“Catenary*” is a word I learned in architecture school and haven’t used since. Obviously that degree was well worth the my time and my parents’ money!
But it was still in my head, all these years later**, and when I looked at the arc of those curtains and the arcs of the power line shadows, it popped up.
*Catenary = a curve formed by a wire, rope, or chain hanging freely from two points and forming a U shape.
**Here are some things from architecture school that didn’t stick around in my head: anything involving calculus or structural design, most of architectural history, the difference between a muntin and a mullion, and whatever the hell hegemony is.