1927 Solvay Conference
Witness one of the most iconic moments in 20th-century physics, where Einstein clashed with Niels Bohr on the foundation of quantum theory.
The Fifth Solvay Conference was the first major meeting where the foundations of quantum mechanics were publicly debated. The conference took place at the Solvay Institute in Brussels from October 24 to 29, 1927. Among the attendees were the most prominent physicists of the time—Einstein, Niels Bohr, Werner Heisenberg, Max Born, Paul Dirac, Erwin Schrödinger, and Marie Curie, among others.
The event is particularly notable for the intense debate between Einstein and Bohr. While Bohr supported the Copenhagen interpretation of quantum mechanics—which emphasized the role of the observer in determining quantum outcomes—Einstein was deeply skeptical. He famously expressed his dissatisfaction with the theory’s probabilistic nature by stating, “God does not play dice with the universe.”
During the conference, Einstein presented a number of thought experiments challenging the uncertainty principle. These thought experiments were met with counter-arguments from Bohr, and the discussion marked the beginning of one of the most famous scientific dialogues of the 20th century.
In the photo below, Einstein is seen sitting in the back row, surrounded by some of the greatest minds of his time.
Despite Einstein’s criticisms, the conference helped promote quantum theory to the broader scientific community. While Einstein later collaborated with Boris Podolsky and Nathan Rosen to propose the EPR paradox in 1935, the 1927 Solvay Conference marked a pivotal moment in the development of quantum mechanics.