caption doctoral_advisor death_date death_place birth_place image_size nationality doctoral_students field work_institutions birth_date known_for residence prizes image article_title name alma_mater
at in potsdam , september 2007 the award ceremony for the charles university medal pascual jordan 20 may 2008 potsdam , brandenburg , germany hamburg , germany 138 german thomas buchert , matthias bartelmann physics university planck institute for gravitational physics of hamburg max planck institute for astrophysics max 29 december 1929 general relativity mathematical physics germany max planck medal -lrb- 2002 -rrb- juergen ehlers.jpg jürgen ehlers
 jürgen ehlers university of hamburg
jürgen ehlers

jürgen ehlers -lrb- ; december 29 , 1929 -- may 20 , 2008 -rrb- was a german physicist who contributed to the understanding of albert einstein 's theory of general relativity .
from graduate and postgraduate work in pascual jordan 's relativity research group at hamburg university , he held various posts as a lecturer and , later , as a professor before joining the max planck institute for astrophysics in munich as a director .
in 1995 , he became the founding director of the newly created max planck institute for gravitational physics in potsdam , germany .
ehlers ' research focused on the foundations of general relativity as well as on the theory 's applications to astrophysics .
he formulated a suitable classification of exact solutions to einstein 's field equations and proved the ehlers -- geren -- sachs theorem that justifies the application of simple , general-relativistic model universes to modern cosmology .
he created a spacetime-oriented description of gravitational lensing and clarified the relationship between models formulated within the framework of general relativity and those of newtonian gravity .
in addition , ehlers had a keen interest in both the history and philosophy of physics and was an ardent populariser of science .
