Anders Jonas Ångström

Anders Jonas Ångström (1814 to 1874) was a Swedish physicist and one of the founders of spectroscopy, born in Medelpad and schooled in Harnosand. He studied at Uppsala University, became docent in physics there in 1839, gained practical experience at the Stockholm Observatory in 1842 and was keeper of the Uppsala Astronomical Observatory from 1843. In 1858 he took over the chair of physics at Uppsala. His Optiska undersokningar, presented to the Royal Swedish Academy of Sciences in 1853, pointed out that an electric spark gives two superposed spectra and that an incandescent gas emits light of the same refrangibility as it can absorb, a basic principle of spectrum analysis. From 1861 he studied the solar spectrum, joining the spectroscope to photography, found hydrogen in the Sun's atmosphere, published a map of the normal solar spectrum in 1868 and was the first, in 1867, to examine the spectrum of the aurora borealis. The Royal Society gave him the Rumford Medal in 1872, and the angstrom unit of length is named after him.