Cover Picture: Fortschritte der Physik 7 / 2018

Signal from space: Two black holes with 31 and 25 solar masses inspiral and merge, thereby emitting gravitational waves. The colors characterize the strength of the field. By comparing the measured waveform with predictions from General Relativity, scientists concluded that the merger happened at a distance of about 1.8 billion light‐years. (Image on the title page by courtesy of Max Planck Institute for Gravitational Physics, Potsdam, Germany; © Numerical‐relativistic simulation: S. Ossokine, A. Buonanno (Max Planck Institute for Gravitational Physics), Simulating eXtreme Spacetimes Project; Scientific Visualization: T. Dietrich (Max Planck Institute for Gravitational Physics), R. Haas (NCSA))