The collective IQ of this lot must be way over 6,000. It’s the group photo of the Fifth Solvay International Conference in 1927. There was only one girl in the class, and she was French. She’s Marie Curie, third from left on the front row.

The International Solvay Institutes for Physics and Chemistry, located in Brussels, were founded by the Belgian industrialist Ernest Solvay in 1912.

The Solvay Conferences have been devoted to outstanding preeminent open problems in both physics and chemistry. The usual schedule is every three years, but there have been larger gaps.

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.