KEY HIGHLIGHTS
- Projecting a (3D) sphere onto a 2D surface distorts a combination of the shape, size, scale, direction or distance of countries.
- Mercator projection is the most commonly used world map.
- Greenland looks the size of North America or Africa on a Mercator map despite being 14.5 times smaller.
No world map is accurate
What an absolute bummer note to begin an article with, right? Well, all-round accuracy has no utility in day-to-day navigation. But finding a tool that shows the Earth for what it truly is, may not be something we have to worry about any more. Not in the digital age. But let’s first understand why world maps suck.
So why is there no world map to scale? Simply put, making a 2D map so it represents a globe, results in distortion of the relative size of the different landmasses of the Earth. No matter how hard you try, you will inevitably compromise on the shape, size, scale, direction or distance.
What’s wrong with our world map?
There are 10 different kinds of world map projections but the most commonly used map is the Mercator projection. You probably came across this projection in your geography class. It was designed by cartographer Gerardus Mercator in 1569 as a navigational tool for sailors providing accurate directions.
The biggest criticism against the projection is that while it preserves the shape of landmasses which earlier maps struggled to, they get increasingly distorted the closer you go towards the poles. For example, Greenland is actually way smaller than it appears.
Mercator makes the island look a size comparable to Africa, the second-largest continent on Earth. In reality, Africa is 14.5 times bigger than Greenland. Even some of the Scandinavian countries look bigger than India despite clearly not being anywhere close.
The projection is also equally notorious for exaggerating the size of historically imperialist powers like North America and Europe at the expense of Africa and South America.
What are some alternatives to Mercator projection?
The Gall-Peters projection
Presented in 1974 by German historian and filmmaker Arno Peters, the Gall-Peters projection is considered by some people as a reasonabe answer to the popularly used Mercator projection. This is because it depicts the size of countries more accurately.
The Gall-Peters projection came to be adopted by schools in Boston as well as the United Kingdom and is promoted by the United Nations. However, the map projection comes with its own inaccuracies.
Gall-Peters shows the correct sizes of countries to a certain extent but also distorts their shape. It is evident from the map that countries are stretched horizontally near the poles and vertically around the equator.
The Winkel-Tripel projection (Winkle III)
Proposed by German cartographer Oswald Winkel in 1921, the Winkel-Tripel projection, the map attempts to minimise the three major types of distortions - area, direction and distance.
The National Geographic Society adopted the projection in 1998 and has since drawn all maps using it. However, while Winkel-Tripel preserves other distortions, it does little to maintain the angles, making its use in navigation impractical.
Robinson projection
American geographer and cartographer Arthur Robinson’s brainchild, the Robinson projection is known as a ‘compromise’ as it preserves neither the shape nor the size of the landmasses.
He developed it in 1963 with the primary purpose to create a visually appealing map of the world.
In fact, he said in a 1998 interview, “I visualised the best-looking shapes and sizes. I worked with the variables, until it got to the point where, if I changed one of them, it didn’t get any better.
It was only at this point that he worked out the mathematical formula. The curved meridians give it a nice spherical look.”
AuthaGraph
In 1999, Japanese architect Hajime Narukava invented the AuthaGraph by dividing the spherical surface of the map into 96 triangles. These are then projected onto a tetrahedron (also known as the triangular pyramid), which goes a long way into preserving the proportional sizes of the continents and the oceans and can be, as seen above, unfolded into a rectangle.
AuthaGraph is said to be the most accurate map projection in existence and also includes the generally neglected continent of Antarctica. However, for the eye used to seeing North at the top of the map, this layout is not recommended for navigation.
Cylindrical Equal Area projection
In this projection, the latitude and longitude are straight lines the same length as the equator and parallel to the meridians. The shape of countries is compromised to preserve the proportional sizes by narrowing the space between the lines of latitude and longitude the further away you go from the equator. This helps compensate for the missing convergence of longitudinal lines near the poles.
The Cylindrical Equal Area projection is recommended for large-scale mapping of areas near the equator such as Indonesia and some areas of the Pacific ocean.
