On 9 July 1925, in a letter to Wolfgang Pauli, Werner Heisenberg revealed his new ideas, which were to revolutionise physics Left: The first lines of the letter sent by Werner Heisenberg to Wolfgang Pauli on 9 July 1925, explaining his efforts to interpret quantum physics differently. (Copyright: Heisenberg Society) Right: Wolfgang Pauli, Werner Heisenberg and Enrico Fermi take a break by Lake Como during the 1927 International Congress of Physicists, where the new quantum mechanics was discusse...