Obituary of Hans-Jürgen Treder

Hans-Jürgen Treder died on November 18, 2006 in Potsdam, Germany, after a distinguished career as a scientists, administrator and educator. He made many important contributions to theoretical physics, relativity, gravitation, and geo- and cosmical physics.

Treder, born Februaqry 4, 1928 in Berlin, studied in Berlin Mathematics and Physics. In 1956 he became Ph. D, and then moved to the Institute of Mathematics of the German Academy of Sciences in Berlin . Becoming later Director, he was elected 1966 as Fellow of the German Academy of Sciences and started in 1968 as Chairman of the “Forschungsbereich Kosmische Physik, Research Council of Cosmical Physics” of the Academy. In that time he was also Director of the Observatory of Babelsberg, a wellknown old astronomical research Institute. From 1982 on he was Director of the “Einstein Laboratoty of theoretical Physics” of the Academy, and editor in general of the wellknown “Annalen der Physik”. During his scientific work he was well influenced by the internationally wellknown hydrodynamicst Hans Ertel and also by Robert Rompe, Max Steenbeck, Nobel Laureate Gustav Hertz, all members of the Academy. With his friend Wolfgang Yourgrau he was a founder of the wellknown journal “Foundations of Physics” and furthermore editor of “Gerlands Beiträge zur Geophysik”, “Astronomische Nachrichten” and others.He organized following the decision by the Academy the international Einstein-Conferences in 1956 and 1979 in Berlin, which gave him contact to all leading scientist in this field (e.g. Rosenfeld, Möller, Fock, Janossy, Kawaguchi, Wigner, Bergmann, and others). Treder also become member of editorial board of “Tensor”. In 2000 he became chairman of the “Society for History of Geophysics and Cosmical Physics”. In this job he was leader of some scientific meetings in his home in Potsdam.

From the beginning of his career Treder was well interested in all parts of “Einstein’s physics”. He gave fundamental contributions in theoretical physics, gravitation, relativity ,the gravitation field theory in unified quantum field, the Einstein-Bohr-experiment, global and local principles of relativity, on the meaning of the Einstein- and the Lorentz-covariant derivations, the Boltzmann equations, the Ertel Potential Vorticity theorem, on some effects connected with Einstein’s principle of equivalence, the anti-matter and the particle-problem in Einstein’s cosmology and field theory of elementary particles, the Einstein-shift in Einstein’s box experiment, gravitation and universal Fermi coupling in general relativity, on the signatures of the canonical and the metrical energy densities of vector fields, on gravitational shock waves, (partly with Wolfgang Yourgrau), on self-gravitation, on the problem of physical meaning of quantization of gravitation, the Mach-Einstein doctrine (partly with Wilfried Schröder), the generalization and application of Ertel’s Potential vorticity Theorem (with Wilfried Schröder) and many other aspects, also in cosmology, geophysical hydrodynamics, and astronomy. His broad interest and his knowledge in many scientific disciplines, such philosophy, history of science, geophysics, astronomy gave him the singular chance to work in various fields.

Needless to say that Treder has done a great part in the sources of Einstein, because many documents are in the central archive of the Academy. Treder published the well-known books “Einstein in Berlin”, he introduced the letter and elections document books for physicists of the Academy, and gave a review in history of physics in his book “Great physicists” (in German). He was also partly Co-Editor of the “Collected works of Hans Ertel”, 1993-2006. His active role in the Einstein congresse in Berlin gave him the chance for international cooperation. He was the “motor” to rebuilt and reconstruct the Einstein House in Caputh and it becomes a international house for congresse and meetings, e.g. Nobel Laureat Hannes Alfven, Carl Friedrich von Weizsäcker and much other leading scientist are guest in this house.

For his long work Treder recived many prizes and medals, partly during the Einstein years, partly by the Academy of Sciences and other scientific bodies.

Hans-Jürgen Treder had a full life in every respect. Those of us who knew him well will truly miss him.