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.
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Famous quotes containing the words physical sciences, modern, meaning, physical and/or sciences:
“I hope I may claim in the present work to have made it probable that the laws of arithmetic are analytic judgments and consequently a priori. Arithmetic thus becomes simply a development of logic, and every proposition of arithmetic a law of logic, albeit a derivative one. To apply arithmetic in the physical sciences is to bring logic to bear on observed facts; calculation becomes deduction.”
—Gottlob Frege (1848–1925)
“I lately met with an old volume from a London bookshop, containing the Greek Minor Poets, and it was a pleasure to read once more only the words Orpheus, Linus, Musæus,—those faint poetic sounds and echoes of a name, dying away on the ears of us modern men; and those hardly more substantial sounds, Mimnermus, Ibycus, Alcæus, Stesichorus, Menander. They lived not in vain. We can converse with these bodiless fames without reserve or personality.”
—Henry David Thoreau (1817–1862)
“To help, to continually help and share, that is the sum of all knowledge; that is the meaning of art.”
—Eleonora Duse (1859–1924)
“Perhaps it is the lowest of the qualities of an orator, but it is, on so many occasions, of chief importance,—a certain robust and radiant physical health; or—shall I say?—great volumes of animal heat.”
—Ralph Waldo Emerson (1803–1882)
“Criticism is a study by which men grow important and formidable at very small expense. The power of invention has been conferred by nature upon few, and the labour of learning those sciences which may, by mere labour, be obtained, is too great to be willingly endured; but every man can exert some judgment as he has upon the works of others; and he whom nature has made weak, and idleness keeps ignorant, may yet support his vanity by the name of critic.”
—Samuel Johnson (1709–1784)