A Tribute to Manne Siegbahn

Spectroscopy came to dominate the 19th century, with a crucial role for Swedish physicists. It was Anders Ångström who introduced the tenmillionth part of a millimeter as the wavelength unit (1868), a unit that was adopted by Rowland for his tables of the solar spectral lines (1887-1893). Janne Rydberg, then, followed in Ångström's footsteps in searching for relations between the emission spectra of the elements and their place in the Periodic Table. Röntgen's new rays became a next challenge, demanding a form of spectroscopy of their own. Manne Siegbahn, an assistant of Rydberg, then, devised appropriate instruments of ever increasing precision