Map Madness
What does the world really look like?
Adil, 3–21–17
We’ve been looking at maps of the world since before we even started school. And once we got to school, we soon became familiar with the shape of the world (except maybe Davis) — after all, these things were plastered all over the walls of our classrooms. With the tech revolution of the 21st century, maps have become even more ubiquitous and advanced. We transitioned from paper maps bought at the travel agent or gas station to MapQuest to Google Maps. So we think we’re pretty hot stuff when it comes to maps… but what does the world actually look like?
As it turns out, the vast majority of us have a pretty distorted mental representation of the globe. This errant psychology can in fact be traced back to those same elementary school classrooms. The most common map of our world looks like this:
This is called the Mercator Projection, and it’s been our standard for almost half a millennium. Shoutout@Davis who, paradoxically, probably already knows this because of his “Power of Maps” freshman seminar… regrettable that they didn’t sprinkle some geography into that course. But I digress.
The Mercator Projection is actually pretty damn wrong, at least in one major way: area. This article notes some egregious examples:
“A few major misconceptions based on this map:
- Alaska is nearly as large as the continental U.S.
- Greenland is roughly the same size as Africa.
- Europe (excluding Russia) is only a bit larger than South America.
- Antarctica dwarfs all the continents.
In reality:
- Alaska can fit inside the continental U.S. about three times.
- Greenland can fit inside Africa about 14 times.
- South America nearly doubles Europe’s land mass.
- Antarctica looks like the second-smallest continent.”
There’s a tool called Tissot’s indicatrix (new favorite word), which is used to illustrate how maps’ distortions change across the map. There’s some complex math behind it, but you’ll get the idea by just looking at this image:
The takeaway is basically that, as you move toward the poles, places have increasingly exaggerated areas.
If you’re like me, at this point you’re probably doubting that the maps you’ve grown to love and trust really look this ridiculous (the Greenland and Antarctica things, in particular, really baffled me). So, I did the reasonable thing and turned to the Dark Overlord of Our Universe: Google. Surely Google Maps wouldn’t look so wrong. Alas, as per screenshots taken on my computer minutes ago (couldn’t fit whole world on my laptop screen, so just took fragments):
Okay so that was a lame way to present Google Maps, but just check on your iPhone: Greenland and Antarctica are absolute behemoths. As it turns out, according to Google Maps’ API, the program does indeed use a variant of the Mercator Projection.
The Mercator Projection was developed by the Flemish geographer and cartographer Gerardus Mercator in 1569, when its primary purpose was clearly for marine navigation. Mercator himself titled his map Nova et Aucta Orbis Terrae Descriptio ad Usum Navigantium Emendata: “new and augmented description of Earth corrected for the use of sailors.” For this use, the Mercator Projection is indeed very useful: it preserves directionality by presenting rhumb lines (imaginary lines which cross meridians at the same angle), which serve as lines of constant course for sailers. But Mercator himself used the equal-area sinusoidal projection to demonstrate relative areas, because he knew his map wasn’t meant for this purpose. Nonetheless, in the 19th and 20th centuries, the Mercator Projection became the most common general map of the world.
Several people today have criticized this widespread, blind adoption of the Mercator, arguing that it feeds (both literally and subliminally) the ideas of European and North American countries being “bigger” and hence more important. When all these counties in Africa near the equator are being visualized as disproportionately small, we come to ignore them.
Just a few days ago, a Boston public school district decided to drop the Mercator Projection for an alternative choice, becoming the first American school district to do so. It’s no coincidence that, of this school district’s 57,000 students, 86% are non-white (mostly black and Latino). Officials noted that it is important for these students to be part of the “paradigm shift” away from this Euro-centric map. All in all, a neat example of science and society shaping each other.
So what’s the alternative? I present to you, the Gall-Peters Projection:
Though this map wouldn’t be nearly as useful for sailing, it does preserve relative areas. The list of interesting comparisons is huge, but just note the previous points about Greenland, Africa, Antartica, and Alaska. To throw in another example: in the Mercator, the north-south distance of Finland is roughly equal to that of India. The Gall-Peters Projection shows this to be laughable.
This version is much newer. The Scot James Gall first described the projection in an 1855 geographers’ conference (with a published paper in 1885… weirdly long gap), and the German historian Arno Peters made it more popular in the early 1970s. This map is actually already commonly used in British schools.
Here’s Tissot’s indicatrix applied to Gall-Peters:
Note that the area of the circles are now all approximately equal, but the shape is distorted. Of course, when trying to put a 3D shape onto a 2D surface, you have to make compromises, and these are arbitrary at some point. For example, in the 16th century world of cartographers, it was customary for the mapmaker to place the his own country at the center of the map. Accordingly, Mercator shifted the equator 2/3 of the way up the map (instead of halfway) to position Germany at the center. In a far less egregious but still arbitrary move, the Galls-Peter Projection chooses latitudes 45° north and south to be the ones with no shape distortion.
Hayden Frederick-Clarke, the director of cultural proficiency for Boston Public Schools, makes the obvious but good point defending the switch:
When our instructors, our schools, hang up maps, we are hanging them up not for our students to sail from Boston to London, we are hanging them up to say this is what the world looks like. With that intention in mind, and with that specific goal, it necessitates that we be truthful and give accurate representations. I can guarantee you that 999 times out of 1,000, these maps are hanging up in classrooms just as depictions of what the world looks like … sailing is not what we purport to teach kids.
I would provide the small counter-point that shape is actually another useful feature to be wary of, but that’s a bit besides the point. In reality, we should obviously use different maps for different purposes, and there isn’t one “best” map. But I do think it’s important to be aware that other visualizations exist; considering them together likely paints the most accurate mental picture of our world. But for real… my simple solution: just try to use 3D globes more. *facepalm*
Naturally, there’s more than just these 2 maps. In fact, there’s 15–20 projections used for different purposes throughout the world today. Here’s Tissot’s indicatrix applied to several different maps, some of which look pretty funky:
And of course, people are always working on making even more accurate/weird maps. In 1999, Japanese architect Hajime Narukawa created the Authagraph Projection, an almost-equal-area map created by “dividing a spherical surface into 96 triangles, transferring it to a tetrahedron while maintaining area proportions, and unfolding it onto a rectangle.” It looks like this:
This map has won multiple science and design awards, and as of 2015 it actually used in official Japanese high school text books. It’s hailed for providing a “decentralized world view” (no pun intended?) and is useful for tessellation, thus “[allowing] for depicting temporal themes, such as a satellite’s long-term movement around the earth in a continuous line.” Took the dude seven years of trial and error before getting this version. Baller.
For all you West Wing fans out there (@Mehgusta) (everyone should be), this Mercator vs. Gall-Peters issue was actually presented in a funny exchange. Now you don’t have to be as confused/surprised as CJ in this clip! Taking “social equality” to the next level, I particularly enjoyed 3:33 to 3:59 (linked below, but I recommend watching the whole thing now that y’all know wassup).
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