From Mercator’s to Gall-Peters projections, how the world maps vary and change

Mercator’s Projection. Source: Wikimedia Commons

Mercator’s Projection vis-a-vis Gall Peters Projection

For almost 500 years, the Mercator’s projection has been the norm for maps of the world including Apple and Google Maps. It ubiquitously resides in atlases, and has been widely used by students in schools. Gerardus Mercator, a renowned Flemish Cartographer, devised his map in 1569. Modern cartography originated with the era of European colonialism as maps were indispensable for exploring sailors to navigate the oceans. Mercator’s main concern in his projection, thus, had been to provide a means of exploration by aiding navigation along colonial trade routes by drawing straight lines across the oceans. 

The Mercator’s projection may not be a bad map per se for its purpose, however, it has been in the wrong place for too long. It enlarges and puts Europe in the relative center of the map, by pushing the equator below. The Gall-Peters projection, which gives priority to the relative proportions of the landmasses, set a cat amongst pigeons when it was first re-introduced in the 1974. Its main achievement was a revision of the Eurocentrism inherent to Mercator’s projection — which in itself is a paradigm shift.

Here are some key proportional irregularities of Mercator’s projection that it checks: The African continent is vast but appears squashed in size on the Mercator’s projection, where Greenland appears to be of the same size. In reality 14 Greenland islands could fit into the African landmass.  South America looks almost the same size as Europe, when in actuality it is almost twice as large. Also, Finland oddly looks longer from north to south than India, when it is actually the other way round.

Playing with cartographic projections can be no less than a paradigm shift. lefruitbat / Via imgur.com

One result of switching to Gall-Peters projection is that on one hand, it immediately cuts US, Britain and Europe down to size and on the other hand, Africa and South America appear narrower but also much larger than usual. Its cartographer, Dr. Arno Peters, had criticised Mercator’s projection in 1973 by saying, “It over-values the white man and distorts the picture of the world to the advantage of the colonial masters of the time.” A spirited discussion about the vis-a-vis implications even featured in an episode of the popular American political drama The West Wing, in which characters had argued for the Peters map to be used in American public schools and told the administration that the Mercator projection had “fostered European imperialist attitudes for centuries” and created an “ethical bias” for “western civilisation” against the developing world. Watch it below:

The Gall-Peters projection is widely used in British schools and promoted by the UNESCO. Although politically more correct, it is not without flaws: it distorts the shapes of the continents as a result of two dimensional visualisation of three dimensional landmasses.

All maps lie to some extent. 

Dutch designer Ruben Pater, who creates visual narratives about complex political issues, notes that the notion that maps provide a mostly objective or scientific depiction of the world is a myth. “The graphic nature of maps simplifies reality, giving makers and users a sense of power without social and ecological responsibilities”, he writes. In the colonial days, maps not only provided means for navigation, but also legitimised the territorial conquests.

The north-up orientation of the maps is also a construct of convention (which in turn is due to an interplay of chance, technology and politics), as planet earth is moving through three dimensional space without any reference point of ‘up’ or ‘down’. McArthur’s universal corrective map, was world’s first modern South-up map published in 1979 by Stuart McArthur, an Australian tormented for being told that he came from the “bottom of the world”. It literally turned the map on its head, with the southern hemisphere appearing on top.

McArthur’s Universal Corrective Map of the World. Credit: Pinterest / odt.org

There is widespread agreement on the fact that the globe can’t be beaten in its accuracy — but it does not permit a view of the world at a glance, which is what necessitated maps. The way a sphere is translated into a flat surface called a projection. There is no such thing as the most accurate projection, since no curved surface can be projected without distortion.

The basic problem of mapping the globe — how to transfer an oblate spheroid onto a flat surface — is not a straightforward formula. In a passage within Zia Haider Ali’s novel ‘In the light of what we know‘, the narrator compares the cartographer’s job to that of a translator of a poem: “Both of them face the same problem, namely, that they cannot capture everything exactly and they have to give up some things in order to convey anything at all.” There is an unavoidable case of ‘lost in translation’ because the cartographer cannot let the globe stay a globe and the translator cannot simply hand the readers the same exact Hungarian poem with a word dictionary. In going from the curved surface of the earth to the bounded flat surface of the map, the cartographer would ideally want to preserve a number of aspects such as the relative distances, relative areas, angles, shapes and so on. But they can’t have keep all of the information and must therefore prioritise.

A compromise: Winkel Tripel Projection

Winkel Tripel projection. Source: Wikimedia Commons

Finally, there are also a series of compromise projections. The Winkel Tripel projection, for example, was developed in 1921 by Oscar Winkel. It is special as it is a compromise projection, which means that it mitigates extreme distortion to all geometrical properties: area, distance and angular, by “compromising” to an extent on all of them. In other words, it is neither equal-area (area preserving), conformal (shape preserving) nor equidistant (distance preserving) – but an overall, relative compromise between all these aspects. National Geographic officially adopted this projection in 1998.

It is thus important to understand the map before using it on face value to understand the world as it depicts.