Spectrum

A spectrum (plural spectra or spectrums) is a condition that is not limited to a specific set of values but can vary infinitely within a continuum. The word saw its first scientific use within the field of optics to describe the rainbow of colors in visible light when separated using a prism; it has since been applied by analogy to many fields other than optics. Thus, one might talk about the spectrum of political opinion, or the spectrum of activity of a drug, or the autism spectrum. In these uses, values within a spectrum may not be associated with precisely quantifiable numbers or definitions. Such uses imply a broad range of conditions or behaviors grouped together and studied under a single title for ease of discussion.

In most modern usages of spectrum there is a unifying theme between extremes at either end. Some older usages of the word did not have a unifying theme, but they led to modern ones through a sequence of events set out below. Modern usages in mathematics did evolve from a unifying theme, but this may be difficult to recognize.

Read more about Spectrum:  Origins, Modern Meaning in The Physical Sciences

Other articles related to "spectrum":

Spectrum - 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 ... The term spectrum was expanded to apply to other waves, such as sound waves that could also be measured as a function of frequency ... Spectrum is also used to refer to a graphical representation of the as a function of the dependent variable ...
World Of Spectrum
... World of Spectrum is a website devoted to cataloging and archiving material for the ZX Spectrum home computer popular in the 1980s, and has been officially endorsed by Amstrad which holds the rights to ... der Heide in 1995 as a website dedicated to hosting Spectrum games, but grew into hosting anything and everything that was remotely connected to the ZX Spectrum ... In December 2005 Retro Gamer wrote "World of Spectrum is not just the best Speccy site on the Web, but arguably the best retro resource full stop." From the FAQ "'The WoS is ...
Flicker Noise - Measurement
... The measurement of 1/f noise spectrum in voltage or current is done in the same way as the measurement of other types of noises ... Sampling spectrum analyzers take a finite-time sample from the noise and calculate the Fourier transform by FFT algorithm ... Then, after calculating the squared absolute value of the Fourier spectrum, they calculate its average value by repeating this sampling process by a ...
Spectrohelioscope
... The name comes from three Latin-based words Spectro, referring to the optical spectrum, Helio, referring to the Sun and Scope, as in telescope ... through a prism or diffraction grating to spread the light into a spectrum ... The spectrum is then focused on another slit that allows only a narrow part of the spectrum (the desired wavelength of light for viewing) to pass ...
Spectrum (band)
... Spectrum is an Australian progressive rock band that formed in Melbourne in 1969 and, in its original period, remained in existence until 1973 ... They reformed, initially as Spectrum Plays The Blues, in 1999 ...