Strange Projections part 1

I've always liked maps. I can remember being a child and fascinated by the western coast of Africa, the eastern coast of South America and how they seemed to fit together. I used to pick out shapes in the coastlines and borders on the map the way you might find shapes in the clouds. I always thought Newfoundland looked like a thumbs-up sign. In spite of spending lots of time looking at the large, outdated world map on my wall - which still showed the Soviet Union - I never really questioned how it was that the surface of a sphere could be flattened into a rectangle. This question continued to vex me until my first year of university, when I took an introductory geography course. Once the professor explained the mechanism behind this sort of projection, it seemed painfully obvious. It haunts me to think that if I hadn't attended that first lecture (full disclosure - I dropped the course after a week) I might have continued throughout my life with a wholly inaccurate mental image of Earth.


I learned a number of things in my short lived career as a geography student. First of all, I learned that the map I was used to used what's called the Mercator projection, and it dates back to 1569. The principle behind this sort of cylindrical projection is simple: in order to represent the lines of latitude (running east-west) and lines of longitudes (running north-south) as perpendicular to each other (in other words to have the map appear as if it's divided into a grid of squares) certain parts of the world have to be deformed and appear disproportionately large. The parts of the world that will appear the most deformed are the parts furthers away from the equator since lines of longitude seem to converge together at the north and south poles. This is illustrated nicely by Tissot's indicatrix.

It is easy to take the relative size of the different landmasses at face value, especially since the Mercator projection seems to correspond nicely with the common piece of trivia that identifies Russia and Canada are the world's two largest countries

Tissot's indicatrix - all the red circles represent equal amount of surface area

Notice how in the above image Africa and Greenland appear the same size. In reality the surface area of Greenland is 2 166 086 km², while Africa has a surface area of 30 200 000 km². Africa is 13.94 times as big as Greenland, and yet you wouldn't know it to look at a map with the Mercator projection.

So what's the point? Why bother to go through so much trouble to point out such a banal fact about the relative sizes of Greenland and Africa? For one, as humans we place importance on the size of objects. The relative importance of an object can sometimes be conflated with its relative physical size. It is no secret that Africa is the one region of the world that has been "left behind" nearly across the board in the race to achieve the same high standards of living we enjoy in the WEIRD (western, educated, industrialized, rich and democratic) countries (and we really are weird, comparitively speaking). As countries like China and India experience demographic shifts associated with a growing middle class, such as an increased life expectancy, reduced child mortality and fewer children per family, Africa (with some exceptions) has not really changed much since the early to mid-20th century. According to Wikipedia, 94% of child deaths occur in 60 countries and half of all child deaths occur in Africa. It is ridiculous to compartmentalize African social problems as something that only affects the "third world" when Africa represents 14% of the population of all humanity. Africa is all of all of humanity's ancestral home, and I personally feel a sense of moral obligation to help improve the quality of life there. I'm not advocating any particular cause, I only include this hyperlink (which leads to a list of dozens of different charities you could choose from) because it was the first thing served to me by the Goog and I feel like I would be morally bankrupt if I didn't provide at least an easy starting point for someone wants to contribute aid.

I want to make something clear - I don't think that the Mercator projection is purposely deceptive. I don't think there is some grand geographic conspiracy to minimize the psychological impact of the challenges faced in Africa. I simply believe it's time to start including the Mercator projection in the appendix of the geography book instead of presenting it as the default image of our world. Compare the Mercator projection above with the following images of Earth using the Mollweide projection.

Mollweide projection

Tissot's indicatrix of deformation - Mollweide projection

I think it's clear how this map gives a more accurate mental image of the world than the Mercator projection. The important thing to remember is that any two-dimensional representation of a sphere is going to be flawed in certain ways. For that reason no particular projection is absolutely superior to another. They all have their uses - as I mentioned, the Mercator projection is particularly good for 16th century navigation.

I have a lot more to say about maps, but I don't have time to go into it tonight. I didn't even get to address the "strange projection" that inspired me to start writing in the first place. For now I will leave you with some more interesting projections of Earth's surface that you may not have seen before. Perspective makes all the difference - some of these look like alien planets or prehistoric supercontinents! Seeing these maps makes me reflect on how the world might have been perceived in worlds where Europe was not considered to be the crux of civilization.