Doubling time is what ? (definition needed and explanation)

typing an essay for ap human geography so me

Ecumene is a term used by geographers to mean inhabited land. It generally refers to land where people have made their permanent home, and to all work areas that are considered occupied and used for agricultural or any other economic purpose.

Explanation:

The ecumene (US) or oecumene (UK; Greek: οἰκουμένη, oikouménē, lit. "inhabited") was an ancient Greek term for the known, the inhabited, or the habitable world. Under the Roman Empire, it came to refer to civilization as well as the secular and religious imperial administration. In present usage, it is most often used in the context of "ecumenical" and describes the Christian Church as a unified whole, or the unified modern world civilization. It is also used in cartography to describe a type of world map (mappa mundi) used in late Antiquity and the Middle Ages.