The phone
A table of contents of the world, in your hand.
What you are holding is a table of contents of the world. Five parts are enough to take it apart: the cover, the battery, the board, the camera, the screen. Each one asks two questions that look nothing alike. Where it comes from: the mine, the furnace, the factory, backwards all the way to the rock. How it works: the layer underneath, then the one below that, down to the atom. Some threads are open, others are waiting their turn. And this phone is typical, not yours: real supply chains are secret, these are true in general.