You Are Empty Space

A marble alone on a stadium’s centre spot, a fleck of dust out in the back row, a finger that never quite reaches a tabletop, and eight billion people squeezed into a sugar cube. Three of those four pictures turn out to be wrong, and working out which is the whole of what follows.

Before you start. You need only what’s left over from school: that everything is made of atoms, and that an atom has a heavy speck at its middle with something lighter around it. This lesson explains exactly what that lighter something is, and builds every number in it from scratch, in front of you.