Perhaps the most famous conference was the October 1927 Fifth Solvay International Conference on Electrons and Photons, where the world’s most notable physicists met to discuss the newly formulated Quantum Theory. The leading figures were Albert Einstein, Erwin Schrödinger, Werner Heisenberg, Max Planck and Niels Bohr. Seventeen of the 29 attendees were or became Nobel Prize winners, including Marie Curie, who alone among them, had won Nobel Prizes in two separate scientific disciplines. Can you recognise any of them?