Africa in different projections - Gall-Peters, Google's and Winkel Tripel
As the world's oldest printed atlas sells for £2m, our impression of what the Earth looks like has changed almost beyond recognition. But even now, it's hard to find a truly accurate picture of our planet.
Looking down at a map, the viewer thinks their eyes are taking in a snapshot of the Earth. But are they?
Between the oldest and the most modern incarnation of the printed atlas there are 500 years of mapping history filled with debate over how to represent the world. How to show countries' size, relief and relations? How to project an almost-spherical surface on to a flat one, but keep it accurate?
Cosmographia - Not right, but still valuable
"If you peel an orange, you can't lay it flat and there's never an answer to that," says Steve Chilton, chair of the Society of Cartographers.
And that is the problem: map-makers have always compromised for their art - tweaking scale, distance or area to paste the world down. Making Greenland loom large, or squashing Africa to a narrow frame in the process.
The oldest printed atlas, Claudius Ptolemaneus' Cosmographia, has sold at auction for £2.1m. The buyer paid not for a good grasp of the world, but for a picture of three continents, with England butting the Bay of Biscay and Scotland floating in the German Sea.
In the race for reality, maps have come a long way since then. But with internet tools like Google Earth, cartographers feel they have taken a major step forward in showing a real picture.
On a world scale, the pictures on Google Earth, and programs like it, look accurate. The view is less skewed than with some other projections, such as cartographic models used to set out the world.
It is a step forward in the way satellite and map images combine; and it hands control of the view to the user, says Jethro Lennox, senior publishing editor of world atlases at Collins Reference - behind the Times Concise and Comprehensive Atlas of the World.
Mr Chilton agrees: "It's revolutionised the understanding of the earth in visual means. There's a sense people now expect to see things not as a static map, but flipping it around and from different perspectives.
"You can see aspects you couldn't see before. You can zoom in on the Antarctic, the rainforests, and see the rapid change in the world - like the development of the Dubai Palm islands."
In high places
Does it matter that we achieve an absolutely accurate picture of the Earth for common use? Yes, not least because knowledge is power.
The latest Times Concise, out this month, uses different projections for world maps or magnified regions, to try and make them as definitive as possible. It is updated with new and controversial structures - Tibet's 1,118km-long new railway; the Three Gorges Dam in China (with the 100 drowned settlements scrubbed out); France's ambitious Millau bridge.
Maps have come a long way...
It and its larger sister publication, the Comprehensive, inform decision makers in the Foreign Office, the UN, World Bank, down to schools and libraries.
Along with the new computer-based maps, they present a different picture of the world from something like the Peters projection. It has been backed by some Christian groups and left-wingers since the 1970s as a "non-racist" map that makes it easier to understand international relations.
Looking unlike the world and more like wet washing on a line, and largely discredited, it made it to the West Wing - but only as a topic of discussion in Martin Sheen's TV series version.
Handing the tools from the cartographer to the user has encouraged other programs - Nasa's World Wind and Wikimapia - like the online encyclopaedia.
People are making their own maps, like the OpenStreetMap project, and "mashups" have been born - where maps are customised with data for practical and frivolous purposes: to make an "earth sandwich" between opposite spots on the globe; explore shops on Oxford Street; or find the supposed location of North Korea's nuclear tests.
Death of the map?
So do cartographers feel threatened?
Not yet. Many sites are free and make no expensive promise about fact-checking or updates. Outside North America they are less comprehensive and information is limited.
... but the 2D problem remains
"It may be intelligent software, but it has to be used intelligently," says Mr Chilton. "It's a 'wow' thing - people look at it and say, 'I can see my house'. But in reality, what is it doing apart from showing us something rather cool?
"Google Earth is just the satellite image. It doesn't show us land use, slope, precipitation. So the need for cartographers still exists. The paper map hasn't died."
And it still does not solve the age-old problem. On a world scale, all's well, "but when you zoom in you still get that distortion, because it's on a flat screen", says Mr Lennox.
The solution? A globe. But to show us the world in useful detail it "would have to be massive".
I'm glad there is a story highlighting the variations amongst maps. However, we should recognise that maps are not objective projections of the world. In order to understand maps, we have to understand them as images, as stories, as political tools. Each projection is defined by its author, its political origins, the angle at which it is drawn, the colours used and indeed the reason for its existence. To suggest there is one 'accurate' map out there is arrogant and absurd. There will always be thousands of interpretations of maps - each map is valid, even if interpretations are wildly different. Maps are not inate projections of 'what is there' - they can highlight or obscure certain features, political arrangements, and even marginalise people. They are powerful, political prescriptions of what should be there.
Joe G, Oxford, UK
It's a shame you didn't mention Buckminster Fuller's Dymaxion World Map, which is still considered by some to be the most accurate representation of the landmasses of the Earth, albeit at the coast of splitting the oceans up into separate regions.
Steve Wheeler, London
This problem was elegantly solved by Buckminster Fuller with his Dymaxion Map Projection - which shows the Earth's landmass as 'one island in one ocean' without distortion.
Julian Pixton, Cambridge, UK
Maps are simple works of art serving a practical purpose. The trouble with digitising geographical information is that computers can't perform either job particularly well. You only have to look at the poor quality of data-generated online maps and sat nav maps to appreciate the skills of an experienced cartographer.
Tarun Patel, Gloucestershire
I'm lucky enough to have circled the world, both directions more than 6 times. However to those who dont travel, here at home, explaining to someone directions to a restaurant in some remote town in a far flung place is meaningless...until Google.. now I can show the world, zoom to the city, find a picture of the street and sometimes even see people sat at the table .. then the map comes to life as more than just some coloured lines and labels !
john hyde, London, UK
It crossed my mind at the end of this article that instead of a globe, you could have a sheet screen (using the same kind of tech that the roll-out computer screens in development rely on) that could deform in real-time. So it could start out quite severely curved and showing the whole of Europe, and then as you zoom in, it would flatten out until it was essentially flat at a local scale.
Possible in the next few years, and would certainly be cool.
Google earth's feature set extends far beyond mere satellite image mapping and projects this onto a truly 3d representation of our planet. Elevations, land boundaries, roads, route planning, community-contributed place-marking and dynamic data overlays (for precipitation, charting satellites, boat voyages and so on) are all available even in the free version.
Christopher Thorpe, York, UK
A timely reminder of that classic axiom "The map is not the territory". It would have been nice to have seen a mention of R Buckminster Fuller's Dymaxion map of the 1940s/50s - where Bucky tried to address this same scaling issue using his geodesic designs. Ah well, can't have everything...
Tom Lennon, Birmingham U
The Peters projection is not, as your article says, "discredited" but rather disliked. As a two-dimensional map, it's no less an accurate representation of the world than any other attempt to tranfer a three-dimensional world onto a two-dimensional plane. At least with the Peters projection you don't have Greenland blown up to the size of Africa...
As a projection it's been around since the nineteenth century
I remember the map of the world on the classroom wall at school showed Greenland the same size as Africa. I always thought that couldn't be right.
Steve in Notts, Notts, UK
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