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 modern, meaning, physical and/or sciences:
“I am not afraid of the priests in the long-run. Scientific method is the white ant which will slowly but surely destroy their fortifications. And the importance of scientific method in modern practical life—always growing and increasing—is the guarantee for the gradual emancipation of the ignorant upper and lower classes, the former of whom especially are the strength of the priests.”
—Thomas Henry Huxley (1825–95)
“The sick are parasites on society. In a certain state it is indecent to go on living. To continue vegetating in cowardly dependence on physicians and machinations once the meaning of life, the right to life, has been lost ought to occasion a deep contempt within society.”
—Friedrich Nietzsche (1844–1900)
“The peace loving nations must make a concerted effort in opposition to those violations of treaties and those ignorings of humane instincts which today are creating a state of international anarchy and instability from which there is no escape through mere isolation or neutrality.... When an epidemic of physical disease starts to spread, the community approves and joins in a quarantine of the patients in order to protect the health of the community against the spread of the disease.”
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“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)