Don’t worry, Star Wars fans – I’m not really advocating avoiding the movie release this weekend – just the title of this article by Roland Hughes, at the BBC amused me.
For those of you who clicked this article really wanting to avoid Star Wars, I’ll quickly summarise Roland’s advice:
- Move to Bhutan
- Don’t go to the cinema
- Avoid human contact
- Don’t go online
- Retreat from society completely
- Stay in and read a book instead
As a science fiction fan, I have no idea why anyone would want to avoid seeing the film – but I was really puzzled by Roland’s advice: Move to Bhutan.
The above map chart is a visual representation of search data by country on the new film. Aside from the obvious point that the data set is incomplete (Roland himself admits there is no data for some African or South East Asian countries) – there is no scale or explanation of what the ‘trend rating’ is actually about.
More disturbingly to me, is the distorted representation of the planet. You see, Google has chosen to use a Mercator projection in order to represent a global picture in a two-dimensional chart. The challenge with any map is how to faithfully represent an outline on a sphere projected onto a flat surface. There is no right or wrong answer to this- it’s a question of for what the map is to be used for.
The Mercator projection of the world (above) is something we’re all very familiar with. Most of us don’t even realise though how distorted a view on the planet it provides us with. The original intention of the 16th Century Flemish cartographer Gerardus Mercator was to be able to help seafarers navigate around the planet by being able to draw a straight line course on the map that would also correspond to a straight line course by sea. You can see, for navigation it is perfect – for a representation of comparative data it’s pretty misleading.
The biggest problem with the Mercator projection is that it ‘explodes’ proportions of shapes the further from the equator a particular outline is. If you look for example at Greenland, it appears to be an equivalent landmass to Africa but in in reality Greenland is about 1/15th the area (2m sq/km vs 30 sq/km). Similarly Canada and the Russian Federation are enormously out-proportioned to South America and India.
An alternative to the Mercator projection is provided by 19th Century German cartographer Karl Mollweide. Compromising a distorted outline of countries for a faithful representation of proportion; it’s the map with the most integrity for any form of comparative data, such as global interest in the new Star Wars movie.
Unfortunately, though the Mollweide projection suffers from a few drawbacks. Because of the elliptical silhouette of the projection, its aesthetic is not seen to be as attractive as the Mercator. That is why it’s often de-selected as the projection of choice.
Secondly, and perhaps cynically – the world at least until the early 21st Century has been dominated by Europe and North America. One of the greatest coups of the British was to win the war for time-zone supremacy, thereby destining the United Kingdom to sit at the top-centre of most depictions of the world. What better therefore, to subtlety promote a view of the world that provides even greater prominence to the UK by distorting its relative size (about 5x greater using this projection method).
The problem is that we seldom challenge what is placed in front of us. We live in a world where science is accepted as fact, and things which appear to be a product of the scientific method are not questioned. We therefore see a map of the world, and recognise it to be what it says it is. In no other aspect of data visualisation would such a gross misrepresentation be acceptable. Increasingly also has our source of authority shifted from academics to informatics. Wikipedia is the repository for all knowledge, Google is the great Oracle for any question. This is why the burden for organisations such as Google when they present information like this to get it right, and not mislead, is even more important. Their error perpetuates the fallacy, which is carried generation to generation, unchallenged and unrestrained.
When thinking about how best to represent global distribution data by map, this great philosopher probably has the wisest words of wisdom:
“Judge me by my size, do you?” – Yoda in The Empire Strikes Back
May the force be with you.