Africa: bigger than you think! Greenland: much smaller.

We’ve been looking at a lot of maps recently (probably because of the amazing wind maps we linked to), and we came across an old favorite from a few years ago.

Kai Krause, German software and graphical user interface designer, has invented a word for the lack of sufficient geographical knowledge. He calls it immappacy:

In addition to the well known social issues of illiteracy and innumeracy, there also should be such a concept as “immappacy,” meaning insufficient geographical knowledge. A survey of random American schoolkids let them guess the population and land area of their country. Not entirely unexpected, but still rather unsettling, the majority chose “1-2 billion” and “largest in the world,” respectively. Even with Asian and European college students, geographical estimates were often off by factors of 2-3. This is partly due to the highly distored nature of the predominantly used mapping projections (such as Mercator). A particularly extreme example is the worldwide misjudgment of the true size of Africa. This single image tries to embody the massive scale, which is larger than the USA, China, India, Japan, and all of Europe … combined!

Most maps use the Mercator projection to display the world (Google maps, for example, use a variant of the Mercator projection). The Mercator projection is an easy-to-read cylindrical map projection first proposed in 1569 by Flemish geographer and cartographer Gerardus Mercator.

All map projections distort the actual layout of the Earth to some degree, and the Mercator projection is no exception – Gerardus Mercator created this projection to aid navigation, and its use in world maps leads to significant distortion. The Mercator projection distorts both the size and shape of large objects, and the scale of the distortion increases between the Equator and the poles.

Here’s an example of Mercator projection:

Standard Mercator projection. Image: Wikimedia.

And here’s an illustration of the distortion inherent in the Mercator projection using Tissot’s indicatrix (first presented by French mathematician Nicolas Auguste Tissot in 1859):

Tissot’s Indicatrices on the Mercator projection. Image: Wikimedia

Notice how the distortion appears to dramatically increase around Greenland? This is why Greenland appears to be so large on standard Mercator projection maps, when really Australia is over 3.5 times larger!

Poor Australians.

Back to Kai Krause’s map – this is a clever way to illustrate the vastness of the African continent as well as show the comparative size of other countries. I learned geography at an early age from a Mercator projection map, and I can never quite wrap my head around the idea that Africa is so enormous (not to mention Australia). Here’s Krause’s complete image linked to the high-res version:

True size of Africa. Image: Kai Krause

The one true map

Now we know the true area of Africa, right? Well…not really. While Krause’s map illustrates the size of the continent, there are other ways we can view its shape. During the late 20th century, a controversial projection was proposed as a replacement for the poorly implemented Mercator projection world maps. This is now known as the Gall–Peters projection:

Gall–Peters projection. Image: Wikimedia

So! This must be the perfect map, and that’s the real shape of Africa, right?

Nope. The history of the Gall–Peters projection is worthy of a soap opera, filled with social & political agendas, and false claims of provenance and accuracy. It’s like I wrote above – all map projections distort the actual layout of the Earth to some degree. It’s just not possible to display the spherical, three-dimensional Earth on a flat surface. Expecting 100% accuracy from a map projection is like trying to build a house with a single tool. What we really need is a complete toolbox, and fortunately there are a number of tools to choose and learn from.

• National Atlas is a good place to start
• The Future Mapping Company gives a brief history of the Robinson projection (a superior projection to the Mercator and the Gall-Peters projections)
• NASA’s G.Projector is free software to display a large number of projections
• Wikipedia also has a list of several map projection models

Finally, there’s the fabulous Dymaxion map by Buckminster Fuller, which has no right side up. It folds into a 3D icosahedron:

Dymaxion map folds into an icosahedron. Image: Wikimedia

Fuller’s map is only for representations of the entire globe. Like the others, it’s not perfectly accurate, but it has a generosity of spirit that makes it by far my favorite view of the world – a unified view, where we all seem to share one big island.