CLAUS KIEFER is a professor of theoretical physics at the University of Cologne, Germany. He has earned his PhD from Heidelberg University in 1988. He has held positions at the Universities of Heidelberg, Zurich, and Freiburg, and was an invited visitor to the Universities of Alberta, Bern, Cambridge, Montpellier, and others. His main interests are quantum gravity, cosmology, black holes, and the foundations of quantum theory. He has published several books including the monograph "Quantum Gravity" (second edition: Oxford 2007). He is a member of The Foundational Questions Institute since 2006.