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
Alessandro Volta with brine-soaked paper, and detected the flow of electricity by other means familiar to him from his previous studies. In this way he discovered the electrochemical series, and the law that the electromotive force (emf) of a galvanic cell, consisting of a pair of metal electrodes separated by electrolyte, is the difference between their two electrode potentials (thus, two identical electrodes and a common electrolyte give zero net emf). This may be called Volta's Law of the electrochemical series. In 1800, as the result of a professional disagreement over the galvanic response advocated by Galvani, Volta invented the voltaic pile,