Spectrum - Modern Meaning in The Physical Sciences

Modern Meaning in The Physical Sciences

In the 17th century the word spectrum was introduced into optics, referring to the range of colors observed when white light was dispersed through a prism. Soon the term referred to a plot of light intensity or power as a function of frequency or wavelength, also known as a spectral density.

The term spectrum was expanded to apply to other waves, such as sound waves that could also be measured as a function of frequency. The term now applies to any signal that can be measured or decomposed along a continuous variable such as energy in electron spectroscopy or mass to charge ratio in mass spectrometry. Spectrum is also used to refer to a graphical representation of the as a function of the dependent variable.

Read more about this topic:  Spectrum

Famous quotes containing the words modern, meaning, physical and/or sciences:

    Sir Walter Raleigh might well be studied, if only for the excellence of his style, for he is remarkable in the midst of so many masters. There is a natural emphasis in his style, like a man’s tread, and a breathing space between the sentences, which the best of modern writing does not furnish. His chapters are like English parks, or say rather like a Western forest, where the larger growth keeps down the underwood, and one may ride on horseback through the openings.
    Henry David Thoreau (1817–1862)

    All my life I believed I knew something. But then one strange day came when I realized that I knew nothing, yes, I knew nothing. And so words became void of meaning ... I have arrived too late at ultimate uncertainty.
    Ezra Pound (1885–1972)

    ... people with heavy physical vibrations rule the world.
    Margaret Anderson (1886–1973)

    The well-educated young woman of 1950 will blend art and sciences in a way we do not dream of; the science will steady the art and the art will give charm to the science. This young woman will marry—yes, indeed, but she will take her pick of men, who will by that time have begun to realize what sort of men it behooves them to be.
    Ellen Henrietta Swallow Richards (1842–1911)