Theory
In physics, monochromatic refers to electromagnetic radiation of a single frequency. In the physical sense, no source of electromagnetic radiation is purely monochromatic, since that would require a wave of infinite duration as a consequence of the Fourier transform's localization property (cf. spectral coherence). Even very controlled sources such as lasers operate in a range of frequencies (known as the spectral linewidth). In practice, filtered light, diffraction grating separated light and laser light are all routinely referred to as monochromatic. Often light sources can be compared and one be labeled as “more monochromatic” (in a similar usage as monodispersity). And a device which isolates light sources of a narrow bandwidth are called monochromators, even though the bandwidth is often explicitly specified, and thus a collection of frequencies is understood.
Read more about this topic: Monochrome
Famous quotes containing the word theory:
“The theory of rights enables us to rise and overthrow obstacles, but not to found a strong and lasting accord between all the elements which compose the nation.”
—Giuseppe Mazzini (1805–1872)
“A theory of the middle class: that it is not to be determined by its financial situation but rather by its relation to government. That is, one could shade down from an actual ruling or governing class to a class hopelessly out of relation to government, thinking of gov’t as beyond its control, of itself as wholly controlled by gov’t. Somewhere in between and in gradations is the group that has the sense that gov’t exists for it, and shapes its consciousness accordingly.”
—Lionel Trilling (1905–1975)
“There could be no fairer destiny for any physical theory than that it should point the way to a more comprehensive theory in which it lives on as a limiting case.”
—Albert Einstein (1879–1955)