As a physicist working on questions in biology, research projects come in many different shapes and forms.  But they all are vast clouds of ideas. Bringing these ideas into the linear form of a text is where I rely on my digital recorder. In this way, for a decade now, more than half of my texts gather shape during long walks in the streets of my favorite cities (and with my HIAS stay, Hamburg has joined this list). With this process of designing texts, I feel a bit like becoming part of the long tradition of deep reflection while meandering through city streets.