Editing Gustav Kirchhoff (section)

=== Kirchhoff's three laws of spectroscopy ===
{{See also|History of spectroscopy}}
[[File:Kirchhof laws.svg|thumb|Visual depiction of Kirchhoff's laws of spectroscopy|alt=|left]]
#A solid, liquid, or dense gas excited to emit light will radiate at all wavelengths and thus produce a continuous spectrum.
#A low-density gas excited to emit light will do so at specific wavelengths, and this produces an [[emission spectrum]]. 
# If light composing a continuous spectrum passes through a cool, low-density gas, the result will be an absorption spectrum.

Kirchhoff did not know about the existence of [[energy level]]s in atoms. The existence of discrete spectral lines had been known since [[Fraunhofer lines|Fraunhofer]] discovered them in 1814. That the lines formed a discrete mathematical pattern was described by [[Johann Balmer]] in 1885. [[Joseph Larmor]] explained the splitting of the [[spectral line]]s in a [[magnetic field]] known as the [[Zeeman Effect]] by the [[oscillation]] of electrons.<ref>Buchwald, Jed Z.; and Warwick, Andrew; editors; ''Histories of the Electron: The Birth of Microphysics''</ref><ref>{{Citation |last=Larmor |first=Joseph |year=1897 |title=On a Dynamical Theory of the Electric and Luminiferous Medium, Part 3, Relations with material media |journal=Philosophical Transactions of the Royal Society |volume=190 |pages=205–300 |doi=10.1098/rsta.1897.0020|bibcode = 1897RSPTA.190..205L |title-link=s:Dynamical Theory of the Electric and Luminiferous Medium III |doi-access=free }}</ref> These discrete spectral lines were not explained as electron transitions until the [[Bohr model]] of the atom in 1913, which helped lead to [[quantum mechanics]].{{clear}}