The nature of space

The engraving in Figure 1.1 shows the edge of the world as it was conceived in ancient times. The known land was surrounded by a vast expanse of sea close to whose end waters were inhabited by sea serpents, dragons and other fearsome creatures.

Monsters aside, a fact at odds with our contemporary perception of the world is that the surface of the world was – waves, mountains and other accidents of this surface ignored – flat. This feature is inconsistent with the images of the Earth that satellites bring daily to us but was perfectly consistent with the information available to, say, the ancient Greeks. Indeed, moving north one was led to an increasingly cold landscape and moving south to an increasingly hot one. And at both east and west boundaries of the known land mass, oceans extended which were navigable only close to the land (and hence whose end could neither be seen nor refuted). In addition, it was not possible to distance oneself enough from the surface of the Earth to appreciate its curvature. All these enclosures created a confinement within which the flatness of the Earth was as likely as its spherical curvature.