From coconuts to GPS: A brief history of navigation

It's good, but it's no coconut. Image: Getty.

If I ask Google:

It helpfully displays a map of where I used to live:

Google is very good at knowing where I used to be. My phone is constantly keeping track of my location and uploading it to their servers. It has stored my location 579,088 times since September 2013.

Each location stored looks like this:

{
 “timestampMs” : “1431497952458”,
 “latitudeE7” : 513453840,
 “longitudeE7” : -1015043,
 “accuracy” : 27,
}

This isn’t that easy to read. The E7 is an instruction to divide by 10,000,000, to reach a traditional set of latitude and longitude coordinates. “timestampMs” tells us that wherever 51.345384° N -0.1015043° E is, I was there at 1,4314,9795,2458 milliseconds after midnight on the 1st January 1970.

Even knowing what each of those numbers represent, we need to do some work to get these back into a human context. By putting the numbers through mapping software I can find out that “51.345384°, -0.1015043°” is Purley Oaks station in South Croydon. By running the timestamp through a conversion system, I can see I was apparently there at 7:19:12 AM on the 13 May 2015. This makes perfect sense, it was part of my daily commute at the time — I’d have been there most days at that time.

Most of the data stored about my location places me somewhere I lived or somewhere I worked. Just occasionally, I do something interesting and the database gets to store whole new sets of coordinates. If I take several years of this data I can produce maps of the sums of my positions over time:

This is my life as latitude and longitude, expressed in a way that can be easily understood by a human. Where I’ve spent any amount of time the map is redder; journeys appear as snail trails across the country.

Google’s algorithms don’t require any of this “coloured in map” nonsense. After a few weeks, your Android phone can make a reasonable guess at where your work and home are, based on where you spend most of your days and where you spend most of your nights. It doesn’t need to ask — that would be intrusive.

To determine a position on a globe while inconveniently being stuck on that globe you need fixed external references. Fortunately the universe is full of these.

One of simpler means sailors used to work out their relative position from destination was a kamal – a board with a hole in the middle. By putting a string through the hole and holding one end of the string in your teeth, you position the lower edge of the board on the horizon and move it further away until the board obscures your target star (typically Polaris — if visible).

An enthusiastic Wikipedia editor showing how the kamal works. Image: Markus Nielbock/Wikimedia Commons.

The length of the string between your teeth and the board tells you your latitude. By knowing the length of string required for certain ports, you could adjust course to navigate to a place. Using nothing more than your teeth, a string, a plank of wood, a star – and the horizon.

In Polynesia (lacking in a helpful pole star) titiro ‘ētū – “star peekers” – made of nothing but coconuts and seawater were used to navigate to specific islands. To use these, you cut off the top of the coconut and make a ring of holes around the base. You then make a hole near the top for the target star and fill it with water up to the holes (with coconut oil to maintain surface tension). You look through the device at the star at its highest point; if the water inside the device is flat, you are on the same latitude as your destination. The stars will guide you with the simplest of tools, if you know how to use them.


Progression east-west (longitude) can be understood if you know the difference between high-noon on a clock set at a fixed location (Greenwich) and a clock set at the current location. Each hour difference represents 15° of travel longitudinally (1/24 of 360°). Simple enough, if you have a clock that can keep time on the ocean – but that was a complicated problem to solve. Before that, all sailors could really do is line up on the right latitude and go for it.

To make use of more markers than the sun and North Star, you could use nautical almanacs and sextants. These almanacs were essentially large lists of what celestial objects should appear at certain points of the sky, and at what time they can be expected to do so. By using the sextant to compare predicted appearances to actual locations, you can determine the distance to fixed positions.

The Global Positioning System (GPS) has mostly replaced the need for these tables. Reliable but not available on-demand stars have been replaced by artificial celestial bodies that spend their whole lives yelling about where they are and what time they think it is. By comparing signals from several different satellites to the time your GPS device thinks it is, you can triangulate your position on the earth within a few meters.

Few mobile phones contain true GPS: mostly they use aGPS or WPS. aGPS uses the resources of the mobile network to speed up reconciliation based on fragmented signals, but WPS (Wireless Positioning System) is something different altogether. It takes advantage of the fact that we littered our world (especially urban areas, where GPS struggles) with millions of radio location beacons, in the form of Wi-Fi access points.

While the vans with the weird cameras were taking pictures of every road in the world, they were also mapping the radio landscape we have made: each house with a Wi-Fi access point, broadcasting a unique identifier. By mapping these to a true GPS reading, location services can provide a guide to any device with a wifi chip. If you read Device #1053443 with 50 per cent strength and Device #10232321 with 74 per cent strength and Device #24324239 with 60 per cent strength, the chances are you are “here” — the most likely place where those signals converge at that strength.

These vans are no longer necessary: while walking around your phone will pick up on any new or unknown access points. With sufficient logs of these devices, their location can be deduced by comparison to known devices and used for future navigation. As well as recording our every step, our phones are automated radio cartographers. This is still ultimately working on similar principles to the nautical almanac and sextant, it just has a much larger look-up table and uses thousands of man-made stars to light the way.

As navigation has become much easier there is also the risk of becoming too dependent on what might turn out to be fragile technology. The US Navy is currently re-introducing celestial navigation training. so that its sailors can figure out where they are in the event of an attack on the GPS system. After the apocalypse, we might find ourselves getting around by holding a bricked phone up to the horizon and measuring the length of the headphone cord to our teeth. 

 
 
 
 

What are Europe’s longest train journeys?

The Orient Express was a pretty long train. Image: Getty.

For reasons that aren’t clear even to me, a question popped into my head and refused to leave: what’s longer? Britain’s longest train joruney, or Germany’s?

On the one hand, Germany is quite a bit larger – its area is 70 per cent more than Great Britain’s. On the other hand, Great Britain is long, skinny island and Germany is much rounder – the distance from John O’ Groats to Lands End is over 1,400 km, but you never have walk over 1,000 km to cross Germany in any direction.

And it turns out these factors balance almost each other out. Britain’s longest train, the CrossCountry from Aberdeen in Scotland to Penzance in Cornwall, runs 785 miles or 1,263 km. Germany’s longest train, the IC 2216 from Offenburg in the Black Forest to Greifswald on the Baltic coast, is exactly 1,300 km. Germany wins by a tiny distance.

Except then I was hooked. What about the longest train in France? Spain? Italy?

So I did what anyone would do. I made a map.

The map above was all drawn with the Deutsche Bahn (Germany Railways) travel planning tool, which rather incredibly has nearly every railway in Europe. The data quality is better for some countries than others (the lines in France aren’t quite that straight in real life), and the measurements may be a bit off – it’s not always easy to find the length of a train service, especially when routes can vary over the year – but it gives us a good idea of what the routes look like.

Let’s start with the UK. The Aberdeen to Penzance route isn’t really for people who want to go all the way across the country. Instead, it’s a way to link together several railway lines and connect some medium-to-large cities that otherwise don’t have many direct services. “Cross-country” trains like these have existed for a century, but because they crossed multiple different company’s lines – and later, multiple British Rail regions – they tended to get ignored.

 

That’s why, when it privatised the railways, the government created a specific CrossCountry franchise so there was a company dedicated to these underused routes. If you want to get from Edinburgh to Leeds or Derby to Bristol, you’ll probably want a CrossCountry train.

The usual route is Edinburgh to Plymouth, but once a day they run an extra long one. Just one way though – there’s no Penzance to Aberdeen train. 

The longest train in Germany is weird – at 1,400 km, it’s substantially longer than the country itself. On the map, the reason is obvious – it takes a huge C shaped route. (It also doubles back on itself at one point in order to reach Stuttgart).

This route takes it down the Rhine, the biggest river in west Germany, and through the most densely populated patch of the country around Cologne and Dusseldorf known as the Ruhr. Germany’s second and third longest trains also have quite similar routes – they start and end in remote corners of the country, but all three have the Rhine-Ruhr metropolitan area in the middle.

You’re not meant to take the IC 2216 all the way from north east to south west – there are much more direct options available. Instead, it’s for people who want to travel to these major cities. They could run two separate trains – say, Offenburg-Dusseldorf and Griefswald-Cologne – but making it a single route means passengers benefit from a bit more flexibility and helps DB use its rolling stock more effectively.

France’s longest train exists for a very good reason. Most of France’s high-speed lines radiate out from Paris, and it’s very hard to get around the country without going to the capital. Usually to get from Marseille on the Mediterranean to Nantes near the Atlantic, you’d need to take a TGV to Paris Gare de Lyon station, then get the Métro across the city to Gare Montparnasse.

Once a day though, this TGV avoids this faff by stopping in the suburb of Juvisy and turning around without going into the centre. This lets passengers travel direct between the coasts and reduces the traffic through Paris’s terminals in the rush hour. The exact length of this route isn’t clear, but Wikipedia says it’s about 1,130 km.

Spain’s longest train is very different. This is the Trenhotel sleeper service from Barcelona to Vigo, and it’s pretty fancy. This is a train for tourists and business travellers, with some quite luxurious sleeping cabins. But it is a regularly scheduled train run by the state operator Renfe, not a luxury charter, and it does appear in the timetables.

Being dry, hot and quite mountainous in its middle, most of Spain’s cities are on its coast (Madrid is the one major exception) and as a result the train passes through relatively few urban areas. (Zaragoza, Spain’s 5th largest city, is on the route, but after that the next biggest city is Burgos, its 35th largest,) This is partly why overnight trains work so well on the route – without many stops in the middle, most passengers can just sleep right through the journey, although there are occasional day time trains on that route too if you want to savour the view on that 1,314 km journey.

Finally, there’s Italy. This is another sleeper train, from Milan in the north to Syracuse on the island of Sicily. It goes via Rome and travels along the west coast of... wait, it’s a train to the island of Sicily? How, when there’s no bridge?

Well, this train takes a boat. I don’t really have anything else to add here. It’s just a train that they literally drive onto a ferry, sail across the water, and then drive off again at the other side. That’s pretty cool.

(As I was writing this, someone on Twitter got in touch to tell me the route will get even longer in September when the line to Palermo reopens. That should be exciting.)

So those are the longest trains in each country. But they aren’t the longest in Europe.

For one thing, there are some countries we haven’t looked at yet with very long trains. Sweden has some spectacular routes from its southern tip up into the Arctic north, and although the Donbass War appears to have cut Ukraine’s Uzhorod to Luhansk service short, even Uzhorod to Kharkiv is over 1,400 km. And then there are the international routes.

To encourage the Russian rich to take the train for their holiday, Russian Railways now run a luxury sleeper from Moscow to Nice, passing through France, Monaco, Italy, Austria, Czechia, Poland, Belarus and Russia. This monster line is 3,315 km long and stretches across most of the continent. That’s got to be the longest in Europe, right?

Nope. Incredibly, the longest train in Europe doesn’t actually cross a single border. Unsurprisingly, it’s in Russia, but it’s not the Trans-Siberian – the vast majority of that’s route is in Asia, not Europe. No, if you really want a long European train journey, head to Adler, just south of the Olympic host city Sochi. From there, you can catch a train up to Vorkuta on the edge of the Arctic Circle. The route zigzags a bit over its 89 hour, 4,200 km journey, but it always stays on the European side of the Ural mountains.

Bring a good book.

Stephen Jorgenson-Murray often tweets about this kind of nonsense at @stejormur.


All maps courtesy of Deutsche Bahn.