flattening the Earth

Some thoughts on

Mercator: The man who mapped the planet
Nicholas Crane
Weidenfeld & Nicolson 2002 / Phoenix paperback 2003

The Mercator projection is everywhere these days, although some of us are aware that it is problematic because it inflates the size of countries further away from the equator, thus creating the wrong impression that South America is no bigger than Greenland, and Africa smaller than North America. Alternatives are available but rarely used.

The reason is, of course, Google maps. The Mercator projection is mathematically the simplest way of straightening a globe to make a flat map. You just use the longitude and latitude lines as an orthogonal coordinate system, as your x and y axes. So once you know coordinates of places, it is computationally extremely simple to create a flat map. Nothing wrong with that when you do that for a city map or even a small country, but when people use Mercator to (mis)represent the globe, as Royal Mail does, I come out in a rash.

Reading the biography of the man behind the projection, I learned that mathematical simplicity wasn’t his motivation. He had happily drawn heart-shaped maps of the world before, and he had produced much-coveted globes. The problem he set out to solve was based on the fact that sailors in his time navigated by compass bearing, i.e. the angle between their direction of travel and the measured direction of magnetic north. The simplest way to navigate would be to keep this bearing constant throughout. However, this isn’t the shortest route on a globe, and on most maps it isn’t a straight line. So, to Mercator, the attraction of the orthogonal projection was that the longitude lines will always be straight and vertical, so a route following compass bearing will always be at the same angle to them and thus also be a straight line. Simples.

Born in 1512 as Gerard Kremer, the son of a cobbler latinised his name in line with humanist contemporaries such as Erasmus. His life of just over 80 years neatly falls into two halves, split by a near death experience courtesy of the Spanish Inquisition, after which he decided the Spanish Netherlands weren’t safe for him and settled in the small town of Duisburg on the other side of the river Rhine. Having grown up not too far from that place, which in the 20th century became a major centre of heavy industry complete with Europe’s largest inland harbour, I found it cute to read about the peace and quiet Mercator found in the town, where he completed most of the work that he is remembered for, including the first maps using his famous projection and the book of maps that gave us the word “atlas”.

His move was linked to plans to launch a university at Duisburg, which then fell through. The town later did get a university, which was founded in 1655 but dissolved in 1815. The modern university was set up in 1972 as a Gesamthochschule. In 1994 it was named Gerhard-Mercator-Universität, but in 2003 Mercator lost this honour again, as his university merged with the University of Essen.

Another irony is that, while Mercator mapped all of the known world, and even some speculative geographies that turned out to be fictional, such as a ring of islands surrounding the North Pole, he never left the boundaries of a map of the Rhineland area shown at the front of the book, which covers around 400 km by 600 km. (It amused me that this map prefacing a book about a map maker shows Cologne on the wrong side of the river Rhine. As Colonia is a Roman foundation, it’s not hard to remember that it belongs on the left bank.)

Crane published the biography in 2002, before Google maps started flooding the world with Mercator projections, but I was still a bit disappointed that the epilogue doesn’t even mention the perception problems it creates and the alternative projections that others have produced to create a fairer representation of the planet. The biography is available as an e-book but the paper version seems to have gone out of print, unfortunately. Mercator's 500th birthday in 2012 would have been an opportunity for a new edition both to celebrate his work and re-assess it in the brave new world of Google maps.

PS: I just discovered his descendants are on GedBas. No obvious connection to my family history, but good to know.

prisoners of climate change

book review:

Prisoners of geography: Ten Maps That Tell You Everything You Need to Know About Global Politics

Tim Marshall

Elliott and Thompson paperback edition last updated 2019

If you’ve always wondered why Russia, China and the USA are so large, while other parts of the world present a patchwork of smaller countries, or why some areas seem to have permanent conflicts while others don’t, Tim Marshall has some very simple geographic answers for you, based on where the mountains and the plains are, how the rivers are navigable, and whether the coasts have natural harbours.

The vast North East European plain, for instance, where both Napoleon and Hitler sent their troops towards Moscow, explains why Russia had to grow big to find safety in strategic depth, and why it sought additional layers of shielding in the shape of the Soviet Union and the Warsaw Pact. It is also why Russians don’t like the idea of a westernised Ukraine. Marshall explains similar geographic drivers behind China’s obsession with Tibet, or Israel’s problems with Gaza and the West Bank.

Elsewhere, it’s not so much the geography that drives conflict, but the colonialists’ complete recklessness at ignoring it and just drawing lines on their maps of Africa and the Middle East to create states that have no rhyme or reason to exist. Thus, people in Iraq or the DRC are not only prisoners of geography but also of the fallout from colonialism.

This is all good and well and does a good job at giving a round-the-globe overview for a globalised time, bringing together issues that many people will have only registered separately or partially. Marshall published the original version in 2015, and has done some patching up to fit in developments like Brexit and the fall-out from the Trump presidency.

What he fails to include adequately, however, is climate change. While he dedicates a chapter to the changing reality of the Arctic and also mentions elsewhere that Bangladesh is at risk of disappearing under rising sea levels, his discussion of the strategic importance of energy resources such as new gas and oil reserves in the Arctic never once mentions the fact that humanity cannot afford to use these resources if we are hoping to keep warming under the Paris goal of 2 degrees. Heck, if we do use the fossil fuels in the Arctic, we’re probably going to go over 4 degrees in my lifetime.

Unless we’re going to live in a world run by a cynically operating Russia – standing to benefit from climate change and not giving a damn about the rest of the world – the whole geopolitical reasoning explained in the book will have to change fundamentally, because we are not only prisoners of geography, but also prisoners of the man-made climate catastrophe.

finding Minden

In the course of my project concerning Heinrich the cello (and Frieda the piano) it dawned on me that in the 1960s, my family not only lost the musical tradition, but also the habit of living in civilised cities (as opposed to in the middle of a field which is where I grew up).

Having obsessed about Elberfeld and Strasbourg already, I have now decided to make this a series, called #lostcities and using period postcards for illustration. I’ll pick a few nice examples out of the around 20 places where the three generations before me (i.e. 14 people with their offspring) lived, basically, the places where I wouldn’t mind moving in myself.

Minden in 1907. The Fishers' district and the canal crossing are to the right of this frame.
Source.

Number 3 in the series is Minden, where my grandmother Frieda, the pianist, grew up. Her mother died relatively young but her father stayed in Minden half a century, from his marriage to his death, so this may be a record for the longest stay in the same town in this generation of otherwise quite mobile people.

There is a geography board game using the tag line “Finden Sie Minden?” (Can you find Minden?) which seems to suggest that it is so obscure many people don’t know where to find it. In fact, the reason why it remained small when other cities grew in the 19th century is linked to its special location. Let me explain.

Minden is located on the river Weser just downstream of where it cuts through a mountain range, so it’s presiding over the most convenient place to travel North-South without having to cross those mountains. Accordingly it has always been militarised and fortified, and the city walls strangled its growth in the 19th century when other cities that had been less significant, started to industrialise and grow rapidly, including eg Elberfeld. The walls only came down in 1879, by which time industrialists had set up their industries elsewhere.

On the other hand, this location also made Minden a transport hub. One of the earliest long-distance railway lines in Germany connected Cologne with Minden, and the town also had early rail links to Berlin and Hannover, so it was an important rail hub in the 19th century and it still is, to an extent There are still direct trains running Cologne to Minden, and even some ICE trains stop there. They are a bit hard to find but I checked and, for instance, on Monday at 23:47h you can catch ICE102 from Minden to Hannover.

It is also a central crossing of water ways, as the major East-West canal (Mittellandkanal) crosses the river Weser just to the North of the city. The canal stretch connecting the rivers Ems and Weser as well as the spectacular river crossing were completed in 1915. At that time, Frieda and her parents lived just a short walk away from the canal bridge, in the picturesque fisher’s quarter (Fischerstadt) in the corner between the former city wall and the river bank. Frieda’s parents stayed there for the rest of their lives and looking at the old photos I can see the attraction (although Minden fails my official residence criteria for not having a university).

Update 16.10.2021: In September 2021, I revisited Minden the first time after 35 years. New blog entry here, lots of photos on flickr.

20000 leagues under the sea

Open Archive Day

A year ago, I enjoyed reading up about the late 19th / early 20th century pioneers of bathymetry, or the measurement of ocean depth (or sea floor topography, depending on whether you prefer your glass half full or half empty). Much of it sounded like a Jules Verne novel, with the sense of awe for the as yet unexplored which we appear to have forgotten, even though the sea floor remains poorly described to this day. So the vague memory I retain of the feature I wrote is that it was all about Captain Nemo, although in truth it probably wasn't.

The feature is now on open access so you can check for yourself:

How deep are the oceans?

evolution of cities

towns and cities seem to be growing "naturally" wherever humans decide to settle and start to trade. Intriguingly, some key parameters of their growth appear to have remained constant from antiquity to this day, suggesting that neither technology nor political organisation has had much of a say over the human tendency to aggregate. Now, however, as the majority of people already live in towns and cities and billions more are to follow, we can't allow settlements to grow on their own. Good and sustainable planning is required to make sure that the dramatic urbanisation of our species doesn't lead to large scale disaster.

I've explored these issues in my latest feature which is out now in Current Biology:

The urbanisation of our species

Current Biology Volume 26, Issue 23, pR1205–R1208, 5 December 2016

FREE access to full text and PDF download

The mathematical equations relating the growth of population density of a city to its population size apply to medieval cities just as well as to modern ones. The photo shows a side road in the historic part of Mainz, Germany (own photo).

sea floor mapping

I have on various occasions used the statement that we know the surface structure of Mars in greater detail than that of the sea floor on our on planet, and I understand that it is still true overall, but oceanographers are now working to close that gap in our knowledge. Just over 100 years after bathymetry, the science of measuring the depth of the oceans, and thus the topography of the sea floor, began in earnest, experts now met to lay out plans for future progress in exploring what's under the water. This knowledge is important not just for seafarers and fishing industries, but also for the safety of landlubbers in the face of sea level rise and tsunamis.

Read all about it in my latest feature:

How deep are the oceans?

Current Biology Volume 26, Issue 11, pR445–R447, 6 June 2016

permanent link to full text and PDF download
(open access)

The combination of advanced sonar and satellite technology can produce high-resolution 3D models of seascapes like this one in the Caribbean. However, for much of the sea floor, there is still insufficient data. (Source: http://pubs.usgs.gov/of/2004/1400/).

the world according to Royal Mail

in attempt to get my brain round the staggering price increases, I had a good look at Royal Mail's new price leaflet and found that according to them, Greenland is larger than South America:

Now I do know that applications like Google maps use the Mercator projection because it is easiest to calculate when you want to zoom in and out of maps. However, in my opinion, if you display a static map like this there is simply no excuse for using it. It distorts the relative importance of various parts of the world and is thus offensive to anybody who cares about such "small" places like Africa and South America.

The full leaflet with the offending picture is also online as a PDF file.

what the world doesn't look like

I find the use of the Mercator projection to portray the world offensive in any context (as it hugely distorts the sizes of countries and continents, Greenland isn't really larger than South America, it's a lot smaller!), but in the context of trying to help developing countries (which all appear small and insignificant in this projection) it really drives me up the wall.

Apparently, applications that allow you to zoom in and out of maps, like Google maps routinely use the Mercator projection, as this is the easiest one to calculate (it’s all in squares), but that’s no excuse for displaying the world in a blatantly misleading way, as, for instance, Oxfam does here:

Food price volatility map

I am sure the clever people working at Google and other internet companies can come up with a way to program interactive maps without making tropical countries shrink to insignificance?

If one has to have a cylindrical projection (where all the longitudes and latitudes are straight lines), one could use the Gall-Peters projection:



(Wikipedia)

which with its very unfamiliar look reminds us how wrong the maps are that we see more often. Personally, I prefer the round or oval projections, as they also remind us that our planet isn't rectangular, e.g. the Lambert azimuthal equal-area projection.

PS checking up on Google I realised that even their satellite view is in Mercator projection. Surely the satellites don't observe a cylindrical planet from space?

magnificent maps

On my last visit to London, I had a few hours spare and went to the Magnificent Maps exhibition at the British Library, just because it happened to be on my way. Found it really interesting in the way it shows the different ways in which maps have been used in different contexts - each represented by a room of the venue, e.g. the audience chamber, the bedchamber, the merchant's house, etc.

I actually tend to put maps on my walls as well, have a huge pseudo-realistic view of Europe on display, and an aerial photograph of Oxford (kind of a map as well). Sad though that satnavs and google maps will drive all map makers out of business, so I'm not sure whether there will be any maps from the 21st century to feature in future exhibitions.

Magnificent Maps continues until Sept.19