Editing Spectrum (section)

==Etymology==
In [[Latin]], ''spectrum'' means "image" or "[[apparitional experience|apparition]]", including the meaning "[[Ghost#Terminology|spectre]]". [[Spectral evidence]] is testimony about what was done by spectres of persons not present physically, or [[hearsay]] evidence about what ghosts or apparitions of [[Satan]] said. It was used to convict a number of persons of [[witchcraft]] at [[Salem, Massachusetts]] in the late 17th century. The word "spectrum" [Spektrum] was strictly used to designate a ghostly optical [[afterimage]] by [[Johann Wolfgang von Goethe|Goethe]] in his ''[[Theory of Colours (book)|Theory of Colors]]'' and [[Arthur Schopenhauer|Schopenhauer]] in ''[[On Vision and Colors]]''.

The prefix "spectro-" is used to form words relating to spectra. For example, a [[spectrometer]] is a device used to record spectra and [[spectroscopy]] is the use of a spectrometer for [[chemical analysis]].