Solvay Conference, 1927 (fifth conference) Group photograph of the attendees of the fifth Solvay Conference on Physics, taken outside the Institute of Physiology in Leopold Park, Brussels, Belgium. Back row (left to right): A. Piccard, E. Henriot, P. Ehrenfest, Ed. Herzen, Th. De Donder, E. Schrödinger, E. Verschaffelt, W. Pauli, W. Heisenberg, R. H. Fowler, L. Brillouin. Middle row (left to right): P. Debye, M. Knudsen, W. L. Bragg, H. A. Kramers, P. A. M. Dirac, A. H. Compton, L. V. de Broglie, M. Born, N. Bohr. Front row (left to right): I. Langmuir, M. Planck, M. Skłodowska-Curie, H. A. Lorentz, A. Einstein, P. Langevin, Ch. E. Guye, C. T. R. Wilson, O. W. Richardson. 1927