• Spectrum


    • Canada IPA: /ˈspektrəm/
    • US IPA: /ˈspɛkt(ʃ)ɹəm/
    • Rhymes: -ɛktrəm


    From Latin spectrum ("appearance, image, apparition"), from speciō ("look at, view"). (see scope)

    Full definition of spectrum



    (plural spectra or spectrums)
    1. Specter, apparition. from early 17th c.
    2. A range; a continuous, infinite, one-dimensional set, possibly bounded by extremes.
    3. 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.
    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.
    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.

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