Left to my own devices on airplanes I often turn off the screen and think about mathematics, ecology, or both. Often I think with pen and paper, giving me a record of questions to look into when I get home.

A page filled with handwritten notes and detailed sketches of shells and a star-like shape. Sketches of mussels and a sea star. Sketches of construction of a pentagon with compass and straightedge. The text is full of notes about how nature builds various structures.