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:

    I do not approve the extermination of the enemy; the policy of exterminating or, as it is barbarously said, liquidating enemies, is one of the most alarming developments of modern war and peace, from the point of view of those who desire the survival of culture. One needs the enemy.
    —T.S. (Thomas Stearns)

    The popularity of disaster movies ... expresses a collective perception of a world threatened by irresistible and unforeseen forces which nevertheless are thwarted at the last moment. Their thinly veiled symbolic meaning might be translated thus: We are innocent of wrongdoing. We are attacked by unforeseeable forces come to harm us. We are, thus, innocent even of negligence. Though those forces are insuperable, chance will come to our aid and we shall emerge victorious.
    David Mamet (b. 1947)

    There are two kinds of timidity—timidity of mind, and timidity of the nerves; physical timidity, and moral timidity. Each is independent of the other. The body may be frightened and quake while the mind remains calm and bold, and vice versë. This is the key to many eccentricities of conduct. When both kinds meet in the same man he will be good for nothing all his life.
    Honoré De Balzac (1799–1850)

    The sciences have ever been the surest guides to virtue.
    Frances Wright (1795–1852)