Wow, this is really cool! An original 1924 manuscript of Einstein’s 1925 paper on “Quantum theory of the monatomic ideal gas” has just been found at the University of Leiden (which just happens to be where Matt is right now for his astrophysics conference… wonder if he’ll get to see it?). The full manuscript is available as high-res images here.
I love looking at the handwriting and the editor’s marks and the process of this scientific work in general. What an amazing find.