We often talk about rebuilding after a disaster, but we leave so little thought for rthe materials needed. Have you ever thought about where all the rubble goes after a war or a flood? That’s the question that led Guilherme Iablonovski, a geospatial data scientist at the UN Sustainable Development Solutions Network, to dedicate his career to mapping matter itself — from concrete and steel to the global flow of sand, food, and everything in between. In this week’s episode of 15-Minute Maps, Gu...