Johann Jakob Balmer

Johann Jakob Balmer (1 May 1825 – 12 March 1898) was a Swiss mathematician best known for his work in physics, the Balmer series of the hydrogen atom.

Early life and education

Balmer was born on 1 May 1825 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 he decided to focus on that field when he attended university.

He studied at the University of Karlsruhe and the University of Berlin, then completed his PhD from the University of Basel in 1849 with a dissertation on the cycloid.

Career

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 1850 he married Christine Pauline Rinck. The couple had 3 children.

Despite being a mathematician, Balmer is best remembered for his work on spectral series. His major contribution (made at the age of sixty, in 1885) was an empirical formula for the visible spectral lines of the hydrogen atom, the study of which he took up at the suggestion of Eduard Hagenbach also of Basel. Using Ångström's measurements of the hydrogen lines, he arrived at a formula for computing the wavelength as follows:

{\displaystyle \lambda \ =h\,{\frac {n^{2}}{n^{2}-m^{2}}}}

for m = 2 and n = 3, 4, 5, 6, and so forth; h = 3.6456 · 10−7 m = 364.56 nm.

In his 1885 notice, he referred to h as the "fundamental number of hydrogen." Today, h is known as the Balmer constant. Balmer used his formula to predict the wavelength for n = 7: