Prof. Paolo Rossi (Università di Pisa - Dipartimento di Fisica “E. Fermi”)
In the years 1922-1926 Enrico Fermi, then in his early twenties, was scientifically active in Pisa, Gottingen, Leiden and Florence. Apart from his experimental thesis on X rays, most of his research activity was purely theoretical, and covered a wide spectrum of issues, from general relativity (Fermi coordinates, electromagnetic mass) to statistical mechanics (Fermi statistics), from atomic physics to collision theory (method of virtual photons) and to the newborn wave mechanics. We briefly review the main results he obtained in that period, stressing their originality and permanent relevance.