One of the most famous photographs from the history of physics, showing the participants of the 1927 Solvay Conference in Brussels, Belgium, discussing "Electrons and Photons."

Front row, from the left: Langmuir, Planck, Curie, Lorentz, Einstein, Langevin, Guye, Wilson, Richardson. Second row: Debye, Knudsen, Bragg, Kramers, Dirac, Compton, de Broglie, Born, Bohr. Standing: Piccard, Henriot, Ehrenfest, Herzen, De Donder, Schroedinger, Verschaffelt, Pauli, Heisenberg, Fowler, Brillouin.