Spectrum

Certain properties of objects or physical processes, such as the frequency of light or sound, the masses of the component parts of a molecule, or even the ideals of a political party, may have a wide variety of values. The distribution of these values, arranged in increasing or decreasing order, is the spectrum of that property. For example, sunlight is made up of many different colors of light, the full spectrum of which are revealed when sunlight is dispersed, as it is in a rainbow. Similarly, the distribution of sounds over a range of frequencies, such as a musical scale, is a sound spectrum. The masses of fragments from an ionized molecule, separated according to their mass-to-charge ratio, constitute a mass spectrum. Opposing political parties are often said to be on opposite ends of the (political) spectrum. The term spectrum is also used to describe the graphical illustration of a spectrum of values. The plural of spectrum is spectra.