Einstein's Blackboard

In a recent visit to Oxford, we went to the small but FOC history of science museum open there. We saw all the usual archaic instruments used for research throughout the years from telescopes and planetariums for astronomy to Leyden jars and electroscopes for physics. But the most famous exhibit available was a black board hung on the wall. On it was a differential equation describing the expansion and density of the universe over time. What made the black board so special though is that the text on it was hand written by Albert Einstein himself in 1931. Someone decided to keep and preserve the board all this time. I find it pretty awesome to say that I have seen the original work of one of my idols in real life.