Wealth often appears to the perception as static: a heap of gold, or a glittering kingdom, sitting. But really it is constantly in circulation, which has all sorts of implications of its own.
For example, the planes moving traffic from Los Angeles to Chicago and back again are virtually brand new, spacious, fancy. But the planes moving traffic from Chicago to Detroit and back again are aging and run-down.
Further, both of these circuits of transport represent wealth, but they are wealth in different stages: a wealth that is passing, and a wealth that is renewing.
