1927 Solvay Congress
"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 and Niels Bohr. Einstein, disenchanted with Heisenberg's "Uncertainty Principle," remarked "God does not play dice." Bohr replied, "Einstein, stop telling God what to do." Seventeen of the twenty-nine attendees were or became Nobel Prize winners, including Marie Curie, who alone among them, had won Nobel Prizes in two separate scientific disciplines."
Thanks to Tamoor for the picture!]