Hans-Jürgen Treder (born September 4, 1928 in Berlin, † November 18, 2006 in Potsdam) was one of the leading theoretical physicists and astrophysicists in the German Democratic Republic (GDR), and an internationally recognized authority in the field of gravitational physics (general relativity) and cosmology. Visiting Scholar Dieter Hoffmann has published, on the 90th anniversary of Treder's birth, an article in Das Blättchen on his prevailing image as a genius, aloof, and quirky professor, who as the "Einstein of the GDR" was hot on the trail towards an understanding of the mysteries of the cosmos.