On April 21, 1921, two of the most influential theoretical physicists of the 20th century, Albert Einstein and Hendrik Lorentz, gathered in Leiden, the Netherlands, for a historic meeting. This marked the first of two meetings that took place in Leiden, with the second taking place just a year later in 1922.

During their time in Leiden, these two giants of physics discussed their various theories and research, with a particular focus on Einstein’s Theory of Relativity and Lorentz’s work on the Electromagnetic Field Theory. It was these conversations that ultimately led Einstein to make some of his most important breakthroughs in physics.

The impact of this meeting between Einstein and Lorentz can still be felt today, with their theories and research still having a profound effect on the world of physics. It is a testament to their brilliance that their theories, which were formulated during a single meeting in Leiden, continue to shape the way we think about the universe.