A group of scientists participated in the 7th Solvay Conference, Bruxelles (October 1933). Seated (left to right): Erwin Schrödinger, Irène Joliot, Niels Henrik David Bohr, Abram Ioffe, Marie Curie, Paul Langevin, Owen Willans Richardson, Lord Ernest Rutherford, Théophile de Donder, Maurice de Broglie, Louis de Broglie, Lise Meitner, James Chadwick. Standing (left to right): Émile Henriot, Francis Perrin, Frédéric Joliot, Werner Heisenberg, Hendrik Anthony Kramers, E. Stahel, Enrico Fermi, Ernest Thomas Sinton Walton, Paul Dirac, Peter Joseph William Debye, Nevill Francis Mott, Blas Cabrera, George Gamow, Walther Bothe, Patrick Blackett, M.S. Rosenblum, Jacques Errera, Ed. Bauer, Wolfgang Pauli, Jules-Émile Verschaffelt, M. Cosyns, E. Herzen, John Douglas Cockcroft, Charles Drummond Ellis, Rudolf Peierls, Auguste Piccard, Ernest O. Lawrence, Léon Rosenfeld. Absents: Albert Einstein and Charles Eugène Guye