Enrico Fermi Enrico Fermi, an Italian, was one of the first experts on the nucleus of the atom. He was educated at the University of Pisa and other leading centers for physics in Europe. In 1926 he became a professor at the University of Rome. In 1934 he came up with a theory about beta-decay. That's when a nucleus breaks down. It has to do with radioactivity. In 1938 he came to the United States, where he worked with the team of scientists which developed the first atomic bomb. He was one of the leaders on atomic structure research and won the Nobel Prize for Physics for his work on radioactivity.