Mercator projection, the Comic Sans of map projections

You might have heard it before, but the Mercator projection, a projection that is probably the most common way to display the surface of the earth, is wrong in so many ways. Most cartographers cringe a little when they see this projection being used out of place, just as designers, or literally anyone else cringes a little when they see Comic Sans being used where it is not suited at all.

What can be wrong with maps?

First let me give you a brief introduction about map projections and why the most common way to show the earth, distorts so much.

Before talking about any projection you must know that every map in existence, and probably every map ever to come of the surface of the earth, is false and lies in some way. This is just plain mathematics. The earth is a sphere and any attempt to display the surface of a sphere on a flat, 2D surface will lead to stretching somewhere on the map. So if you want to display the surface of the earth you need to 'project' it to a flat surface in some way. Try peeling fruit for example and laying the peel flat on the table. It will be hard to shape the peel into a map without stretching or tearing the peel. But there are literally a billion ways to project the surface on a map, so why exactly did this one gain popularity?

_{Peeled fruit. If the fruit was the earth you can see it would be dificult to 'peel' it in such a way that the peel becomes an undistorted 2D map. Photo by waferboard shared under CC BY 2.0}

Why Mercator's projection was useful and how it distorts

The Mercator projection was first introduced by the Flemish geographer and cartographer, Gerardus Mercator (#proud) in 1569. It became the standard map for nautical navigation because a straight line on the map corresponded to a straight course to sail. You can imagine how convenient this was for seafarers as they could conveniently plot a course on the map and just maintain that direction until they reach there destination.. These lines of constant course are also known as loxodromes, or rhumb lines. This is not necessarily the shortest route but in the early ages convenience and lack of errors was much more important than saving time.

How does the map does this? Well, when you go to the poles, the circles of latitude become smaller and smaller. The biggest circle of latitude is the equator. So at the poles of the map, the areas will be stretched horizontally to create a square map. Then, when you stretch the Y axis just as much as the X axis is stretched at a given location, you maintain proportions, shapes and angles remain the same. This is the strength of the Mercator projection but has the great disadvantage that the actual surface area at the poles becomes stretched. A convenient way to visualize this is by showing circles on the map that have the same area. When shown on a globe, the circles are equal, but how these circles are then stretched on the map makes it clear in what way the surface itself is stretched. These clever circles on the map are called the Tissot's indicatrix of deformation.

_{Tissot's indicatrix of deformation. Both X and Y directions are stretched to maintain shapes and angles, but results in an overestimation of land near the poles. Illustration by Justin Kunimune shared under CC BY 4.0}

_{Animation shows how the Mercator projection distorts land area while keeping shape constant. Illustration by Jakub Nowosad shared under CC BY 4.0}

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Why this projection remains in use

The aspects that make this map ideal for sea faring also proved to be the easiest way to display dynamic maps on the internet. Most of these online maps were used for navigation as well, just think about Google Maps, Bing Maps, OpenStreetMap, Yahoo! Maps etc. and since the shape of countries does not change with this projection, you only need to adjust the scale when a user goes from the equator to the poles. This is much easier than working with multiple projections and dynamically switching between them when the user scrolls through your map. The disadvantage is that when you zoom all the way out, you get a completely wrong image of the world.

It is also much more computationally easy to change the scale depending on where the user is than do complex math calculations with maps. But due to advances in computational power, Google Maps did make this switch a few months ago! If you missed it, I wrote a dedicated post to this change, and why it is so important that the largest provider of knowledge stops showing a distorted world.

Similarities to Comic Sans

I mentioned Comic Sans in the title but haven't really discussed this until now. The reason why Comic Sans is so hated amongst many is somewhat similar to why the Mercator projection annoys cartographers.
Comic Sans was also created with a very specific intent just like our projection. Created by Vincent Connare in 1994, the font was designed as a casual font for informal documents and children's materials. It was inspired by comic book lettering and was originally intended for the text boxes in the Microsoft Bob software but never made it in the final product.

_{A regular font 'Product Sans' (top) compared to 'Comic Sans' (bottom). Note the small imperfections to mimic the handwritten, playfull comic-style font.}
It may not have made it in the program it was intended for, but since it was developed, it was included in the standard microsoft font set and became distributed to computers worldwide. Already 4 years after its release, designers argued the exuberant use of the font.


_{Not even CERN is safe from the trap! This is there announcement presentation for the Higgs Boson in 2012. you can find the presentation here.}
When choosing a font you have to be careful to match to occasion. This kind, overly-cheerful, nonchalant and slightly weird typeface can become offensive en totally out of place when used for the wrong occasion. This is not the fault of the font, but rather the fault of the user misplacing it. Which is exactly the case with the projections. It is not the fault of the projection that there are shortcomings, just as no font is suited for every occasion. it is up to the creator to fit the right projection/font in the right use case.

Conclusion

Projections and typefaces at first do not have a lot in common, but when you look at how they are used they are more similar than you might think. Both are created for specific purposes. Whether it is for correctly displaying shape, area or distances, or showing elegance, playfulness or design, not every projection/font is suited for every occasion. It is always up to the creator to decide which projection/font bests conveys the message.

Both the Mercator projection and Comic Sans became widespread very early on which poses the risk that it is the go-to projection/font for unknowing users. So next time you see a font or a map, try determining, why did he choose this projection or font? in what way does it distort my world view or what message does it try to convey? Because both maps and fonts can have a significant, unconscious effect on our mood and opinion.

Thanks for stopping by! If you liked this post I would love to hear your feedback. If you have any comments, definitely leave it below. Have a great day.

Sources

_{https://www.esri.com/arcgis-blog/products/product/mapping/tissots-indicatrix-helps-illustrate-map-projection-distortion/
https://map-projections.net/
https://www.bbc.com/news/magazine-11582548
https://www.pattondstudios.com.au/blog/typography-in-context-part-ii-the-problem-with-comic-sans-1
https://en.wikipedia.org/wiki/Mercator_projection
https://misguidedmaps.com/2010/04/22/mercator-projection-evil-or-superevil/}