Anders Jonas Ångström made significant contributions to several areas of physics, but is most known as one of the founders of optical spectroscopy. He introduced a unit for electromagnetic wavelength, equivalent to 0.1 nanometres, which later on was adopted as an international standard under the name ångström.
Spectral analysis is a method for studying the composition of different materials based on their electromagnetic spectra. Anders Ångström’s first work in the field was his paper “Optical Investigations” which was published in 1853, but there are differences of opinion on to what degree he predated physicist Gustav Kirchhoff’s and chemist Robert Bunsen’s work from 1859 to 1861 which laid the foundation for modern spectral analysis. Ångström suggested that his study essentially included an equivalent to Kirchhoff’s law of thermal radiation. In addition, he meant that his results explained the so-called Fraunhofer lines – dark absorption lines in the spectrum of sunlight named after Joseph von Fraunhofer who discovered them.
During the 1860s, Ångström resumed his research on spectral analysis. His study on solar spectra, Recherches sur le spectre solaire (1868), contained exact measurements of the wavelengths of the Fraunhofer lines. The study gained great international attention.
Anders Ångström was appointed professor of physics in 1858. The following year the physicists at Uppsala University moved to the new building Chemicum, which gave them much more suitable facilities than before. This enabled Ångström to introduce lab exercises as part of the physics teaching. But Ångström was a scientist rather than a teacher. As a person he was reserved and to students he could seem inaccessible.
Ångström was elected a member of several academies and learned societies, including the Royal Society in London, which awarded him the Rumford medal shown here. (The medal is part of the permanent exhibition at Uppsala University Coin Cabinet.)
Anders Ångström died in June 1874 from meningitis, shortly before his sixtieth birthday. At the Ångström Laboratory, building 1, floor 1, there is today an exhibition about him and his son, Knut Ångström.