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. 

 
 
 
 

In New Zealand, climate change is driving an eco-nationalist revival

The green and pleasant land of the South Island. Image: Getty.

“Ten years ago I would have called them settler f*****g land squatters,” Mike Smith, Maori-dom’s most tenacious activist, said last November as he reflected on the agriculture industry’s central role in driving climate change. “Now I have to try and get these people on board.”

Smith is infamous for taking a chainsaw to Auckland’s most prominent tree on a damp October night in 1994 in protest of the “Pākehā” – or white European –dominated government’s fiscal envelope restraining treaty settlements. Now he’s turned his hand to another cause close-to-home for the Maori, New Zealand’s indigenous population: the environment.

“We’re super vulnerable, like we are to anything,” Smith says. “When it comes to climate change it’s like the poorest people in the world are going to be hit the hardest first, and that’s a lot of us.”

Prime Minister Jacinda Ardern appears, at least rhetorically, the most sympathetic leader to his cause in a decade. In her campaign launch speech late last year, she made the future government’s position clear: “Climate change is my generation’s nuclear free moment.”

This message should resonate with followers of her Labour party: the NZ left has long nurtured an environment-orientated “culture-of-protest”. So Ardern’s call to arms was bound to gain her loyal support among children of the 1960s and ‘70s, who led the march against nuclear ship visits, spurring on the government of the time to wriggle out from the US nuclear umbrella, and place a ban on foreign nuclear ship visits.

Now, it is to the tycoons of deep sea oil exploration they aim to close NZ’s ports.

In this, Smith is not short of support locally, with marches run by grassroots organisations and international animal welfare funds beginning to gain traction with every day New Zealanders. In this, Ardern’s prediction is correct: the Coal Action Network Aotearoa (CANA), is reminiscent of the Campaign for Nuclear Disarmament (CND), an earlier cluster of left-wing pacifists and nature lovers who drove the creation of the nuclear free zone.  

In December, 15,000 passionate protesters marched through the capital. And with the government’s recent ban of offshore oil exploration projects, Jeanette Fitzsimons, former Green party co-leader and the head of CANA, is optimistic about similar change to the energy and farming sectors.

The Labour-NZ First-Green party coalition seems focused on setting a new global precedent, weaning NZ away from a United States which has jettisoned the Paris Agreement. The move replicates another 20 years ago, when New Zealand’s anti-nuclear movement was central to an upsurge in New Zealand nationalism. Now, the same sense of going it alone on foreign policy is apparent both locally and in Parliament.

Dr. Gradon Diprose, a senior lecturer at Massey University, argues that this echoes an older expression of colonial nationalism, that saw “New Zealand as a land of natural abundance”. This: “eco-nationalism” is centered on “protecting certain visions of picturesque landscapes and unspoiled natural beauty”. The slogan “Clean, green New Zealand” is prevalent in popular culture and tourism marketing. The public seems to have latched onto it too, and ranked keeping NZ’s waterways “clean and green” top of a recent survey of of kiwis’ top concerns.

Three decades ago, it was the 10 July 1985 sinking of the Greenpeace flagship Rainbow Warrior that thrust local activists’ fears into the public eye, resulting in an almost nation-wide expression of climate-protectionism.


The bombing, a French intelligence operation sparked by Greenpeace’s calls for an end to foreign nuclear testing in the Pacific, galvanised a great deal of change to New Zealand’s overseas defence policies. A lack of censure from New Zealand’s Western allies drove Wellington to distance itself from the United States, while the shock of seeing a friendly nation violate NZ’s sovereignty left many at home seething.

Thirty years on, the foreign policy split throughout the Anglosphere, regarding Russian-Western relations, globalism, and the old international rules-based order, is becoming wider. Climate change is just the tip of the iceberg.

Most Kiwis you talk to will shake their heads in disapproval at US president Donald Trump’s scandalous outing last year in Helsinki. But US defiance of internationally brokered climate resolutions is something they can see clearly reflected in rural communities across the country.

The country saw records broken at both ends of the extreme weather spectrum last year. As 2018 kicked off, Kiwis sweltered through the hottest summer on record, while in Golden Bay, a small inlet near the northern tip of the South Island, residents endured the largest flood in 150 years. So, when President Trump tweets “So much for Global Warming”, the majority of New Zealanders look back fondly on NZ’s 1985 decision to boycott the “ANZUS” treaty, putting New Zealand at odds with its war-time ally America on defence legislation.

Public calls to take the same track on environmental regulation have become louder in the wake of Donald Trump’s election. The former US Secretary of State, Rex Tillerson, received a frosty “unwelcome” while on a flyby to the capital in 2017, with the New York Times’ Washington correspondent, Gardiner Harris remarking: “I’ve never seen so many people flip the bird at an American motorcade as I saw today”. Protests against President Trump’s stance on climate change are beginning to gain greater traction further still, with the hundred-strong “march for science” setting the tone for the new government later that year.

New Zealand certainly isn’t afraid of radicalism, and its activists are persistent. It’s already banned single use plastics in supermarkets. Plenty more is to come, Smith says.

And yes, reform is going to inhibit sometimes vital industries: “It doesn’t matter which way you spin the dice on this, whatever’s being done is going to hurt. People who are looking for a painless way of mitigating climate change, [but] I don’t think there is one.”

But among Smith’s troupe of climate agitators, the feeling is that, without drastic change, “the land”, the heart of the Maori ethos, is going to be hurt far more.

Back in Auckland, NZ’s financial hub, an electric scooter craze is gripping the city. This, too, has gained the support of local environmentalists. In New Zealand, a national sense of pride is always coupled with a certain eccentricity. In a country this size, change always starts small.