Prof. Dr. Jürgen Ehlers has died
The Albert Einstein Institute mourns the loss of its founding director.
Jürgen Ehlers primarily dealt with questions of general relativity and cosmology. In his doctoral thesis, he already provided, among other things, one of the first contributions to what later became the theory of black holes. He defined the “point of no return,” the distance from the centre that is now called the “event horizon,” where gravity becomes so strong that even light cannot escape and as a result no information is available about what is happening inside the black hole. In his post-doctoral thesis and later work, Ehlers devoted himself to the description of matter within the framework of the general theory of relativity and the application of models developed in this way to cosmology.
Jürgen Ehlers also worked on the theory of gravitational waves. These "ripples of space-time" should be created through the accelerated movements of massive structures, such as the collision of black holes. “The sudden death of Jürgen Ehlers has shaken us to the core!", said Prof. Hermann Nicolai, Managing Director of the Max Planck Institute for Gravitational Physics. “Up to his very last day, he was an enthusiastic researcher and brilliant scientist. Despite his outstanding scientific achievements, Jürgen Ehlers was always a modest person who lent us support like a fatherly friend.”
Jürgen Ehlers (29.12.1929 - 20.5.2008)
Jürgen Ehlers, born in Hamburg on 29.12.1929, studied physics, mathematics and philosophy there from 1949 to 1955. He obtained his doctorate in 1958 under the guidance of Pascual Jordan and earned his qualifications for a full university professorship in 1961 there with him. After spending time teaching and researching in Kiel, Syracuse (NY) and Hamburg, he took positions in the USA, from 1964 to 1965 at the Graduate Research Center of the Southwest in Dallas and from 1965 to 1971 in Austin, both in Texas. From 1967 on he was a professor of physics in Austin. He maintained contact with German colleagues as a visiting professor in Würzburg and Bonn. In 1971 Jürgen Ehlers accepted a call to the Max Planck Institute for Physics and Astrophysics in Munich, where he headed the "Gravitation Theory" Group until 1995. With the founding of the Max Planck Institute for Gravitational Physics (Albert Einstein Institute) in Potsdam-Golm in 1995, of which he was the first Director, he was a leader in establishing an independent research Institute in the area of gravitational physics in Germany. Jürgen Ehlers retired in 1998, but continued to pursue his scientific activities until the day of his death.
Jürgen Ehlers has been honoured for his scientific achievements many times, including with the Max Planck Medal of the German Physical Society and the Volta Medal in Gold from the Italian University of Pavia. He was a founding member of the Berlin-Brandenburg Academy of Sciences and a member of the Academy of Sciences and Literature, Mainz, the Deutsche Akademie der Naturforscher Leopoldina, Halle and the Bavarian Academy of Sciences and Humanities, Munich. Ehlers was honorary fellow of the Inter-University Centre for Astronomy and Astrophysics (IUCAA). Von 1995 – 1997 he was President of the International Society of General Relativity and Gravitation.