Johannes Robert Rydberg

Born Nov. 8, 1854, in Halmstad; died Dec. 28, 1919, in Lund. Swedish physicist.

After graduating from the University of Lund in 1879, Rydberg became a docent at the university; he became a professor in 1901. His main work was devoted to D. I. Mendeleev’s periodic system of the elements and to atomic spectra. Rydberg showed that the position of the lines in atomic emission spectra may be described by equations analogous to the Balmer equation for the spectrum of hydrogen. The constant introduced into these equations is called the Rydberg constant.