Why does Africa seem so small on the planispheres?

The area of ​​Africa is larger than that of the United States, Europe and China combined. Not easy to know when looking at a map of the world. A historic debate surrounds this affair.

The world map is a projection of the terrestrial globe, which in turn is a deformation of the first. It is for this reason that by observing a planisphere, Africa appears much smaller than it really is.

Ever since Gerardus Mercator in 1539 projected the map of the world onto the earliest known representation of the Earth, as an ellipsoid, its representation has monopolized humans' perspective of the world map. So much so that over time, scientists of all stripes have in turn adopted the three-dimensional form of Mercator for mapping.

The common perception is that Africa is very big. Its surface area of ​​30 million square kilometers represents 20% of that of the land mass of the globe. However, looking at a map, Africa looks smaller than Greenland, even though it is said to be fourteen times larger in terms of area!

A simple visual trap? Not only. “The Mercator” was designed to oppose emerging lands, so that sailors can draw straight lines between the departure ports and those of arrival. In summary, on a representation of the globe, the earth is compressed while the oceans are larger.

One could therefore wonder why the countries of the North are oversized compared to the lands closer to the equator? Until today, the theory was that it was necessary to reduce a part of the earth in order to reveal all the inhabited countries, while finding a homogeneous scale to this deformation. Therefore, it is the equator that has been designated as the axis of this imperfection.

In 1973, the German cartographer Arno Peters proposed the "Peters", a two-dimensional projection of the world map. He used an approach exactly identical to that of Mercator, taking the time zone of Coordinated Universal Time (UTC) as the axis of deformation. And the results highlighted the Third World countries, but also brought Africa closer to its real size.

Maps, physics and philosophy

Peters established his own approach to challenge what he believed to be a privilege for rich countries at the expense of poor countries. Nevertheless, the Peters projection, despite its lack of notoriety, is the only one that maintains the proportion between the drawing of the map and the real surface of the Earth.

It is therefore no coincidence that the Third World and later anti-globalization movements, in Africa and South America, have adopted Peters' map as a symbol of struggle. It is also no coincidence that maps of the world, throughout history, have depicted Africa with different sizes.

The scientific procedure of mapping has two distinct doctrines. One is of Greek origin, it was developed by Dicearque who was based over time more on mathematics, it is this method which was applied by Mercator. The second school of cartography is Roman and it was inspired by the first, it was developed by Marinos de Tire, and was based more on physics and philosophy, it is also the point of origin of the approach by Peters.

It is important to point out that cartographers, as much as Eastern or African politicians, have always adopted Roman cartography, like Al Idrissi. While their Western counterparts have always opted for Greek cartography, including the Mercator, which is still essential today. The reasons therefore seem to be indeed political, but it is difficult to prove it.

The most important thing is to know that it is impossible to measure a distance or two areas on a physical map, despite the indication of a scale. And the lesson to be learned from this story is that Africa is much larger than people might think when looking at a planisphere or a globe.