Johann Rafelski is a theoretical physicist working at The University of Arizona in Tucson, USA. Born in Kraków, Poland in 1950, he received his Ph.D. with Walter Greiner at Johann Wolfgang Goethe University, Frankfurt, Germany in 1973. In 1977 Rafelski arrived at CERN-Geneva, where with Rolf Hagedorn he developed the search for quark-gluon plasma in relativistic heavy ion collision as a novel research domain. He invented and developed the strangeness quark flavor as the signature of quark-gluon plasma, advancing the discovery of this new phase of primordial matter. Professor Rafelski teaches Relativity, Quantum, Particle and Nuclear Physics; in addition to CERN and Arizona, he also has held professional appointments at the University of Pennsylvania in Philadelphia, Argonne National Laboratory in Chicago, the University of Frankfurt, the University of Cape Town, the University of Paris-Jussieu, and the Ecole Polytechnique. He has been a DFG Excellence Initiative Professor atLudwig-Maximillian University Munich. In collaboration with researchers from the Ecole Polytechnique in Paris and ELI-Beamlines in Prague he is using ultra-intense lasers in nuclear and fundamental physics. Prof. Rafelski is the editor of the open-access book: Melting Hadrons, Boiling Quarks – From Hagedorn Temperature to Ultra-Relativistic Heavy-Ion Collisions at CERN - With a Tribute to Rolf Hagedorn (Springer, 2016) and he has authored the book: Relativity Matters – From Einstein's EMC2 to Laser Particle Acceleration and Quark-Gluon Plasma (Springer, 2017).