Alessandra Buonanno, Director at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute) in Potsdam, Head of the division Astrophysical and Cosmological Relativity, visited CENTRA and delivered a Colloquium at the IST Physics Department on "Probing the nature of gravity and extreme matter with gravitational-wave observations". Gravitational wave astronomy is now here, and precise understanding of dynamical events dominated by gravity is mandatory. Alessandra Buonanno told us about efforts aimed at understanding the binary black hole and binary neutron star problem. And here we are at the celebration dinner.