Global Positioning System Reference
In-Depth Information
FIGURE 2.2.
Our planet seen
from space. It is clearly
round and not flat; the
ancients knew this, even
without such direct visual
confirmation.
Image from
NASA.
times—such as those of Pytheas, or of the Portuguese, Spanish, English,
and Dutch who so determinedly set their sights on the other side of the
known world—may also have come close to rebellion. Magellan and Drake
both had to suppress mutinies. The reason, however, was much more
mundane than a fear of falling o√ the edge of the world, or dread of sea
dragons or other monsters of the imagination. Lack of food and water and a
fear of death amid towering waves understandably cut through the enthu-
siasm of mariners. Their captains may have been driven by zeal of one sort
or another—the desire to spread the word of God, the desire to become
very rich, or simply the desire to see what was out there—but the average
sailor was understandably more down to earth. He will have been, no
doubt, quite happy to become rich, or to see sights never before spied by
man, but not at the cost of his life.
The drive of the early explorers—the captains who strived for years to
find sponsors for their expeditions, and who persevered relentlessly de-
spite the fears of their crews—is all the more admirable to us, glimpsed
centuries later from the comfort of our armchairs, precisely because they
were swimming against the tide, so to say. They overcame many obstacles,
but the ancient fear of falling o√ the edge of the world was not one of them.
Measuring the Earth's Radius in Ancient Times
Homer (ninth century BCE) was a flat-earther, as were most people in his
times. More particularly, the earth to him was a disk on a plateau that was
surrounded by the river Oceanus. After all, if the earth were not flat then
