- Johann Jakob Balmer
name = Johann Jakob Balmer
caption = Johann Jakob Balmer
May 1 1825
March 12 1898
University of Basel
Johann Jakob Balmer (
May 1 1825– March 12 1898) was a Swiss mathematicianand an honorary physicist.
Life and work
He was born in
Lausen, Switzerland, the son of a Chief Justice also named Johann Jakob Balmer. His mother was Elizabeth Rolle Balmer, and he was the oldest son. During his schooling he excelled in mathematics, and so decided to focus on that field when he attended university.
He studied at the
University of Karlsruheand the University of Berlin, then completed his Ph.D.from the University of Baselin 1849 with a dissertationon the cycloid. Johann then spent his entire life in Basel, where he taught at a school for girls. He also lectured at the University of Basel. In 1868 he married Christine Pauline Rinck at the age of 43. The couple had a total of six children.
Despite being a mathematician, he is not remembered for any work in that field; rather, his major contribution (made at the age of sixty, in 1885) was an
empiricalformula for the visible spectral lines of the hydrogenatom the study of which he took up at the suggestion of Eduard Hagenbach also of Basel [cite book|last=Magie|first=William Francis|title=A Source Book in Physics|publisher=Harvard University Press|location=Cambridge, Mass|year=1969 p 360] . Using Ångström's measurements of the hydrogen lines, he arrived at a formula for computing the wavelength as follows:
for "n" = 2, "h" = 3.6456×10−7 m, and "m" = 3, 4, 5, 6, and so forth. In his 1885 notice he referred to "h" as the "fundamental number of hydrogen." Balmer then used this formula to predict the wavelength for "m" = 7 and Hagenbach informed him that Ångström had observed a line with wavelength 4968.1 Å. Two of his colleagues, H. W. Vogel and Huggins, were able to confirm the existence of other lines of the series for the spectrum of hydrogen of white stars.
Balmer's formula was later found to be a special case of the
Rydberg formula, devised by Johannes Rydberg.
with being the Rydberg constant for hydrogen, for Balmer's formula, and .
A full explanation of why these formulas worked, however, had to wait until the presentation of the
Bohr model of the atomby Niels Bohrin 1913.
Johann Balmer died in Basel.
Balmer lines and Balmer seriesare named after him.
*Balmer crater on the
Moonis named after him.
Wikimedia Foundation. 2010.