance, image, apparition”), from speciō (“look at, view”). Doublet of specter. See also scope.

Pronunciation[edit]

• (Canada, UK) IPA^(key): /ˈspektɹəm/
• (US) IPA^(key): /ˈspɛkt͡ʃɹəm/

  • Audio (Mid-Atlantic)

    (file)

• Rhymes: -ɛktɹəm

Noun[edit]

spectrum (plural spectra or spectrums)

1. A range; a continuous, infinite, one-dimensional set, possibly bounded by extremes.

   • 2012 November 7, Matt Bai, “Winning a Second Term, Obama Will Confront Familiar Headwinds”, in New York Times‎^[1]:

     As Mr. Obama prepared to take the oath, his approval rating touched a remarkable 70 percent in some polling — a reflection of good will across the political spectrum.

2. Specifically, a range of colours representing light (electromagnetic radiation) of contiguous frequencies; hence electromagnetic spectrum, visible spectrum, ultraviolet spectrum, etc. [from later 17th c.]
   • 2010 October 30, Jim Giles, Jammed!, in New Scientist,

     Current 3G technologies can send roughly 1 bit of data — a one or a zero — per second over each 1 Hz of spectrum that the operator owns.

3. (psychology, education, usually with the) The autism spectrum.
4. (chemistry) The pattern of absorption or emission of radiation produced by a substance when subjected to energy (radiation, heat, electricity, etc.).
5. (mathematics, linear algebra) The set of eigenvalues of a matrix.

   Synonym: eigenspectrum

6. (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.
7. (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

8. (obsolete) Specter, apparition. [from early 17th c.]
9. The image of something seen that persists after the eyes are closed.

Derived terms[edit]

• autism spectrum
• cepstrum
• light spectrum
• spectro-
• spectrum disorder
• political spectrum

[edit]

• spectral

Translations[edit]

Anagrams[edit]

• cepstrum, crumpets

Dutch[edit]

Etymology[edit]

From Latin spectrum (“appearance, image, apparition”), from speciō (“look at, view”).

Pronunciation[edit]

Noun[edit]

spectrum n (plural spectrums or spectra, diminutive spectrumpje n)

1. spectrum

Derived terms[edit]

• spectraal
• spectroscoop

Latin[edit]

Etymology[edit]

From spec(iō) (“look at, behold”) +‎ -trum (making it a doublet of speculum).

The only attestation in Classical antiquity is in a pair of letters between Cicero and Cassius Longinus which imply that the Epicurean Catius (fl. c. 50s–40s BC) used spectrum as a translation of the Greek philosophical term εἴδωλον (eídōlon, “image”).^[1] It may therefore have been coined by Catius as a neologism, although alternatively, it could be an undocumented but preexisting word that he repurposed as a technical term.

After Cicero, the word is extremely sparsely attested until being revived around the start of the sixteenth century by Renaissance humanist authors with the meaning «apparition» or «phantom», possibly influenced by the fact that Greek εἴδωλον also had this sense.^[2]

The scientific use to refer to the visible spectrum of colored light was first introduced by Isaac Newton, who used the word in the second half of the seventeenth century in both his English writings and in his first Latin draft of the Opticks, the Fundamentum Opticae, although the 1706 Latin translation of Opticks by Samuel Clarke translates Newton’s English spectrum into Latin as imago.^[3]

Pronunciation[edit]

• (Classical) IPA^(key): /ˈspek.trum/, [ˈs̠pɛkt̪rʊ̃ˑ]
• (Ecclesiastical) IPA^(key): /ˈspek.trum/, [ˈspɛkt̪rum]

Noun[edit]

spectrum n (genitive spectrī); second declension

1. appearance, image

   • 62 BCE – 43 BCE, Cicero, Epistulae ad Familiares 15.16.1–2:

     fit enim nescio qui ut quasi coram adesse videare cum scribo aliquid ad te, neque id κατ’ εἰδ<ώλ>ων φαντασίας, ut dicunt tui amici novi, qui putant etiam διανοητικὰς φαντασίας spectris Catianis excitari. nam, ne te fugiat, Catius Insuber Ἐπικούρειος, qui nuper est mortuus, quae ille Gargettius et iam ante Democritus εἴδωλα, hic spectra nominat. his autem spectris etiam si oculi possent feriri, quod <pup>ulis ipsa incurrunt, animus qui possit ego non video; doceas tu me oportebit cum salvus veneris. in meane potestate ut sit spectrum tuum, ut, simul ac mihi collibitum sit de te cogitare, illud occurrat? neque solum de te, qui mihi haeres in medullis, sed si insulam Britanniam coepero cogitare, eius εἴδωλον mihi advolabit ad pectus?

     • 1900 translation by Evelyn Shuckburgh^[4]

       For somehow it makes you seem almost present when I write anything to you, and that not ‘by way of phantoms of images,’ as your new friends express it, who hold that ‘mental pictures’ are caused by what Catius called ‘spectres’ — for I must remind you that Catius Insuber the Epicurean, lately dead, calls ‘spectres’ what the famous Gargettius, and before him Democritus, used to call ‘images.’ Well, even if my eyes were capable of being struck by these ‘spectres,’ because they spontaneously run in upon them at your will, I do not see how the mind can be struck. You will be obliged to explain it to me, when you return safe and sound, whether the ‘spectre’ of you is at my command, so as to occur to me as soon as I have taken the fancy to think about you; and not only about you, who are in my heart’s core, but supposing I begin thinking about the island of Britain — will its image fly at once into my mind?

2. apparition, specter, phantom

   • 1524, Desiderius Erasmus, Exorcismus sive spectrum :

     Iam pridem vagabatur rumor ac fabula per eius loci rusticos, iuxta ponticulum hunc observari spectrum quoddam, cuius subinde exaudirentur miserandi eiulatus: suspicabantur, animam esse cuiuspiam, quae diris cruciatibus torqueretur.

3. (New Latin) spectrum (band of light arranged in order by wavelength)

   • c. 1687-88, Isaac Newton, Fundamentum Opticae^[5] :

     Considerabam praeterea quod latitudine foraminis F per quod lux in cubiculum ingreditur fit penumbra in circuitu spectri Y, et penumbra illa permanet in lateribus rectilineis spectrorum PT et pt.

     • Translation by Alan E. Shapiro

       I further considered that by the breadth of the hole F, through which the light enters the room, a penumbra is made in the border of the spectrum Y, and that penumbra remains in the straight sides of the spectra PT and pt.

Declension[edit]

Second-declension noun (neuter).

Synonyms[edit]

• īdōlum, simulācrum, imāgō, speciēs, figūra, fōrma, effigiēs, phantasma

[edit]

• speciō
• spectiō
• spectō

Descendants[edit]

• → Catalan: espectre
• → Dutch: spectrum
• → English: spectre, specter; spectrum
• → French: spectre
• → German: Spektrum
• → Irish: speictream
• → Italian: spettro
• → Portuguese: espectro
• → Romanian: spectru
• → Russian: спектр (spektr)
• → Spanish: espectro
• → Swedish: spektrum

References[edit]

Further reading[edit]

• “spectrum”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• “spectrum”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
• spectrum in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
• spectrum in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette

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  English-Russian dictionary of biology and biotechnology > spectrum

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  spectrum
  
  

  Англо-русский словарь строительных терминов > spectrum

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  spectrum
  
  

  spectrum [ˊspektrəm]

  n

  (

  pl

  — ra)

  физ.

  1) спектр

  Англо-русский словарь Мюллера > spectrum

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  spectrum
  
  

  Персональный Сократ > spectrum

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  spectrum
  
  

  2) спектральная характеристика; спектральная зависимость

  •

  Англо-русский словарь технических терминов > spectrum

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  spectrum
  
  

  English-Russian electronics dictionary > spectrum

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  spectrum
  
  

  The New English-Russian Dictionary of Radio-electronics > spectrum

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  spectrum
  
  

  English-Russian scientific dictionary > spectrum

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  spectrum
  
  

  Англо-русский технический словарь > spectrum

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  spectrum
  
  

  English-Russian dictionary of telecommunications and their abbreviations > spectrum

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  spectrum
  
  

  airspeed spectrum

  clipped spectrum

  compression-dominated spectrum

  discrete spectrum

  Dryden spectrum

  Dryden gust spectrum

  eigenvalue spectrum

  FALSTAFF spectrum

  fatigue spectrum

  fighter attack spectrum

  flight-by-flight spectrum

  frequency spectrum

  gust spectrum

  input spectrum

  loading spectrum

  maneuver spectrum

  mission spectrum

  natural frequency spectrum

  noise spectrum

  operating spectrum

  operational spectrum

  optical spectrum

  output spectrum

  response spectrum

  service loading spectrum

  strain spectrum

  stress spectrum

  test spectrum

  truncated spectrum

  turbulence spectrum

  Авиасловарь > spectrum

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  spectrum
  
  

  English-Russian dictionary of mechanical engineering and automation > spectrum

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  spectrum
  
  

  спектр; область; диапазон; многообразие

  Englsh-Russian aviation and space dictionary > spectrum

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  spectrum
  
  

  Англо-русский словарь нефтегазовой промышленности > spectrum

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  spectrum
  
  

  спектр

  @spectrum analysis

  спектральный анализ

  @spectrum variables

  спектрально-переменные звезды

  @flare spectrum

  спектр вспышки

  @flash spectrum

  спектр вспышки

  @infrared spectrum

  инфракрасная область спектра

  @nebular spectrum

  спектр туманности

  @nova spectrum

  спектр новой

  @pecular spectrum

  @photospheric spectrum

  @pre-nova spectrum

  спектр новой до вспышки

  @shell spectrum

  @sky spectrum

  @solar spectrum

  солнечный спектр

  @star spectrum

  спектр звезды

  @stellar spectrum

  звездный спектр

  @sunspot spectrum

  спектр солнечного пятна

  @twilight spectrum

  спектр сумеречного неба

  @ultraviolet spectrum

  ультрафиолетовая область спектра

  @visible light spectrum

  @visible spectrum

  видимая часть спектра

  @X-ray spectrum

  рентгеновский диапазон спектра

  @XUV spectrum

  ренгеновская и ультрафиолетовая область спектра

  @

  English-Russian astronomy dictionary > spectrum

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  spectrum
  
  

  English-russian biological dictionary > spectrum

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  spectrum
  
  

  Английский-русский словарь по теории вероятностей, статистике и комбинаторике > spectrum

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  spectrum
  
  

  спектр
  absorption spectrum спектр поглощения
  arc spectrum дуговой спектр
  band spectrum полосчатый спектр
  continuous spectrum сплошной спектр
  emission spectrum спектр испускания, эмиссионный спектр
  line spectrum линейчатый спектр
  Mossbauer spectrum спектр Мёссбауэра
  phase spectrum фазочастотный спектр
  pollen spectrum пыльцевой спектр
  power spectrum энергетический спектр
  pulse-height spectrum амплитудно-импульсный спектр
  Raman spectrum раман-спектр
  reflection spectrum спектр отражения
  solar spectrum солнечный спектр
  spark spectrum искровой спектр
  turbulence spectrum вихревой спектр
  vibrational spectrum колебательный спектр
  X-ray spectrum рентгеновский спектр

  English-Russian dictionary of geology > spectrum

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  spectrum
  
  

  English-Russian dictionary of aviation and space materials > spectrum

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  spectrum
  
  

  1. n физ. спектр

  2. n спец. диапазон

  3. n разнообразие; размах, широкий диапазон

  4. n изображение, образ

  5. n привидение, призрак

  6. n редк. образ, видение

  Синонимический ряд:

  1. apparition (noun) apparition; bogey; eidolon; ghost; phantasm; phantom; revenant; shade; shadow; specter; spirit; umbra; wraith

  2. entire range (noun) compass; diapason; entire range; extent; gamut; range; scale; sweep

  English-Russian base dictionary > spectrum

Translations

Last Updated:
31 Mar 2023
— Updated example sentences