**Dr. Raul Jimenez** describes one of the most fascinating enigmas in science: gamma ray bursts (GRBs), the most powerful explosions in the universe. He explains the relationship between GRBs and life: areas of the universe where planets might be relatively safe --or not-- from the destructive force of GRB radiation. Earth, we learn, has been relatively fortunate, but at least one of the ancient mass extinctions on our planet may have been due to the radiation from a GRB.
Raúl Jiménez is a theoretical astrophysicist working in cosmology and an ICREA Research Professor in physical cosmology at the University of Barcelona. His main line of research has been to use astronomical observations to understand the laws of nature. Most of his research concerns the early universe and the evolution of galaxies.