Walter Friedrich (25.12.1883-16.10.1968) was a German physicist and biophysicist, a member of the Academy of Sciences of the GDR (1949) and its president in 1951-56. He was born in Salbke. He studied at the universities of Geneva and Munich (1905-11). In 1912-14 he worked at the University of Munich, in 1914 —22 at the University of Freiburg. From 1923 he was a professor at the University of Berlin (rector in 1949-52). In 1923-45 he was also director of the Institute for Radiation Research at the University of Berlin, in 1948 — 61 of the Institute of Medicine and Biology, and from 1961 president of the Medical and Biological Scientific Centre of the Academy of Sciences of the GDR.
His work concerned X-ray spectroscopy and the use of X-rays in biology and medicine. In 1912, with M. Laue and P. Knipping, he discovered the diffraction of X-rays by crystals. He laid the foundations of X-ray therapy.
He was president of the German Peace Council and a vice-president of the World Peace Council.