Hans Jacob Reissner

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Josefine and Hans Jacob Reissner.

Hans Jacob Reissner (born January 18, 1874 in Berlin , † October 2, 1967 in Colton (Oregon) , USA ) was a German engineer , mathematician and physicist .

Life

Studies and beginnings

After completing his school education in Berlin, Reissner obtained the title of civil engineer in 1897, after having successfully graduated from the Technical University in Charlottenburg (now the Technical University of Berlin ). He then went to the USA for a year to work as a technical draftsman. On his return he first studied physics with Max Planck at the Berlin University . In 1900 he went back to the Technical University in order to complete his habilitation in engineering with Heinrich Müller-Breslau in 1902 with a thesis on vibrations in half-timbered structures. He became an employee of the university, worked a. a. but also for Ferdinand Graf von Zeppelin and carried out calculations for the structures of the airships .

Time at RWTH Aachen University (1906–1912)

In 1904 he received a scholarship to study the use of steel in construction in the USA, from where he returned to Germany in 1906 to accept a professorship for mechanics at the Technical University in Aachen . He turned to the then new discipline of aviation and initiated basic research on stability and controllability as well as propulsion issues and set up the Aerodynamic Institute . He summarized his work in the seminal essay Scientific questions from aviation technology . During this time he made contacts with Arnold Sommerfeld . On June 6, 1906, he married Josefine Reichenberger. The couple had four children, Max Erich ( Eric Reissner ), Edgar Wilhelm, Dorothea Gertrud (Thea) and Eva Sabine.

His first airplane, a large tubular steel double-decker, carried out several flights of over 100 m in length at a height of four to six meters on the Branderheide near Aachen in April 1909 . From autumn he built a duck-shaped monoplane, i. H. with the wing at the rear and in front, on a boom, seated tail unit, the Reissner duck , which flew in 1912. The pilot was the Swiss Robert Gsell . As a special feature, Reissner used the corrugated light metal sheet supplied by his colleague Hugo Junkers as a supporting surface instead of the usual fabric covering . The aircraft can thus be regarded as the first all-metal aircraft.

Reissner's efforts in Aachen for the development of aviation and aircraft models, the scientific and technical research in the field of aircraft construction at the Technical University, the public interest and the necessary coordination of a planned long-haul flight to Berlin led to the founding of the Aachen Association on March 12, 1911 Airship travel. Four scientific associations, the Aachen district association in the Association of German Engineers , the Society for Geography and Weathering , the Natural Science Association in Aachen and the Electrotechnical Association as well as 76 private individuals, including Reissner and Professors Hugo Junkers, August Hertwig , Georg Frentzen , Wallichs , Peter Polis , Felix Rötscher , the aviation pioneer Erich Lochner , the incumbent Lord Mayor Philipp Veltman , representatives of the authorities, city councilors, officers and even eight wives, including ladies Lochner, Polis, Rötscher, Reissner and Delius, were among the signatories of the founding deed. More than 170 members joined the association and Reissner was elected to the first association board.

In Aachen Reissner also dealt with the theory of earth pressure .

Time at the Technical University of Berlin (1913–1935)

In 1913 Reissner accepted a call to his old technical university in Berlin, where he received a professorship for mathematics. The design of his country house in Berlin-Charlottenburg came from the architect Fritz Crzellitzer . During the First World War, Reissner carried out structural calculations for the giant Zeppelin-Staaken aircraft and began developing controllable pitch propellers. For his work he received the Iron Cross 2nd class for non-soldiers. At the same time he dealt with the theory of relativity . In 1916 he wrote the essay on the self-gravity of the electric field according to Einstein's theory , where he gave a solution to Einstein's field equations that corresponds to an electrically charged black hole . A similar work was presented by Gunnar Nordström in 1918 . This so-called Reissner-Nordström metric could be derived from the Maxwell equation and was used as the basis for quantum geometry . Because of his work, Reissner was also in contact with Erwin Schrödinger .

In 1929 he met Moritz Straus , the owner of both Argus-Werke and von Horch . When Reissner was forced into retirement under the Nazi regime in 1935 due to his Jewish origins, he signed a consultancy agreement with Argus Motoren Gesellschaft and constructed adjustable propellers , which he had been working on since the early 1930s.

Emigration to the United States of America

When Straus was forced to give up the Argus works in the course of " Aryanization " in 1938 , Reissner emigrated to the USA. There he built a second career and taught from 1938 to 1944 at the Illinois Institute of Technology . He then moved to the Polytechnic Institute of Brooklyn , where he worked until his retirement in 1954.

His son Eric Reissner was a mechanics professor at MIT .

literature

Web links

Individual evidence

  1. Recorded in his article in the Encyclopedia of Mathematical Sciences of 1908 and in a conference contribution to the earth pressure problem , Proc. 1st Int. Conf. Applied Mechanics, 1924, Delft