South At The Top

The United Nations recently updated the generally-accepted map of the world. But why do we habitually put north at the top on maps? Here is a second reason for putting south at the top, besides what I have already written here about the moon.

The second reason is based on traditional clocks, where the hands move around the clock. The hands moving around the clock represents the rotation of the earth, which gives us night and day, except that the hour hand goes around the clock every 12 hours instead of every 24. This is so it goes around the clock once for day and once for night.

We have selected a direction for the hands to move, which we call "clockwise". The earth rotates eastward. We habitually put north at the top on maps but if we look at the earth from above the north pole, it will appear as rotating counter-clockwise. It is only if we look at the earth from above the south pole that it will be rotating in the same direction as the hands on a clock.

South should be at the top, based on the moon. Whenever you see a lunar or solar eclipse you can see that the moon moves leftward, from right to left. We know that the earth rotates eastward and the moon orbits the earth in the same direction. So the moon moves leftward and eastward. For east to be to the left we have to be facing south. Therefore south should be at the top on maps. Maps with north at the top are accurate only if we are looking at the earth from above the orbit of the moon. I have written about this here before but noticed it only recently.

Image from Google Earth. The moon moves according to the red arrow. During an eclipse we can see that the moon is moving leftward. This means that south should be at the top on maps.