Map Making

Jerry Brotton argues in his book, A History of the World in 12 Maps, that mapmaking has always been a contentious topic, from Ptolemy to Google Maps. Or at least that’s what one book review says. Maps always “shaped—and were shaped by—various political, religious and social movements”, says the review.

There were 3 maps I found interesting from his list. The first was the eponymous Mercator map, the one we have all grown up from school, named after the Belgian cartographer Gerard Mercator. It was drawn way back in 1569 and has surprisingly never been improved on, despite its obvious drawback. As a less than 7 year old, I remember a jigsaw puzzle of the world’s map that made it look like Greenland was bigger than India! Wikipedia goes one further and points out that:

“Greenland takes as much space on the map as Africa, when in reality Africa's area is 14 times greater.”

The cause of such severe distortion is obvious: The Mercator map attempts to “chart the contours of the globe on a flat surface”. Obviously the map is missing the distortion compensation factor…but to really see how wrong the map is in terms of relative sizes, check this out: Africa can house the US, China, India, most of Europe, Japan and still have some room left! Don’t believe me? Remember, a pic is worth a thousand words:

Despite such severe distortions, the first serious shot at the Mercator Map only came 40 years back when Arno Peters came up with, well, the Peter’s Map. This is how his projection looks:

Compared to the maps we are all used to, check out how small Europe looks? And how big Africa looks? More importantly, if this was more accurate, why didn’t it catch on? Well, not everyone agreed that this too didn’t have its own distortions. And not everyone (read the richer countries) liked Peter’s political agenda of “forcing residents of wealthy nations to adjust their worldview”.

The third map of the book was the one I totally disagree with: its criticism of the latest attempt to map the world, Google Maps. So what is Brotton’s issue?

“(T)here is a crucial difference between what Google is doing and what went before, which is not simply about scale: it concerns the computerized source code used to build its geospatial applications…For obvious commercial reasons, Google does not disclose the specific details of its code, which means that for the first time in recorded history, a world view is being constructed according to information which is not publicly and freely available.”

I do agree that Google’s (source) information is private. Where I disagree with Brotton is on the accuracy of Google’s maps. Unlike other maps, Google’s maps are used by everyone to get distances and driving directions on a daily basis all over the world. If the maps were wrong, wouldn’t everyone see it? Why would they still use it? And if you agree that Google’s maps are correct on the smaller scales just mentioned, where would the (big) errors come in when putting the smaller maps together to create the world map, one town at a time? If for no other reason, I trust Google to get this right simply because they are doing it for money and they get verified by daily users of their maps, not some “authority” in an ivory tower.