I think, therefore I harm
Early civilizations saw the need to represent their world on maps, so they could keep track of the location of features and the limits of their territories. This was easy at first, but as these cultures developed into large nations and empires, drawing and maintaining these maps became tedious. They had to come up with more complex methods and systems which they would agree upon and understand.
As these nations made allies and conquered foes, maps became an expensive currency, something they exchanged with those they really trusted. At that point, it was necessary to adopt a system the other nations would agree with. Things as simple as which way should be up was a problem because nobody had the same vision of their world.
The system in use today consists of a coordinate system which refers to a point on the surface of the planet. Latitudes are horizontal lines which circle the Earth, with its origin at the equator. Latitudes are equidistant and parallel. Longitudes or meridians are the vertical lines which run pole to pole, with the prime meridian at Greenwich, UK. They are farther apart at the equator, and join each other at the poles. In the past, other systems were used, including one in which the length of the longest day of the year was used to determine the position of a place relative to a pole.
The best representation of the Earth is a globe. While a globe makes for a pretty piece of furniture, it isn’t convenient in every situation. For instance, you cannot fit a globe in your pocket. Furthermore, it would be a ridiculously wasteful representation for smaller detailed areas. Even if Google Earth is technically a globe that you can bring with you and zoom into small details, it still keeps one further inconvenience of globes. That is, you cannot see the entire world at the same time.
A common misconception is that educated people at the time of the European explorations thought the Earth was flat. The myth is portrayed in many representations of Columbus, insinuating that the aim of his voyages was to prove the world wrong. In fact, the concept of a spherical Earth was introduced by the Greek astronomers circa 500 BC. By 300 BC, the idea was widely understood and accepted in Greece and other European countries.
Still, it was necessary to draw maps on flat surfaces. A perfect 2D representation of the world is impossible. Have you ever tried to flatten the crust of an orange on a table? No matter how hard you try, projecting the 3D Earth on a 2D surface is sure to introduce many imperfections. Shapes are going to be distorted, relative sizes of areas of land will be broken, or calculation of distances will get inaccurate. For small areas, such as city maps, these inaccuracies may be insignificant. For larger areas however, such as for a world map, such inaccuracies may become unacceptable.
Projections may be chosen for particular purposes to get some qualities, at the expense of the ones that are not required. In 1569, Gerardus Mercator introduced a world map which is known as the Mercator. He chose a projection that was easy to use to teach geography and usable as a sea navigational tool. By using straight horizontal and vertical lines to represent latitude and longitude, effectively splicing the world into squares of equal size, the Mercator makes it easy to locate places using coordinates, and easy to understand by people. It is usable for navigation because small objects retain their size.
The Mercator however introduces a number of problems. On a spherical Earth, the meridians join each other at each pole, so that the distance between them is shorter near a pole than near the equator. The Mercator makes the distance between the meridians equal at any point. In effect, every object near a pole appears larger relative to those near the equator. For instance, on the Mercator projection, Greenland appears the size of Africa, when in reality Africa is 14 times as large. Antarctica appears like an infinite landmass to the south, though it is actually about the size of Australia. It is thought that this projection was adopted by the European empires to make them appear larger than their foes to the south. In particular Africa, being the center of the map, seems a lot smaller than it really is in comparison to the rest of the world. Africa is a huge continent in which fit both the United States and Europe.
Almost 450 years later, the Mercator projection is still in common use today, and probably the most popular projection. For instance, the Mercator is used by Google Maps, probably because it is easier to move around and zoom in. It’s popularity is also attributed to its convenient rectangle shape which fills well as a wall map, but also because it is mostly very familiar to mostly everyone. The problem of its incorrect relative representation of sizes, however, was already frequently quoted in the 1940s and cartographers were pushing the media to pick different projections. It was stated that the Mercator was almost always chosen while other projections would have been more suitable in most cases.
In 1973, German historian Arno Peters presented the Peters projection, which he claimed he invented, not knowing that the same exact projection had been published by Scottish clergyman James Gall in 1885. Because of the accidental reinvention, this projection is known today as the Gall-Peters projection. Peters compressed the latitudes toward the poles so that objects near poles would appear the right size relative to objects near the equator. Initially ignored by the cartographers, in part because it was yet another new projection among many that had been proposed over the previous few decades, The Gall-Peters projection gained popularity and was adopted by social centric groups, which had been looking for a projection that wouldn’t reduce the apparent size of emerging countries. Peters also claimed that his projection was better at preserving shapes, angles and distances, all of which were false. In fact, to the problems already present on the Mercator, the Gall-Peters projection adds a greater distortion to all of the landmasses near the poles. By fixing the problem of relative sizes, Peters actually worsened the Mercator. Only accurate along the 45th latitude N/S, the landmasses appear vertically elongated toward the equator and compressed toward the poles.
Initially amused by Peters erroneous claims toward his projection, cartographers soon turned hostile when they realized the Gall-Peters was gaining popularity. In the 1980s, irritated by the overuse of the Mercator and the adoption of the Gall-Peters as a worst replacement, cartographer associations began publishing pamphlets and booklets to educate the public regarding map projections and distortion in maps. By the early 1990s, many geographic associations had adopted a resolution to avoid any rectangular world map, a category which includes both the Mercator and the Gall-Peters projections.
The Earth is round, and for most purposes only a round or elliptical map is suitable. Over the years, many such projections were introduced, all of which showed different qualities, which made them suitable for different purposes.
Mathematician and astronomer Karl Brandan Mollweide introduced such a projection in 1805. Known as the Mollweide projection, this world map favors accurate proportion of areas, but sacrifices angles and shapes. The Mollweide projection is basically a 2:1 ellipse that depicts the entire planet centered with the equator as a straight horizontal line and the mean meridian as a straight vertical line. All other meridians are curved and join correctly at the poles, two points at the top and bottom of the map. The Mollweide weakest feature is to exaggeratedly curve all the continents outward.
In 1923, American cartographer John Paul Goode experimented by interrupting the Mollweide, breaking the map in the oceans, and thus giving the continents their correct shape, while preserving Mollweide’s property of correctly representing relative size of areas. Often called interrupted Mollweide, or orange-peel map because of its ressemblance to a flattened peeled orange crust, it is formally known as the Goode homolosine projection. This map gained popularity in the 1960s and is often used to portray global phenomenons. A variant where the map is interrupted in the middle of continents rather than the seas is also used to show the oceans in their correct size and shape.
American cartographer Arthur H. Robinson created a map that was meant to look good. You guess it, it’s called the Robinson projection. Halfway between Mercator and Mollweide, it is still an elliptical map but the poles are stretched into long lines rather than just points. Sacrificing exact land proportion and perfect accuracy, Robinson worked out a projection that was visually pleasant. It was adopted by Rand McNally in 1963, the company that drew all the maps in every single encyclopedia, dictionary and school book printed in the western world in the last few centuries, and adopted by National Geographic in 1988. If you are under 45, this is the one non-rectangle map that you grew up with, and you hated it because it wasn’t the Mercator you used to see at the front of the class.
In 1998 though, National Geographic switched to Winkel-Tripel. Proposed by Oswald Winkel in 1921, and thus preceding the Robinson, the word tripel, German for triple, was meant to represent its three major qualities. The Winkel-Tripel shows correct proportions, directions and distances. Shapes are reasonably maintained, except for the curves which are inherent to any round map, though they are here acceptable. The pole lines are shorter than the Robinson, but the Winkel-Tripel most noticed difference is the curved latitudes.
So, which one is the best representation of the world? It happens that there is not a single answer. Some projections are better for some particular purposes. Each particular purpose may require a particular set of qualities, and no 2D map could ever perform well in all areas.
My choice is Winkel-Tripel. Because I love National Geographic. And hell, you got to love that name. Just picture yourself mentioning the Winkel-Tripel projection in a casual conversation.
But if you can, prefer a globe. But, pretty please, don’t pick one with the pseudo-textures of mountain ranges. At the same size, the Earth would be smoother than a billiard ball.
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