Commemorative stamp series - Germany / German Democratic Republic 1974 - 5 Pfennig

Important Personalities, Edition 1974 The Ministry of Posts and Telecommunications of the German Democratic Republic publishes five special postage stamps with illustrations of important personalities. No special First Day Cover Covering Important Figures 5 Pfennig Value: Gustav Robert Kirchhoff Gustav Robert Kirchhoff is one of the physicists of the 19th century who had a decisive influence on physics. Gustav Robert Kirchhoff was born on March 12, 1824 in Königsberg (now Koliningrad). He studied there at the University of Mathematics and Physics. Part of his study time he spent in Berlin, where he habilitated in 1847 for the subject of physics. In 1850 he was - as a 26-year-old professor of physics at the University of Wroclaw (now Wroclaw) and appointed in 1854 as a full professor at the University of Heidelberg. Here he succeeded in 1860 - together with the chemist Robert Bunsen, with whom he had a close friendship - the discovery of spectral analysis, which has a high importance. Kirchhoff posited the famous theorem of the proportionality of emission and absorption capacity for any temperature radiation, regardless of the other physical nature of the body. The discovery of spectral analysis has a double meaning. She has opened up the chemistry of the universe. Their application to the sun and the stars has allowed a new demonstration of the inner unity of the universe, independent of Newton's laws of gravity. On the other hand, Kirchhoff's theorem on emission and absorption capacity forms the basis for the entire theory of heat radiation, which culminates in Planck's law of radiation. Kirchhoff owes physics to other important research results and discoveries. Kirchhoff was elected as a corresponding member in 1861, and in 1875 as a full member of the Berlin Academy, today the Academy of Sciences of the GDR. He was one of their best known representatives in the field of science. In his later years he worked at the University of Berlin and as a member of the Academy in Berlin. He died on October 17, 1887 in Berlin.