Round Earth, Flat Maps (or, how can we fix the world if we can't read the map?)

Map comparison of the Mercator and Gall-Peters Map, overlaid 

One of the purposes of this blog is to show that you can embed social justice thinking into any subject that is taught.  As a socio-historian (at least that's what my graduate work was in) I like to see  political and sociological implications in everything from the things I watch on TV to the books I read and the music I listen to.  Nothing that we learn and consume happens in a vacuum- that is everything that has to do with people is touched by society (which can be a really complicated concept that we won't be looking at in this post, but there are some great articles and books about it.)

One geography unit that I love to teach is the comparison of map projections and their purpose for development.  Its really interesting- really!

For the introduction, the students participate in an activity that show the difficulties in mapping the planet (a sphere, in 3D) into a flat map (in 2D- Math is EVERYWHERE!). Depending on how long you want this lesson to be, you can look at 2 to 3 different map projections in this lesson: The Mercator projection (the oldest, 1512), the Gall-Peters projection (1973) and the Winkel-Tripel projection (1921, but standardized in 1998).  As we examine the maps, we also need to look at what societal changes happened to change the focus of the maps.  Then we end the lesson with a consolidation exercise on our big ideas.

If cartography is completely new to you, have a read of this great article about maps as representation here.

The Introduction:

To begin students thinking around the problems of mapping a round planet on a flat surface, I usually begin with a demonstration and group project.  I begin with an activity created by geographer David J. Smith (who wrote If the World was a Village) To show students the difficulty in mapping the planet.

For the demonstration:

1. Provide each group students with a grapefruit.  (Or you can demonstrate with one and have students assist you, which is how I usually do this.)
2. Challenge the students to think of the grapefruit as Earth.
3. Identify and mark on the grapefruit the locations of the North Pole and South Pole.
4. Then locate the spot that is halfway between the two poles using a measuring tape,  and use a marker to draw a line around the Earth at that point, which geographers refer to as the equator.
5. Draw a few lines of longitude on the map.
6. Then draw shapes to represent the continents on Earth.
7. Use a knife to pierce the skin of the grapefruit, then use your fingers to get under the skin to peel it off the grapefruit. Try to keep as much of the "globe" intact as possible.
8. Next, challenge students to create from the sphere (grapefruit) a map that is flat and readable. Students will come up with really interesting ways to try and "map" the grapefruit   One of my students tried tracing over the raised "land masses" to create a map, but it didn't work.  We tried "stamping" each of the land masses and then piecing it together like a puzzle.  
9. As students try to create the map,  they come to understand the difficulty that geographers have in creating an accurate flat representation of Earth. This leads into the lesson that there are many map projections of Earth and none of them is a totally accurate depiction of Earth; each of them is distorted in some way- which is why we have so many versions of the map of Earth. And each map carries a little bias in its own way.  (My students usually ask, "How can a map have bias?" I love it when they fall into my learning traps.) 

It's a good idea to introduce some of the terms we will use in the lesson, such as "projection," "representation," "distortion," "globe" and "map" because we will be using those terms a lot.

The Unit Lessons: 

Students get a comparison worksheet to complete as we go through the lessons.  It helps if groups have a device to access the internet to help them complete the historical context column during the lesson.  First we look at the famous Mercator Projection: 

The Mercator Projection (1569):

The Mercator Projection, 1569 from NatGeoEd.org

While looking at this projection, we start looking at different parts of the map.  

Lines of Longitude: straight up and down, which we can compare to a globe, where the line of longitude are NOT straight up and down- they can't be on a sphere.  

Provide some background on the projection:

"The Mercator map was designed as an aid to navigators with straight lines, loxodromes or rhumb lines—representing lines of constant compass bearing—that are perfect for "true" direction.

If a navigator wishes to sail from Spain to the Caribbean using this map, all they have to do is draw a line between the two points. This tells them which compass direction to continually sail in until they reach their destination." 

What distortions do you see?: I lead my students through the distortions- first I have them look at Antarctica- Its HUGE!  I have someone search for the size of Antarctica compared to other continents (Antarctica is about the size of the USA and Mexico together) and definitely not the largest continent like it is shown here.

I have another student search the size of Africa compared to the size of North America.  Africa is actually about 6 million square kms larger than North America but it is shown as smaller than North America significantly.

Last, I have a student search the size of Greenland versus the size of South America.  South America is 8.2 times larger than Greenland, but it definitely doesn't look that way on the Mercator map.

After we get this information down (I use an anchor chart and write with them) We look at the next section- the historical context to explain the choices that Gerardus Mercator (the guy who drew this map first) made when creating his projection.

Historical Context: For students younger than 8th Grade, this part takes a lot of explanation.  For my 6th graders, we use the devices, and groups get 10 minutes to look up a historical term definitions that reflects the era of the Mercator map.

• Colonialism
• Imperialism
• Explorer Vasco Da Gama
• Explorer Francis Drake
• Conquistador, Hernon Cortez
• Mercantilism

Each group gives us a little information about the historical subjects, and then we get to the point of debating whether or not we should use this map.

Use this projection?  Why or Why not?:

I usually give the students a spoiler here-- most institutions do not use this map anymore as it is obsolete.  Sailors don't depend on maps to sail anymore now that we have GPS and satellite imaging guidance.  However, for a very long time (404 years) this was the map that was used.  So our question is why was it used, and why have we stopped.

Why?

On the one hand, "Mercator projection made world exploration much easier and became an essential map projection for navigation."  "Sailors could mark their starting and ending points and simply follow the line along their expeditions." - they would always be going in the right direction.   It was one of the reasons that explorers could sail around the world (like Francis Drake) and colonize different places.  

Why not?

The main criticisms of the Mercator projection are that it gives people a false impression of the size of the world’s landmasses. Greenland, for instance is not bigger than South America, but it appears to be on Mercator maps. 

Maps with an agenda: Critics of this map say that this projection and the large size of continents like Europe gave an advantage to the colonial powers because it made them appear larger than they really are.  Maps have also frequently been used as political tools. As Robert Edsall (2007) states, "some maps…do not serve the traditional purposes of maps but, rather, exist as symbols themselves, much like corporate logos, communicating meaning and evoking emotional responses" (Edsall, R. M. (2007). Iconic Maps in American Political Discourse. Cartographica, 42(4), 335.)  

"In our society we equate size with importance and even power."   

-Salvatore Natoli, Educational Affairs Director of the American Association of Geographers

And thinkers like Arno Peters (developer of the Gall-Peters Projection) and Anti-Racist Activist Jane Eliot thought this map was an example of "Cartographic Imperialism" in that the Mercator map made the small European dominated countries bigger (and therefore more important) than continents that were dominated by colonialism (like Africa and South America.)  They are that Mercator's bias is part of how he decided to draw his map projection.

The Galls- Peters Projection (1973):

Lines of Longitude: straight up and down, just like on the Mercator map.

Provide some background on the projection: 

"[Peters] promoted [his map] as a superior alternative to the Mercator projection, which was suited to navigation but also used commonly in world maps. The Mercator projection increasingly inflates the sizes of regions according to their distance from the equator. This inflation results, for example, in a representation of Greenland that is larger than Africa, which has a geographic area 14 times greater than Greenland's. Since much of the technologically underdeveloped world lies near the equator, these countries appear smaller on a Mercator and therefore, according to Peters, seem less significant.  On Peters's projection, by contrast, areas of equal size on the globe are also equally sized on the map. By using his "new" projection, Peters argued that poorer, less powerful nations could be restored to their rightful proportions."

What distortions do you see?: This one is a little easier to see the distortions on.  Students can see that the North and Antarctica are almost non-existent on this map, and the they seem crammed into the picture at the top.  Also, the continents look stretched out, so that they are representative of the size of the continents, but not the shape.  You can't see the island nations in the Pacific at all.  Students will see more distortions and have really interesting observations.

Historical Context: For students younger than 8th Grade, this part takes a lot of explanation.  For my 6th graders, we use the devices, and groups get 10 minutes to look up a historical term definitions that reflects the era of the Mercator map.

• Decolonization of Angola and Mozambique
• Space Race
• Green Revolution
• Anti-War Movement/ Civil Rights Movement
• Iranian Revolution

Each group gives us a little information about the historical subjects, and then we get to the point of debating whether or not we should use this map.

Use this projection?  Why or Why not?:

The Gall-Peters Map was adapted by Boston Public Schools in 2017 as the standard maps for classrooms.  And the map is promoted for use by the UN.  Should it be used this way?

Why?

The Gall-Peters map was still useful for ocean navigation, just like the Mercator map was.  Additionally, Peters sought to remove the bias he saw in the Mercator map, by resizing the continents so that they reflect the proper size, trying to fix the eurocentric bias of the Mercator map-- this map started the conversation of the impact of maps on society.  It shows the area of the oceans appropriately, and equal positioning of the continents- one isn't centered over another.  Last, it is good for looking at social and human geography like comparing population density.  

Why not?

This map is still very distorted, especially at the poles.  Also, the "distance fidelity"-- the representation of distance is also distorted.  Points from one place to another look closer and father than they actually are on this map.  Antarctica looks like it stretches all the way across the planet, making it look bigger than it is.  And, it cuts off part of Russia and attaches it to the opposite side of the map.    Finally, the bias of Arno Peters is an important part of why he developed this map-  to fix the inequity of the Mercator map was his agenda.  Even though it is a progressive idea, its a political map and caused quite the controversy in the 1970s and 1980s.  

The Winkel-Tripel Projection (1921)

The Winkel-Tripel Projection, from NatGeoEd.org

Lines of Longitude: curved trying to reflect the rounded lines on a globe.

Provide some background on the projection: 

Created by German cartographer Oswald Winkel in 1921.  "Winkel's goal in his map projections was to minimize three kinds of distortion: area, direction, and distance."  This map centres the Pacific ocean, putting Africa on the left side of the map instead of in the lower right centre of the other projections. This projection was not popular when it was created in 1921- as it became buried in the history of this era.  This map was created at a time of optimism: World War 1 had ended, and society saw an uptake in modernity- that anything was possible through modern technology.  But the rise of the Nazi Party in Winkel's country of Germany, was not the best environment to foster progressive thinking, and so Winkel's projection was not popularized until 1998.


What distortions do you see?: The distortions happen at the side edges of the projection and in the North.  

Historical Context:

• Roaring Twenties
• USSR/ Communism
• Interwar Europe
• Nazism

Each group gives us a little information about the historical subjects, and then we get to the point of debating whether or not we should use this map.

Use this projection?  Why or Why not?:

The Winkel-Tripel Map was adopted as the standard map by the National Geographic Society in 1998 and is most likely the map projection you would see in books and websites today.  

Why?

The Winkel-Tripel map has the least amount of distortion of any projection (using Tissot's indicatrix), and represents area, direction and distance the most accurately of any flat map because it attempts to model the roundness of a globe. This map is best used to map an entire planet, and not usually anything smaller than that.  

Why not?

No map is distortion free, and the Winkel-Tripel Map does have some distortion in the representation of Land masses at the poles.  

Conclusion:

Students get a sheet of chart paper with one of the following sentences: 

1. Maps are embedded with cultural significance.  
2. Maps can be deceiving.
3. Maps have different uses.
4. Maps reflect the history of the time they are created.
5. Maps require a critical gaze to be effective.

As a group, they create a graffiti chart that captures their ideas of what they think this sentence means using their learning from the unit.

1.  Maps are embedded with cultural significance: the Mercator map was a political tool that emphasized certain countries over another, and this was not accidental.  (it make have been unconscious, but not and accident.)  Eurocentrism (that Europe is the centre of the world) became the defining way we saw our maps for 400+ years.  Changing these components of the map resulted in controversy.  Geographers have noted that maps have been and are used as political tools, and it is important to have a critical view of the maps we use. 

2. Maps can be deceiving:  Maps can represent geographical information in a variety of ways.  But because mapmakers are trying to capture a 3D surface on a 2D image, there has to be some distortions to make the map readable and usable.  Geographer Mark Monmonier notes that an accurate map "tells white lies."  Because a map needs to simplify in order to present information, as map readers, we need to accept the limits of the map to use them  This is very different than other "lies" that maps can tell- such as "cartographic imperialism"-- that we need to recognize and be critical of.

3. Maps have different uses: Maps will emphasize certain elements over others depending on the purpose.  The Mercator map was important for sailing- so the representation of the continents was secondary to having straight longitude lines.  The Gall-Peters map is great for population density mapping, but not for mapping distances.  The Winkel-Tripel map is the most accurate, but is only good for mapping entire planets and not portions of a planet.  Each map will have a purpose, and there is no map that would work for all purposes.  That is why it is important to recognize that there is more than one map.  This is crucial for the visual landscape that people inhabit today.  We are bombarded with images, that are used to justify opinions and theories.  Critical reading of these images is important.

4.  Maps reflect the history in which they were created:  The Mercator Map was created to assist in exploration and colonization for European powers.  It makes sense that if would reflect the values in colonization.  The Gall- Peters Map was unveiled in the 1970s, a time in which revolution and social change were happening.  Last, The Winkel-Tripel map was created at a time where the world was optimistic about the future, after the first world war ended, and technology was going to change the world for the better.  Because mapmakers were people living in these specific times, their experiences and values were part of their work.  

5.  Maps require a critical gaze to be effective: Because of the culture, history, politics, and distortion involved in making a map, those of use who look at them need to be "Smart Map Viewers."  That is, we need to recognize the necessary distortions and be suspicious of the lies in our maps.

Sources:

• https://www.juliantrubin.com/encyclopedia/mathematics/mercator_projection.html
• https://www.thoughtco.com/peters-projection-and-the-mercator-map-4068412
• https://www.thoughtco.com/how-maps-can-deceive-us-1435680
• https://www.nationalgeographic.org/activity/investigating-map-projections/
• http://www.educationworld.com/a_lesson/dailylp/dailylp/dailylp009.shtml
• https://source.opennews.org/articles/choosing-right-map-projection/
• https://learn.arcgis.com/en/projects/choose-the-right-projection/
• https://www.youtube.com/watch?v=m7-y8MNzJKI- Jane Elliot "A World of Difference"

How is this Social Justice?

A critical view is the cornerstone of a social justice education.  All our culture is shaped by the politics and values of our society at a given time- even something like maps.  Some thinkers would argue that absolute truth is not achievable because people do not exist outside their experience of society.  So studying how maps can shape inequitable views of some people on our planet, we see that inequity is insidious and is part of all our institutions, and more that inequity is systemic.  

How does this fit into the Curriculum?

Grade 6- B2.1 formulate questions to guide investigations into global issues of political, social, economic, and/or environmental importance

B2.3 analyse and construct different types of maps, both print and digital, as part of their investigations into global issues, their impact, and responses to them

Grade 8- B2.1 formulate questions to guide investigations into issues related to global development and quality of life from a geographic perspective