Since ancient times geometric concepts have been used to model astronomical phenomena such as the motion of the planets. In modern times geometry has merged with analysis to provide accurate models of gravitational phenomena involving stars and their planets, black holes and gravitational waves in the context of General Relativity - with the new mathematical insights leading also to progress in the understanding of many other phenomena surrounding us. The lecture describes in a non-technical way how ancient geometric concepts such as the isoperimetric inequality as well as classical concepts from Newtonian physics reappear in the curved space-times of General Relativity.

**Gerhard Huisken** PhD in Mathematics, University of Heidelberg 1983. Postdoctoral Fellow, Australian National University, Canberra. Habilitation University of Heidelberg 1986. Visiting Professor, University of California San Diego, 1986. Faculty position, Australian National University, Canberra 1986-1992. Professor, University of Tübingen 1992-2002. Dean, Faculty of Mathematics, Tübingen, 1996-1998. Visiting Professor, Princeton University 1990-2000. Director, Max Planck Institut für Gravitational Physics, 2002-2013. Since 2013 Director of the Mathematische Forschungsinstitut Oberwolfach and Professor at the University of Tübingen. Medal of the Australian Mathematical Society 1991. Leibniz Prize 2003. Fellow of the Heidelberg Academy for Sciences and Humanities, the Berlin-Brandenburg Academy of Sciences and Humanities, the German Academy of Sciences Leopoldina, and the American Mathematical Society.

**The Hirzebruch Lecture** is an annual one hour lecture for a general academic audience featuring a prominent speaker, which aims at illustrating the relation between mathematics and other fields like society, art, etc. It has been established on the occasion of Prof. Friedrich Hirzebruch's 80th birthday in 2007 and is jointly organized by the Max Planck Institute for Mathematics, the University Club, and the Hausdorff Center for Mathematics in Bonn. It is followed by a reception.