Note how most of the land of earth is above the equator, in the Northern Hemisphere. I
have no explanation for why this is, but it probably explains why most maps of the world
are oriented with the North side up. People don't like to look down on themselves.
The majority of land and hence the majority of the world's population is in the Northern
Hemisphere, so we tend to orient world maps with North at the top.
This also explains why globes are oriented with the North Pole upwards, as this makes it
easier to see most of the land. If a globe was mounted with the South Pole upwards then
most of the land would be on the underside of the globe and we'd all be bending over to
see the land.
People also like to place themselves in the center, so world maps made by Europeans place
Europe in the center, as we have above, while world maps made by Americans place America
in the center.
Known as the cartographic "rule of ethnocentricity," the placement of one's own territory
at the center of a world map is an almost-universal feature of cartographic devices,
including cosmic diagrams of pre-Columbian North American Indians; ancient Babylonia,
Greece, and China; and the medieval maps of the Islamic world or Christian Europe.1
Having most of the land in the Northern Hemisphere also explains why clocks go clockwise.
Since most of the land is in the Northern Hemisphere, it's natural that the people who
invented mechanical clocks would live in the Northern Hemisphere and would make the hands
on their clocks mimic the direction a shadow moves on a sundial. "Clockwise" is the
direction shadows move in the Northern Hemisphere. (See lesson on Sundials)
Most measuring devices with dials also go clockwise because of this.
The convention of placing North at the top came a few centuries ago when
European navigators started using the North star and the magnetic compass.
Before that, the top of the map was to the East, which is where the word
orient as in orientation comes from.
The Chinese, however, put South at the tops of their maps,
while Australians still like to refer to their country as "down under".