Italy in Cosmic Rays and X-ray astronomy) and a number of Italian physicists were forced to leave Italy in the 1930s by Fascist laws against Jews. Other prominent physicists include: Amedeo Avogadro (most noted for his contributions to molecular theory, in particular the Avogadro's law and the Avogadro constant), Evangelista Torricelli (inventor of barometer), Alessandro Volta (inventor of electric battery), Guglielmo Marconi (inventor of radio), Galileo Ferraris and Antonio Pacinotti, pioneers of the induction motor, Alessandro Cruto, pioneer of light bulb and Innocenzo Manzetti, eclectic pioneer of auto and robotics, Ettore Majorana (who discovered the Majorana fermions), Carlo Rubbia (1984 Nobel
Volta potential Volta potential The Volta potential (also called Volta potential difference, contact potential difference, outer potential difference, Δψ, or "delta psi") in electrochemistry, is the electrostatic potential difference between two metals (or one metal and one electrolyte) that are in contact and are in thermodynamic equilibrium. Specifically, it is the potential difference between a point close to the surface of the first metal, and a point close to the surface of the second metal (or electrolyte). The Volta potential is named after Alessandro Volta. When two metals are electrically isolated from each other, an arbitrary potential difference may exist between them.