Why is it Called One-North?
Why is it called one-north?
Despite being a name that means the same thing in different languages, there is a surprising amount of confusion surrounding this concept. Some people have heard the term as a reference to the north axis of rotation on a planet, while others have seen it as a name that indicates the direction from which a ship or airplane would go.
There are three main ways to define the north of a place or region: True North, Grid North, and Magnetic North. The terms are often used interchangeably, and it is important to know the difference so you can find your way correctly on a map.
True North
Also known as geodetic north, this is the line of longitude that converges to points at the north and south poles. The star symbol on the diagram at the bottom of most USGS topographic maps indicates this direction.
However, it is not a precise line on the surface of the earth, and its distance from any point on the map can vary. This is because the earth’s magnetic field can be influenced by atmospheric conditions.
Magnetism
The earth’s magnetic field is a result of an attraction between the planet’s iron-based core and magnetized material. A compass needle is attracted to this magnetism and therefore points north.
It is this attraction that makes it possible to identify the direction from which a ship or plane would fly, and it is also how most compasses are oriented.
This is because a compass needle will always point towards the north pole of the planet when it is aligned properly with the Earth’s magnetic field. This can be a bit confusing, but once you understand it, you will see that it is quite easy to find your way.
A compass needle is able to orient itself because it can adjust its angle of deviation from the Earth’s magnetic field based on what is known as the “magnetic declination” (the horizontal dip or inclination of the world’s magnetic lines). This difference fluctuates from place to place, and may be significant in some cases.
Another explanation for why it is called one-north is that this is where the light from the sun comes from on a rotating object. This is why it is usually placed on a map at the top or on a compass rose.
The earliest maps of the world were made by Eratosthenes, a Greek who lived in Alexandria, Egypt. He was the first to create a real map that actually showed the surface of the earth in full detail.
Although not all of his maps are surviving, he did publish Geographia, which listed the latitude and longitude of all of the most important places in the world as they were then known. This allowed later map makers to reconstruct his view of the world.
He even invented the concept of the atlas, in which the world is subdivided into a series of maps. This is a concept that is still being applied today. the hill one north