Editing Phosphorescence (section)

==Etymology==
The term ''phosphorescence'' comes from the [[Ancient Greek]] word ''φῶς'' (''phos''), meaning "light", and the Greek suffix ''-φόρος'' (''-phoros''), meaning "to bear", combined with the [[Latin]] suffix ''-escentem'', meaning "becoming of", "having a tendency towards", or "with the essence of".<ref>{{OEtymD|-escent}}</ref> Thus, phosphorescence literally means "having a tendency to bear light". It was first recorded in 1766.<ref>{{OEtymD|phosphorescent}}</ref>

The term ''phosphor'' had been used since the [[Middle Ages]] to describe minerals that glowed in the dark. One of the most famous, but not the first, was Bolognian phosphor. Around 1604, Vincenzo Casciarolo discovered a "[[De Phenomenis in Orbe Lunae|lapis solaris]]" near Bologna, Italy. Once [[Calcination|heated in an oxygen-rich furnace]], it thereafter absorbed sunlight and glowed in the dark. In 1677, [[Hennig Brand]] isolated a new [[Chemical element|element]] that glowed due to a chemiluminescent reaction when exposed to air, and named it "[[phosphorus]]".<ref>''New Trends in Fluorescence Spectroscopy'' by B Valeur -- Springer Page 1--6</ref>

In contrast, the term ''luminescence'' (from the Latin ''lumen'' for "light"), was coined by Eilhardt Wiedemann in 1888 as a term to refer to "light without heat", while "fluorescence" by [[Sir George Stokes, 1st Baronet|Sir George Stokes]] in 1852, when he noticed that, when exposing a solution of [[Quinine Sulfate|quinine sulfate]] to light refracted through a [[Prism (optics)|prism]], the solution glowed when exposed to the mysterious invisible-light (now known to be UV light) beyond the violet end of the spectrum. Stokes formed the term from a combination of [[fluorspar]] and [[opalescence]] (preferring to use a mineral instead of a solution), albeit it was later discovered that fluorspar glows due to phosphorescence.<ref>''New Trends in Fluorescence Spectroscopy'' by B Valeur -- Springer Page 1--6</ref>

There was much confusion between the meanings of these terms throughout the late nineteenth to mid-twentieth centuries. Whereas the term "fluorescence" tended to refer to luminescence that ceased immediately (by human-eye standards) when removed from excitation, "phosphorescence" referred to virtually any substance that glowed for appreciable periods in darkness, sometimes to include even chemiluminescence (which occasionally produced substantial amounts of heat). Only after the 1950s and 1960s did advances in [[quantum electronics]], [[spectroscopy]], and [[laser]]s provide a measure to distinguish between the various processes that emit the light, although in common speech the distinctions are still often rather vague.<ref>''New Trends in Fluorescence Spectroscopy'' by B Valeur -- Springer Page 1--6</ref>