- Spectrum is the range of colors of wavelength energy sent out from a light source when viewed through a prism.
An example of a spectrum is a rainbow.
- Spectrum is a broad range of related ideas, qualities or activities.
An example of a spectrum is a group of activities used for teaching someone how to play basketball.
An example of a spectrum is a rainbow.Licensed from iStockPhoto
- the series of colored bands dispersed and arranged in the order of their respective wavelengths by the passage of white light through a prism or other dispersing device and shading continuously from red (produced by the longest wave visible) through violet (produced by the shortest): the six main colors of the spectrum are red, orange, yellow, green, blue, and violet, with a seventh color (indigo) sometimes specified, between blue and violet
- the intensity of any radiation or motion displayed as a function of frequency, or wavelength
- an afterimage
- a continuous range or entire extent: a wide spectrum of opinion
- radio spectrum
- electromagnetic spectrum
Origin: ModL, special use (by Sir Isaac Newton, 1671) of Classical Latin spectrum: see specter
Used by arrangement with John Wiley & Sons, Inc.
noun pl. spec·tra or spec·trums
- Physics The distribution of a characteristic of a physical system or phenomenon, especially:a. The distribution of energy emitted by a radiant source, as by an incandescent body, arranged in order of wavelengths.b. The distribution of atomic or subatomic particles in a system, as in a magnetically resolved molecular beam, arranged in order of masses.
- A graphic or photographic representation of such a distribution.
- a. A range of values of a quantity or set of related quantities.b. A broad sequence or range of related qualities, ideas, or activities: the whole spectrum of 20th-century thought.
Origin: Latin, appearance, from specere, to look at; see spek- in Indo-European roots.
spectrum - Computer Definition
Generally referring to frequency spectrum. See electromagnetic spectrum.
Used by arrangement with John Wiley & Sons, Inc.
The range of electromagnetic radiation (electromagnetic waves) in our known universe, which includes visible light. The radio spectrum, which includes both licensed and unlicensed frequencies up to 300 GHz has been defined worldwide in three regions: Europe and Northern Asia (Region 1); North and South America (Region 2), and Southern Asia and Australia (Region 3). Some frequency bands are used for the same purpose in all three regions while others differ. See satellite bands and optical bands. Higher Frequencies Frequencies above 40 GHz have not been licensed, but are expected to be made available in the future as the technology is developed to transmit at these smaller wavelengths (higher frequencies). The spectrum can be viewed in meticulous detail from the Federal Communications Commission (FCC) and National Telecommunications and Information Administration (NTIA) by visiting www.fcc.gov/oet/spectrum and www.ntia.doc.gov/osmhome/osmhome.html. See electromagnetic radiation and wave.
Should Airwaves Be Licensed?There is a great deal of controversy over the licensing of frequencies. In Kevin Werbach's very educational white paper, "Radio Revolution," the author says an artificial scarcity has been created because policy makers do not understand the technology. He states that many believe the traditional policy of dividing the airwaves into licensed bands now impedes progress because today's radio technologies allow for much more sharing of the spectrum than ever before. The old notion that radio waves interfere with and cancel each other is a false one. Waves just mix together and become more difficult to differentiate, but modern electronics can, in fact, separate them. To obtain a copy of this insightful report written in 2003, as well as other related articles, visit Werbach's Web site at www.werbach.com. See smart radio.
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spectrum - Cultural Definition
spectrum - Medical Definition
noun pl. spec·trums or spec·tra
- The distribution of a characteristic of a physical system or phenomenon, especially the distribution of energy emitted by a radiant source arranged in order of wavelengths.
- The color image presented when white light is resolved into its constituent colors: red, orange, yellow, green, blue, indigo, violet.
- The plot of intensity as opposed to wavelength of light emitted or absorbed by a substance, usually characteristic of the substance and used in qualitative and quantitative analysis.
- The distribution of atomic or subatomic particles in a system, as in a magnetically resolved molecular beam, arranged in order of masses.
- The group of pathogenic organisms against which an antibiotic or other antibacterial agent is effective.
spectrum - Science Definition
Plural spectra spectra or spectrums
- A range over which some measurable property of a physical phenomenon, such as the frequency of sound or electromagnetic radiation, or the mass of specific kinds of particles, can vary. For example, the spectrum of visible light is the range of electromagnetic radiation with frequencies between between 4.7 × 1014 and 7.5 × 1014 hertz.
- The observed distribution of a phenomenon across a range of measurement. See more at atomic spectrum, spectroscopy.
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