This post is entirely the work of Patrick Weidhaas, a mathematician and friend.
Patrick Weidhaas: “I recently wrote a math article on the very successful definition of the real numbers by the German mathematician Richard Dedekind (1831-1916). He came up with the “Dedekind cuts.” I learned about this in college and never fully understood it — and wasn’t that interested in it. Only lately did I fully appreciate the significance of his attempt to define the real numbers purely through arithmetic — without any help from geometry.”
Patrick Weidhaas: “This is a photo I took in Berlin on September 11, 2010. It is one of my favorite shots. I still remember the late sunny afternoon as I encountered this blue bridge and the small lake (“Königssee”) below.”