Thermodynamic equilibrium

Interviewed by
Owen Gingerich
Interview date
Bad Gastein, Austria

Family background; education at Tubigen Univ.; Schrodinger Theory thesis at Univ. of Munich (1927), influence of Sommerfeld, Heisenberg. Potsdam experiments inspired by K. Schwarzschild, Emden: Local thermodynamic equilibrium and curve of growth. Spent 1928 at Mt. Wilson. Return to Germany to teach physics during Depression; use of microphotometer, Coude spectrograph; analysis of Tau Scorpii. Pre-war professorship at Yerkes with Struve: line profile information, stellar composition. WWII return to Kiel, star temperature detection, solar spectrum analysis, elements/energy production. Isolation and destruction of German physics, anti-German attitude. Remarks on history of science, views on contemporaries and astrophysical (radio) research; fate of Unsold's correspondence.