Small wonder that they understood their world so poorly. Small wonder as well that even when we know better in principle and when we can grasp the age and reach of the universe, we still fail to explore and explain this world on a scale expansive enough to make it genuinely intelligible. Science measures boldly the unimaginably large and small of the cosmos, the breathtakingly fast and unspeakably slow movements of bodies. History struggles to contain those universes in its imagination while observing in minute detail as well. Historians struggle to think of human experience in a way both congruent with the experience of mortals and expansive enough to offer real explanation.
The sky of the Greeks and Romans, carrying the names of their gods and heroes in arbitrary patterns of stars, still passes over our heads at night. The Great Bear and Little Bear circle each other at the top of the sky, while Orion and his dog go hunting in the fall. They will do so long after all of us now alive are gone, long after all our descendants have destroyed themselves with nuclear fission or automotive exhausts Unscholarly duties as provost of a great university. The ancient communities that put those names on the sky have already disappeared or altered beyond recognition, and yet they continue to shape the world in which we live.
This is a book about changes on earth below that left ancient heroes marooned in the sky, stripped of their celestial powers. If we can understand those changes—and what has not changed—we may have a better chance of avoiding calamities of our own.
We will begin with a man who thought that the world below the stars was flat.
CGSMAS THE VOYAGER
The two visitors, skillful and knowledgeable merchants, found the obelisk and the throne facing west, away from the sea. They stood at the gate of the city of Adoulis, a trading town on the Red Sea coast of what is now Eritrea. The land’s distinctive products were ivory from elephants, horn from rhinoceroses, and tortoiseshell. Both obelisk and throne pointed up into the mountains, toward the great city of Axum, more than 100 miles away in what was already called Ethiopia. Their inscriptions honored the Hellenistic king Ptolemy III Euergetes (“Benefactor”), by then dead for about 750 years. Ptolemy had probably never come this far south, but these lands still paid tribute—you could call it a tax, or you could call it protection money—to Egypt when they were not at war with the Egyptians.
